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openssl/ssl/s2_srvr.c
Viktor Dukhovni d81a160058 Better SSLv2 cipher-suite enforcement 
Based on patch by: Nimrod Aviram <nimrod.aviram@gmail.com>

CVE-2015-3197

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
2016-01-28 13:48:24 +00:00

1171 lines
40 KiB
C
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/* ssl/s2_srvr.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include "ssl_locl.h"
#ifndef OPENSSL_NO_SSL2
#include "../crypto/constant_time_locl.h"
# include <stdio.h>
# include <openssl/bio.h>
# include <openssl/rand.h>
# include <openssl/objects.h>
# include <openssl/evp.h>
static const SSL_METHOD *ssl2_get_server_method(int ver);
static int get_client_master_key(SSL *s);
static int get_client_hello(SSL *s);
static int server_hello(SSL *s);
static int get_client_finished(SSL *s);
static int server_verify(SSL *s);
static int server_finish(SSL *s);
static int request_certificate(SSL *s);
static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
unsigned char *to, int padding);
# define BREAK break
static const SSL_METHOD *ssl2_get_server_method(int ver)
{
if (ver == SSL2_VERSION)
return (SSLv2_server_method());
else
return (NULL);
}
IMPLEMENT_ssl2_meth_func(SSLv2_server_method,
ssl2_accept,
ssl_undefined_function, ssl2_get_server_method)
int ssl2_accept(SSL *s)
{
unsigned long l = (unsigned long)time(NULL);
BUF_MEM *buf = NULL;
int ret = -1;
long num1;
void (*cb) (const SSL *ssl, int type, int val) = NULL;
int new_state, state;
RAND_add(&l, sizeof(l), 0);
ERR_clear_error();
clear_sys_error();
if (s->info_callback != NULL)
cb = s->info_callback;
else if (s->ctx->info_callback != NULL)
cb = s->ctx->info_callback;
/* init things to blank */
s->in_handshake++;
if (!SSL_in_init(s) || SSL_in_before(s))
SSL_clear(s);
if (s->cert == NULL) {
SSLerr(SSL_F_SSL2_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
return (-1);
}
clear_sys_error();
for (;;) {
state = s->state;
switch (s->state) {
case SSL_ST_BEFORE:
case SSL_ST_ACCEPT:
case SSL_ST_BEFORE | SSL_ST_ACCEPT:
case SSL_ST_OK | SSL_ST_ACCEPT:
s->server = 1;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_START, 1);
s->version = SSL2_VERSION;
s->type = SSL_ST_ACCEPT;
if (s->init_buf == NULL) {
if ((buf = BUF_MEM_new()) == NULL) {
ret = -1;
goto end;
}
if (!BUF_MEM_grow
(buf, (int)SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) {
BUF_MEM_free(buf);
ret = -1;
goto end;
}
s->init_buf = buf;
}
s->init_num = 0;
s->ctx->stats.sess_accept++;
s->handshake_func = ssl2_accept;
s->state = SSL2_ST_GET_CLIENT_HELLO_A;
BREAK;
case SSL2_ST_GET_CLIENT_HELLO_A:
case SSL2_ST_GET_CLIENT_HELLO_B:
case SSL2_ST_GET_CLIENT_HELLO_C:
s->shutdown = 0;
ret = get_client_hello(s);
if (ret <= 0)
goto end;
s->init_num = 0;
s->state = SSL2_ST_SEND_SERVER_HELLO_A;
BREAK;
case SSL2_ST_SEND_SERVER_HELLO_A:
case SSL2_ST_SEND_SERVER_HELLO_B:
ret = server_hello(s);
if (ret <= 0)
goto end;
s->init_num = 0;
if (!s->hit) {
s->state = SSL2_ST_GET_CLIENT_MASTER_KEY_A;
BREAK;
} else {
s->state = SSL2_ST_SERVER_START_ENCRYPTION;
BREAK;
}
case SSL2_ST_GET_CLIENT_MASTER_KEY_A:
case SSL2_ST_GET_CLIENT_MASTER_KEY_B:
ret = get_client_master_key(s);
if (ret <= 0)
goto end;
s->init_num = 0;
s->state = SSL2_ST_SERVER_START_ENCRYPTION;
BREAK;
case SSL2_ST_SERVER_START_ENCRYPTION:
/*
* Ok we how have sent all the stuff needed to start encrypting,
* the next packet back will be encrypted.
*/
if (!ssl2_enc_init(s, 0)) {
ret = -1;
goto end;
}
s->s2->clear_text = 0;
s->state = SSL2_ST_SEND_SERVER_VERIFY_A;
BREAK;
case SSL2_ST_SEND_SERVER_VERIFY_A:
case SSL2_ST_SEND_SERVER_VERIFY_B:
ret = server_verify(s);
if (ret <= 0)
goto end;
s->init_num = 0;
if (s->hit) {
/*
* If we are in here, we have been buffering the output, so
* we need to flush it and remove buffering from future
* traffic
*/
s->state = SSL2_ST_SEND_SERVER_VERIFY_C;
BREAK;
} else {
s->state = SSL2_ST_GET_CLIENT_FINISHED_A;
break;
}
case SSL2_ST_SEND_SERVER_VERIFY_C:
/* get the number of bytes to write */
num1 = BIO_ctrl(s->wbio, BIO_CTRL_INFO, 0, NULL);
if (num1 > 0) {
s->rwstate = SSL_WRITING;
num1 = BIO_flush(s->wbio);
if (num1 <= 0) {
ret = -1;
goto end;
}
s->rwstate = SSL_NOTHING;
}
/* flushed and now remove buffering */
s->wbio = BIO_pop(s->wbio);
s->state = SSL2_ST_GET_CLIENT_FINISHED_A;
BREAK;
case SSL2_ST_GET_CLIENT_FINISHED_A:
case SSL2_ST_GET_CLIENT_FINISHED_B:
ret = get_client_finished(s);
if (ret <= 0)
goto end;
s->init_num = 0;
s->state = SSL2_ST_SEND_REQUEST_CERTIFICATE_A;
BREAK;
case SSL2_ST_SEND_REQUEST_CERTIFICATE_A:
case SSL2_ST_SEND_REQUEST_CERTIFICATE_B:
case SSL2_ST_SEND_REQUEST_CERTIFICATE_C:
case SSL2_ST_SEND_REQUEST_CERTIFICATE_D:
/*
* don't do a 'request certificate' if we don't want to, or we
* already have one, and we only want to do it once.
*/
if (!(s->verify_mode & SSL_VERIFY_PEER) ||
((s->session->peer != NULL) &&
(s->verify_mode & SSL_VERIFY_CLIENT_ONCE))) {
s->state = SSL2_ST_SEND_SERVER_FINISHED_A;
break;
} else {
ret = request_certificate(s);
if (ret <= 0)
goto end;
s->init_num = 0;
s->state = SSL2_ST_SEND_SERVER_FINISHED_A;
}
BREAK;
case SSL2_ST_SEND_SERVER_FINISHED_A:
case SSL2_ST_SEND_SERVER_FINISHED_B:
ret = server_finish(s);
if (ret <= 0)
goto end;
s->init_num = 0;
s->state = SSL_ST_OK;
break;
case SSL_ST_OK:
BUF_MEM_free(s->init_buf);
ssl_free_wbio_buffer(s);
s->init_buf = NULL;
s->init_num = 0;
/* ERR_clear_error(); */
ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
s->ctx->stats.sess_accept_good++;
/* s->server=1; */
ret = 1;
if (cb != NULL)
cb(s, SSL_CB_HANDSHAKE_DONE, 1);
goto end;
/* BREAK; */
default:
SSLerr(SSL_F_SSL2_ACCEPT, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
/* BREAK; */
}
if ((cb != NULL) && (s->state != state)) {
new_state = s->state;
s->state = state;
cb(s, SSL_CB_ACCEPT_LOOP, 1);
s->state = new_state;
}
}
end:
s->in_handshake--;
if (cb != NULL)
cb(s, SSL_CB_ACCEPT_EXIT, ret);
return (ret);
}
static int get_client_master_key(SSL *s)
{
int is_export, i, n, keya;
unsigned int num_encrypted_key_bytes, key_length;
unsigned long len;
unsigned char *p;
const SSL_CIPHER *cp;
const EVP_CIPHER *c;
const EVP_MD *md;
unsigned char rand_premaster_secret[SSL_MAX_MASTER_KEY_LENGTH];
unsigned char decrypt_good;
size_t j;
p = (unsigned char *)s->init_buf->data;
if (s->state == SSL2_ST_GET_CLIENT_MASTER_KEY_A) {
i = ssl2_read(s, (char *)&(p[s->init_num]), 10 - s->init_num);
if (i < (10 - s->init_num))
return (ssl2_part_read(s, SSL_F_GET_CLIENT_MASTER_KEY, i));
s->init_num = 10;
if (*(p++) != SSL2_MT_CLIENT_MASTER_KEY) {
if (p[-1] != SSL2_MT_ERROR) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
SSL_R_READ_WRONG_PACKET_TYPE);
} else
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_PEER_ERROR);
return (-1);
}
cp = ssl2_get_cipher_by_char(p);
if (cp == NULL || sk_SSL_CIPHER_find(s->session->ciphers, cp) < 0) {
ssl2_return_error(s, SSL2_PE_NO_CIPHER);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_CIPHER_MATCH);
return (-1);
}
s->session->cipher = cp;
p += 3;
n2s(p, i);
s->s2->tmp.clear = i;
n2s(p, i);
s->s2->tmp.enc = i;
n2s(p, i);
if (i > SSL_MAX_KEY_ARG_LENGTH) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_KEY_ARG_TOO_LONG);
return -1;
}
s->session->key_arg_length = i;
s->state = SSL2_ST_GET_CLIENT_MASTER_KEY_B;
}
/* SSL2_ST_GET_CLIENT_MASTER_KEY_B */
p = (unsigned char *)s->init_buf->data;
if (s->init_buf->length < SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, ERR_R_INTERNAL_ERROR);
return -1;
}
keya = s->session->key_arg_length;
len =
10 + (unsigned long)s->s2->tmp.clear + (unsigned long)s->s2->tmp.enc +
(unsigned long)keya;
if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_MESSAGE_TOO_LONG);
return -1;
}
n = (int)len - s->init_num;
i = ssl2_read(s, (char *)&(p[s->init_num]), n);
if (i != n)
return (ssl2_part_read(s, SSL_F_GET_CLIENT_MASTER_KEY, i));
if (s->msg_callback) {
/* CLIENT-MASTER-KEY */
s->msg_callback(0, s->version, 0, p, (size_t)len, s,
s->msg_callback_arg);
}
p += 10;
memcpy(s->session->key_arg, &(p[s->s2->tmp.clear + s->s2->tmp.enc]),
(unsigned int)keya);
if (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_PRIVATEKEY);
return (-1);
}
is_export = SSL_C_IS_EXPORT(s->session->cipher);
if (!ssl_cipher_get_evp(s->session, &c, &md, NULL, NULL, NULL)) {
ssl2_return_error(s, SSL2_PE_NO_CIPHER);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,
SSL_R_PROBLEMS_MAPPING_CIPHER_FUNCTIONS);
return (0);
}
/*
* The format of the CLIENT-MASTER-KEY message is
* 1 byte message type
* 3 bytes cipher
* 2-byte clear key length (stored in s->s2->tmp.clear)
* 2-byte encrypted key length (stored in s->s2->tmp.enc)
* 2-byte key args length (IV etc)
* clear key
* encrypted key
* key args
*
* If the cipher is an export cipher, then the encrypted key bytes
* are a fixed portion of the total key (5 or 8 bytes). The size of
* this portion is in |num_encrypted_key_bytes|. If the cipher is not an
* export cipher, then the entire key material is encrypted (i.e., clear
* key length must be zero).
*/
key_length = (unsigned int)EVP_CIPHER_key_length(c);
if (key_length > SSL_MAX_MASTER_KEY_LENGTH) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, ERR_R_INTERNAL_ERROR);
return -1;
}
if (s->session->cipher->algorithm2 & SSL2_CF_8_BYTE_ENC) {
is_export = 1;
num_encrypted_key_bytes = 8;
} else if (is_export) {
num_encrypted_key_bytes = 5;
} else {
num_encrypted_key_bytes = key_length;
}
if (s->s2->tmp.clear + num_encrypted_key_bytes != key_length) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_BAD_LENGTH);
return -1;
}
/*
* The encrypted blob must decrypt to the encrypted portion of the key.
* Decryption can't be expanding, so if we don't have enough encrypted
* bytes to fit the key in the buffer, stop now.
*/
if (s->s2->tmp.enc < num_encrypted_key_bytes) {
ssl2_return_error(s,SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_MASTER_KEY,SSL_R_LENGTH_TOO_SHORT);
return -1;
}
/*
* We must not leak whether a decryption failure occurs because of
* Bleichenbacher's attack on PKCS #1 v1.5 RSA padding (see RFC 2246,
* section 7.4.7.1). The code follows that advice of the TLS RFC and
* generates a random premaster secret for the case that the decrypt
* fails. See https://tools.ietf.org/html/rfc5246#section-7.4.7.1
*/
/*
* should be RAND_bytes, but we cannot work around a failure.
*/
if (RAND_pseudo_bytes(rand_premaster_secret,
(int)num_encrypted_key_bytes) <= 0)
return 0;
i = ssl_rsa_private_decrypt(s->cert, s->s2->tmp.enc,
&(p[s->s2->tmp.clear]),
&(p[s->s2->tmp.clear]),
(s->s2->ssl2_rollback) ? RSA_SSLV23_PADDING :
RSA_PKCS1_PADDING);
ERR_clear_error();
/*
* If a bad decrypt, continue with protocol but with a random master
* secret (Bleichenbacher attack)
*/
decrypt_good = constant_time_eq_int_8(i, (int)num_encrypted_key_bytes);
for (j = 0; j < num_encrypted_key_bytes; j++) {
p[s->s2->tmp.clear + j] =
constant_time_select_8(decrypt_good, p[s->s2->tmp.clear + j],
rand_premaster_secret[j]);
}
s->session->master_key_length = (int)key_length;
memcpy(s->session->master_key, p, key_length);
OPENSSL_cleanse(p, key_length);
return 1;
}
static int get_client_hello(SSL *s)
{
int i, n;
unsigned long len;
unsigned char *p;
STACK_OF(SSL_CIPHER) *cs; /* a stack of SSL_CIPHERS */
STACK_OF(SSL_CIPHER) *cl; /* the ones we want to use */
STACK_OF(SSL_CIPHER) *prio, *allow;
int z;
/*
* This is a bit of a hack to check for the correct packet type the first
* time round.
*/
if (s->state == SSL2_ST_GET_CLIENT_HELLO_A) {
s->first_packet = 1;
s->state = SSL2_ST_GET_CLIENT_HELLO_B;
}
p = (unsigned char *)s->init_buf->data;
if (s->state == SSL2_ST_GET_CLIENT_HELLO_B) {
i = ssl2_read(s, (char *)&(p[s->init_num]), 9 - s->init_num);
if (i < (9 - s->init_num))
return (ssl2_part_read(s, SSL_F_GET_CLIENT_HELLO, i));
s->init_num = 9;
if (*(p++) != SSL2_MT_CLIENT_HELLO) {
if (p[-1] != SSL2_MT_ERROR) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_READ_WRONG_PACKET_TYPE);
} else
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_PEER_ERROR);
return (-1);
}
n2s(p, i);
if (i < s->version)
s->version = i;
n2s(p, i);
s->s2->tmp.cipher_spec_length = i;
n2s(p, i);
s->s2->tmp.session_id_length = i;
if ((i < 0) || (i > SSL_MAX_SSL_SESSION_ID_LENGTH)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_LENGTH_MISMATCH);
return -1;
}
n2s(p, i);
s->s2->challenge_length = i;
if ((i < SSL2_MIN_CHALLENGE_LENGTH) ||
(i > SSL2_MAX_CHALLENGE_LENGTH)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_INVALID_CHALLENGE_LENGTH);
return (-1);
}
s->state = SSL2_ST_GET_CLIENT_HELLO_C;
}
/* SSL2_ST_GET_CLIENT_HELLO_C */
p = (unsigned char *)s->init_buf->data;
len =
9 + (unsigned long)s->s2->tmp.cipher_spec_length +
(unsigned long)s->s2->challenge_length +
(unsigned long)s->s2->tmp.session_id_length;
if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_MESSAGE_TOO_LONG);
return -1;
}
n = (int)len - s->init_num;
i = ssl2_read(s, (char *)&(p[s->init_num]), n);
if (i != n)
return (ssl2_part_read(s, SSL_F_GET_CLIENT_HELLO, i));
if (s->msg_callback) {
/* CLIENT-HELLO */
s->msg_callback(0, s->version, 0, p, (size_t)len, s,
s->msg_callback_arg);
}
p += 9;
/*
* get session-id before cipher stuff so we can get out session structure
* if it is cached
*/
/* session-id */
if ((s->s2->tmp.session_id_length != 0) &&
(s->s2->tmp.session_id_length != SSL2_SSL_SESSION_ID_LENGTH)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_BAD_SSL_SESSION_ID_LENGTH);
return (-1);
}
if (s->s2->tmp.session_id_length == 0) {
if (!ssl_get_new_session(s, 1)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
return (-1);
}
} else {
i = ssl_get_prev_session(s, &(p[s->s2->tmp.cipher_spec_length]),
s->s2->tmp.session_id_length, NULL);
if (i == 1) { /* previous session */
s->hit = 1;
} else if (i == -1) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
return (-1);
} else {
if (s->cert == NULL) {
ssl2_return_error(s, SSL2_PE_NO_CERTIFICATE);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_NO_CERTIFICATE_SET);
return (-1);
}
if (!ssl_get_new_session(s, 1)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
return (-1);
}
}
}
if (!s->hit) {
cs = ssl_bytes_to_cipher_list(s, p, s->s2->tmp.cipher_spec_length,
&s->session->ciphers);
if (cs == NULL)
goto mem_err;
cl = SSL_get_ciphers(s);
if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
prio = sk_SSL_CIPHER_dup(cl);
if (prio == NULL)
goto mem_err;
allow = cs;
} else {
prio = cs;
allow = cl;
}
/* Generate list of SSLv2 ciphers shared between client and server */
for (z = 0; z < sk_SSL_CIPHER_num(prio); z++) {
const SSL_CIPHER *cp = sk_SSL_CIPHER_value(prio, z);
if ((cp->algorithm_ssl & SSL_SSLV2) == 0 ||
sk_SSL_CIPHER_find(allow, cp) < 0) {
(void)sk_SSL_CIPHER_delete(prio, z);
z--;
}
}
if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
sk_SSL_CIPHER_free(s->session->ciphers);
s->session->ciphers = prio;
}
/* Make sure we have at least one cipher in common */
if (sk_SSL_CIPHER_num(s->session->ciphers) == 0) {
ssl2_return_error(s, SSL2_PE_NO_CIPHER);
SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_NO_CIPHER_MATCH);
return -1;
}
/*
* s->session->ciphers should now have a list of ciphers that are on
* both the client and server. This list is ordered by the order the
* client sent the ciphers or in the order of the server's preference
* if SSL_OP_CIPHER_SERVER_PREFERENCE was set.
*/
}
p += s->s2->tmp.cipher_spec_length;
/* done cipher selection */
/* session id extracted already */
p += s->s2->tmp.session_id_length;
/* challenge */
if (s->s2->challenge_length > sizeof s->s2->challenge) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
return -1;
}
memcpy(s->s2->challenge, p, (unsigned int)s->s2->challenge_length);
return (1);
mem_err:
SSLerr(SSL_F_GET_CLIENT_HELLO, ERR_R_MALLOC_FAILURE);
return (0);
}
static int server_hello(SSL *s)
{
unsigned char *p, *d;
int n, hit;
p = (unsigned char *)s->init_buf->data;
if (s->state == SSL2_ST_SEND_SERVER_HELLO_A) {
d = p + 11;
*(p++) = SSL2_MT_SERVER_HELLO; /* type */
hit = s->hit;
*(p++) = (unsigned char)hit;
# if 1
if (!hit) {
if (s->session->sess_cert != NULL)
/*
* This can't really happen because get_client_hello has
* called ssl_get_new_session, which does not set sess_cert.
*/
ssl_sess_cert_free(s->session->sess_cert);
s->session->sess_cert = ssl_sess_cert_new();
if (s->session->sess_cert == NULL) {
SSLerr(SSL_F_SERVER_HELLO, ERR_R_MALLOC_FAILURE);
return (-1);
}
}
/*
* If 'hit' is set, then s->sess_cert may be non-NULL or NULL,
* depending on whether it survived in the internal cache or was
* retrieved from an external cache. If it is NULL, we cannot put any
* useful data in it anyway, so we don't touch it.
*/
# else /* That's what used to be done when cert_st
* and sess_cert_st were * the same. */
if (!hit) { /* else add cert to session */
CRYPTO_add(&s->cert->references, 1, CRYPTO_LOCK_SSL_CERT);
if (s->session->sess_cert != NULL)
ssl_cert_free(s->session->sess_cert);
s->session->sess_cert = s->cert;
} else { /* We have a session id-cache hit, if the *
* session-id has no certificate listed
* against * the 'cert' structure, grab the
* 'old' one * listed against the SSL
* connection */
if (s->session->sess_cert == NULL) {
CRYPTO_add(&s->cert->references, 1, CRYPTO_LOCK_SSL_CERT);
s->session->sess_cert = s->cert;
}
}
# endif
if (s->cert == NULL) {
ssl2_return_error(s, SSL2_PE_NO_CERTIFICATE);
SSLerr(SSL_F_SERVER_HELLO, SSL_R_NO_CERTIFICATE_SPECIFIED);
return (-1);
}
if (hit) {
*(p++) = 0; /* no certificate type */
s2n(s->version, p); /* version */
s2n(0, p); /* cert len */
s2n(0, p); /* ciphers len */
} else {
/* EAY EAY */
/* put certificate type */
*(p++) = SSL2_CT_X509_CERTIFICATE;
s2n(s->version, p); /* version */
n = i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509, NULL);
s2n(n, p); /* certificate length */
i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509, &d);
n = 0;
/*
* lets send out the ciphers we like in the prefered order
*/
n = ssl_cipher_list_to_bytes(s, s->session->ciphers, d, 0);
d += n;
s2n(n, p); /* add cipher length */
}
/* make and send conn_id */
s2n(SSL2_CONNECTION_ID_LENGTH, p); /* add conn_id length */
s->s2->conn_id_length = SSL2_CONNECTION_ID_LENGTH;
if (RAND_pseudo_bytes(s->s2->conn_id, (int)s->s2->conn_id_length) <=
0)
return -1;
memcpy(d, s->s2->conn_id, SSL2_CONNECTION_ID_LENGTH);
d += SSL2_CONNECTION_ID_LENGTH;
s->state = SSL2_ST_SEND_SERVER_HELLO_B;
s->init_num = d - (unsigned char *)s->init_buf->data;
s->init_off = 0;
}
/* SSL2_ST_SEND_SERVER_HELLO_B */
/*
* If we are using TCP/IP, the performance is bad if we do 2 writes
* without a read between them. This occurs when Session-id reuse is
* used, so I will put in a buffering module
*/
if (s->hit) {
if (!ssl_init_wbio_buffer(s, 1))
return (-1);
}
return (ssl2_do_write(s));
}
static int get_client_finished(SSL *s)
{
unsigned char *p;
int i, n;
unsigned long len;
p = (unsigned char *)s->init_buf->data;
if (s->state == SSL2_ST_GET_CLIENT_FINISHED_A) {
i = ssl2_read(s, (char *)&(p[s->init_num]), 1 - s->init_num);
if (i < 1 - s->init_num)
return (ssl2_part_read(s, SSL_F_GET_CLIENT_FINISHED, i));
s->init_num += i;
if (*p != SSL2_MT_CLIENT_FINISHED) {
if (*p != SSL2_MT_ERROR) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_FINISHED,
SSL_R_READ_WRONG_PACKET_TYPE);
} else {
SSLerr(SSL_F_GET_CLIENT_FINISHED, SSL_R_PEER_ERROR);
/* try to read the error message */
i = ssl2_read(s, (char *)&(p[s->init_num]), 3 - s->init_num);
return ssl2_part_read(s, SSL_F_GET_SERVER_VERIFY, i);
}
return (-1);
}
s->state = SSL2_ST_GET_CLIENT_FINISHED_B;
}
/* SSL2_ST_GET_CLIENT_FINISHED_B */
if (s->s2->conn_id_length > sizeof s->s2->conn_id) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_FINISHED, ERR_R_INTERNAL_ERROR);
return -1;
}
len = 1 + (unsigned long)s->s2->conn_id_length;
n = (int)len - s->init_num;
i = ssl2_read(s, (char *)&(p[s->init_num]), n);
if (i < n) {
return (ssl2_part_read(s, SSL_F_GET_CLIENT_FINISHED, i));
}
if (s->msg_callback) {
/* CLIENT-FINISHED */
s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg);
}
p += 1;
if (memcmp(p, s->s2->conn_id, s->s2->conn_id_length) != 0) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_GET_CLIENT_FINISHED, SSL_R_CONNECTION_ID_IS_DIFFERENT);
return (-1);
}
return (1);
}
static int server_verify(SSL *s)
{
unsigned char *p;
if (s->state == SSL2_ST_SEND_SERVER_VERIFY_A) {
p = (unsigned char *)s->init_buf->data;
*(p++) = SSL2_MT_SERVER_VERIFY;
if (s->s2->challenge_length > sizeof s->s2->challenge) {
SSLerr(SSL_F_SERVER_VERIFY, ERR_R_INTERNAL_ERROR);
return -1;
}
memcpy(p, s->s2->challenge, (unsigned int)s->s2->challenge_length);
/* p+=s->s2->challenge_length; */
s->state = SSL2_ST_SEND_SERVER_VERIFY_B;
s->init_num = s->s2->challenge_length + 1;
s->init_off = 0;
}
return (ssl2_do_write(s));
}
static int server_finish(SSL *s)
{
unsigned char *p;
if (s->state == SSL2_ST_SEND_SERVER_FINISHED_A) {
p = (unsigned char *)s->init_buf->data;
*(p++) = SSL2_MT_SERVER_FINISHED;
if (s->session->session_id_length > sizeof s->session->session_id) {
SSLerr(SSL_F_SERVER_FINISH, ERR_R_INTERNAL_ERROR);
return -1;
}
memcpy(p, s->session->session_id,
(unsigned int)s->session->session_id_length);
/* p+=s->session->session_id_length; */
s->state = SSL2_ST_SEND_SERVER_FINISHED_B;
s->init_num = s->session->session_id_length + 1;
s->init_off = 0;
}
/* SSL2_ST_SEND_SERVER_FINISHED_B */
return (ssl2_do_write(s));
}
/* send the request and check the response */
static int request_certificate(SSL *s)
{
const unsigned char *cp;
unsigned char *p, *p2, *buf2;
unsigned char *ccd;
int i, j, ctype, ret = -1;
unsigned long len;
X509 *x509 = NULL;
STACK_OF(X509) *sk = NULL;
ccd = s->s2->tmp.ccl;
if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_A) {
p = (unsigned char *)s->init_buf->data;
*(p++) = SSL2_MT_REQUEST_CERTIFICATE;
*(p++) = SSL2_AT_MD5_WITH_RSA_ENCRYPTION;
if (RAND_pseudo_bytes(ccd, SSL2_MIN_CERT_CHALLENGE_LENGTH) <= 0)
return -1;
memcpy(p, ccd, SSL2_MIN_CERT_CHALLENGE_LENGTH);
s->state = SSL2_ST_SEND_REQUEST_CERTIFICATE_B;
s->init_num = SSL2_MIN_CERT_CHALLENGE_LENGTH + 2;
s->init_off = 0;
}
if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_B) {
i = ssl2_do_write(s);
if (i <= 0) {
ret = i;
goto end;
}
s->init_num = 0;
s->state = SSL2_ST_SEND_REQUEST_CERTIFICATE_C;
}
if (s->state == SSL2_ST_SEND_REQUEST_CERTIFICATE_C) {
p = (unsigned char *)s->init_buf->data;
/* try to read 6 octets ... */
i = ssl2_read(s, (char *)&(p[s->init_num]), 6 - s->init_num);
/*
* ... but don't call ssl2_part_read now if we got at least 3
* (probably NO-CERTIFICATE-ERROR)
*/
if (i < 3 - s->init_num) {
ret = ssl2_part_read(s, SSL_F_REQUEST_CERTIFICATE, i);
goto end;
}
s->init_num += i;
if ((s->init_num >= 3) && (p[0] == SSL2_MT_ERROR)) {
n2s(p, i);
if (i != SSL2_PE_NO_CERTIFICATE) {
/*
* not the error message we expected -- let ssl2_part_read
* handle it
*/
s->init_num -= 3;
ret = ssl2_part_read(s, SSL_F_REQUEST_CERTIFICATE, 3);
goto end;
}
if (s->msg_callback) {
/* ERROR */
s->msg_callback(0, s->version, 0, p, 3, s,
s->msg_callback_arg);
}
/*
* this is the one place where we can recover from an SSL 2.0
* error
*/
if (s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
ssl2_return_error(s, SSL2_PE_BAD_CERTIFICATE);
SSLerr(SSL_F_REQUEST_CERTIFICATE,
SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
goto end;
}
ret = 1;
goto end;
}
if ((*(p++) != SSL2_MT_CLIENT_CERTIFICATE) || (s->init_num < 6)) {
ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
SSLerr(SSL_F_REQUEST_CERTIFICATE, SSL_R_SHORT_READ);
goto end;
}
if (s->init_num != 6) {
SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_INTERNAL_ERROR);
goto end;
}
/* ok we have a response */
/* certificate type, there is only one right now. */
ctype = *(p++);
if (ctype != SSL2_AT_MD5_WITH_RSA_ENCRYPTION) {
ssl2_return_error(s, SSL2_PE_UNSUPPORTED_CERTIFICATE_TYPE);
SSLerr(SSL_F_REQUEST_CERTIFICATE, SSL_R_BAD_RESPONSE_ARGUMENT);
goto end;
}
n2s(p, i);
s->s2->tmp.clen = i;
n2s(p, i);
s->s2->tmp.rlen = i;
s->state = SSL2_ST_SEND_REQUEST_CERTIFICATE_D;
}
/* SSL2_ST_SEND_REQUEST_CERTIFICATE_D */
p = (unsigned char *)s->init_buf->data;
len = 6 + (unsigned long)s->s2->tmp.clen + (unsigned long)s->s2->tmp.rlen;
if (len > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) {
SSLerr(SSL_F_REQUEST_CERTIFICATE, SSL_R_MESSAGE_TOO_LONG);
goto end;
}
j = (int)len - s->init_num;
i = ssl2_read(s, (char *)&(p[s->init_num]), j);
if (i < j) {
ret = ssl2_part_read(s, SSL_F_REQUEST_CERTIFICATE, i);
goto end;
}
if (s->msg_callback) {
/* CLIENT-CERTIFICATE */
s->msg_callback(0, s->version, 0, p, len, s, s->msg_callback_arg);
}
p += 6;
cp = p;
x509 = (X509 *)d2i_X509(NULL, &cp, (long)s->s2->tmp.clen);
if (x509 == NULL) {
SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_X509_LIB);
goto msg_end;
}
if (((sk = sk_X509_new_null()) == NULL) || (!sk_X509_push(sk, x509))) {
SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_MALLOC_FAILURE);
goto msg_end;
}
i = ssl_verify_cert_chain(s, sk);
if (i > 0) { /* we like the packet, now check the chksum */
EVP_MD_CTX ctx;
EVP_PKEY *pkey = NULL;
EVP_MD_CTX_init(&ctx);
if (!EVP_VerifyInit_ex(&ctx, s->ctx->rsa_md5, NULL)
|| !EVP_VerifyUpdate(&ctx, s->s2->key_material,
s->s2->key_material_length)
|| !EVP_VerifyUpdate(&ctx, ccd, SSL2_MIN_CERT_CHALLENGE_LENGTH))
goto msg_end;
i = i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509, NULL);
buf2 = OPENSSL_malloc((unsigned int)i);
if (buf2 == NULL) {
SSLerr(SSL_F_REQUEST_CERTIFICATE, ERR_R_MALLOC_FAILURE);
goto msg_end;
}
p2 = buf2;
i = i2d_X509(s->cert->pkeys[SSL_PKEY_RSA_ENC].x509, &p2);
if (!EVP_VerifyUpdate(&ctx, buf2, (unsigned int)i)) {
OPENSSL_free(buf2);
goto msg_end;
}
OPENSSL_free(buf2);
pkey = X509_get_pubkey(x509);
if (pkey == NULL)
goto end;
i = EVP_VerifyFinal(&ctx, cp, s->s2->tmp.rlen, pkey);
EVP_PKEY_free(pkey);
EVP_MD_CTX_cleanup(&ctx);
if (i > 0) {
if (s->session->peer != NULL)
X509_free(s->session->peer);
s->session->peer = x509;
CRYPTO_add(&x509->references, 1, CRYPTO_LOCK_X509);
s->session->verify_result = s->verify_result;
ret = 1;
goto end;
} else {
SSLerr(SSL_F_REQUEST_CERTIFICATE, SSL_R_BAD_CHECKSUM);
goto msg_end;
}
} else {
msg_end:
ssl2_return_error(s, SSL2_PE_BAD_CERTIFICATE);
}
end:
sk_X509_free(sk);
X509_free(x509);
return (ret);
}
static int ssl_rsa_private_decrypt(CERT *c, int len, unsigned char *from,
unsigned char *to, int padding)
{
RSA *rsa;
int i;
if ((c == NULL) || (c->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL)) {
SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT, SSL_R_NO_PRIVATEKEY);
return (-1);
}
if (c->pkeys[SSL_PKEY_RSA_ENC].privatekey->type != EVP_PKEY_RSA) {
SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT, SSL_R_PUBLIC_KEY_IS_NOT_RSA);
return (-1);
}
rsa = c->pkeys[SSL_PKEY_RSA_ENC].privatekey->pkey.rsa;
/* we have the public key */
i = RSA_private_decrypt(len, from, to, rsa, padding);
if (i < 0)
SSLerr(SSL_F_SSL_RSA_PRIVATE_DECRYPT, ERR_R_RSA_LIB);
return (i);
}
#else /* !OPENSSL_NO_SSL2 */
# if PEDANTIC
static void *dummy = &dummy;
# endif
#endif
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