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openssl/ssl/t1_lib.c
Dr. Stephen Henson 77ab2b0193 remove encrypt then mac ifdefs 
Reviewed-by: Rich Salz <rsalz@openssl.org>
2016-05-23 19:15:20 +01:00

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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <stdlib.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/ocsp.h>
#include <openssl/conf.h>
#include <openssl/x509v3.h>
#include <openssl/rand.h>
#include <openssl/dh.h>
#include <openssl/bn.h>
#include "ssl_locl.h"
#include <openssl/ct.h>
static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
const unsigned char *sess_id, int sesslen,
SSL_SESSION **psess);
static int ssl_check_clienthello_tlsext_early(SSL *s);
static int ssl_check_serverhello_tlsext(SSL *s);
SSL3_ENC_METHOD const TLSv1_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
0,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD const TLSv1_1_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_EXPLICIT_IV,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
SSL3_ENC_METHOD const TLSv1_2_enc_data = {
tls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS,
SSL3_HM_HEADER_LENGTH,
ssl3_set_handshake_header,
ssl3_handshake_write
};
long tls1_default_timeout(void)
{
/*
* 2 hours, the 24 hours mentioned in the TLSv1 spec is way too long for
* http, the cache would over fill
*/
return (60 * 60 * 2);
}
int tls1_new(SSL *s)
{
if (!ssl3_new(s))
return (0);
s->method->ssl_clear(s);
return (1);
}
void tls1_free(SSL *s)
{
OPENSSL_free(s->tlsext_session_ticket);
ssl3_free(s);
}
void tls1_clear(SSL *s)
{
ssl3_clear(s);
if (s->method->version == TLS_ANY_VERSION)
s->version = TLS_MAX_VERSION;
else
s->version = s->method->version;
}
#ifndef OPENSSL_NO_EC
typedef struct {
int nid; /* Curve NID */
int secbits; /* Bits of security (from SP800-57) */
unsigned int flags; /* Flags: currently just field type */
} tls_curve_info;
/* Mask for curve type */
# define TLS_CURVE_TYPE 0x3
# define TLS_CURVE_PRIME 0x0
# define TLS_CURVE_CHAR2 0x1
# define TLS_CURVE_CUSTOM 0x2
/*
* Table of curve information.
* Do not delete entries or reorder this array! It is used as a lookup
* table: the index of each entry is one less than the TLS curve id.
*/
static const tls_curve_info nid_list[] = {
{NID_sect163k1, 80, TLS_CURVE_CHAR2}, /* sect163k1 (1) */
{NID_sect163r1, 80, TLS_CURVE_CHAR2}, /* sect163r1 (2) */
{NID_sect163r2, 80, TLS_CURVE_CHAR2}, /* sect163r2 (3) */
{NID_sect193r1, 80, TLS_CURVE_CHAR2}, /* sect193r1 (4) */
{NID_sect193r2, 80, TLS_CURVE_CHAR2}, /* sect193r2 (5) */
{NID_sect233k1, 112, TLS_CURVE_CHAR2}, /* sect233k1 (6) */
{NID_sect233r1, 112, TLS_CURVE_CHAR2}, /* sect233r1 (7) */
{NID_sect239k1, 112, TLS_CURVE_CHAR2}, /* sect239k1 (8) */
{NID_sect283k1, 128, TLS_CURVE_CHAR2}, /* sect283k1 (9) */
{NID_sect283r1, 128, TLS_CURVE_CHAR2}, /* sect283r1 (10) */
{NID_sect409k1, 192, TLS_CURVE_CHAR2}, /* sect409k1 (11) */
{NID_sect409r1, 192, TLS_CURVE_CHAR2}, /* sect409r1 (12) */
{NID_sect571k1, 256, TLS_CURVE_CHAR2}, /* sect571k1 (13) */
{NID_sect571r1, 256, TLS_CURVE_CHAR2}, /* sect571r1 (14) */
{NID_secp160k1, 80, TLS_CURVE_PRIME}, /* secp160k1 (15) */
{NID_secp160r1, 80, TLS_CURVE_PRIME}, /* secp160r1 (16) */
{NID_secp160r2, 80, TLS_CURVE_PRIME}, /* secp160r2 (17) */
{NID_secp192k1, 80, TLS_CURVE_PRIME}, /* secp192k1 (18) */
{NID_X9_62_prime192v1, 80, TLS_CURVE_PRIME}, /* secp192r1 (19) */
{NID_secp224k1, 112, TLS_CURVE_PRIME}, /* secp224k1 (20) */
{NID_secp224r1, 112, TLS_CURVE_PRIME}, /* secp224r1 (21) */
{NID_secp256k1, 128, TLS_CURVE_PRIME}, /* secp256k1 (22) */
{NID_X9_62_prime256v1, 128, TLS_CURVE_PRIME}, /* secp256r1 (23) */
{NID_secp384r1, 192, TLS_CURVE_PRIME}, /* secp384r1 (24) */
{NID_secp521r1, 256, TLS_CURVE_PRIME}, /* secp521r1 (25) */
{NID_brainpoolP256r1, 128, TLS_CURVE_PRIME}, /* brainpoolP256r1 (26) */
{NID_brainpoolP384r1, 192, TLS_CURVE_PRIME}, /* brainpoolP384r1 (27) */
{NID_brainpoolP512r1, 256, TLS_CURVE_PRIME}, /* brainpool512r1 (28) */
/* X25519 (29) */
{NID_X25519, 128, TLS_CURVE_CUSTOM},
};
static const unsigned char ecformats_default[] = {
TLSEXT_ECPOINTFORMAT_uncompressed,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
};
/* The default curves */
static const unsigned char eccurves_default[] = {
0, 29, /* X25519 (29) */
0, 23, /* secp256r1 (23) */
0, 25, /* secp521r1 (25) */
0, 24, /* secp384r1 (24) */
};
static const unsigned char eccurves_all[] = {
0, 29, /* X25519 (29) */
0, 23, /* secp256r1 (23) */
0, 25, /* secp521r1 (25) */
0, 24, /* secp384r1 (24) */
0, 26, /* brainpoolP256r1 (26) */
0, 27, /* brainpoolP384r1 (27) */
0, 28, /* brainpool512r1 (28) */
/*
* Remaining curves disabled by default but still permitted if set
* via an explicit callback or parameters.
*/
0, 22, /* secp256k1 (22) */
0, 14, /* sect571r1 (14) */
0, 13, /* sect571k1 (13) */
0, 11, /* sect409k1 (11) */
0, 12, /* sect409r1 (12) */
0, 9, /* sect283k1 (9) */
0, 10, /* sect283r1 (10) */
0, 20, /* secp224k1 (20) */
0, 21, /* secp224r1 (21) */
0, 18, /* secp192k1 (18) */
0, 19, /* secp192r1 (19) */
0, 15, /* secp160k1 (15) */
0, 16, /* secp160r1 (16) */
0, 17, /* secp160r2 (17) */
0, 8, /* sect239k1 (8) */
0, 6, /* sect233k1 (6) */
0, 7, /* sect233r1 (7) */
0, 4, /* sect193r1 (4) */
0, 5, /* sect193r2 (5) */
0, 1, /* sect163k1 (1) */
0, 2, /* sect163r1 (2) */
0, 3, /* sect163r2 (3) */
};
static const unsigned char suiteb_curves[] = {
0, TLSEXT_curve_P_256,
0, TLSEXT_curve_P_384
};
int tls1_ec_curve_id2nid(int curve_id)
{
/* ECC curves from RFC 4492 and RFC 7027 */
if ((curve_id < 1) || ((unsigned int)curve_id > OSSL_NELEM(nid_list)))
return 0;
return nid_list[curve_id - 1].nid;
}
int tls1_ec_nid2curve_id(int nid)
{
size_t i;
for (i = 0; i < OSSL_NELEM(nid_list); i++) {
if (nid_list[i].nid == nid)
return i + 1;
}
return 0;
}
/*
* Get curves list, if "sess" is set return client curves otherwise
* preferred list.
* Sets |num_curves| to the number of curves in the list, i.e.,
* the length of |pcurves| is 2 * num_curves.
* Returns 1 on success and 0 if the client curves list has invalid format.
* The latter indicates an internal error: we should not be accepting such
* lists in the first place.
* TODO(emilia): we should really be storing the curves list in explicitly
* parsed form instead. (However, this would affect binary compatibility
* so cannot happen in the 1.0.x series.)
*/
static int tls1_get_curvelist(SSL *s, int sess,
const unsigned char **pcurves,
size_t *num_curves)
{
size_t pcurveslen = 0;
if (sess) {
*pcurves = s->session->tlsext_ellipticcurvelist;
pcurveslen = s->session->tlsext_ellipticcurvelist_length;
} else {
/* For Suite B mode only include P-256, P-384 */
switch (tls1_suiteb(s)) {
case SSL_CERT_FLAG_SUITEB_128_LOS:
*pcurves = suiteb_curves;
pcurveslen = sizeof(suiteb_curves);
break;
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*pcurves = suiteb_curves;
pcurveslen = 2;
break;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*pcurves = suiteb_curves + 2;
pcurveslen = 2;
break;
default:
*pcurves = s->tlsext_ellipticcurvelist;
pcurveslen = s->tlsext_ellipticcurvelist_length;
}
if (!*pcurves) {
*pcurves = eccurves_default;
pcurveslen = sizeof(eccurves_default);
}
}
/* We do not allow odd length arrays to enter the system. */
if (pcurveslen & 1) {
SSLerr(SSL_F_TLS1_GET_CURVELIST, ERR_R_INTERNAL_ERROR);
*num_curves = 0;
return 0;
} else {
*num_curves = pcurveslen / 2;
return 1;
}
}
/* See if curve is allowed by security callback */
static int tls_curve_allowed(SSL *s, const unsigned char *curve, int op)
{
const tls_curve_info *cinfo;
if (curve[0])
return 1;
if ((curve[1] < 1) || ((size_t)curve[1] > OSSL_NELEM(nid_list)))
return 0;
cinfo = &nid_list[curve[1] - 1];
# ifdef OPENSSL_NO_EC2M
if (cinfo->flags & TLS_CURVE_CHAR2)
return 0;
# endif
return ssl_security(s, op, cinfo->secbits, cinfo->nid, (void *)curve);
}
/* Check a curve is one of our preferences */
int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
{
const unsigned char *curves;
size_t num_curves, i;
unsigned int suiteb_flags = tls1_suiteb(s);
if (len != 3 || p[0] != NAMED_CURVE_TYPE)
return 0;
/* Check curve matches Suite B preferences */
if (suiteb_flags) {
unsigned long cid = s->s3->tmp.new_cipher->id;
if (p[1])
return 0;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) {
if (p[2] != TLSEXT_curve_P_256)
return 0;
} else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384) {
if (p[2] != TLSEXT_curve_P_384)
return 0;
} else /* Should never happen */
return 0;
}
if (!tls1_get_curvelist(s, 0, &curves, &num_curves))
return 0;
for (i = 0; i < num_curves; i++, curves += 2) {
if (p[1] == curves[0] && p[2] == curves[1])
return tls_curve_allowed(s, p + 1, SSL_SECOP_CURVE_CHECK);
}
return 0;
}
/*-
* For nmatch >= 0, return the NID of the |nmatch|th shared curve or NID_undef
* if there is no match.
* For nmatch == -1, return number of matches
* For nmatch == -2, return the NID of the curve to use for
* an EC tmp key, or NID_undef if there is no match.
*/
int tls1_shared_curve(SSL *s, int nmatch)
{
const unsigned char *pref, *supp;
size_t num_pref, num_supp, i, j;
int k;
/* Can't do anything on client side */
if (s->server == 0)
return -1;
if (nmatch == -2) {
if (tls1_suiteb(s)) {
/*
* For Suite B ciphersuite determines curve: we already know
* these are acceptable due to previous checks.
*/
unsigned long cid = s->s3->tmp.new_cipher->id;
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
return NID_X9_62_prime256v1; /* P-256 */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
return NID_secp384r1; /* P-384 */
/* Should never happen */
return NID_undef;
}
/* If not Suite B just return first preference shared curve */
nmatch = 0;
}
/*
* Avoid truncation. tls1_get_curvelist takes an int
* but s->options is a long...
*/
if (!tls1_get_curvelist
(s, (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0, &supp,
&num_supp))
/* In practice, NID_undef == 0 but let's be precise. */
return nmatch == -1 ? 0 : NID_undef;
if (!tls1_get_curvelist
(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE), &pref,
&num_pref))
return nmatch == -1 ? 0 : NID_undef;
/*
* If the client didn't send the elliptic_curves extension all of them
* are allowed.
*/
if (num_supp == 0 && (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0) {
supp = eccurves_all;
num_supp = sizeof(eccurves_all) / 2;
} else if (num_pref == 0 &&
(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) == 0) {
pref = eccurves_all;
num_pref = sizeof(eccurves_all) / 2;
}
k = 0;
for (i = 0; i < num_pref; i++, pref += 2) {
const unsigned char *tsupp = supp;
for (j = 0; j < num_supp; j++, tsupp += 2) {
if (pref[0] == tsupp[0] && pref[1] == tsupp[1]) {
if (!tls_curve_allowed(s, pref, SSL_SECOP_CURVE_SHARED))
continue;
if (nmatch == k) {
int id = (pref[0] << 8) | pref[1];
return tls1_ec_curve_id2nid(id);
}
k++;
}
}
}
if (nmatch == -1)
return k;
/* Out of range (nmatch > k). */
return NID_undef;
}
int tls1_set_curves(unsigned char **pext, size_t *pextlen,
int *curves, size_t ncurves)
{
unsigned char *clist, *p;
size_t i;
/*
* Bitmap of curves included to detect duplicates: only works while curve
* ids < 32
*/
unsigned long dup_list = 0;
clist = OPENSSL_malloc(ncurves * 2);
if (clist == NULL)
return 0;
for (i = 0, p = clist; i < ncurves; i++) {
unsigned long idmask;
int id;
id = tls1_ec_nid2curve_id(curves[i]);
idmask = 1L << id;
if (!id || (dup_list & idmask)) {
OPENSSL_free(clist);
return 0;
}
dup_list |= idmask;
s2n(id, p);
}
OPENSSL_free(*pext);
*pext = clist;
*pextlen = ncurves * 2;
return 1;
}
# define MAX_CURVELIST 28
typedef struct {
size_t nidcnt;
int nid_arr[MAX_CURVELIST];
} nid_cb_st;
static int nid_cb(const char *elem, int len, void *arg)
{
nid_cb_st *narg = arg;
size_t i;
int nid;
char etmp[20];
if (elem == NULL)
return 0;
if (narg->nidcnt == MAX_CURVELIST)
return 0;
if (len > (int)(sizeof(etmp) - 1))
return 0;
memcpy(etmp, elem, len);
etmp[len] = 0;
nid = EC_curve_nist2nid(etmp);
if (nid == NID_undef)
nid = OBJ_sn2nid(etmp);
if (nid == NID_undef)
nid = OBJ_ln2nid(etmp);
if (nid == NID_undef)
return 0;
for (i = 0; i < narg->nidcnt; i++)
if (narg->nid_arr[i] == nid)
return 0;
narg->nid_arr[narg->nidcnt++] = nid;
return 1;
}
/* Set curves based on a colon separate list */
int tls1_set_curves_list(unsigned char **pext, size_t *pextlen,
const char *str)
{
nid_cb_st ncb;
ncb.nidcnt = 0;
if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
return 0;
if (pext == NULL)
return 1;
return tls1_set_curves(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
}
/* For an EC key set TLS id and required compression based on parameters */
static int tls1_set_ec_id(unsigned char *curve_id, unsigned char *comp_id,
EC_KEY *ec)
{
int id;
const EC_GROUP *grp;
if (!ec)
return 0;
/* Determine if it is a prime field */
grp = EC_KEY_get0_group(ec);
if (!grp)
return 0;
/* Determine curve ID */
id = EC_GROUP_get_curve_name(grp);
id = tls1_ec_nid2curve_id(id);
/* If no id return error: we don't support arbitrary explicit curves */
if (id == 0)
return 0;
curve_id[0] = 0;
curve_id[1] = (unsigned char)id;
if (comp_id) {
if (EC_KEY_get0_public_key(ec) == NULL)
return 0;
if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_UNCOMPRESSED) {
*comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
} else {
if ((nid_list[id - 1].flags & TLS_CURVE_TYPE) == TLS_CURVE_PRIME)
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
else
*comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
}
}
return 1;
}
/* Check an EC key is compatible with extensions */
static int tls1_check_ec_key(SSL *s,
unsigned char *curve_id, unsigned char *comp_id)
{
const unsigned char *pformats, *pcurves;
size_t num_formats, num_curves, i;
int j;
/*
* If point formats extension present check it, otherwise everything is
* supported (see RFC4492).
*/
if (comp_id && s->session->tlsext_ecpointformatlist) {
pformats = s->session->tlsext_ecpointformatlist;
num_formats = s->session->tlsext_ecpointformatlist_length;
for (i = 0; i < num_formats; i++, pformats++) {
if (*comp_id == *pformats)
break;
}
if (i == num_formats)
return 0;
}
if (!curve_id)
return 1;
/* Check curve is consistent with client and server preferences */
for (j = 0; j <= 1; j++) {
if (!tls1_get_curvelist(s, j, &pcurves, &num_curves))
return 0;
if (j == 1 && num_curves == 0) {
/*
* If we've not received any curves then skip this check.
* RFC 4492 does not require the supported elliptic curves extension
* so if it is not sent we can just choose any curve.
* It is invalid to send an empty list in the elliptic curves
* extension, so num_curves == 0 always means no extension.
*/
break;
}
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (pcurves[0] == curve_id[0] && pcurves[1] == curve_id[1])
break;
}
if (i == num_curves)
return 0;
/* For clients can only check sent curve list */
if (!s->server)
break;
}
return 1;
}
static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
size_t *num_formats)
{
/*
* If we have a custom point format list use it otherwise use default
*/
if (s->tlsext_ecpointformatlist) {
*pformats = s->tlsext_ecpointformatlist;
*num_formats = s->tlsext_ecpointformatlist_length;
} else {
*pformats = ecformats_default;
/* For Suite B we don't support char2 fields */
if (tls1_suiteb(s))
*num_formats = sizeof(ecformats_default) - 1;
else
*num_formats = sizeof(ecformats_default);
}
}
/*
* Check cert parameters compatible with extensions: currently just checks EC
* certificates have compatible curves and compression.
*/
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
unsigned char comp_id, curve_id[2];
EVP_PKEY *pkey;
int rv;
pkey = X509_get0_pubkey(x);
if (!pkey)
return 0;
/* If not EC nothing to do */
if (EVP_PKEY_id(pkey) != EVP_PKEY_EC)
return 1;
rv = tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey));
if (!rv)
return 0;
/*
* Can't check curve_id for client certs as we don't have a supported
* curves extension.
*/
rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
if (!rv)
return 0;
/*
* Special case for suite B. We *MUST* sign using SHA256+P-256 or
* SHA384+P-384, adjust digest if necessary.
*/
if (set_ee_md && tls1_suiteb(s)) {
int check_md;
size_t i;
CERT *c = s->cert;
if (curve_id[0])
return 0;
/* Check to see we have necessary signing algorithm */
if (curve_id[1] == TLSEXT_curve_P_256)
check_md = NID_ecdsa_with_SHA256;
else if (curve_id[1] == TLSEXT_curve_P_384)
check_md = NID_ecdsa_with_SHA384;
else
return 0; /* Should never happen */
for (i = 0; i < c->shared_sigalgslen; i++)
if (check_md == c->shared_sigalgs[i].signandhash_nid)
break;
if (i == c->shared_sigalgslen)
return 0;
if (set_ee_md == 2) {
if (check_md == NID_ecdsa_with_SHA256)
s->s3->tmp.md[SSL_PKEY_ECC] = EVP_sha256();
else
s->s3->tmp.md[SSL_PKEY_ECC] = EVP_sha384();
}
}
return rv;
}
# ifndef OPENSSL_NO_EC
/*
* tls1_check_ec_tmp_key - Check EC temporary key compatibility
* @s: SSL connection
* @cid: Cipher ID we're considering using
*
* Checks that the kECDHE cipher suite we're considering using
* is compatible with the client extensions.
*
* Returns 0 when the cipher can't be used or 1 when it can.
*/
int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
{
/*
* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384, no other
* curves permitted.
*/
if (tls1_suiteb(s)) {
unsigned char curve_id[2];
/* Curve to check determined by ciphersuite */
if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
curve_id[1] = TLSEXT_curve_P_256;
else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
curve_id[1] = TLSEXT_curve_P_384;
else
return 0;
curve_id[0] = 0;
/* Check this curve is acceptable */
if (!tls1_check_ec_key(s, curve_id, NULL))
return 0;
return 1;
}
/* Need a shared curve */
if (tls1_shared_curve(s, 0))
return 1;
return 0;
}
# endif /* OPENSSL_NO_EC */
#else
static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
{
return 1;
}
#endif /* OPENSSL_NO_EC */
/*
* List of supported signature algorithms and hashes. Should make this
* customisable at some point, for now include everything we support.
*/
#ifdef OPENSSL_NO_RSA
# define tlsext_sigalg_rsa(md) /* */
#else
# define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
#endif
#ifdef OPENSSL_NO_DSA
# define tlsext_sigalg_dsa(md) /* */
#else
# define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
#endif
#ifdef OPENSSL_NO_EC
# define tlsext_sigalg_ecdsa(md) /* */
#else
# define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
#endif
#define tlsext_sigalg(md) \
tlsext_sigalg_rsa(md) \
tlsext_sigalg_dsa(md) \
tlsext_sigalg_ecdsa(md)
static const unsigned char tls12_sigalgs[] = {
tlsext_sigalg(TLSEXT_hash_sha512)
tlsext_sigalg(TLSEXT_hash_sha384)
tlsext_sigalg(TLSEXT_hash_sha256)
tlsext_sigalg(TLSEXT_hash_sha224)
tlsext_sigalg(TLSEXT_hash_sha1)
#ifndef OPENSSL_NO_GOST
TLSEXT_hash_gostr3411, TLSEXT_signature_gostr34102001,
TLSEXT_hash_gostr34112012_256, TLSEXT_signature_gostr34102012_256,
TLSEXT_hash_gostr34112012_512, TLSEXT_signature_gostr34102012_512
#endif
};
#ifndef OPENSSL_NO_EC
static const unsigned char suiteb_sigalgs[] = {
tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
};
#endif
size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
{
/*
* If Suite B mode use Suite B sigalgs only, ignore any other
* preferences.
*/
#ifndef OPENSSL_NO_EC
switch (tls1_suiteb(s)) {
case SSL_CERT_FLAG_SUITEB_128_LOS:
*psigs = suiteb_sigalgs;
return sizeof(suiteb_sigalgs);
case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
*psigs = suiteb_sigalgs;
return 2;
case SSL_CERT_FLAG_SUITEB_192_LOS:
*psigs = suiteb_sigalgs + 2;
return 2;
}
#endif
/* If server use client authentication sigalgs if not NULL */
if (s->server && s->cert->client_sigalgs) {
*psigs = s->cert->client_sigalgs;
return s->cert->client_sigalgslen;
} else if (s->cert->conf_sigalgs) {
*psigs = s->cert->conf_sigalgs;
return s->cert->conf_sigalgslen;
} else {
*psigs = tls12_sigalgs;
return sizeof(tls12_sigalgs);
}
}
/*
* Check signature algorithm is consistent with sent supported signature
* algorithms and if so return relevant digest.
*/
int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
const unsigned char *sig, EVP_PKEY *pkey)
{
const unsigned char *sent_sigs;
size_t sent_sigslen, i;
int sigalg = tls12_get_sigid(pkey);
/* Should never happen */
if (sigalg == -1)
return -1;
/* Check key type is consistent with signature */
if (sigalg != (int)sig[1]) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
#ifndef OPENSSL_NO_EC
if (EVP_PKEY_id(pkey) == EVP_PKEY_EC) {
unsigned char curve_id[2], comp_id;
/* Check compression and curve matches extensions */
if (!tls1_set_ec_id(curve_id, &comp_id, EVP_PKEY_get0_EC_KEY(pkey)))
return 0;
if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
return 0;
}
/* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
if (tls1_suiteb(s)) {
if (curve_id[0])
return 0;
if (curve_id[1] == TLSEXT_curve_P_256) {
if (sig[0] != TLSEXT_hash_sha256) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
SSL_R_ILLEGAL_SUITEB_DIGEST);
return 0;
}
} else if (curve_id[1] == TLSEXT_curve_P_384) {
if (sig[0] != TLSEXT_hash_sha384) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
SSL_R_ILLEGAL_SUITEB_DIGEST);
return 0;
}
} else
return 0;
}
} else if (tls1_suiteb(s))
return 0;
#endif
/* Check signature matches a type we sent */
sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
for (i = 0; i < sent_sigslen; i += 2, sent_sigs += 2) {
if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
break;
}
/* Allow fallback to SHA1 if not strict mode */
if (i == sent_sigslen
&& (sig[0] != TLSEXT_hash_sha1
|| s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
*pmd = tls12_get_hash(sig[0]);
if (*pmd == NULL) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_UNKNOWN_DIGEST);
return 0;
}
/* Make sure security callback allows algorithm */
if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
EVP_MD_size(*pmd) * 4, EVP_MD_type(*pmd),
(void *)sig)) {
SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
return 0;
}
/*
* Store the digest used so applications can retrieve it if they wish.
*/
s->s3->tmp.peer_md = *pmd;
return 1;
}
/*
* Set a mask of disabled algorithms: an algorithm is disabled if it isn't
* supported, doesn't appear in supported signature algorithms, isn't supported
* by the enabled protocol versions or by the security level.
*
* This function should only be used for checking which ciphers are supported
* by the client.
*
* Call ssl_cipher_disabled() to check that it's enabled or not.
*/
void ssl_set_client_disabled(SSL *s)
{
s->s3->tmp.mask_a = 0;
s->s3->tmp.mask_k = 0;
ssl_set_sig_mask(&s->s3->tmp.mask_a, s, SSL_SECOP_SIGALG_MASK);
ssl_get_client_min_max_version(s, &s->s3->tmp.min_ver, &s->s3->tmp.max_ver);
# ifndef OPENSSL_NO_PSK
/* with PSK there must be client callback set */
if (!s->psk_client_callback) {
s->s3->tmp.mask_a |= SSL_aPSK;
s->s3->tmp.mask_k |= SSL_PSK;
}
#endif /* OPENSSL_NO_PSK */
#ifndef OPENSSL_NO_SRP
if (!(s->srp_ctx.srp_Mask & SSL_kSRP)) {
s->s3->tmp.mask_a |= SSL_aSRP;
s->s3->tmp.mask_k |= SSL_kSRP;
}
#endif
}
/*
* ssl_cipher_disabled - check that a cipher is disabled or not
* @s: SSL connection that you want to use the cipher on
* @c: cipher to check
* @op: Security check that you want to do
*
* Returns 1 when it's disabled, 0 when enabled.
*/
int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op)
{
if (c->algorithm_mkey & s->s3->tmp.mask_k
|| c->algorithm_auth & s->s3->tmp.mask_a)
return 1;
if (s->s3->tmp.max_ver == 0)
return 1;
if (!SSL_IS_DTLS(s) && ((c->min_tls > s->s3->tmp.max_ver)
|| (c->max_tls < s->s3->tmp.min_ver)))
return 1;
if (SSL_IS_DTLS(s) && (DTLS_VERSION_GT(c->min_dtls, s->s3->tmp.max_ver)
|| DTLS_VERSION_LT(c->max_dtls, s->s3->tmp.min_ver)))
return 1;
return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
}
static int tls_use_ticket(SSL *s)
{
if (s->options & SSL_OP_NO_TICKET)
return 0;
return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
}
static int compare_uint(const void *p1, const void *p2) {
unsigned int u1 = *((const unsigned int *)p1);
unsigned int u2 = *((const unsigned int *)p2);
if (u1 < u2)
return -1;
else if (u1 > u2)
return 1;
else
return 0;
}
/*
* Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be
* more than one extension of the same type in a ClientHello or ServerHello.
* This function does an initial scan over the extensions block to filter those
* out. It returns 1 if all extensions are unique, and 0 if the extensions
* contain duplicates, could not be successfully parsed, or an internal error
* occurred.
*/
static int tls1_check_duplicate_extensions(const PACKET *packet) {
PACKET extensions = *packet;
size_t num_extensions = 0, i = 0;
unsigned int *extension_types = NULL;
int ret = 0;
/* First pass: count the extensions. */
while (PACKET_remaining(&extensions) > 0) {
unsigned int type;
PACKET extension;
if (!PACKET_get_net_2(&extensions, &type) ||
!PACKET_get_length_prefixed_2(&extensions, &extension)) {
goto done;
}
num_extensions++;
}
if (num_extensions <= 1)
return 1;
extension_types = OPENSSL_malloc(sizeof(unsigned int) * num_extensions);
if (extension_types == NULL) {
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_MALLOC_FAILURE);
goto done;
}
/* Second pass: gather the extension types. */
extensions = *packet;
for (i = 0; i < num_extensions; i++) {
PACKET extension;
if (!PACKET_get_net_2(&extensions, &extension_types[i]) ||
!PACKET_get_length_prefixed_2(&extensions, &extension)) {
/* This should not happen. */
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_INTERNAL_ERROR);
goto done;
}
}
if (PACKET_remaining(&extensions) != 0) {
SSLerr(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS, ERR_R_INTERNAL_ERROR);
goto done;
}
/* Sort the extensions and make sure there are no duplicates. */
qsort(extension_types, num_extensions, sizeof(unsigned int), compare_uint);
for (i = 1; i < num_extensions; i++) {
if (extension_types[i - 1] == extension_types[i])
goto done;
}
ret = 1;
done:
OPENSSL_free(extension_types);
return ret;
}
unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit, int *al)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
#ifndef OPENSSL_NO_EC
/* See if we support any ECC ciphersuites */
int using_ecc = 0;
if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s)) {
int i;
unsigned long alg_k, alg_a;
STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) {
const SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
alg_k = c->algorithm_mkey;
alg_a = c->algorithm_auth;
if ((alg_k & (SSL_kECDHE | SSL_kECDHEPSK))
|| (alg_a & SSL_aECDSA)) {
using_ecc = 1;
break;
}
}
}
#endif
ret += 2;
if (ret >= limit)
return NULL; /* this really never occurs, but ... */
/* Add RI if renegotiating */
if (s->renegotiate) {
int el;
if (!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_renegotiate, ret);
s2n(el, ret);
if (!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
/* Only add RI for SSLv3 */
if (s->client_version == SSL3_VERSION)
goto done;
if (s->tlsext_hostname != NULL) {
/* Add TLS extension servername to the Client Hello message */
unsigned long size_str;
long lenmax;
/*-
* check for enough space.
* 4 for the servername type and extension length
* 2 for servernamelist length
* 1 for the hostname type
* 2 for hostname length
* + hostname length
*/
if ((lenmax = limit - ret - 9) < 0
|| (size_str =
strlen(s->tlsext_hostname)) > (unsigned long)lenmax)
return NULL;
/* extension type and length */
s2n(TLSEXT_TYPE_server_name, ret);
s2n(size_str + 5, ret);
/* length of servername list */
s2n(size_str + 3, ret);
/* hostname type, length and hostname */
*(ret++) = (unsigned char)TLSEXT_NAMETYPE_host_name;
s2n(size_str, ret);
memcpy(ret, s->tlsext_hostname, size_str);
ret += size_str;
}
#ifndef OPENSSL_NO_SRP
/* Add SRP username if there is one */
if (s->srp_ctx.login != NULL) { /* Add TLS extension SRP username to the
* Client Hello message */
int login_len = strlen(s->srp_ctx.login);
if (login_len > 255 || login_len == 0) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
/*-
* check for enough space.
* 4 for the srp type type and extension length
* 1 for the srp user identity
* + srp user identity length
*/
if ((limit - ret - 5 - login_len) < 0)
return NULL;
/* fill in the extension */
s2n(TLSEXT_TYPE_srp, ret);
s2n(login_len + 1, ret);
(*ret++) = (unsigned char)login_len;
memcpy(ret, s->srp_ctx.login, login_len);
ret += login_len;
}
#endif
#ifndef OPENSSL_NO_EC
if (using_ecc) {
/*
* Add TLS extension ECPointFormats to the ClientHello message
*/
long lenmax;
const unsigned char *pcurves, *pformats;
size_t num_curves, num_formats, curves_list_len;
size_t i;
unsigned char *etmp;
tls1_get_formatlist(s, &pformats, &num_formats);
if ((lenmax = limit - ret - 5) < 0)
return NULL;
if (num_formats > (size_t)lenmax)
return NULL;
if (num_formats > 255) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats, ret);
/* The point format list has 1-byte length. */
s2n(num_formats + 1, ret);
*(ret++) = (unsigned char)num_formats;
memcpy(ret, pformats, num_formats);
ret += num_formats;
/*
* Add TLS extension EllipticCurves to the ClientHello message
*/
pcurves = s->tlsext_ellipticcurvelist;
if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves))
return NULL;
if ((lenmax = limit - ret - 6) < 0)
return NULL;
if (num_curves > (size_t)lenmax / 2)
return NULL;
if (num_curves > 65532 / 2) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_elliptic_curves, ret);
etmp = ret + 4;
/* Copy curve ID if supported */
for (i = 0; i < num_curves; i++, pcurves += 2) {
if (tls_curve_allowed(s, pcurves, SSL_SECOP_CURVE_SUPPORTED)) {
*etmp++ = pcurves[0];
*etmp++ = pcurves[1];
}
}
curves_list_len = etmp - ret - 4;
s2n(curves_list_len + 2, ret);
s2n(curves_list_len, ret);
ret += curves_list_len;
}
#endif /* OPENSSL_NO_EC */
if (tls_use_ticket(s)) {
int ticklen;
if (!s->new_session && s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
else if (s->session && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data) {
ticklen = s->tlsext_session_ticket->length;
s->session->tlsext_tick = OPENSSL_malloc(ticklen);
if (s->session->tlsext_tick == NULL)
return NULL;
memcpy(s->session->tlsext_tick,
s->tlsext_session_ticket->data, ticklen);
s->session->tlsext_ticklen = ticklen;
} else
ticklen = 0;
if (ticklen == 0 && s->tlsext_session_ticket &&
s->tlsext_session_ticket->data == NULL)
goto skip_ext;
/*
* Check for enough room 2 for extension type, 2 for len rest for
* ticket
*/
if ((long)(limit - ret - 4 - ticklen) < 0)
return NULL;
s2n(TLSEXT_TYPE_session_ticket, ret);
s2n(ticklen, ret);
if (ticklen) {
memcpy(ret, s->session->tlsext_tick, ticklen);
ret += ticklen;
}
}
skip_ext:
if (SSL_CLIENT_USE_SIGALGS(s)) {
size_t salglen;
const unsigned char *salg;
unsigned char *etmp;
salglen = tls12_get_psigalgs(s, &salg);
if ((size_t)(limit - ret) < salglen + 6)
return NULL;
s2n(TLSEXT_TYPE_signature_algorithms, ret);
etmp = ret;
/* Skip over lengths for now */
ret += 4;
salglen = tls12_copy_sigalgs(s, ret, salg, salglen);
/* Fill in lengths */
s2n(salglen + 2, etmp);
s2n(salglen, etmp);
ret += salglen;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
int i;
long extlen, idlen, itmp;
OCSP_RESPID *id;
idlen = 0;
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
itmp = i2d_OCSP_RESPID(id, NULL);
if (itmp <= 0)
return NULL;
idlen += itmp + 2;
}
if (s->tlsext_ocsp_exts) {
extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
if (extlen < 0)
return NULL;
} else
extlen = 0;
if ((long)(limit - ret - 7 - extlen - idlen) < 0)
return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
if (extlen + idlen > 0xFFF0)
return NULL;
s2n(extlen + idlen + 5, ret);
*(ret++) = TLSEXT_STATUSTYPE_ocsp;
s2n(idlen, ret);
for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
/* save position of id len */
unsigned char *q = ret;
id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
/* skip over id len */
ret += 2;
itmp = i2d_OCSP_RESPID(id, &ret);
/* write id len */
s2n(itmp, q);
}
s2n(extlen, ret);
if (extlen > 0)
i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
}
#endif
#ifndef OPENSSL_NO_HEARTBEATS
if (SSL_IS_DTLS(s)) {
/* Add Heartbeat extension */
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_DTLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_DTLSEXT_HB_ENABLED;
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len) {
/*
* The client advertises an empty extension to indicate its support
* for Next Protocol Negotiation
*/
if (limit - ret - 4 < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(0, ret);
}
#endif
/*
* finish_md_len is non-zero during a renegotiation, so
* this avoids sending ALPN during the renegotiation
* (see longer comment below)
*/
if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len) {
if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
s2n(2 + s->alpn_client_proto_list_len, ret);
s2n(s->alpn_client_proto_list_len, ret);
memcpy(ret, s->alpn_client_proto_list, s->alpn_client_proto_list_len);
ret += s->alpn_client_proto_list_len;
s->s3->alpn_sent = 1;
}
#ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) {
int el;
/* Returns 0 on success!! */
if (ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#endif
custom_ext_init(&s->cert->cli_ext);
/* Add custom TLS Extensions to ClientHello */
if (!custom_ext_add(s, 0, &ret, limit, al))
return NULL;
s2n(TLSEXT_TYPE_encrypt_then_mac, ret);
s2n(0, ret);
#ifndef OPENSSL_NO_CT
if (s->ct_validation_callback != NULL) {
s2n(TLSEXT_TYPE_signed_certificate_timestamp, ret);
s2n(0, ret);
}
#endif
s2n(TLSEXT_TYPE_extended_master_secret, ret);
s2n(0, ret);
/*
* Add padding to workaround bugs in F5 terminators. See
* https://tools.ietf.org/html/draft-agl-tls-padding-03 NB: because this
* code works out the length of all existing extensions it MUST always
* appear last.
*/
if (s->options & SSL_OP_TLSEXT_PADDING) {
int hlen = ret - (unsigned char *)s->init_buf->data;
if (hlen > 0xff && hlen < 0x200) {
hlen = 0x200 - hlen;
if (hlen >= 4)
hlen -= 4;
else
hlen = 0;
s2n(TLSEXT_TYPE_padding, ret);
s2n(hlen, ret);
memset(ret, 0, hlen);
ret += hlen;
}
}
done:
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf,
unsigned char *limit, int *al)
{
int extdatalen = 0;
unsigned char *orig = buf;
unsigned char *ret = buf;
#ifndef OPENSSL_NO_NEXTPROTONEG
int next_proto_neg_seen;
#endif
#ifndef OPENSSL_NO_EC
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
int using_ecc = (alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA);
using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
#endif
ret += 2;
if (ret >= limit)
return NULL; /* this really never occurs, but ... */
if (s->s3->send_connection_binding) {
int el;
if (!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_renegotiate, ret);
s2n(el, ret);
if (!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
/* Only add RI for SSLv3 */
if (s->version == SSL3_VERSION)
goto done;
if (!s->hit && s->servername_done == 1
&& s->session->tlsext_hostname != NULL) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_server_name, ret);
s2n(0, ret);
}
#ifndef OPENSSL_NO_EC
if (using_ecc) {
const unsigned char *plist;
size_t plistlen;
/*
* Add TLS extension ECPointFormats to the ServerHello message
*/
long lenmax;
tls1_get_formatlist(s, &plist, &plistlen);
if ((lenmax = limit - ret - 5) < 0)
return NULL;
if (plistlen > (size_t)lenmax)
return NULL;
if (plistlen > 255) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
s2n(TLSEXT_TYPE_ec_point_formats, ret);
s2n(plistlen + 1, ret);
*(ret++) = (unsigned char)plistlen;
memcpy(ret, plist, plistlen);
ret += plistlen;
}
/*
* Currently the server should not respond with a SupportedCurves
* extension
*/
#endif /* OPENSSL_NO_EC */
if (s->tlsext_ticket_expected && tls_use_ticket(s)) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_session_ticket, ret);
s2n(0, ret);
}
if (s->tlsext_status_expected) {
if ((long)(limit - ret - 4) < 0)
return NULL;
s2n(TLSEXT_TYPE_status_request, ret);
s2n(0, ret);
}
#ifndef OPENSSL_NO_SRTP
if (SSL_IS_DTLS(s) && s->srtp_profile) {
int el;
/* Returns 0 on success!! */
if (ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
if ((limit - ret - 4 - el) < 0)
return NULL;
s2n(TLSEXT_TYPE_use_srtp, ret);
s2n(el, ret);
if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
return NULL;
}
ret += el;
}
#endif
if (((s->s3->tmp.new_cipher->id & 0xFFFF) == 0x80
|| (s->s3->tmp.new_cipher->id & 0xFFFF) == 0x81)
&& (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG)) {
const unsigned char cryptopro_ext[36] = {
0xfd, 0xe8, /* 65000 */
0x00, 0x20, /* 32 bytes length */
0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
};
if (limit - ret < 36)
return NULL;
memcpy(ret, cryptopro_ext, 36);
ret += 36;
}
#ifndef OPENSSL_NO_HEARTBEATS
/* Add Heartbeat extension if we've received one */
if (SSL_IS_DTLS(s) && (s->tlsext_heartbeat & SSL_DTLSEXT_HB_ENABLED)) {
if ((limit - ret - 4 - 1) < 0)
return NULL;
s2n(TLSEXT_TYPE_heartbeat, ret);
s2n(1, ret);
/*-
* Set mode:
* 1: peer may send requests
* 2: peer not allowed to send requests
*/
if (s->tlsext_heartbeat & SSL_DTLSEXT_HB_DONT_RECV_REQUESTS)
*(ret++) = SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
else
*(ret++) = SSL_DTLSEXT_HB_ENABLED;
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
next_proto_neg_seen = s->s3->next_proto_neg_seen;
s->s3->next_proto_neg_seen = 0;
if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb) {
const unsigned char *npa;
unsigned int npalen;
int r;
r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
s->
ctx->next_protos_advertised_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
if ((long)(limit - ret - 4 - npalen) < 0)
return NULL;
s2n(TLSEXT_TYPE_next_proto_neg, ret);
s2n(npalen, ret);
memcpy(ret, npa, npalen);
ret += npalen;
s->s3->next_proto_neg_seen = 1;
}
}
#endif
if (!custom_ext_add(s, 1, &ret, limit, al))
return NULL;
if (s->s3->flags & TLS1_FLAGS_ENCRYPT_THEN_MAC) {
/*
* Don't use encrypt_then_mac if AEAD or RC4 might want to disable
* for other cases too.
*/
if (s->s3->tmp.new_cipher->algorithm_mac == SSL_AEAD
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_RC4
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT
|| s->s3->tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT12)
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
else {
s2n(TLSEXT_TYPE_encrypt_then_mac, ret);
s2n(0, ret);
}
}
if (s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) {
s2n(TLSEXT_TYPE_extended_master_secret, ret);
s2n(0, ret);
}
if (s->s3->alpn_selected != NULL) {
const unsigned char *selected = s->s3->alpn_selected;
unsigned int len = s->s3->alpn_selected_len;
if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
return NULL;
s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
s2n(3 + len, ret);
s2n(1 + len, ret);
*ret++ = len;
memcpy(ret, selected, len);
ret += len;
}
done:
if ((extdatalen = ret - orig - 2) == 0)
return orig;
s2n(extdatalen, orig);
return ret;
}
/*
* Save the ALPN extension in a ClientHello.
* pkt: the contents of the ALPN extension, not including type and length.
* al: a pointer to the alert value to send in the event of a failure.
* returns: 1 on success, 0 on error.
*/
static int tls1_alpn_handle_client_hello(SSL *s, PACKET *pkt, int *al)
{
PACKET protocol_list, save_protocol_list, protocol;
*al = SSL_AD_DECODE_ERROR;
if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
|| PACKET_remaining(&protocol_list) < 2) {
return 0;
}
save_protocol_list = protocol_list;
do {
/* Protocol names can't be empty. */
if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
|| PACKET_remaining(&protocol) == 0) {
return 0;
}
} while (PACKET_remaining(&protocol_list) != 0);
if (!PACKET_memdup(&save_protocol_list,
&s->s3->alpn_proposed,
&s->s3->alpn_proposed_len)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
return 1;
}
/*
* Process the ALPN extension in a ClientHello.
* ret: a pointer to the TLSEXT return value: SSL_TLSEXT_ERR_*
* al: a pointer to the alert value to send in the event of a failure.
* returns 1 on success, 0
*/
static int tls1_alpn_handle_client_hello_late(SSL *s, int *ret, int *al)
{
const unsigned char *selected = NULL;
unsigned char selected_len = 0;
if (s->ctx->alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) {
int r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
s->s3->alpn_proposed,
s->s3->alpn_proposed_len,
s->ctx->alpn_select_cb_arg);
if (r == SSL_TLSEXT_ERR_OK) {
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len);
if (s->s3->alpn_selected == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
*ret = SSL_TLSEXT_ERR_ALERT_FATAL;
return 0;
}
s->s3->alpn_selected_len = selected_len;
#ifndef OPENSSL_NO_NEXTPROTONEG
/* ALPN takes precedence over NPN. */
s->s3->next_proto_neg_seen = 0;
#endif
} else {
*al = SSL_AD_NO_APPLICATION_PROTOCOL;
*ret = SSL_TLSEXT_ERR_ALERT_FATAL;
return 0;
}
}
return 1;
}
#ifndef OPENSSL_NO_EC
/*-
* ssl_check_for_safari attempts to fingerprint Safari using OS X
* SecureTransport using the TLS extension block in |pkt|.
* Safari, since 10.6, sends exactly these extensions, in this order:
* SNI,
* elliptic_curves
* ec_point_formats
*
* We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
* but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
* Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
* 10.8..10.8.3 (which don't work).
*/
static void ssl_check_for_safari(SSL *s, const PACKET *pkt)
{
unsigned int type;
PACKET sni, tmppkt;
size_t ext_len;
static const unsigned char kSafariExtensionsBlock[] = {
0x00, 0x0a, /* elliptic_curves extension */
0x00, 0x08, /* 8 bytes */
0x00, 0x06, /* 6 bytes of curve ids */
0x00, 0x17, /* P-256 */
0x00, 0x18, /* P-384 */
0x00, 0x19, /* P-521 */
0x00, 0x0b, /* ec_point_formats */
0x00, 0x02, /* 2 bytes */
0x01, /* 1 point format */
0x00, /* uncompressed */
/* The following is only present in TLS 1.2 */
0x00, 0x0d, /* signature_algorithms */
0x00, 0x0c, /* 12 bytes */
0x00, 0x0a, /* 10 bytes */
0x05, 0x01, /* SHA-384/RSA */
0x04, 0x01, /* SHA-256/RSA */
0x02, 0x01, /* SHA-1/RSA */
0x04, 0x03, /* SHA-256/ECDSA */
0x02, 0x03, /* SHA-1/ECDSA */
};
/* Length of the common prefix (first two extensions). */
static const size_t kSafariCommonExtensionsLength = 18;
tmppkt = *pkt;
if (!PACKET_forward(&tmppkt, 2)
|| !PACKET_get_net_2(&tmppkt, &type)
|| !PACKET_get_length_prefixed_2(&tmppkt, &sni)) {
return;
}
if (type != TLSEXT_TYPE_server_name)
return;
ext_len = TLS1_get_client_version(s) >= TLS1_2_VERSION ?
sizeof(kSafariExtensionsBlock) : kSafariCommonExtensionsLength;
s->s3->is_probably_safari = PACKET_equal(&tmppkt, kSafariExtensionsBlock,
ext_len);
}
#endif /* !OPENSSL_NO_EC */
/*
* Parse ClientHello extensions and stash extension info in various parts of
* the SSL object. Verify that there are no duplicate extensions.
*
* Behaviour upon resumption is extension-specific. If the extension has no
* effect during resumption, it is parsed (to verify its format) but otherwise
* ignored.
*
* Consumes the entire packet in |pkt|. Returns 1 on success and 0 on failure.
* Upon failure, sets |al| to the appropriate alert.
*/
static int ssl_scan_clienthello_tlsext(SSL *s, PACKET *pkt, int *al)
{
unsigned int type;
int renegotiate_seen = 0;
PACKET extensions;
*al = SSL_AD_DECODE_ERROR;
s->servername_done = 0;
s->tlsext_status_type = -1;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
s->s3->alpn_selected_len = 0;
OPENSSL_free(s->s3->alpn_proposed);
s->s3->alpn_proposed = NULL;
s->s3->alpn_proposed_len = 0;
#ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_DTLSEXT_HB_ENABLED |
SSL_DTLSEXT_HB_DONT_SEND_REQUESTS);
#endif
#ifndef OPENSSL_NO_EC
if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
ssl_check_for_safari(s, pkt);
# endif /* !OPENSSL_NO_EC */
/* Clear any signature algorithms extension received */
OPENSSL_free(s->s3->tmp.peer_sigalgs);
s->s3->tmp.peer_sigalgs = NULL;
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
#ifndef OPENSSL_NO_SRP
OPENSSL_free(s->srp_ctx.login);
s->srp_ctx.login = NULL;
#endif
s->srtp_profile = NULL;
if (PACKET_remaining(pkt) == 0)
goto ri_check;
if (!PACKET_as_length_prefixed_2(pkt, &extensions))
return 0;
if (!tls1_check_duplicate_extensions(&extensions))
return 0;
/*
* We parse all extensions to ensure the ClientHello is well-formed but,
* unless an extension specifies otherwise, we ignore extensions upon
* resumption.
*/
while (PACKET_get_net_2(&extensions, &type)) {
PACKET extension;
if (!PACKET_get_length_prefixed_2(&extensions, &extension))
return 0;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 0, type, PACKET_data(&extension),
PACKET_remaining(&extension),
s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_renegotiate) {
if (!ssl_parse_clienthello_renegotiate_ext(s, &extension, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
}
/*-
* The servername extension is treated as follows:
*
* - Only the hostname type is supported with a maximum length of 255.
* - The servername is rejected if too long or if it contains zeros,
* in which case an fatal alert is generated.
* - The servername field is maintained together with the session cache.
* - When a session is resumed, the servername call back invoked in order
* to allow the application to position itself to the right context.
* - The servername is acknowledged if it is new for a session or when
* it is identical to a previously used for the same session.
* Applications can control the behaviour. They can at any time
* set a 'desirable' servername for a new SSL object. This can be the
* case for example with HTTPS when a Host: header field is received and
* a renegotiation is requested. In this case, a possible servername
* presented in the new client hello is only acknowledged if it matches
* the value of the Host: field.
* - Applications must use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
* if they provide for changing an explicit servername context for the
* session, i.e. when the session has been established with a servername
* extension.
* - On session reconnect, the servername extension may be absent.
*
*/
else if (type == TLSEXT_TYPE_server_name) {
unsigned int servname_type;
PACKET sni, hostname;
if (!PACKET_as_length_prefixed_2(&extension, &sni)
/* ServerNameList must be at least 1 byte long. */
|| PACKET_remaining(&sni) == 0) {
return 0;
}
/*
* Although the server_name extension was intended to be
* extensible to new name types, RFC 4366 defined the
* syntax inextensibility and OpenSSL 1.0.x parses it as
* such.
* RFC 6066 corrected the mistake but adding new name types
* is nevertheless no longer feasible, so act as if no other
* SNI types can exist, to simplify parsing.
*
* Also note that the RFC permits only one SNI value per type,
* i.e., we can only have a single hostname.
*/
if (!PACKET_get_1(&sni, &servname_type)
|| servname_type != TLSEXT_NAMETYPE_host_name
|| !PACKET_as_length_prefixed_2(&sni, &hostname)) {
return 0;
}
if (!s->hit) {
if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (PACKET_contains_zero_byte(&hostname)) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
if (!PACKET_strndup(&hostname, &s->session->tlsext_hostname)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->servername_done = 1;
} else {
/*
* TODO(openssl-team): if the SNI doesn't match, we MUST
* fall back to a full handshake.
*/
s->servername_done = s->session->tlsext_hostname
&& PACKET_equal(&hostname, s->session->tlsext_hostname,
strlen(s->session->tlsext_hostname));
}
}
#ifndef OPENSSL_NO_SRP
else if (type == TLSEXT_TYPE_srp) {
PACKET srp_I;
if (!PACKET_as_length_prefixed_1(&extension, &srp_I))
return 0;
if (PACKET_contains_zero_byte(&srp_I))
return 0;
/*
* TODO(openssl-team): currently, we re-authenticate the user
* upon resumption. Instead, we MUST ignore the login.
*/
if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
PACKET ec_point_format_list;
if (!PACKET_as_length_prefixed_1(&extension,
&ec_point_format_list)
|| PACKET_remaining(&ec_point_format_list) == 0) {
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&ec_point_format_list,
&s->session->tlsext_ecpointformatlist,
&s->session->tlsext_ecpointformatlist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
} else if (type == TLSEXT_TYPE_elliptic_curves) {
PACKET elliptic_curve_list;
/* Each NamedCurve is 2 bytes and we must have at least 1. */
if (!PACKET_as_length_prefixed_2(&extension,
&elliptic_curve_list)
|| PACKET_remaining(&elliptic_curve_list) == 0
|| (PACKET_remaining(&elliptic_curve_list) % 2) != 0) {
return 0;
}
if (!s->hit) {
if (!PACKET_memdup(&elliptic_curve_list,
&s->session->tlsext_ellipticcurvelist,
&s->session->tlsext_ellipticcurvelist_length)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
}
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket) {
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, PACKET_data(&extension),
PACKET_remaining(&extension),
s->tls_session_ticket_ext_cb_arg)) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
} else if (type == TLSEXT_TYPE_signature_algorithms) {
PACKET supported_sig_algs;
if (!PACKET_as_length_prefixed_2(&extension, &supported_sig_algs)
|| (PACKET_remaining(&supported_sig_algs) % 2) != 0
|| PACKET_remaining(&supported_sig_algs) == 0) {
return 0;
}
if (!s->hit) {
if (!tls1_save_sigalgs(s, PACKET_data(&supported_sig_algs),
PACKET_remaining(&supported_sig_algs))) {
return 0;
}
}
} else if (type == TLSEXT_TYPE_status_request) {
if (!PACKET_get_1(&extension,
(unsigned int *)&s->tlsext_status_type)) {
return 0;
}
#ifndef OPENSSL_NO_OCSP
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
const unsigned char *ext_data;
PACKET responder_id_list, exts;
if (!PACKET_get_length_prefixed_2(&extension, &responder_id_list))
return 0;
while (PACKET_remaining(&responder_id_list) > 0) {
OCSP_RESPID *id;
PACKET responder_id;
const unsigned char *id_data;
if (!PACKET_get_length_prefixed_2(&responder_id_list,
&responder_id)
|| PACKET_remaining(&responder_id) == 0) {
return 0;
}
if (s->tlsext_ocsp_ids == NULL
&& (s->tlsext_ocsp_ids =
sk_OCSP_RESPID_new_null()) == NULL) {
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
id_data = PACKET_data(&responder_id);
id = d2i_OCSP_RESPID(NULL, &id_data,
PACKET_remaining(&responder_id));
if (id == NULL)
return 0;
if (id_data != PACKET_end(&responder_id)) {
OCSP_RESPID_free(id);
return 0;
}
if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
OCSP_RESPID_free(id);
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
}
/* Read in request_extensions */
if (!PACKET_as_length_prefixed_2(&extension, &exts))
return 0;
if (PACKET_remaining(&exts) > 0) {
ext_data = PACKET_data(&exts);
sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
X509_EXTENSION_free);
s->tlsext_ocsp_exts =
d2i_X509_EXTENSIONS(NULL, &ext_data,
PACKET_remaining(&exts));
if (s->tlsext_ocsp_exts == NULL
|| ext_data != PACKET_end(&exts)) {
return 0;
}
}
} else
#endif
{
/*
* We don't know what to do with any other type so ignore it.
*/
s->tlsext_status_type = -1;
}
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_heartbeat) {
unsigned int hbtype;
if (!PACKET_get_1(&extension, &hbtype)
|| PACKET_remaining(&extension)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
switch (hbtype) {
case 0x01: /* Client allows us to send HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
break;
case 0x02: /* Client doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
/*-
* We shouldn't accept this extension on a
* renegotiation.
*
* s->new_session will be set on renegotiation, but we
* probably shouldn't rely that it couldn't be set on
* the initial renegotiation too in certain cases (when
* there's some other reason to disallow resuming an
* earlier session -- the current code won't be doing
* anything like that, but this might change).
*
* A valid sign that there's been a previous handshake
* in this connection is if s->s3->tmp.finish_md_len >
* 0. (We are talking about a check that will happen
* in the Hello protocol round, well before a new
* Finished message could have been computed.)
*/
s->s3->next_proto_neg_seen = 1;
}
#endif
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
s->s3->tmp.finish_md_len == 0) {
if (!tls1_alpn_handle_client_hello(s, &extension, al))
return 0;
}
/* session ticket processed earlier */
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
&& type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_clienthello_use_srtp_ext(s, &extension, al))
return 0;
}
#endif
else if (type == TLSEXT_TYPE_encrypt_then_mac)
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
/*
* Note: extended master secret extension handled in
* tls_check_serverhello_tlsext_early()
*/
/*
* If this ClientHello extension was unhandled and this is a
* nonresumed connection, check whether the extension is a custom
* TLS Extension (has a custom_srv_ext_record), and if so call the
* callback and record the extension number so that an appropriate
* ServerHello may be later returned.
*/
else if (!s->hit) {
if (custom_ext_parse(s, 1, type, PACKET_data(&extension),
PACKET_remaining(&extension), al) <= 0)
return 0;
}
}
if (PACKET_remaining(pkt) != 0) {
/* tls1_check_duplicate_extensions should ensure this never happens. */
*al = SSL_AD_INTERNAL_ERROR;
return 0;
}
ri_check:
/* Need RI if renegotiating */
if (!renegotiate_seen && s->renegotiate &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
/*
* This function currently has no state to clean up, so it returns directly.
* If parsing fails at any point, the function returns early.
* The SSL object may be left with partial data from extensions, but it must
* then no longer be used, and clearing it up will free the leftovers.
*/
return 1;
}
int ssl_parse_clienthello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
custom_ext_init(&s->cert->srv_ext);
if (ssl_scan_clienthello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
if (ssl_check_clienthello_tlsext_early(s) <= 0) {
SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_CLIENTHELLO_TLSEXT);
return 0;
}
return 1;
}
#ifndef OPENSSL_NO_NEXTPROTONEG
/*
* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
* elements of zero length are allowed and the set of elements must exactly
* fill the length of the block.
*/
static char ssl_next_proto_validate(PACKET *pkt)
{
PACKET tmp_protocol;
while (PACKET_remaining(pkt)) {
if (!PACKET_get_length_prefixed_1(pkt, &tmp_protocol)
|| PACKET_remaining(&tmp_protocol) == 0)
return 0;
}
return 1;
}
#endif
static int ssl_scan_serverhello_tlsext(SSL *s, PACKET *pkt, int *al)
{
unsigned int length, type, size;
int tlsext_servername = 0;
int renegotiate_seen = 0;
#ifndef OPENSSL_NO_NEXTPROTONEG
s->s3->next_proto_neg_seen = 0;
#endif
s->tlsext_ticket_expected = 0;
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = NULL;
#ifndef OPENSSL_NO_HEARTBEATS
s->tlsext_heartbeat &= ~(SSL_DTLSEXT_HB_ENABLED |
SSL_DTLSEXT_HB_DONT_SEND_REQUESTS);
#endif
s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
if (!PACKET_get_net_2(pkt, &length))
goto ri_check;
if (PACKET_remaining(pkt) != length) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!tls1_check_duplicate_extensions(pkt)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
while (PACKET_get_net_2(pkt, &type) && PACKET_get_net_2(pkt, &size)) {
const unsigned char *data;
PACKET spkt;
if (!PACKET_get_sub_packet(pkt, &spkt, size)
|| !PACKET_peek_bytes(&spkt, &data, size))
goto ri_check;
if (s->tlsext_debug_cb)
s->tlsext_debug_cb(s, 1, type, data, size, s->tlsext_debug_arg);
if (type == TLSEXT_TYPE_renegotiate) {
if (!ssl_parse_serverhello_renegotiate_ext(s, &spkt, al))
return 0;
renegotiate_seen = 1;
} else if (s->version == SSL3_VERSION) {
} else if (type == TLSEXT_TYPE_server_name) {
if (s->tlsext_hostname == NULL || size > 0) {
*al = TLS1_AD_UNRECOGNIZED_NAME;
return 0;
}
tlsext_servername = 1;
}
#ifndef OPENSSL_NO_EC
else if (type == TLSEXT_TYPE_ec_point_formats) {
unsigned int ecpointformatlist_length;
if (!PACKET_get_1(&spkt, &ecpointformatlist_length)
|| ecpointformatlist_length != size - 1) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (!s->hit) {
s->session->tlsext_ecpointformatlist_length = 0;
OPENSSL_free(s->session->tlsext_ecpointformatlist);
if ((s->session->tlsext_ecpointformatlist =
OPENSSL_malloc(ecpointformatlist_length)) == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->session->tlsext_ecpointformatlist_length =
ecpointformatlist_length;
if (!PACKET_copy_bytes(&spkt,
s->session->tlsext_ecpointformatlist,
ecpointformatlist_length)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
}
}
#endif /* OPENSSL_NO_EC */
else if (type == TLSEXT_TYPE_session_ticket) {
if (s->tls_session_ticket_ext_cb &&
!s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
{
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
if (!tls_use_ticket(s) || (size > 0)) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
s->tlsext_ticket_expected = 1;
}
else if (type == TLSEXT_TYPE_status_request) {
/*
* MUST be empty and only sent if we've requested a status
* request message.
*/
if ((s->tlsext_status_type == -1) || (size > 0)) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* Set flag to expect CertificateStatus message */
s->tlsext_status_expected = 1;
}
#ifndef OPENSSL_NO_CT
/*
* Only take it if we asked for it - i.e if there is no CT validation
* callback set, then a custom extension MAY be processing it, so we
* need to let control continue to flow to that.
*/
else if (type == TLSEXT_TYPE_signed_certificate_timestamp &&
s->ct_validation_callback != NULL) {
/* Simply copy it off for later processing */
if (s->tlsext_scts != NULL) {
OPENSSL_free(s->tlsext_scts);
s->tlsext_scts = NULL;
}
s->tlsext_scts_len = size;
if (size > 0) {
s->tlsext_scts = OPENSSL_malloc(size);
if (s->tlsext_scts == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
memcpy(s->tlsext_scts, data, size);
}
}
#endif
#ifndef OPENSSL_NO_NEXTPROTONEG
else if (type == TLSEXT_TYPE_next_proto_neg &&
s->s3->tmp.finish_md_len == 0) {
unsigned char *selected;
unsigned char selected_len;
/* We must have requested it. */
if (s->ctx->next_proto_select_cb == NULL) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/* The data must be valid */
if (!ssl_next_proto_validate(&spkt)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
if (s->
ctx->next_proto_select_cb(s, &selected, &selected_len, data,
size,
s->ctx->next_proto_select_cb_arg) !=
SSL_TLSEXT_ERR_OK) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
s->next_proto_negotiated = OPENSSL_malloc(selected_len);
if (s->next_proto_negotiated == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
memcpy(s->next_proto_negotiated, selected, selected_len);
s->next_proto_negotiated_len = selected_len;
s->s3->next_proto_neg_seen = 1;
}
#endif
else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation) {
unsigned len;
/* We must have requested it. */
if (!s->s3->alpn_sent) {
*al = TLS1_AD_UNSUPPORTED_EXTENSION;
return 0;
}
/*-
* The extension data consists of:
* uint16 list_length
* uint8 proto_length;
* uint8 proto[proto_length];
*/
if (!PACKET_get_net_2(&spkt, &len)
|| PACKET_remaining(&spkt) != len
|| !PACKET_get_1(&spkt, &len)
|| PACKET_remaining(&spkt) != len) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
OPENSSL_free(s->s3->alpn_selected);
s->s3->alpn_selected = OPENSSL_malloc(len);
if (s->s3->alpn_selected == NULL) {
*al = TLS1_AD_INTERNAL_ERROR;
return 0;
}
if (!PACKET_copy_bytes(&spkt, s->s3->alpn_selected, len)) {
*al = TLS1_AD_DECODE_ERROR;
return 0;
}
s->s3->alpn_selected_len = len;
}
#ifndef OPENSSL_NO_HEARTBEATS
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_heartbeat) {
unsigned int hbtype;
if (!PACKET_get_1(&spkt, &hbtype)) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
switch (hbtype) {
case 0x01: /* Server allows us to send HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
break;
case 0x02: /* Server doesn't accept HB requests */
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_ENABLED;
s->tlsext_heartbeat |= SSL_DTLSEXT_HB_DONT_SEND_REQUESTS;
break;
default:
*al = SSL_AD_ILLEGAL_PARAMETER;
return 0;
}
}
#endif
#ifndef OPENSSL_NO_SRTP
else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
if (ssl_parse_serverhello_use_srtp_ext(s, &spkt, al))
return 0;
}
#endif
else if (type == TLSEXT_TYPE_encrypt_then_mac) {
/* Ignore if inappropriate ciphersuite */
if (s->s3->tmp.new_cipher->algorithm_mac != SSL_AEAD
&& s->s3->tmp.new_cipher->algorithm_enc != SSL_RC4)
s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
}
else if (type == TLSEXT_TYPE_extended_master_secret) {
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
if (!s->hit)
s->session->flags |= SSL_SESS_FLAG_EXTMS;
}
/*
* If this extension type was not otherwise handled, but matches a
* custom_cli_ext_record, then send it to the c callback
*/
else if (custom_ext_parse(s, 0, type, data, size, al) <= 0)
return 0;
}
if (PACKET_remaining(pkt) != 0) {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
if (!s->hit && tlsext_servername == 1) {
if (s->tlsext_hostname) {
if (s->session->tlsext_hostname == NULL) {
s->session->tlsext_hostname = OPENSSL_strdup(s->tlsext_hostname);
if (!s->session->tlsext_hostname) {
*al = SSL_AD_UNRECOGNIZED_NAME;
return 0;
}
} else {
*al = SSL_AD_DECODE_ERROR;
return 0;
}
}
}
ri_check:
/*
* Determine if we need to see RI. Strictly speaking if we want to avoid
* an attack we should *always* see RI even on initial server hello
* because the client doesn't see any renegotiation during an attack.
* However this would mean we could not connect to any server which
* doesn't support RI so for the immediate future tolerate RI absence on
* initial connect only.
*/
if (!renegotiate_seen && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
&& !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT,
SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
return 0;
}
if (s->hit) {
/*
* Check extended master secret extension is consistent with
* original session.
*/
if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) !=
!(s->session->flags & SSL_SESS_FLAG_EXTMS)) {
*al = SSL_AD_HANDSHAKE_FAILURE;
SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT, SSL_R_INCONSISTENT_EXTMS);
return 0;
}
}
return 1;
}
int ssl_prepare_clienthello_tlsext(SSL *s)
{
s->s3->alpn_sent = 0;
return 1;
}
int ssl_prepare_serverhello_tlsext(SSL *s)
{
return 1;
}
static int ssl_check_clienthello_tlsext_early(SSL *s)
{
int ret = SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/*
* The handling of the ECPointFormats extension is done elsewhere, namely
* in ssl3_choose_cipher in s3_lib.c.
*/
/*
* The handling of the EllipticCurves extension is done elsewhere, namely
* in ssl3_choose_cipher in s3_lib.c.
*/
#endif
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret =
s->ctx->tlsext_servername_callback(s, &al,
s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL
&& s->initial_ctx->tlsext_servername_callback != 0)
ret =
s->initial_ctx->tlsext_servername_callback(s, &al,
s->
initial_ctx->tlsext_servername_arg);
switch (ret) {
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s, SSL3_AL_WARNING, al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done = 0;
default:
return 1;
}
}
/* Initialise digests to default values */
void ssl_set_default_md(SSL *s)
{
const EVP_MD **pmd = s->s3->tmp.md;
#ifndef OPENSSL_NO_DSA
pmd[SSL_PKEY_DSA_SIGN] = ssl_md(SSL_MD_SHA1_IDX);
#endif
#ifndef OPENSSL_NO_RSA
if (SSL_USE_SIGALGS(s))
pmd[SSL_PKEY_RSA_SIGN] = ssl_md(SSL_MD_SHA1_IDX);
else
pmd[SSL_PKEY_RSA_SIGN] = ssl_md(SSL_MD_MD5_SHA1_IDX);
pmd[SSL_PKEY_RSA_ENC] = pmd[SSL_PKEY_RSA_SIGN];
#endif
#ifndef OPENSSL_NO_EC
pmd[SSL_PKEY_ECC] = ssl_md(SSL_MD_SHA1_IDX);
#endif
#ifndef OPENSSL_NO_GOST
pmd[SSL_PKEY_GOST01] = ssl_md(SSL_MD_GOST94_IDX);
pmd[SSL_PKEY_GOST12_256] = ssl_md(SSL_MD_GOST12_256_IDX);
pmd[SSL_PKEY_GOST12_512] = ssl_md(SSL_MD_GOST12_512_IDX);
#endif
}
int tls1_set_server_sigalgs(SSL *s)
{
int al;
size_t i;
/* Clear any shared signature algorithms */
OPENSSL_free(s->cert->shared_sigalgs);
s->cert->shared_sigalgs = NULL;
s->cert->shared_sigalgslen = 0;
/* Clear certificate digests and validity flags */
for (i = 0; i < SSL_PKEY_NUM; i++) {
s->s3->tmp.md[i] = NULL;
s->s3->tmp.valid_flags[i] = 0;
}
/* If sigalgs received process it. */
if (s->s3->tmp.peer_sigalgs) {
if (!tls1_process_sigalgs(s)) {
SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS, ERR_R_MALLOC_FAILURE);
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
/* Fatal error is no shared signature algorithms */
if (!s->cert->shared_sigalgs) {
SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS,
SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
al = SSL_AD_ILLEGAL_PARAMETER;
goto err;
}
} else {
ssl_set_default_md(s);
}
return 1;
err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
int ssl_check_clienthello_tlsext_late(SSL *s)
{
int ret = SSL_TLSEXT_ERR_OK;
int al = SSL_AD_INTERNAL_ERROR;
/*
* If status request then ask callback what to do. Note: this must be
* called after servername callbacks in case the certificate has changed,
* and must be called after the cipher has been chosen because this may
* influence which certificate is sent
*/
if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb) {
int r;
CERT_PKEY *certpkey;
certpkey = ssl_get_server_send_pkey(s);
/* If no certificate can't return certificate status */
if (certpkey == NULL) {
s->tlsext_status_expected = 0;
return 1;
}
/*
* Set current certificate to one we will use so SSL_get_certificate
* et al can pick it up.
*/
s->cert->key = certpkey;
r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
switch (r) {
/* We don't want to send a status request response */
case SSL_TLSEXT_ERR_NOACK:
s->tlsext_status_expected = 0;
break;
/* status request response should be sent */
case SSL_TLSEXT_ERR_OK:
if (s->tlsext_ocsp_resp)
s->tlsext_status_expected = 1;
else
s->tlsext_status_expected = 0;
break;
/* something bad happened */
case SSL_TLSEXT_ERR_ALERT_FATAL:
ret = SSL_TLSEXT_ERR_ALERT_FATAL;
al = SSL_AD_INTERNAL_ERROR;
goto err;
}
} else
s->tlsext_status_expected = 0;
if (!tls1_alpn_handle_client_hello_late(s, &ret, &al)) {
goto err;
}
err:
switch (ret) {
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s, SSL3_AL_WARNING, al);
return 1;
default:
return 1;
}
}
int ssl_check_serverhello_tlsext(SSL *s)
{
int ret = SSL_TLSEXT_ERR_NOACK;
int al = SSL_AD_UNRECOGNIZED_NAME;
#ifndef OPENSSL_NO_EC
/*
* If we are client and using an elliptic curve cryptography cipher
* suite, then if server returns an EC point formats lists extension it
* must contain uncompressed.
*/
unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
if ((s->tlsext_ecpointformatlist != NULL)
&& (s->tlsext_ecpointformatlist_length > 0)
&& (s->session->tlsext_ecpointformatlist != NULL)
&& (s->session->tlsext_ecpointformatlist_length > 0)
&& ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) {
/* we are using an ECC cipher */
size_t i;
unsigned char *list;
int found_uncompressed = 0;
list = s->session->tlsext_ecpointformatlist;
for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++) {
if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed) {
found_uncompressed = 1;
break;
}
}
if (!found_uncompressed) {
SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,
SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
return -1;
}
}
ret = SSL_TLSEXT_ERR_OK;
#endif /* OPENSSL_NO_EC */
if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
ret =
s->ctx->tlsext_servername_callback(s, &al,
s->ctx->tlsext_servername_arg);
else if (s->initial_ctx != NULL
&& s->initial_ctx->tlsext_servername_callback != 0)
ret =
s->initial_ctx->tlsext_servername_callback(s, &al,
s->
initial_ctx->tlsext_servername_arg);
/*
* Ensure we get sensible values passed to tlsext_status_cb in the event
* that we don't receive a status message
*/
OPENSSL_free(s->tlsext_ocsp_resp);
s->tlsext_ocsp_resp = NULL;
s->tlsext_ocsp_resplen = -1;
switch (ret) {
case SSL_TLSEXT_ERR_ALERT_FATAL:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
case SSL_TLSEXT_ERR_ALERT_WARNING:
ssl3_send_alert(s, SSL3_AL_WARNING, al);
return 1;
case SSL_TLSEXT_ERR_NOACK:
s->servername_done = 0;
default:
return 1;
}
}
int ssl_parse_serverhello_tlsext(SSL *s, PACKET *pkt)
{
int al = -1;
if (s->version < SSL3_VERSION)
return 1;
if (ssl_scan_serverhello_tlsext(s, pkt, &al) <= 0) {
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return 0;
}
if (ssl_check_serverhello_tlsext(s) <= 0) {
SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_SERVERHELLO_TLSEXT);
return 0;
}
return 1;
}
/*-
* Since the server cache lookup is done early on in the processing of the
* ClientHello and other operations depend on the result some extensions
* need to be handled at the same time.
*
* Two extensions are currently handled, session ticket and extended master
* secret.
*
* session_id: ClientHello session ID.
* ext: ClientHello extensions (including length prefix)
* ret: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* If s->tls_session_secret_cb is set then we are expecting a pre-shared key
* ciphersuite, in which case we have no use for session tickets and one will
* never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
*
* Returns:
* -1: fatal error, either from parsing or decrypting the ticket.
* 0: no ticket was found (or was ignored, based on settings).
* 1: a zero length extension was found, indicating that the client supports
* session tickets but doesn't currently have one to offer.
* 2: either s->tls_session_secret_cb was set, or a ticket was offered but
* couldn't be decrypted because of a non-fatal error.
* 3: a ticket was successfully decrypted and *ret was set.
*
* Side effects:
* Sets s->tlsext_ticket_expected to 1 if the server will have to issue
* a new session ticket to the client because the client indicated support
* (and s->tls_session_secret_cb is NULL) but the client either doesn't have
* a session ticket or we couldn't use the one it gave us, or if
* s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
* Otherwise, s->tlsext_ticket_expected is set to 0.
*
* For extended master secret flag is set if the extension is present.
*
*/
int tls_check_serverhello_tlsext_early(SSL *s, const PACKET *ext,
const PACKET *session_id,
SSL_SESSION **ret)
{
unsigned int i;
PACKET local_ext = *ext;
int retv = -1;
int have_ticket = 0;
int use_ticket = tls_use_ticket(s);
*ret = NULL;
s->tlsext_ticket_expected = 0;
s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS;
/*
* If tickets disabled behave as if no ticket present to permit stateful
* resumption.
*/
if ((s->version <= SSL3_VERSION))
return 0;
if (!PACKET_get_net_2(&local_ext, &i)) {
retv = 0;
goto end;
}
while (PACKET_remaining(&local_ext) >= 4) {
unsigned int type, size;
if (!PACKET_get_net_2(&local_ext, &type)
|| !PACKET_get_net_2(&local_ext, &size)) {
/* Shouldn't ever happen */
retv = -1;
goto end;
}
if (PACKET_remaining(&local_ext) < size) {
retv = 0;
goto end;
}
if (type == TLSEXT_TYPE_session_ticket && use_ticket) {
int r;
const unsigned char *etick;
/* Duplicate extension */
if (have_ticket != 0) {
retv = -1;
goto end;
}
have_ticket = 1;
if (size == 0) {
/*
* The client will accept a ticket but doesn't currently have
* one.
*/
s->tlsext_ticket_expected = 1;
retv = 1;
continue;
}
if (s->tls_session_secret_cb) {
/*
* Indicate that the ticket couldn't be decrypted rather than
* generating the session from ticket now, trigger
* abbreviated handshake based on external mechanism to
* calculate the master secret later.
*/
retv = 2;
continue;
}
if (!PACKET_get_bytes(&local_ext, &etick, size)) {
/* Shouldn't ever happen */
retv = -1;
goto end;
}
r = tls_decrypt_ticket(s, etick, size, PACKET_data(session_id),
PACKET_remaining(session_id), ret);
switch (r) {
case 2: /* ticket couldn't be decrypted */
s->tlsext_ticket_expected = 1;
retv = 2;
break;
case 3: /* ticket was decrypted */
retv = r;
break;
case 4: /* ticket decrypted but need to renew */
s->tlsext_ticket_expected = 1;
retv = 3;
break;
default: /* fatal error */
retv = -1;
break;
}
continue;
} else {
if (type == TLSEXT_TYPE_extended_master_secret)
s->s3->flags |= TLS1_FLAGS_RECEIVED_EXTMS;
if (!PACKET_forward(&local_ext, size)) {
retv = -1;
goto end;
}
}
}
if (have_ticket == 0)
retv = 0;
end:
return retv;
}
/*-
* tls_decrypt_ticket attempts to decrypt a session ticket.
*
* etick: points to the body of the session ticket extension.
* eticklen: the length of the session tickets extension.
* sess_id: points at the session ID.
* sesslen: the length of the session ID.
* psess: (output) on return, if a ticket was decrypted, then this is set to
* point to the resulting session.
*
* Returns:
* -2: fatal error, malloc failure.
* -1: fatal error, either from parsing or decrypting the ticket.
* 2: the ticket couldn't be decrypted.
* 3: a ticket was successfully decrypted and *psess was set.
* 4: same as 3, but the ticket needs to be renewed.
*/
static int tls_decrypt_ticket(SSL *s, const unsigned char *etick,
int eticklen, const unsigned char *sess_id,
int sesslen, SSL_SESSION **psess)
{
SSL_SESSION *sess;
unsigned char *sdec;
const unsigned char *p;
int slen, mlen, renew_ticket = 0, ret = -1;
unsigned char tick_hmac[EVP_MAX_MD_SIZE];
HMAC_CTX *hctx = NULL;
EVP_CIPHER_CTX *ctx;
SSL_CTX *tctx = s->initial_ctx;
/* Need at least keyname + iv + some encrypted data */
if (eticklen < 48)
return 2;
/* Initialize session ticket encryption and HMAC contexts */
hctx = HMAC_CTX_new();
if (hctx == NULL)
return -2;
ctx = EVP_CIPHER_CTX_new();
if (ctx == NULL) {
ret = -2;
goto err;
}
if (tctx->tlsext_ticket_key_cb) {
unsigned char *nctick = (unsigned char *)etick;
int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
ctx, hctx, 0);
if (rv < 0)
goto err;
if (rv == 0) {
ret = 2;
goto err;
}
if (rv == 2)
renew_ticket = 1;
} else {
/* Check key name matches */
if (memcmp(etick, tctx->tlsext_tick_key_name,
sizeof(tctx->tlsext_tick_key_name)) != 0) {
ret = 2;
goto err;
}
if (HMAC_Init_ex(hctx, tctx->tlsext_tick_hmac_key,
sizeof(tctx->tlsext_tick_hmac_key),
EVP_sha256(), NULL) <= 0
|| EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL,
tctx->tlsext_tick_aes_key,
etick + sizeof(tctx->tlsext_tick_key_name)) <= 0) {
goto err;
}
}
/*
* Attempt to process session ticket, first conduct sanity and integrity
* checks on ticket.
*/
mlen = HMAC_size(hctx);
if (mlen < 0) {
goto err;
}
eticklen -= mlen;
/* Check HMAC of encrypted ticket */
if (HMAC_Update(hctx, etick, eticklen) <= 0
|| HMAC_Final(hctx, tick_hmac, NULL) <= 0) {
goto err;
}
HMAC_CTX_free(hctx);
if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) {
EVP_CIPHER_CTX_free(ctx);
return 2;
}
/* Attempt to decrypt session data */
/* Move p after IV to start of encrypted ticket, update length */
p = etick + 16 + EVP_CIPHER_CTX_iv_length(ctx);
eticklen -= 16 + EVP_CIPHER_CTX_iv_length(ctx);
sdec = OPENSSL_malloc(eticklen);
if (sdec == NULL
|| EVP_DecryptUpdate(ctx, sdec, &slen, p, eticklen) <= 0) {
EVP_CIPHER_CTX_free(ctx);
OPENSSL_free(sdec);
return -1;
}
if (EVP_DecryptFinal(ctx, sdec + slen, &mlen) <= 0) {
EVP_CIPHER_CTX_free(ctx);
OPENSSL_free(sdec);
return 2;
}
slen += mlen;
EVP_CIPHER_CTX_free(ctx);
ctx = NULL;
p = sdec;
sess = d2i_SSL_SESSION(NULL, &p, slen);
OPENSSL_free(sdec);
if (sess) {
/*
* The session ID, if non-empty, is used by some clients to detect
* that the ticket has been accepted. So we copy it to the session
* structure. If it is empty set length to zero as required by
* standard.
*/
if (sesslen)
memcpy(sess->session_id, sess_id, sesslen);
sess->session_id_length = sesslen;
*psess = sess;
if (renew_ticket)
return 4;
else
return 3;
}
ERR_clear_error();
/*
* For session parse failure, indicate that we need to send a new ticket.
*/
return 2;
err:
EVP_CIPHER_CTX_free(ctx);
HMAC_CTX_free(hctx);
return ret;
}
/* Tables to translate from NIDs to TLS v1.2 ids */
typedef struct {
int nid;
int id;
} tls12_lookup;
static const tls12_lookup tls12_md[] = {
{NID_md5, TLSEXT_hash_md5},
{NID_sha1, TLSEXT_hash_sha1},
{NID_sha224, TLSEXT_hash_sha224},
{NID_sha256, TLSEXT_hash_sha256},
{NID_sha384, TLSEXT_hash_sha384},
{NID_sha512, TLSEXT_hash_sha512},
{NID_id_GostR3411_94, TLSEXT_hash_gostr3411},
{NID_id_GostR3411_2012_256, TLSEXT_hash_gostr34112012_256},
{NID_id_GostR3411_2012_512, TLSEXT_hash_gostr34112012_512},
};
static const tls12_lookup tls12_sig[] = {
{EVP_PKEY_RSA, TLSEXT_signature_rsa},
{EVP_PKEY_DSA, TLSEXT_signature_dsa},
{EVP_PKEY_EC, TLSEXT_signature_ecdsa},
{NID_id_GostR3410_2001, TLSEXT_signature_gostr34102001},
{NID_id_GostR3410_2012_256, TLSEXT_signature_gostr34102012_256},
{NID_id_GostR3410_2012_512, TLSEXT_signature_gostr34102012_512}
};
static int tls12_find_id(int nid, const tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if (table[i].nid == nid)
return table[i].id;
}
return -1;
}
static int tls12_find_nid(int id, const tls12_lookup *table, size_t tlen)
{
size_t i;
for (i = 0; i < tlen; i++) {
if ((table[i].id) == id)
return table[i].nid;
}
return NID_undef;
}
int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk,
const EVP_MD *md)
{
int sig_id, md_id;
if (!md)
return 0;
md_id = tls12_find_id(EVP_MD_type(md), tls12_md, OSSL_NELEM(tls12_md));
if (md_id == -1)
return 0;
sig_id = tls12_get_sigid(pk);
if (sig_id == -1)
return 0;
p[0] = (unsigned char)md_id;
p[1] = (unsigned char)sig_id;
return 1;
}
int tls12_get_sigid(const EVP_PKEY *pk)
{
return tls12_find_id(EVP_PKEY_id(pk), tls12_sig, OSSL_NELEM(tls12_sig));
}
typedef struct {
int nid;
int secbits;
int md_idx;
unsigned char tlsext_hash;
} tls12_hash_info;
static const tls12_hash_info tls12_md_info[] = {
{NID_md5, 64, SSL_MD_MD5_IDX, TLSEXT_hash_md5},
{NID_sha1, 80, SSL_MD_SHA1_IDX, TLSEXT_hash_sha1},
{NID_sha224, 112, SSL_MD_SHA224_IDX, TLSEXT_hash_sha224},
{NID_sha256, 128, SSL_MD_SHA256_IDX, TLSEXT_hash_sha256},
{NID_sha384, 192, SSL_MD_SHA384_IDX, TLSEXT_hash_sha384},
{NID_sha512, 256, SSL_MD_SHA512_IDX, TLSEXT_hash_sha512},
{NID_id_GostR3411_94, 128, SSL_MD_GOST94_IDX, TLSEXT_hash_gostr3411},
{NID_id_GostR3411_2012_256, 128, SSL_MD_GOST12_256_IDX, TLSEXT_hash_gostr34112012_256},
{NID_id_GostR3411_2012_512, 256, SSL_MD_GOST12_512_IDX, TLSEXT_hash_gostr34112012_512},
};
static const tls12_hash_info *tls12_get_hash_info(unsigned char hash_alg)
{
unsigned int i;
if (hash_alg == 0)
return NULL;
for (i=0; i < OSSL_NELEM(tls12_md_info); i++)
{
if (tls12_md_info[i].tlsext_hash == hash_alg)
return tls12_md_info + i;
}
return NULL;
}
const EVP_MD *tls12_get_hash(unsigned char hash_alg)
{
const tls12_hash_info *inf;
if (hash_alg == TLSEXT_hash_md5 && FIPS_mode())
return NULL;
inf = tls12_get_hash_info(hash_alg);
if (!inf)
return NULL;
return ssl_md(inf->md_idx);
}
static int tls12_get_pkey_idx(unsigned char sig_alg)
{
switch (sig_alg) {
#ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
return SSL_PKEY_RSA_SIGN;
#endif
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
return SSL_PKEY_DSA_SIGN;
#endif
#ifndef OPENSSL_NO_EC
case TLSEXT_signature_ecdsa:
return SSL_PKEY_ECC;
#endif
# ifndef OPENSSL_NO_GOST
case TLSEXT_signature_gostr34102001:
return SSL_PKEY_GOST01;
case TLSEXT_signature_gostr34102012_256:
return SSL_PKEY_GOST12_256;
case TLSEXT_signature_gostr34102012_512:
return SSL_PKEY_GOST12_512;
# endif
}
return -1;
}
/* Convert TLS 1.2 signature algorithm extension values into NIDs */
static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
int *psignhash_nid, const unsigned char *data)
{
int sign_nid = NID_undef, hash_nid = NID_undef;
if (!phash_nid && !psign_nid && !psignhash_nid)
return;
if (phash_nid || psignhash_nid) {
hash_nid = tls12_find_nid(data[0], tls12_md, OSSL_NELEM(tls12_md));
if (phash_nid)
*phash_nid = hash_nid;
}
if (psign_nid || psignhash_nid) {
sign_nid = tls12_find_nid(data[1], tls12_sig, OSSL_NELEM(tls12_sig));
if (psign_nid)
*psign_nid = sign_nid;
}
if (psignhash_nid) {
if (sign_nid == NID_undef || hash_nid == NID_undef
|| OBJ_find_sigid_by_algs(psignhash_nid, hash_nid,
sign_nid) <= 0)
*psignhash_nid = NID_undef;
}
}
/* Check to see if a signature algorithm is allowed */
static int tls12_sigalg_allowed(SSL *s, int op, const unsigned char *ptmp)
{
/* See if we have an entry in the hash table and it is enabled */
const tls12_hash_info *hinf = tls12_get_hash_info(ptmp[0]);
if (hinf == NULL || ssl_md(hinf->md_idx) == NULL)
return 0;
/* See if public key algorithm allowed */
if (tls12_get_pkey_idx(ptmp[1]) == -1)
return 0;
/* Finally see if security callback allows it */
return ssl_security(s, op, hinf->secbits, hinf->nid, (void *)ptmp);
}
/*
* Get a mask of disabled public key algorithms based on supported signature
* algorithms. For example if no signature algorithm supports RSA then RSA is
* disabled.
*/
void ssl_set_sig_mask(uint32_t *pmask_a, SSL *s, int op)
{
const unsigned char *sigalgs;
size_t i, sigalgslen;
int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
/*
* Now go through all signature algorithms seeing if we support any for
* RSA, DSA, ECDSA. Do this for all versions not just TLS 1.2. To keep
* down calls to security callback only check if we have to.
*/
sigalgslen = tls12_get_psigalgs(s, &sigalgs);
for (i = 0; i < sigalgslen; i += 2, sigalgs += 2) {
switch (sigalgs[1]) {
#ifndef OPENSSL_NO_RSA
case TLSEXT_signature_rsa:
if (!have_rsa && tls12_sigalg_allowed(s, op, sigalgs))
have_rsa = 1;
break;
#endif
#ifndef OPENSSL_NO_DSA
case TLSEXT_signature_dsa:
if (!have_dsa && tls12_sigalg_allowed(s, op, sigalgs))
have_dsa = 1;
break;
#endif
#ifndef OPENSSL_NO_EC
case TLSEXT_signature_ecdsa:
if (!have_ecdsa && tls12_sigalg_allowed(s, op, sigalgs))
have_ecdsa = 1;
break;
#endif
}
}
if (!have_rsa)
*pmask_a |= SSL_aRSA;
if (!have_dsa)
*pmask_a |= SSL_aDSS;
if (!have_ecdsa)
*pmask_a |= SSL_aECDSA;
}
size_t tls12_copy_sigalgs(SSL *s, unsigned char *out,
const unsigned char *psig, size_t psiglen)
{
unsigned char *tmpout = out;
size_t i;
for (i = 0; i < psiglen; i += 2, psig += 2) {
if (tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SUPPORTED, psig)) {
*tmpout++ = psig[0];
*tmpout++ = psig[1];
}
}
return tmpout - out;
}
/* Given preference and allowed sigalgs set shared sigalgs */
static int tls12_shared_sigalgs(SSL *s, TLS_SIGALGS *shsig,
const unsigned char *pref, size_t preflen,
const unsigned char *allow, size_t allowlen)
{
const unsigned char *ptmp, *atmp;
size_t i, j, nmatch = 0;
for (i = 0, ptmp = pref; i < preflen; i += 2, ptmp += 2) {
/* Skip disabled hashes or signature algorithms */
if (!tls12_sigalg_allowed(s, SSL_SECOP_SIGALG_SHARED, ptmp))
continue;
for (j = 0, atmp = allow; j < allowlen; j += 2, atmp += 2) {
if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1]) {
nmatch++;
if (shsig) {
shsig->rhash = ptmp[0];
shsig->rsign = ptmp[1];
tls1_lookup_sigalg(&shsig->hash_nid,
&shsig->sign_nid,
&shsig->signandhash_nid, ptmp);
shsig++;
}
break;
}
}
}
return nmatch;
}
/* Set shared signature algorithms for SSL structures */
static int tls1_set_shared_sigalgs(SSL *s)
{
const unsigned char *pref, *allow, *conf;
size_t preflen, allowlen, conflen;
size_t nmatch;
TLS_SIGALGS *salgs = NULL;
CERT *c = s->cert;
unsigned int is_suiteb = tls1_suiteb(s);
OPENSSL_free(c->shared_sigalgs);
c->shared_sigalgs = NULL;
c->shared_sigalgslen = 0;
/* If client use client signature algorithms if not NULL */
if (!s->server && c->client_sigalgs && !is_suiteb) {
conf = c->client_sigalgs;
conflen = c->client_sigalgslen;
} else if (c->conf_sigalgs && !is_suiteb) {
conf = c->conf_sigalgs;
conflen = c->conf_sigalgslen;
} else
conflen = tls12_get_psigalgs(s, &conf);
if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb) {
pref = conf;
preflen = conflen;
allow = s->s3->tmp.peer_sigalgs;
allowlen = s->s3->tmp.peer_sigalgslen;
} else {
allow = conf;
allowlen = conflen;
pref = s->s3->tmp.peer_sigalgs;
preflen = s->s3->tmp.peer_sigalgslen;
}
nmatch = tls12_shared_sigalgs(s, NULL, pref, preflen, allow, allowlen);
if (nmatch) {
salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
if (salgs == NULL)
return 0;
nmatch = tls12_shared_sigalgs(s, salgs, pref, preflen, allow, allowlen);
} else {
salgs = NULL;
}
c->shared_sigalgs = salgs;
c->shared_sigalgslen = nmatch;
return 1;
}
/* Set preferred digest for each key type */
int tls1_save_sigalgs(SSL *s, const unsigned char *data, int dsize)
{
CERT *c = s->cert;
/* Extension ignored for inappropriate versions */
if (!SSL_USE_SIGALGS(s))
return 1;
/* Should never happen */
if (!c)
return 0;
OPENSSL_free(s->s3->tmp.peer_sigalgs);
s->s3->tmp.peer_sigalgs = OPENSSL_malloc(dsize);
if (s->s3->tmp.peer_sigalgs == NULL)
return 0;
s->s3->tmp.peer_sigalgslen = dsize;
memcpy(s->s3->tmp.peer_sigalgs, data, dsize);
return 1;
}
int tls1_process_sigalgs(SSL *s)
{
int idx;
size_t i;
const EVP_MD *md;
const EVP_MD **pmd = s->s3->tmp.md;
uint32_t *pvalid = s->s3->tmp.valid_flags;
CERT *c = s->cert;
TLS_SIGALGS *sigptr;
if (!tls1_set_shared_sigalgs(s))
return 0;
for (i = 0, sigptr = c->shared_sigalgs;
i < c->shared_sigalgslen; i++, sigptr++) {
idx = tls12_get_pkey_idx(sigptr->rsign);
if (idx > 0 && pmd[idx] == NULL) {
md = tls12_get_hash(sigptr->rhash);
pmd[idx] = md;
pvalid[idx] = CERT_PKEY_EXPLICIT_SIGN;
if (idx == SSL_PKEY_RSA_SIGN) {
pvalid[SSL_PKEY_RSA_ENC] = CERT_PKEY_EXPLICIT_SIGN;
pmd[SSL_PKEY_RSA_ENC] = md;
}
}
}
/*
* In strict mode leave unset digests as NULL to indicate we can't use
* the certificate for signing.
*/
if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
/*
* Set any remaining keys to default values. NOTE: if alg is not
* supported it stays as NULL.
*/
#ifndef OPENSSL_NO_DSA
if (pmd[SSL_PKEY_DSA_SIGN] == NULL)
pmd[SSL_PKEY_DSA_SIGN] = EVP_sha1();
#endif
#ifndef OPENSSL_NO_RSA
if (pmd[SSL_PKEY_RSA_SIGN] == NULL) {
pmd[SSL_PKEY_RSA_SIGN] = EVP_sha1();
pmd[SSL_PKEY_RSA_ENC] = EVP_sha1();
}
#endif
#ifndef OPENSSL_NO_EC
if (pmd[SSL_PKEY_ECC] == NULL)
pmd[SSL_PKEY_ECC] = EVP_sha1();
#endif
# ifndef OPENSSL_NO_GOST
if (pmd[SSL_PKEY_GOST01] == NULL)
pmd[SSL_PKEY_GOST01] = EVP_get_digestbynid(NID_id_GostR3411_94);
if (pmd[SSL_PKEY_GOST12_256] == NULL)
pmd[SSL_PKEY_GOST12_256] = EVP_get_digestbynid(NID_id_GostR3411_2012_256);
if (pmd[SSL_PKEY_GOST12_512] == NULL)
pmd[SSL_PKEY_GOST12_512] = EVP_get_digestbynid(NID_id_GostR3411_2012_512);
# endif
}
return 1;
}
int SSL_get_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
const unsigned char *psig = s->s3->tmp.peer_sigalgs;
if (psig == NULL)
return 0;
if (idx >= 0) {
idx <<= 1;
if (idx >= (int)s->s3->tmp.peer_sigalgslen)
return 0;
psig += idx;
if (rhash)
*rhash = psig[0];
if (rsig)
*rsig = psig[1];
tls1_lookup_sigalg(phash, psign, psignhash, psig);
}
return s->s3->tmp.peer_sigalgslen / 2;
}
int SSL_get_shared_sigalgs(SSL *s, int idx,
int *psign, int *phash, int *psignhash,
unsigned char *rsig, unsigned char *rhash)
{
TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs;
if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen)
return 0;
shsigalgs += idx;
if (phash)
*phash = shsigalgs->hash_nid;
if (psign)
*psign = shsigalgs->sign_nid;
if (psignhash)
*psignhash = shsigalgs->signandhash_nid;
if (rsig)
*rsig = shsigalgs->rsign;
if (rhash)
*rhash = shsigalgs->rhash;
return s->cert->shared_sigalgslen;
}
#define MAX_SIGALGLEN (TLSEXT_hash_num * TLSEXT_signature_num * 2)
typedef struct {
size_t sigalgcnt;
int sigalgs[MAX_SIGALGLEN];
} sig_cb_st;
static void get_sigorhash(int *psig, int *phash, const char *str)
{
if (strcmp(str, "RSA") == 0) {
*psig = EVP_PKEY_RSA;
} else if (strcmp(str, "DSA") == 0) {
*psig = EVP_PKEY_DSA;
} else if (strcmp(str, "ECDSA") == 0) {
*psig = EVP_PKEY_EC;
} else {
*phash = OBJ_sn2nid(str);
if (*phash == NID_undef)
*phash = OBJ_ln2nid(str);
}
}
static int sig_cb(const char *elem, int len, void *arg)
{
sig_cb_st *sarg = arg;
size_t i;
char etmp[20], *p;
int sig_alg = NID_undef, hash_alg = NID_undef;
if (elem == NULL)
return 0;
if (sarg->sigalgcnt == MAX_SIGALGLEN)
return 0;
if (len > (int)(sizeof(etmp) - 1))
return 0;
memcpy(etmp, elem, len);
etmp[len] = 0;
p = strchr(etmp, '+');
if (!p)
return 0;
*p = 0;
p++;
if (!*p)
return 0;
get_sigorhash(&sig_alg, &hash_alg, etmp);
get_sigorhash(&sig_alg, &hash_alg, p);
if (sig_alg == NID_undef || hash_alg == NID_undef)
return 0;
for (i = 0; i < sarg->sigalgcnt; i += 2) {
if (sarg->sigalgs[i] == sig_alg && sarg->sigalgs[i + 1] == hash_alg)
return 0;
}
sarg->sigalgs[sarg->sigalgcnt++] = hash_alg;
sarg->sigalgs[sarg->sigalgcnt++] = sig_alg;
return 1;
}
/*
* Set suppored signature algorithms based on a colon separated list of the
* form sig+hash e.g. RSA+SHA512:DSA+SHA512
*/
int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
{
sig_cb_st sig;
sig.sigalgcnt = 0;
if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
return 0;
if (c == NULL)
return 1;
return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
}
int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen,
int client)
{
unsigned char *sigalgs, *sptr;
int rhash, rsign;
size_t i;
if (salglen & 1)
return 0;
sigalgs = OPENSSL_malloc(salglen);
if (sigalgs == NULL)
return 0;
for (i = 0, sptr = sigalgs; i < salglen; i += 2) {
rhash = tls12_find_id(*psig_nids++, tls12_md, OSSL_NELEM(tls12_md));
rsign = tls12_find_id(*psig_nids++, tls12_sig, OSSL_NELEM(tls12_sig));
if (rhash == -1 || rsign == -1)
goto err;
*sptr++ = rhash;
*sptr++ = rsign;
}
if (client) {
OPENSSL_free(c->client_sigalgs);
c->client_sigalgs = sigalgs;
c->client_sigalgslen = salglen;
} else {
OPENSSL_free(c->conf_sigalgs);
c->conf_sigalgs = sigalgs;
c->conf_sigalgslen = salglen;
}
return 1;
err:
OPENSSL_free(sigalgs);
return 0;
}
static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
{
int sig_nid;
size_t i;
if (default_nid == -1)
return 1;
sig_nid = X509_get_signature_nid(x);
if (default_nid)
return sig_nid == default_nid ? 1 : 0;
for (i = 0; i < c->shared_sigalgslen; i++)
if (sig_nid == c->shared_sigalgs[i].signandhash_nid)
return 1;
return 0;
}
/* Check to see if a certificate issuer name matches list of CA names */
static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
{
X509_NAME *nm;
int i;
nm = X509_get_issuer_name(x);
for (i = 0; i < sk_X509_NAME_num(names); i++) {
if (!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
return 1;
}
return 0;
}
/*
* Check certificate chain is consistent with TLS extensions and is usable by
* server. This servers two purposes: it allows users to check chains before
* passing them to the server and it allows the server to check chains before
* attempting to use them.
*/
/* Flags which need to be set for a certificate when stict mode not set */
#define CERT_PKEY_VALID_FLAGS \
(CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
/* Strict mode flags */
#define CERT_PKEY_STRICT_FLAGS \
(CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
| CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
int idx)
{
int i;
int rv = 0;
int check_flags = 0, strict_mode;
CERT_PKEY *cpk = NULL;
CERT *c = s->cert;
uint32_t *pvalid;
unsigned int suiteb_flags = tls1_suiteb(s);
/* idx == -1 means checking server chains */
if (idx != -1) {
/* idx == -2 means checking client certificate chains */
if (idx == -2) {
cpk = c->key;
idx = cpk - c->pkeys;
} else
cpk = c->pkeys + idx;
pvalid = s->s3->tmp.valid_flags + idx;
x = cpk->x509;
pk = cpk->privatekey;
chain = cpk->chain;
strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
/* If no cert or key, forget it */
if (!x || !pk)
goto end;
} else {
if (!x || !pk)
return 0;
idx = ssl_cert_type(x, pk);
if (idx == -1)
return 0;
pvalid = s->s3->tmp.valid_flags + idx;
if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
check_flags = CERT_PKEY_STRICT_FLAGS;
else
check_flags = CERT_PKEY_VALID_FLAGS;
strict_mode = 1;
}
if (suiteb_flags) {
int ok;
if (check_flags)
check_flags |= CERT_PKEY_SUITEB;
ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
if (ok == X509_V_OK)
rv |= CERT_PKEY_SUITEB;
else if (!check_flags)
goto end;
}
/*
* Check all signature algorithms are consistent with signature
* algorithms extension if TLS 1.2 or later and strict mode.
*/
if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode) {
int default_nid;
unsigned char rsign = 0;
if (s->s3->tmp.peer_sigalgs)
default_nid = 0;
/* If no sigalgs extension use defaults from RFC5246 */
else {
switch (idx) {
case SSL_PKEY_RSA_ENC:
case SSL_PKEY_RSA_SIGN:
rsign = TLSEXT_signature_rsa;
default_nid = NID_sha1WithRSAEncryption;
break;
case SSL_PKEY_DSA_SIGN:
rsign = TLSEXT_signature_dsa;
default_nid = NID_dsaWithSHA1;
break;
case SSL_PKEY_ECC:
rsign = TLSEXT_signature_ecdsa;
default_nid = NID_ecdsa_with_SHA1;
break;
case SSL_PKEY_GOST01:
rsign = TLSEXT_signature_gostr34102001;
default_nid = NID_id_GostR3411_94_with_GostR3410_2001;
break;
case SSL_PKEY_GOST12_256:
rsign = TLSEXT_signature_gostr34102012_256;
default_nid = NID_id_tc26_signwithdigest_gost3410_2012_256;
break;
case SSL_PKEY_GOST12_512:
rsign = TLSEXT_signature_gostr34102012_512;
default_nid = NID_id_tc26_signwithdigest_gost3410_2012_512;
break;
default:
default_nid = -1;
break;
}
}
/*
* If peer sent no signature algorithms extension and we have set
* preferred signature algorithms check we support sha1.
*/
if (default_nid > 0 && c->conf_sigalgs) {
size_t j;
const unsigned char *p = c->conf_sigalgs;
for (j = 0; j < c->conf_sigalgslen; j += 2, p += 2) {
if (p[0] == TLSEXT_hash_sha1 && p[1] == rsign)
break;
}
if (j == c->conf_sigalgslen) {
if (check_flags)
goto skip_sigs;
else
goto end;
}
}
/* Check signature algorithm of each cert in chain */
if (!tls1_check_sig_alg(c, x, default_nid)) {
if (!check_flags)
goto end;
} else
rv |= CERT_PKEY_EE_SIGNATURE;
rv |= CERT_PKEY_CA_SIGNATURE;
for (i = 0; i < sk_X509_num(chain); i++) {
if (!tls1_check_sig_alg(c, sk_X509_value(chain, i), default_nid)) {
if (check_flags) {
rv &= ~CERT_PKEY_CA_SIGNATURE;
break;
} else
goto end;
}
}
}
/* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
else if (check_flags)
rv |= CERT_PKEY_EE_SIGNATURE | CERT_PKEY_CA_SIGNATURE;
skip_sigs:
/* Check cert parameters are consistent */
if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
rv |= CERT_PKEY_EE_PARAM;
else if (!check_flags)
goto end;
if (!s->server)
rv |= CERT_PKEY_CA_PARAM;
/* In strict mode check rest of chain too */
else if (strict_mode) {
rv |= CERT_PKEY_CA_PARAM;
for (i = 0; i < sk_X509_num(chain); i++) {
X509 *ca = sk_X509_value(chain, i);
if (!tls1_check_cert_param(s, ca, 0)) {
if (check_flags) {
rv &= ~CERT_PKEY_CA_PARAM;
break;
} else
goto end;
}
}
}
if (!s->server && strict_mode) {
STACK_OF(X509_NAME) *ca_dn;
int check_type = 0;
switch (EVP_PKEY_id(pk)) {
case EVP_PKEY_RSA:
check_type = TLS_CT_RSA_SIGN;
break;
case EVP_PKEY_DSA:
check_type = TLS_CT_DSS_SIGN;
break;
case EVP_PKEY_EC:
check_type = TLS_CT_ECDSA_SIGN;
break;
}
if (check_type) {
const unsigned char *ctypes;
int ctypelen;
if (c->ctypes) {
ctypes = c->ctypes;
ctypelen = (int)c->ctype_num;
} else {
ctypes = (unsigned char *)s->s3->tmp.ctype;
ctypelen = s->s3->tmp.ctype_num;
}
for (i = 0; i < ctypelen; i++) {
if (ctypes[i] == check_type) {
rv |= CERT_PKEY_CERT_TYPE;
break;
}
}
if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
goto end;
} else
rv |= CERT_PKEY_CERT_TYPE;
ca_dn = s->s3->tmp.ca_names;
if (!sk_X509_NAME_num(ca_dn))
rv |= CERT_PKEY_ISSUER_NAME;
if (!(rv & CERT_PKEY_ISSUER_NAME)) {
if (ssl_check_ca_name(ca_dn, x))
rv |= CERT_PKEY_ISSUER_NAME;
}
if (!(rv & CERT_PKEY_ISSUER_NAME)) {
for (i = 0; i < sk_X509_num(chain); i++) {
X509 *xtmp = sk_X509_value(chain, i);
if (ssl_check_ca_name(ca_dn, xtmp)) {
rv |= CERT_PKEY_ISSUER_NAME;
break;
}
}
}
if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
goto end;
} else
rv |= CERT_PKEY_ISSUER_NAME | CERT_PKEY_CERT_TYPE;
if (!check_flags || (rv & check_flags) == check_flags)
rv |= CERT_PKEY_VALID;
end:
if (TLS1_get_version(s) >= TLS1_2_VERSION) {
if (*pvalid & CERT_PKEY_EXPLICIT_SIGN)
rv |= CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
else if (s->s3->tmp.md[idx] != NULL)
rv |= CERT_PKEY_SIGN;
} else
rv |= CERT_PKEY_SIGN | CERT_PKEY_EXPLICIT_SIGN;
/*
* When checking a CERT_PKEY structure all flags are irrelevant if the
* chain is invalid.
*/
if (!check_flags) {
if (rv & CERT_PKEY_VALID)
*pvalid = rv;
else {
/* Preserve explicit sign flag, clear rest */
*pvalid &= CERT_PKEY_EXPLICIT_SIGN;
return 0;
}
}
return rv;
}
/* Set validity of certificates in an SSL structure */
void tls1_set_cert_validity(SSL *s)
{
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_ENC);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST01);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_256);
tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_GOST12_512);
}
/* User level utiity function to check a chain is suitable */
int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
{
return tls1_check_chain(s, x, pk, chain, -1);
}
#ifndef OPENSSL_NO_DH
DH *ssl_get_auto_dh(SSL *s)
{
int dh_secbits = 80;
if (s->cert->dh_tmp_auto == 2)
return DH_get_1024_160();
if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aPSK)) {
if (s->s3->tmp.new_cipher->strength_bits == 256)
dh_secbits = 128;
else
dh_secbits = 80;
} else {
CERT_PKEY *cpk = ssl_get_server_send_pkey(s);
dh_secbits = EVP_PKEY_security_bits(cpk->privatekey);
}
if (dh_secbits >= 128) {
DH *dhp = DH_new();
BIGNUM *p, *g;
if (dhp == NULL)
return NULL;
g = BN_new();
if (g != NULL)
BN_set_word(g, 2);
if (dh_secbits >= 192)
p = BN_get_rfc3526_prime_8192(NULL);
else
p = BN_get_rfc3526_prime_3072(NULL);
if (p == NULL || g == NULL || !DH_set0_pqg(dhp, p, NULL, g)) {
DH_free(dhp);
BN_free(p);
BN_free(g);
return NULL;
}
return dhp;
}
if (dh_secbits >= 112)
return DH_get_2048_224();
return DH_get_1024_160();
}
#endif
static int ssl_security_cert_key(SSL *s, SSL_CTX *ctx, X509 *x, int op)
{
int secbits = -1;
EVP_PKEY *pkey = X509_get0_pubkey(x);
if (pkey) {
/*
* If no parameters this will return -1 and fail using the default
* security callback for any non-zero security level. This will
* reject keys which omit parameters but this only affects DSA and
* omission of parameters is never (?) done in practice.
*/
secbits = EVP_PKEY_security_bits(pkey);
}
if (s)
return ssl_security(s, op, secbits, 0, x);
else
return ssl_ctx_security(ctx, op, secbits, 0, x);
}
static int ssl_security_cert_sig(SSL *s, SSL_CTX *ctx, X509 *x, int op)
{
/* Lookup signature algorithm digest */
int secbits = -1, md_nid = NID_undef, sig_nid;
/* Don't check signature if self signed */
if ((X509_get_extension_flags(x) & EXFLAG_SS) != 0)
return 1;
sig_nid = X509_get_signature_nid(x);
if (sig_nid && OBJ_find_sigid_algs(sig_nid, &md_nid, NULL)) {
const EVP_MD *md;
if (md_nid && (md = EVP_get_digestbynid(md_nid)))
secbits = EVP_MD_size(md) * 4;
}
if (s)
return ssl_security(s, op, secbits, md_nid, x);
else
return ssl_ctx_security(ctx, op, secbits, md_nid, x);
}
int ssl_security_cert(SSL *s, SSL_CTX *ctx, X509 *x, int vfy, int is_ee)
{
if (vfy)
vfy = SSL_SECOP_PEER;
if (is_ee) {
if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_EE_KEY | vfy))
return SSL_R_EE_KEY_TOO_SMALL;
} else {
if (!ssl_security_cert_key(s, ctx, x, SSL_SECOP_CA_KEY | vfy))
return SSL_R_CA_KEY_TOO_SMALL;
}
if (!ssl_security_cert_sig(s, ctx, x, SSL_SECOP_CA_MD | vfy))
return SSL_R_CA_MD_TOO_WEAK;
return 1;
}
/*
* Check security of a chain, if sk includes the end entity certificate then
* x is NULL. If vfy is 1 then we are verifying a peer chain and not sending
* one to the peer. Return values: 1 if ok otherwise error code to use
*/
int ssl_security_cert_chain(SSL *s, STACK_OF(X509) *sk, X509 *x, int vfy)
{
int rv, start_idx, i;
if (x == NULL) {
x = sk_X509_value(sk, 0);
start_idx = 1;
} else
start_idx = 0;
rv = ssl_security_cert(s, NULL, x, vfy, 1);
if (rv != 1)
return rv;
for (i = start_idx; i < sk_X509_num(sk); i++) {
x = sk_X509_value(sk, i);
rv = ssl_security_cert(s, NULL, x, vfy, 0);
if (rv != 1)
return rv;
}
return 1;
}
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