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openssl/crypto/pkcs7/pk7_doit.c
Emilia Kasper c0334c2c92 PKCS#7: avoid NULL pointer dereferences with missing content 
In PKCS#7, the ASN.1 content component is optional.
This typically applies to inner content (detached signatures),
however we must also handle unexpected missing outer content
correctly.

This patch only addresses functions reachable from parsing,
decryption and verification, and functions otherwise associated
with reading potentially untrusted data.

Correcting all low-level API calls requires further work.

CVE-2015-0289

Thanks to Michal Zalewski (Google) for reporting this issue.

Reviewed-by: Steve Henson <steve@openssl.org>
2015-03-19 12:58:35 +00:00

1280 lines
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/* crypto/pkcs7/pk7_doit.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.]
*/
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/err.h>
static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
void *value);
static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid);
static int PKCS7_type_is_other(PKCS7 *p7)
{
int isOther = 1;
int nid = OBJ_obj2nid(p7->type);
switch (nid) {
case NID_pkcs7_data:
case NID_pkcs7_signed:
case NID_pkcs7_enveloped:
case NID_pkcs7_signedAndEnveloped:
case NID_pkcs7_digest:
case NID_pkcs7_encrypted:
isOther = 0;
break;
default:
isOther = 1;
}
return isOther;
}
static ASN1_OCTET_STRING *PKCS7_get_octet_string(PKCS7 *p7)
{
if (PKCS7_type_is_data(p7))
return p7->d.data;
if (PKCS7_type_is_other(p7) && p7->d.other
&& (p7->d.other->type == V_ASN1_OCTET_STRING))
return p7->d.other->value.octet_string;
return NULL;
}
static int PKCS7_bio_add_digest(BIO **pbio, X509_ALGOR *alg)
{
BIO *btmp;
const EVP_MD *md;
if ((btmp = BIO_new(BIO_f_md())) == NULL) {
PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, ERR_R_BIO_LIB);
goto err;
}
md = EVP_get_digestbyobj(alg->algorithm);
if (md == NULL) {
PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, PKCS7_R_UNKNOWN_DIGEST_TYPE);
goto err;
}
BIO_set_md(btmp, md);
if (*pbio == NULL)
*pbio = btmp;
else if (!BIO_push(*pbio, btmp)) {
PKCS7err(PKCS7_F_PKCS7_BIO_ADD_DIGEST, ERR_R_BIO_LIB);
goto err;
}
btmp = NULL;
return 1;
err:
if (btmp)
BIO_free(btmp);
return 0;
}
static int pkcs7_encode_rinfo(PKCS7_RECIP_INFO *ri,
unsigned char *key, int keylen)
{
EVP_PKEY_CTX *pctx = NULL;
EVP_PKEY *pkey = NULL;
unsigned char *ek = NULL;
int ret = 0;
size_t eklen;
pkey = X509_get_pubkey(ri->cert);
if (!pkey)
return 0;
pctx = EVP_PKEY_CTX_new(pkey, NULL);
if (!pctx)
return 0;
if (EVP_PKEY_encrypt_init(pctx) <= 0)
goto err;
if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_ENCRYPT,
EVP_PKEY_CTRL_PKCS7_ENCRYPT, 0, ri) <= 0) {
PKCS7err(PKCS7_F_PKCS7_ENCODE_RINFO, PKCS7_R_CTRL_ERROR);
goto err;
}
if (EVP_PKEY_encrypt(pctx, NULL, &eklen, key, keylen) <= 0)
goto err;
ek = OPENSSL_malloc(eklen);
if (ek == NULL) {
PKCS7err(PKCS7_F_PKCS7_ENCODE_RINFO, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_PKEY_encrypt(pctx, ek, &eklen, key, keylen) <= 0)
goto err;
ASN1_STRING_set0(ri->enc_key, ek, eklen);
ek = NULL;
ret = 1;
err:
if (pkey)
EVP_PKEY_free(pkey);
if (pctx)
EVP_PKEY_CTX_free(pctx);
if (ek)
OPENSSL_free(ek);
return ret;
}
static int pkcs7_decrypt_rinfo(unsigned char **pek, int *peklen,
PKCS7_RECIP_INFO *ri, EVP_PKEY *pkey)
{
EVP_PKEY_CTX *pctx = NULL;
unsigned char *ek = NULL;
size_t eklen;
int ret = -1;
pctx = EVP_PKEY_CTX_new(pkey, NULL);
if (!pctx)
return -1;
if (EVP_PKEY_decrypt_init(pctx) <= 0)
goto err;
if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_DECRYPT,
EVP_PKEY_CTRL_PKCS7_DECRYPT, 0, ri) <= 0) {
PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, PKCS7_R_CTRL_ERROR);
goto err;
}
if (EVP_PKEY_decrypt(pctx, NULL, &eklen,
ri->enc_key->data, ri->enc_key->length) <= 0)
goto err;
ek = OPENSSL_malloc(eklen);
if (ek == NULL) {
PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_PKEY_decrypt(pctx, ek, &eklen,
ri->enc_key->data, ri->enc_key->length) <= 0) {
ret = 0;
PKCS7err(PKCS7_F_PKCS7_DECRYPT_RINFO, ERR_R_EVP_LIB);
goto err;
}
ret = 1;
if (*pek) {
OPENSSL_cleanse(*pek, *peklen);
OPENSSL_free(*pek);
}
*pek = ek;
*peklen = eklen;
err:
if (pctx)
EVP_PKEY_CTX_free(pctx);
if (!ret && ek)
OPENSSL_free(ek);
return ret;
}
BIO *PKCS7_dataInit(PKCS7 *p7, BIO *bio)
{
int i;
BIO *out = NULL, *btmp = NULL;
X509_ALGOR *xa = NULL;
const EVP_CIPHER *evp_cipher = NULL;
STACK_OF(X509_ALGOR) *md_sk = NULL;
STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
X509_ALGOR *xalg = NULL;
PKCS7_RECIP_INFO *ri = NULL;
ASN1_OCTET_STRING *os = NULL;
if (p7 == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_INVALID_NULL_POINTER);
return NULL;
}
/*
* The content field in the PKCS7 ContentInfo is optional, but that really
* only applies to inner content (precisely, detached signatures).
*
* When reading content, missing outer content is therefore treated as an
* error.
*
* When creating content, PKCS7_content_new() must be called before
* calling this method, so a NULL p7->d is always an error.
*/
if (p7->d.ptr == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_NO_CONTENT);
return NULL;
}
i = OBJ_obj2nid(p7->type);
p7->state = PKCS7_S_HEADER;
switch (i) {
case NID_pkcs7_signed:
md_sk = p7->d.sign->md_algs;
os = PKCS7_get_octet_string(p7->d.sign->contents);
break;
case NID_pkcs7_signedAndEnveloped:
rsk = p7->d.signed_and_enveloped->recipientinfo;
md_sk = p7->d.signed_and_enveloped->md_algs;
xalg = p7->d.signed_and_enveloped->enc_data->algorithm;
evp_cipher = p7->d.signed_and_enveloped->enc_data->cipher;
if (evp_cipher == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_CIPHER_NOT_INITIALIZED);
goto err;
}
break;
case NID_pkcs7_enveloped:
rsk = p7->d.enveloped->recipientinfo;
xalg = p7->d.enveloped->enc_data->algorithm;
evp_cipher = p7->d.enveloped->enc_data->cipher;
if (evp_cipher == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_CIPHER_NOT_INITIALIZED);
goto err;
}
break;
case NID_pkcs7_digest:
xa = p7->d.digest->md;
os = PKCS7_get_octet_string(p7->d.digest->contents);
break;
case NID_pkcs7_data:
break;
default:
PKCS7err(PKCS7_F_PKCS7_DATAINIT, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
goto err;
}
for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++)
if (!PKCS7_bio_add_digest(&out, sk_X509_ALGOR_value(md_sk, i)))
goto err;
if (xa && !PKCS7_bio_add_digest(&out, xa))
goto err;
if (evp_cipher != NULL) {
unsigned char key[EVP_MAX_KEY_LENGTH];
unsigned char iv[EVP_MAX_IV_LENGTH];
int keylen, ivlen;
EVP_CIPHER_CTX *ctx;
if ((btmp = BIO_new(BIO_f_cipher())) == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAINIT, ERR_R_BIO_LIB);
goto err;
}
BIO_get_cipher_ctx(btmp, &ctx);
keylen = EVP_CIPHER_key_length(evp_cipher);
ivlen = EVP_CIPHER_iv_length(evp_cipher);
xalg->algorithm = OBJ_nid2obj(EVP_CIPHER_type(evp_cipher));
if (ivlen > 0)
if (RAND_pseudo_bytes(iv, ivlen) <= 0)
goto err;
if (EVP_CipherInit_ex(ctx, evp_cipher, NULL, NULL, NULL, 1) <= 0)
goto err;
if (EVP_CIPHER_CTX_rand_key(ctx, key) <= 0)
goto err;
if (EVP_CipherInit_ex(ctx, NULL, NULL, key, iv, 1) <= 0)
goto err;
if (ivlen > 0) {
if (xalg->parameter == NULL) {
xalg->parameter = ASN1_TYPE_new();
if (xalg->parameter == NULL)
goto err;
}
if (EVP_CIPHER_param_to_asn1(ctx, xalg->parameter) < 0)
goto err;
}
/* Lets do the pub key stuff :-) */
for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
if (pkcs7_encode_rinfo(ri, key, keylen) <= 0)
goto err;
}
OPENSSL_cleanse(key, keylen);
if (out == NULL)
out = btmp;
else
BIO_push(out, btmp);
btmp = NULL;
}
if (bio == NULL) {
if (PKCS7_is_detached(p7))
bio = BIO_new(BIO_s_null());
else if (os && os->length > 0)
bio = BIO_new_mem_buf(os->data, os->length);
if (bio == NULL) {
bio = BIO_new(BIO_s_mem());
if (bio == NULL)
goto err;
BIO_set_mem_eof_return(bio, 0);
}
}
if (out)
BIO_push(out, bio);
else
out = bio;
bio = NULL;
if (0) {
err:
if (out != NULL)
BIO_free_all(out);
if (btmp != NULL)
BIO_free_all(btmp);
out = NULL;
}
return (out);
}
static int pkcs7_cmp_ri(PKCS7_RECIP_INFO *ri, X509 *pcert)
{
int ret;
ret = X509_NAME_cmp(ri->issuer_and_serial->issuer,
pcert->cert_info->issuer);
if (ret)
return ret;
return M_ASN1_INTEGER_cmp(pcert->cert_info->serialNumber,
ri->issuer_and_serial->serial);
}
/* int */
BIO *PKCS7_dataDecode(PKCS7 *p7, EVP_PKEY *pkey, BIO *in_bio, X509 *pcert)
{
int i, j;
BIO *out = NULL, *btmp = NULL, *etmp = NULL, *bio = NULL;
X509_ALGOR *xa;
ASN1_OCTET_STRING *data_body = NULL;
const EVP_MD *evp_md;
const EVP_CIPHER *evp_cipher = NULL;
EVP_CIPHER_CTX *evp_ctx = NULL;
X509_ALGOR *enc_alg = NULL;
STACK_OF(X509_ALGOR) *md_sk = NULL;
STACK_OF(PKCS7_RECIP_INFO) *rsk = NULL;
PKCS7_RECIP_INFO *ri = NULL;
unsigned char *ek = NULL, *tkey = NULL;
int eklen = 0, tkeylen = 0;
if (p7 == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_INVALID_NULL_POINTER);
return NULL;
}
if (p7->d.ptr == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_NO_CONTENT);
return NULL;
}
i = OBJ_obj2nid(p7->type);
p7->state = PKCS7_S_HEADER;
switch (i) {
case NID_pkcs7_signed:
data_body = PKCS7_get_octet_string(p7->d.sign->contents);
if (!PKCS7_is_detached(p7) && data_body == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE,
PKCS7_R_INVALID_SIGNED_DATA_TYPE);
goto err;
}
md_sk = p7->d.sign->md_algs;
break;
case NID_pkcs7_signedAndEnveloped:
rsk = p7->d.signed_and_enveloped->recipientinfo;
md_sk = p7->d.signed_and_enveloped->md_algs;
data_body = p7->d.signed_and_enveloped->enc_data->enc_data;
enc_alg = p7->d.signed_and_enveloped->enc_data->algorithm;
evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
if (evp_cipher == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE,
PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
goto err;
}
break;
case NID_pkcs7_enveloped:
rsk = p7->d.enveloped->recipientinfo;
enc_alg = p7->d.enveloped->enc_data->algorithm;
data_body = p7->d.enveloped->enc_data->enc_data;
evp_cipher = EVP_get_cipherbyobj(enc_alg->algorithm);
if (evp_cipher == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE,
PKCS7_R_UNSUPPORTED_CIPHER_TYPE);
goto err;
}
break;
default:
PKCS7err(PKCS7_F_PKCS7_DATADECODE, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
goto err;
}
/* We will be checking the signature */
if (md_sk != NULL) {
for (i = 0; i < sk_X509_ALGOR_num(md_sk); i++) {
xa = sk_X509_ALGOR_value(md_sk, i);
if ((btmp = BIO_new(BIO_f_md())) == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE, ERR_R_BIO_LIB);
goto err;
}
j = OBJ_obj2nid(xa->algorithm);
evp_md = EVP_get_digestbynid(j);
if (evp_md == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE,
PKCS7_R_UNKNOWN_DIGEST_TYPE);
goto err;
}
BIO_set_md(btmp, evp_md);
if (out == NULL)
out = btmp;
else
BIO_push(out, btmp);
btmp = NULL;
}
}
if (evp_cipher != NULL) {
#if 0
unsigned char key[EVP_MAX_KEY_LENGTH];
unsigned char iv[EVP_MAX_IV_LENGTH];
unsigned char *p;
int keylen, ivlen;
int max;
X509_OBJECT ret;
#endif
if ((etmp = BIO_new(BIO_f_cipher())) == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE, ERR_R_BIO_LIB);
goto err;
}
/*
* It was encrypted, we need to decrypt the secret key with the
* private key
*/
/*
* Find the recipientInfo which matches the passed certificate (if
* any)
*/
if (pcert) {
for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
if (!pkcs7_cmp_ri(ri, pcert))
break;
ri = NULL;
}
if (ri == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATADECODE,
PKCS7_R_NO_RECIPIENT_MATCHES_CERTIFICATE);
goto err;
}
}
/* If we haven't got a certificate try each ri in turn */
if (pcert == NULL) {
/*
* Always attempt to decrypt all rinfo even after sucess as a
* defence against MMA timing attacks.
*/
for (i = 0; i < sk_PKCS7_RECIP_INFO_num(rsk); i++) {
ri = sk_PKCS7_RECIP_INFO_value(rsk, i);
if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) < 0)
goto err;
ERR_clear_error();
}
} else {
/* Only exit on fatal errors, not decrypt failure */
if (pkcs7_decrypt_rinfo(&ek, &eklen, ri, pkey) < 0)
goto err;
ERR_clear_error();
}
evp_ctx = NULL;
BIO_get_cipher_ctx(etmp, &evp_ctx);
if (EVP_CipherInit_ex(evp_ctx, evp_cipher, NULL, NULL, NULL, 0) <= 0)
goto err;
if (EVP_CIPHER_asn1_to_param(evp_ctx, enc_alg->parameter) < 0)
goto err;
/* Generate random key as MMA defence */
tkeylen = EVP_CIPHER_CTX_key_length(evp_ctx);
tkey = OPENSSL_malloc(tkeylen);
if (!tkey)
goto err;
if (EVP_CIPHER_CTX_rand_key(evp_ctx, tkey) <= 0)
goto err;
if (ek == NULL) {
ek = tkey;
eklen = tkeylen;
tkey = NULL;
}
if (eklen != EVP_CIPHER_CTX_key_length(evp_ctx)) {
/*
* Some S/MIME clients don't use the same key and effective key
* length. The key length is determined by the size of the
* decrypted RSA key.
*/
if (!EVP_CIPHER_CTX_set_key_length(evp_ctx, eklen)) {
/* Use random key as MMA defence */
OPENSSL_cleanse(ek, eklen);
OPENSSL_free(ek);
ek = tkey;
eklen = tkeylen;
tkey = NULL;
}
}
/* Clear errors so we don't leak information useful in MMA */
ERR_clear_error();
if (EVP_CipherInit_ex(evp_ctx, NULL, NULL, ek, NULL, 0) <= 0)
goto err;
if (ek) {
OPENSSL_cleanse(ek, eklen);
OPENSSL_free(ek);
ek = NULL;
}
if (tkey) {
OPENSSL_cleanse(tkey, tkeylen);
OPENSSL_free(tkey);
tkey = NULL;
}
if (out == NULL)
out = etmp;
else
BIO_push(out, etmp);
etmp = NULL;
}
#if 1
if (PKCS7_is_detached(p7) || (in_bio != NULL)) {
bio = in_bio;
} else {
# if 0
bio = BIO_new(BIO_s_mem());
/*
* We need to set this so that when we have read all the data, the
* encrypt BIO, if present, will read EOF and encode the last few
* bytes
*/
BIO_set_mem_eof_return(bio, 0);
if (data_body->length > 0)
BIO_write(bio, (char *)data_body->data, data_body->length);
# else
if (data_body->length > 0)
bio = BIO_new_mem_buf(data_body->data, data_body->length);
else {
bio = BIO_new(BIO_s_mem());
BIO_set_mem_eof_return(bio, 0);
}
if (bio == NULL)
goto err;
# endif
}
BIO_push(out, bio);
bio = NULL;
#endif
if (0) {
err:
if (ek) {
OPENSSL_cleanse(ek, eklen);
OPENSSL_free(ek);
}
if (tkey) {
OPENSSL_cleanse(tkey, tkeylen);
OPENSSL_free(tkey);
}
if (out != NULL)
BIO_free_all(out);
if (btmp != NULL)
BIO_free_all(btmp);
if (etmp != NULL)
BIO_free_all(etmp);
if (bio != NULL)
BIO_free_all(bio);
out = NULL;
}
return (out);
}
static BIO *PKCS7_find_digest(EVP_MD_CTX **pmd, BIO *bio, int nid)
{
for (;;) {
bio = BIO_find_type(bio, BIO_TYPE_MD);
if (bio == NULL) {
PKCS7err(PKCS7_F_PKCS7_FIND_DIGEST,
PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
return NULL;
}
BIO_get_md_ctx(bio, pmd);
if (*pmd == NULL) {
PKCS7err(PKCS7_F_PKCS7_FIND_DIGEST, ERR_R_INTERNAL_ERROR);
return NULL;
}
if (EVP_MD_CTX_type(*pmd) == nid)
return bio;
bio = BIO_next(bio);
}
return NULL;
}
static int do_pkcs7_signed_attrib(PKCS7_SIGNER_INFO *si, EVP_MD_CTX *mctx)
{
unsigned char md_data[EVP_MAX_MD_SIZE];
unsigned int md_len;
/* Add signing time if not already present */
if (!PKCS7_get_signed_attribute(si, NID_pkcs9_signingTime)) {
if (!PKCS7_add0_attrib_signing_time(si, NULL)) {
PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_MALLOC_FAILURE);
return 0;
}
}
/* Add digest */
if (!EVP_DigestFinal_ex(mctx, md_data, &md_len)) {
PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_EVP_LIB);
return 0;
}
if (!PKCS7_add1_attrib_digest(si, md_data, md_len)) {
PKCS7err(PKCS7_F_DO_PKCS7_SIGNED_ATTRIB, ERR_R_MALLOC_FAILURE);
return 0;
}
/* Now sign the attributes */
if (!PKCS7_SIGNER_INFO_sign(si))
return 0;
return 1;
}
int PKCS7_dataFinal(PKCS7 *p7, BIO *bio)
{
int ret = 0;
int i, j;
BIO *btmp;
PKCS7_SIGNER_INFO *si;
EVP_MD_CTX *mdc, ctx_tmp;
STACK_OF(X509_ATTRIBUTE) *sk;
STACK_OF(PKCS7_SIGNER_INFO) *si_sk = NULL;
ASN1_OCTET_STRING *os = NULL;
if (p7 == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_INVALID_NULL_POINTER);
return 0;
}
if (p7->d.ptr == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_NO_CONTENT);
return 0;
}
EVP_MD_CTX_init(&ctx_tmp);
i = OBJ_obj2nid(p7->type);
p7->state = PKCS7_S_HEADER;
switch (i) {
case NID_pkcs7_data:
os = p7->d.data;
break;
case NID_pkcs7_signedAndEnveloped:
/* XXXXXXXXXXXXXXXX */
si_sk = p7->d.signed_and_enveloped->signer_info;
os = p7->d.signed_and_enveloped->enc_data->enc_data;
if (!os) {
os = M_ASN1_OCTET_STRING_new();
if (!os) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_MALLOC_FAILURE);
goto err;
}
p7->d.signed_and_enveloped->enc_data->enc_data = os;
}
break;
case NID_pkcs7_enveloped:
/* XXXXXXXXXXXXXXXX */
os = p7->d.enveloped->enc_data->enc_data;
if (!os) {
os = M_ASN1_OCTET_STRING_new();
if (!os) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_MALLOC_FAILURE);
goto err;
}
p7->d.enveloped->enc_data->enc_data = os;
}
break;
case NID_pkcs7_signed:
si_sk = p7->d.sign->signer_info;
os = PKCS7_get_octet_string(p7->d.sign->contents);
/* If detached data then the content is excluded */
if (PKCS7_type_is_data(p7->d.sign->contents) && p7->detached) {
M_ASN1_OCTET_STRING_free(os);
os = NULL;
p7->d.sign->contents->d.data = NULL;
}
break;
case NID_pkcs7_digest:
os = PKCS7_get_octet_string(p7->d.digest->contents);
/* If detached data then the content is excluded */
if (PKCS7_type_is_data(p7->d.digest->contents) && p7->detached) {
M_ASN1_OCTET_STRING_free(os);
os = NULL;
p7->d.digest->contents->d.data = NULL;
}
break;
default:
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_UNSUPPORTED_CONTENT_TYPE);
goto err;
}
if (si_sk != NULL) {
for (i = 0; i < sk_PKCS7_SIGNER_INFO_num(si_sk); i++) {
si = sk_PKCS7_SIGNER_INFO_value(si_sk, i);
if (si->pkey == NULL)
continue;
j = OBJ_obj2nid(si->digest_alg->algorithm);
btmp = bio;
btmp = PKCS7_find_digest(&mdc, btmp, j);
if (btmp == NULL)
goto err;
/*
* We now have the EVP_MD_CTX, lets do the signing.
*/
if (!EVP_MD_CTX_copy_ex(&ctx_tmp, mdc))
goto err;
sk = si->auth_attr;
/*
* If there are attributes, we add the digest attribute and only
* sign the attributes
*/
if (sk_X509_ATTRIBUTE_num(sk) > 0) {
if (!do_pkcs7_signed_attrib(si, &ctx_tmp))
goto err;
} else {
unsigned char *abuf = NULL;
unsigned int abuflen;
abuflen = EVP_PKEY_size(si->pkey);
abuf = OPENSSL_malloc(abuflen);
if (!abuf)
goto err;
if (!EVP_SignFinal(&ctx_tmp, abuf, &abuflen, si->pkey)) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, ERR_R_EVP_LIB);
goto err;
}
ASN1_STRING_set0(si->enc_digest, abuf, abuflen);
}
}
} else if (i == NID_pkcs7_digest) {
unsigned char md_data[EVP_MAX_MD_SIZE];
unsigned int md_len;
if (!PKCS7_find_digest(&mdc, bio,
OBJ_obj2nid(p7->d.digest->md->algorithm)))
goto err;
if (!EVP_DigestFinal_ex(mdc, md_data, &md_len))
goto err;
M_ASN1_OCTET_STRING_set(p7->d.digest->digest, md_data, md_len);
}
if (!PKCS7_is_detached(p7)) {
/*
* NOTE(emilia): I think we only reach os == NULL here because detached
* digested data support is broken.
*/
if (os == NULL)
goto err;
if (!(os->flags & ASN1_STRING_FLAG_NDEF)) {
char *cont;
long contlen;
btmp = BIO_find_type(bio, BIO_TYPE_MEM);
if (btmp == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAFINAL, PKCS7_R_UNABLE_TO_FIND_MEM_BIO);
goto err;
}
contlen = BIO_get_mem_data(btmp, &cont);
/*
* Mark the BIO read only then we can use its copy of the data
* instead of making an extra copy.
*/
BIO_set_flags(btmp, BIO_FLAGS_MEM_RDONLY);
BIO_set_mem_eof_return(btmp, 0);
ASN1_STRING_set0(os, (unsigned char *)cont, contlen);
}
}
ret = 1;
err:
EVP_MD_CTX_cleanup(&ctx_tmp);
return (ret);
}
int PKCS7_SIGNER_INFO_sign(PKCS7_SIGNER_INFO *si)
{
EVP_MD_CTX mctx;
EVP_PKEY_CTX *pctx;
unsigned char *abuf = NULL;
int alen;
size_t siglen;
const EVP_MD *md = NULL;
md = EVP_get_digestbyobj(si->digest_alg->algorithm);
if (md == NULL)
return 0;
EVP_MD_CTX_init(&mctx);
if (EVP_DigestSignInit(&mctx, &pctx, md, NULL, si->pkey) <= 0)
goto err;
if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
EVP_PKEY_CTRL_PKCS7_SIGN, 0, si) <= 0) {
PKCS7err(PKCS7_F_PKCS7_SIGNER_INFO_SIGN, PKCS7_R_CTRL_ERROR);
goto err;
}
alen = ASN1_item_i2d((ASN1_VALUE *)si->auth_attr, &abuf,
ASN1_ITEM_rptr(PKCS7_ATTR_SIGN));
if (!abuf)
goto err;
if (EVP_DigestSignUpdate(&mctx, abuf, alen) <= 0)
goto err;
OPENSSL_free(abuf);
abuf = NULL;
if (EVP_DigestSignFinal(&mctx, NULL, &siglen) <= 0)
goto err;
abuf = OPENSSL_malloc(siglen);
if (!abuf)
goto err;
if (EVP_DigestSignFinal(&mctx, abuf, &siglen) <= 0)
goto err;
if (EVP_PKEY_CTX_ctrl(pctx, -1, EVP_PKEY_OP_SIGN,
EVP_PKEY_CTRL_PKCS7_SIGN, 1, si) <= 0) {
PKCS7err(PKCS7_F_PKCS7_SIGNER_INFO_SIGN, PKCS7_R_CTRL_ERROR);
goto err;
}
EVP_MD_CTX_cleanup(&mctx);
ASN1_STRING_set0(si->enc_digest, abuf, siglen);
return 1;
err:
if (abuf)
OPENSSL_free(abuf);
EVP_MD_CTX_cleanup(&mctx);
return 0;
}
int PKCS7_dataVerify(X509_STORE *cert_store, X509_STORE_CTX *ctx, BIO *bio,
PKCS7 *p7, PKCS7_SIGNER_INFO *si)
{
PKCS7_ISSUER_AND_SERIAL *ias;
int ret = 0, i;
STACK_OF(X509) *cert;
X509 *x509;
if (p7 == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_INVALID_NULL_POINTER);
return 0;
}
if (p7->d.ptr == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_NO_CONTENT);
return 0;
}
if (PKCS7_type_is_signed(p7)) {
cert = p7->d.sign->cert;
} else if (PKCS7_type_is_signedAndEnveloped(p7)) {
cert = p7->d.signed_and_enveloped->cert;
} else {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, PKCS7_R_WRONG_PKCS7_TYPE);
goto err;
}
/* XXXXXXXXXXXXXXXXXXXXXXX */
ias = si->issuer_and_serial;
x509 = X509_find_by_issuer_and_serial(cert, ias->issuer, ias->serial);
/* were we able to find the cert in passed to us */
if (x509 == NULL) {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY,
PKCS7_R_UNABLE_TO_FIND_CERTIFICATE);
goto err;
}
/* Lets verify */
if (!X509_STORE_CTX_init(ctx, cert_store, x509, cert)) {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, ERR_R_X509_LIB);
goto err;
}
X509_STORE_CTX_set_purpose(ctx, X509_PURPOSE_SMIME_SIGN);
i = X509_verify_cert(ctx);
if (i <= 0) {
PKCS7err(PKCS7_F_PKCS7_DATAVERIFY, ERR_R_X509_LIB);
X509_STORE_CTX_cleanup(ctx);
goto err;
}
X509_STORE_CTX_cleanup(ctx);
return PKCS7_signatureVerify(bio, p7, si, x509);
err:
return ret;
}
int PKCS7_signatureVerify(BIO *bio, PKCS7 *p7, PKCS7_SIGNER_INFO *si,
X509 *x509)
{
ASN1_OCTET_STRING *os;
EVP_MD_CTX mdc_tmp, *mdc;
int ret = 0, i;
int md_type;
STACK_OF(X509_ATTRIBUTE) *sk;
BIO *btmp;
EVP_PKEY *pkey;
EVP_MD_CTX_init(&mdc_tmp);
if (!PKCS7_type_is_signed(p7) && !PKCS7_type_is_signedAndEnveloped(p7)) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_WRONG_PKCS7_TYPE);
goto err;
}
md_type = OBJ_obj2nid(si->digest_alg->algorithm);
btmp = bio;
for (;;) {
if ((btmp == NULL) ||
((btmp = BIO_find_type(btmp, BIO_TYPE_MD)) == NULL)) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY,
PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
goto err;
}
BIO_get_md_ctx(btmp, &mdc);
if (mdc == NULL) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, ERR_R_INTERNAL_ERROR);
goto err;
}
if (EVP_MD_CTX_type(mdc) == md_type)
break;
/*
* Workaround for some broken clients that put the signature OID
* instead of the digest OID in digest_alg->algorithm
*/
if (EVP_MD_pkey_type(EVP_MD_CTX_md(mdc)) == md_type)
break;
btmp = BIO_next(btmp);
}
/*
* mdc is the digest ctx that we want, unless there are attributes, in
* which case the digest is the signed attributes
*/
if (!EVP_MD_CTX_copy_ex(&mdc_tmp, mdc))
goto err;
sk = si->auth_attr;
if ((sk != NULL) && (sk_X509_ATTRIBUTE_num(sk) != 0)) {
unsigned char md_dat[EVP_MAX_MD_SIZE], *abuf = NULL;
unsigned int md_len;
int alen;
ASN1_OCTET_STRING *message_digest;
if (!EVP_DigestFinal_ex(&mdc_tmp, md_dat, &md_len))
goto err;
message_digest = PKCS7_digest_from_attributes(sk);
if (!message_digest) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY,
PKCS7_R_UNABLE_TO_FIND_MESSAGE_DIGEST);
goto err;
}
if ((message_digest->length != (int)md_len) ||
(memcmp(message_digest->data, md_dat, md_len))) {
#if 0
{
int ii;
for (ii = 0; ii < message_digest->length; ii++)
printf("%02X", message_digest->data[ii]);
printf(" sent\n");
for (ii = 0; ii < md_len; ii++)
printf("%02X", md_dat[ii]);
printf(" calc\n");
}
#endif
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_DIGEST_FAILURE);
ret = -1;
goto err;
}
if (!EVP_VerifyInit_ex(&mdc_tmp, EVP_get_digestbynid(md_type), NULL))
goto err;
alen = ASN1_item_i2d((ASN1_VALUE *)sk, &abuf,
ASN1_ITEM_rptr(PKCS7_ATTR_VERIFY));
if (alen <= 0) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, ERR_R_ASN1_LIB);
ret = -1;
goto err;
}
if (!EVP_VerifyUpdate(&mdc_tmp, abuf, alen))
goto err;
OPENSSL_free(abuf);
}
os = si->enc_digest;
pkey = X509_get_pubkey(x509);
if (!pkey) {
ret = -1;
goto err;
}
i = EVP_VerifyFinal(&mdc_tmp, os->data, os->length, pkey);
EVP_PKEY_free(pkey);
if (i <= 0) {
PKCS7err(PKCS7_F_PKCS7_SIGNATUREVERIFY, PKCS7_R_SIGNATURE_FAILURE);
ret = -1;
goto err;
} else
ret = 1;
err:
EVP_MD_CTX_cleanup(&mdc_tmp);
return (ret);
}
PKCS7_ISSUER_AND_SERIAL *PKCS7_get_issuer_and_serial(PKCS7 *p7, int idx)
{
STACK_OF(PKCS7_RECIP_INFO) *rsk;
PKCS7_RECIP_INFO *ri;
int i;
i = OBJ_obj2nid(p7->type);
if (i != NID_pkcs7_signedAndEnveloped)
return NULL;
if (p7->d.signed_and_enveloped == NULL)
return NULL;
rsk = p7->d.signed_and_enveloped->recipientinfo;
if (rsk == NULL)
return NULL;
ri = sk_PKCS7_RECIP_INFO_value(rsk, 0);
if (sk_PKCS7_RECIP_INFO_num(rsk) <= idx)
return (NULL);
ri = sk_PKCS7_RECIP_INFO_value(rsk, idx);
return (ri->issuer_and_serial);
}
ASN1_TYPE *PKCS7_get_signed_attribute(PKCS7_SIGNER_INFO *si, int nid)
{
return (get_attribute(si->auth_attr, nid));
}
ASN1_TYPE *PKCS7_get_attribute(PKCS7_SIGNER_INFO *si, int nid)
{
return (get_attribute(si->unauth_attr, nid));
}
static ASN1_TYPE *get_attribute(STACK_OF(X509_ATTRIBUTE) *sk, int nid)
{
int i;
X509_ATTRIBUTE *xa;
ASN1_OBJECT *o;
o = OBJ_nid2obj(nid);
if (!o || !sk)
return (NULL);
for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
xa = sk_X509_ATTRIBUTE_value(sk, i);
if (OBJ_cmp(xa->object, o) == 0) {
if (!xa->single && sk_ASN1_TYPE_num(xa->value.set))
return (sk_ASN1_TYPE_value(xa->value.set, 0));
else
return (NULL);
}
}
return (NULL);
}
ASN1_OCTET_STRING *PKCS7_digest_from_attributes(STACK_OF(X509_ATTRIBUTE) *sk)
{
ASN1_TYPE *astype;
if (!(astype = get_attribute(sk, NID_pkcs9_messageDigest)))
return NULL;
return astype->value.octet_string;
}
int PKCS7_set_signed_attributes(PKCS7_SIGNER_INFO *p7si,
STACK_OF(X509_ATTRIBUTE) *sk)
{
int i;
if (p7si->auth_attr != NULL)
sk_X509_ATTRIBUTE_pop_free(p7si->auth_attr, X509_ATTRIBUTE_free);
p7si->auth_attr = sk_X509_ATTRIBUTE_dup(sk);
if (p7si->auth_attr == NULL)
return 0;
for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
if ((sk_X509_ATTRIBUTE_set(p7si->auth_attr, i,
X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value
(sk, i))))
== NULL)
return (0);
}
return (1);
}
int PKCS7_set_attributes(PKCS7_SIGNER_INFO *p7si,
STACK_OF(X509_ATTRIBUTE) *sk)
{
int i;
if (p7si->unauth_attr != NULL)
sk_X509_ATTRIBUTE_pop_free(p7si->unauth_attr, X509_ATTRIBUTE_free);
p7si->unauth_attr = sk_X509_ATTRIBUTE_dup(sk);
if (p7si->unauth_attr == NULL)
return 0;
for (i = 0; i < sk_X509_ATTRIBUTE_num(sk); i++) {
if ((sk_X509_ATTRIBUTE_set(p7si->unauth_attr, i,
X509_ATTRIBUTE_dup(sk_X509_ATTRIBUTE_value
(sk, i))))
== NULL)
return (0);
}
return (1);
}
int PKCS7_add_signed_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
void *value)
{
return (add_attribute(&(p7si->auth_attr), nid, atrtype, value));
}
int PKCS7_add_attribute(PKCS7_SIGNER_INFO *p7si, int nid, int atrtype,
void *value)
{
return (add_attribute(&(p7si->unauth_attr), nid, atrtype, value));
}
static int add_attribute(STACK_OF(X509_ATTRIBUTE) **sk, int nid, int atrtype,
void *value)
{
X509_ATTRIBUTE *attr = NULL;
if (*sk == NULL) {
*sk = sk_X509_ATTRIBUTE_new_null();
if (*sk == NULL)
return 0;
new_attrib:
if (!(attr = X509_ATTRIBUTE_create(nid, atrtype, value)))
return 0;
if (!sk_X509_ATTRIBUTE_push(*sk, attr)) {
X509_ATTRIBUTE_free(attr);
return 0;
}
} else {
int i;
for (i = 0; i < sk_X509_ATTRIBUTE_num(*sk); i++) {
attr = sk_X509_ATTRIBUTE_value(*sk, i);
if (OBJ_obj2nid(attr->object) == nid) {
X509_ATTRIBUTE_free(attr);
attr = X509_ATTRIBUTE_create(nid, atrtype, value);
if (attr == NULL)
return 0;
if (!sk_X509_ATTRIBUTE_set(*sk, i, attr)) {
X509_ATTRIBUTE_free(attr);
return 0;
}
goto end;
}
}
goto new_attrib;
}
end:
return (1);
}
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