blob: e1f3b534afbc9523c09b4f93a999fb01c2e5e785 [file] [log] [blame]
/* crypto/ts/ts_resp_verify.c */
/* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL
* project 2002.
*/
/* ====================================================================
* Copyright (c) 2006 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
* licensing@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 <stdio.h>
#include "cryptlib.h"
#include <openssl/objects.h>
#include <openssl/ts.h>
#include <openssl/pkcs7.h>
/* Private function declarations. */
static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
X509 *signer, STACK_OF(X509) **chain);
static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain);
static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si);
static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert);
static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo);
static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx,
PKCS7 *token, TS_TST_INFO *tst_info);
static int TS_check_status_info(TS_RESP *response);
static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text);
static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info);
static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
X509_ALGOR **md_alg,
unsigned char **imprint, unsigned *imprint_len);
static int TS_check_imprints(X509_ALGOR *algor_a,
unsigned char *imprint_a, unsigned len_a,
TS_TST_INFO *tst_info);
static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info);
static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer);
static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name);
/*
* Local mapping between response codes and descriptions.
* Don't forget to change TS_STATUS_BUF_SIZE when modifying
* the elements of this array.
*/
static const char *TS_status_text[] =
{ "granted",
"grantedWithMods",
"rejection",
"waiting",
"revocationWarning",
"revocationNotification" };
#define TS_STATUS_TEXT_SIZE (sizeof(TS_status_text)/sizeof(*TS_status_text))
/*
* This must be greater or equal to the sum of the strings in TS_status_text
* plus the number of its elements.
*/
#define TS_STATUS_BUF_SIZE 256
static struct
{
int code;
const char *text;
} TS_failure_info[] =
{ { TS_INFO_BAD_ALG, "badAlg" },
{ TS_INFO_BAD_REQUEST, "badRequest" },
{ TS_INFO_BAD_DATA_FORMAT, "badDataFormat" },
{ TS_INFO_TIME_NOT_AVAILABLE, "timeNotAvailable" },
{ TS_INFO_UNACCEPTED_POLICY, "unacceptedPolicy" },
{ TS_INFO_UNACCEPTED_EXTENSION, "unacceptedExtension" },
{ TS_INFO_ADD_INFO_NOT_AVAILABLE, "addInfoNotAvailable" },
{ TS_INFO_SYSTEM_FAILURE, "systemFailure" } };
#define TS_FAILURE_INFO_SIZE (sizeof(TS_failure_info) / \
sizeof(*TS_failure_info))
/* Functions for verifying a signed TS_TST_INFO structure. */
/*
* This function carries out the following tasks:
* - Checks if there is one and only one signer.
* - Search for the signing certificate in 'certs' and in the response.
* - Check the extended key usage and key usage fields of the signer
* certificate (done by the path validation).
* - Build and validate the certificate path.
* - Check if the certificate path meets the requirements of the
* SigningCertificate ESS signed attribute.
* - Verify the signature value.
* - Returns the signer certificate in 'signer', if 'signer' is not NULL.
*/
int TS_RESP_verify_signature(PKCS7 *token, STACK_OF(X509) *certs,
X509_STORE *store, X509 **signer_out)
{
STACK_OF(PKCS7_SIGNER_INFO) *sinfos = NULL;
PKCS7_SIGNER_INFO *si;
STACK_OF(X509) *signers = NULL;
X509 *signer;
STACK_OF(X509) *chain = NULL;
char buf[4096];
int i, j = 0, ret = 0;
BIO *p7bio = NULL;
/* Some sanity checks first. */
if (!token)
{
TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_INVALID_NULL_POINTER);
goto err;
}
/* Check for the correct content type */
if(!PKCS7_type_is_signed(token))
{
TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE);
goto err;
}
/* Check if there is one and only one signer. */
sinfos = PKCS7_get_signer_info(token);
if (!sinfos || sk_PKCS7_SIGNER_INFO_num(sinfos) != 1)
{
TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE,
TS_R_THERE_MUST_BE_ONE_SIGNER);
goto err;
}
si = sk_PKCS7_SIGNER_INFO_value(sinfos, 0);
/* Check for no content: no data to verify signature. */
if (PKCS7_get_detached(token))
{
TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_NO_CONTENT);
goto err;
}
/* Get hold of the signer certificate, search only internal
certificates if it was requested. */
signers = PKCS7_get0_signers(token, certs, 0);
if (!signers || sk_X509_num(signers) != 1) goto err;
signer = sk_X509_value(signers, 0);
/* Now verify the certificate. */
if (!TS_verify_cert(store, certs, signer, &chain)) goto err;
/* Check if the signer certificate is consistent with the
ESS extension. */
if (!TS_check_signing_certs(si, chain)) goto err;
/* Creating the message digest. */
p7bio = PKCS7_dataInit(token, NULL);
/* We now have to 'read' from p7bio to calculate digests etc. */
while ((i = BIO_read(p7bio,buf,sizeof(buf))) > 0);
/* Verifying the signature. */
j = PKCS7_signatureVerify(p7bio, token, si, signer);
if (j <= 0)
{
TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE);
goto err;
}
/* Return the signer certificate if needed. */
if (signer_out)
{
*signer_out = signer;
CRYPTO_add(&signer->references, 1, CRYPTO_LOCK_X509);
}
ret = 1;
err:
BIO_free_all(p7bio);
sk_X509_pop_free(chain, X509_free);
sk_X509_free(signers);
return ret;
}
/*
* The certificate chain is returned in chain. Caller is responsible for
* freeing the vector.
*/
static int TS_verify_cert(X509_STORE *store, STACK_OF(X509) *untrusted,
X509 *signer, STACK_OF(X509) **chain)
{
X509_STORE_CTX cert_ctx;
int i;
int ret = 1;
/* chain is an out argument. */
*chain = NULL;
X509_STORE_CTX_init(&cert_ctx, store, signer, untrusted);
X509_STORE_CTX_set_purpose(&cert_ctx, X509_PURPOSE_TIMESTAMP_SIGN);
i = X509_verify_cert(&cert_ctx);
if (i <= 0)
{
int j = X509_STORE_CTX_get_error(&cert_ctx);
TSerr(TS_F_TS_VERIFY_CERT, TS_R_CERTIFICATE_VERIFY_ERROR);
ERR_add_error_data(2, "Verify error:",
X509_verify_cert_error_string(j));
ret = 0;
}
else
{
/* Get a copy of the certificate chain. */
*chain = X509_STORE_CTX_get1_chain(&cert_ctx);
}
X509_STORE_CTX_cleanup(&cert_ctx);
return ret;
}
static int TS_check_signing_certs(PKCS7_SIGNER_INFO *si, STACK_OF(X509) *chain)
{
ESS_SIGNING_CERT *ss = ESS_get_signing_cert(si);
STACK_OF(ESS_CERT_ID) *cert_ids = NULL;
X509 *cert;
int i = 0;
int ret = 0;
if (!ss) goto err;
cert_ids = ss->cert_ids;
/* The signer certificate must be the first in cert_ids. */
cert = sk_X509_value(chain, 0);
if (TS_find_cert(cert_ids, cert) != 0) goto err;
/* Check the other certificates of the chain if there are more
than one certificate ids in cert_ids. */
if (sk_ESS_CERT_ID_num(cert_ids) > 1)
{
/* All the certificates of the chain must be in cert_ids. */
for (i = 1; i < sk_X509_num(chain); ++i)
{
cert = sk_X509_value(chain, i);
if (TS_find_cert(cert_ids, cert) < 0) goto err;
}
}
ret = 1;
err:
if (!ret)
TSerr(TS_F_TS_CHECK_SIGNING_CERTS,
TS_R_ESS_SIGNING_CERTIFICATE_ERROR);
ESS_SIGNING_CERT_free(ss);
return ret;
}
static ESS_SIGNING_CERT *ESS_get_signing_cert(PKCS7_SIGNER_INFO *si)
{
ASN1_TYPE *attr;
const unsigned char *p;
attr = PKCS7_get_signed_attribute(si,
NID_id_smime_aa_signingCertificate);
if (!attr) return NULL;
p = attr->value.sequence->data;
return d2i_ESS_SIGNING_CERT(NULL, &p, attr->value.sequence->length);
}
/* Returns < 0 if certificate is not found, certificate index otherwise. */
static int TS_find_cert(STACK_OF(ESS_CERT_ID) *cert_ids, X509 *cert)
{
int i;
if (!cert_ids || !cert) return -1;
/* Recompute SHA1 hash of certificate if necessary (side effect). */
X509_check_purpose(cert, -1, 0);
/* Look for cert in the cert_ids vector. */
for (i = 0; i < sk_ESS_CERT_ID_num(cert_ids); ++i)
{
ESS_CERT_ID *cid = sk_ESS_CERT_ID_value(cert_ids, i);
/* Check the SHA-1 hash first. */
if (cid->hash->length == sizeof(cert->sha1_hash)
&& !memcmp(cid->hash->data, cert->sha1_hash,
sizeof(cert->sha1_hash)))
{
/* Check the issuer/serial as well if specified. */
ESS_ISSUER_SERIAL *is = cid->issuer_serial;
if (!is || !TS_issuer_serial_cmp(is, cert->cert_info))
return i;
}
}
return -1;
}
static int TS_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509_CINF *cinfo)
{
GENERAL_NAME *issuer;
if (!is || !cinfo || sk_GENERAL_NAME_num(is->issuer) != 1) return -1;
/* Check the issuer first. It must be a directory name. */
issuer = sk_GENERAL_NAME_value(is->issuer, 0);
if (issuer->type != GEN_DIRNAME
|| X509_NAME_cmp(issuer->d.dirn, cinfo->issuer))
return -1;
/* Check the serial number, too. */
if (ASN1_INTEGER_cmp(is->serial, cinfo->serialNumber))
return -1;
return 0;
}
/*
* Verifies whether 'response' contains a valid response with regards
* to the settings of the context:
* - Gives an error message if the TS_TST_INFO is not present.
* - Calls _TS_RESP_verify_token to verify the token content.
*/
int TS_RESP_verify_response(TS_VERIFY_CTX *ctx, TS_RESP *response)
{
PKCS7 *token = TS_RESP_get_token(response);
TS_TST_INFO *tst_info = TS_RESP_get_tst_info(response);
int ret = 0;
/* Check if we have a successful TS_TST_INFO object in place. */
if (!TS_check_status_info(response)) goto err;
/* Check the contents of the time stamp token. */
if (!int_TS_RESP_verify_token(ctx, token, tst_info))
goto err;
ret = 1;
err:
return ret;
}
/*
* Tries to extract a TS_TST_INFO structure from the PKCS7 token and
* calls the internal int_TS_RESP_verify_token function for verifying it.
*/
int TS_RESP_verify_token(TS_VERIFY_CTX *ctx, PKCS7 *token)
{
TS_TST_INFO *tst_info = PKCS7_to_TS_TST_INFO(token);
int ret = 0;
if (tst_info)
{
ret = int_TS_RESP_verify_token(ctx, token, tst_info);
TS_TST_INFO_free(tst_info);
}
return ret;
}
/*
* Verifies whether the 'token' contains a valid time stamp token
* with regards to the settings of the context. Only those checks are
* carried out that are specified in the context:
* - Verifies the signature of the TS_TST_INFO.
* - Checks the version number of the response.
* - Check if the requested and returned policies math.
* - Check if the message imprints are the same.
* - Check if the nonces are the same.
* - Check if the TSA name matches the signer.
* - Check if the TSA name is the expected TSA.
*/
static int int_TS_RESP_verify_token(TS_VERIFY_CTX *ctx,
PKCS7 *token, TS_TST_INFO *tst_info)
{
X509 *signer = NULL;
GENERAL_NAME *tsa_name = TS_TST_INFO_get_tsa(tst_info);
X509_ALGOR *md_alg = NULL;
unsigned char *imprint = NULL;
unsigned imprint_len = 0;
int ret = 0;
/* Verify the signature. */
if ((ctx->flags & TS_VFY_SIGNATURE)
&& !TS_RESP_verify_signature(token, ctx->certs, ctx->store,
&signer))
goto err;
/* Check version number of response. */
if ((ctx->flags & TS_VFY_VERSION)
&& TS_TST_INFO_get_version(tst_info) != 1)
{
TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_UNSUPPORTED_VERSION);
goto err;
}
/* Check policies. */
if ((ctx->flags & TS_VFY_POLICY)
&& !TS_check_policy(ctx->policy, tst_info))
goto err;
/* Check message imprints. */
if ((ctx->flags & TS_VFY_IMPRINT)
&& !TS_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len,
tst_info))
goto err;
/* Compute and check message imprints. */
if ((ctx->flags & TS_VFY_DATA)
&& (!TS_compute_imprint(ctx->data, tst_info,
&md_alg, &imprint, &imprint_len)
|| !TS_check_imprints(md_alg, imprint, imprint_len, tst_info)))
goto err;
/* Check nonces. */
if ((ctx->flags & TS_VFY_NONCE)
&& !TS_check_nonces(ctx->nonce, tst_info))
goto err;
/* Check whether TSA name and signer certificate match. */
if ((ctx->flags & TS_VFY_SIGNER)
&& tsa_name && !TS_check_signer_name(tsa_name, signer))
{
TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_NAME_MISMATCH);
goto err;
}
/* Check whether the TSA is the expected one. */
if ((ctx->flags & TS_VFY_TSA_NAME)
&& !TS_check_signer_name(ctx->tsa_name, signer))
{
TSerr(TS_F_INT_TS_RESP_VERIFY_TOKEN, TS_R_TSA_UNTRUSTED);
goto err;
}
ret = 1;
err:
X509_free(signer);
X509_ALGOR_free(md_alg);
OPENSSL_free(imprint);
return ret;
}
static int TS_check_status_info(TS_RESP *response)
{
TS_STATUS_INFO *info = TS_RESP_get_status_info(response);
long status = ASN1_INTEGER_get(info->status);
const char *status_text = NULL;
char *embedded_status_text = NULL;
char failure_text[TS_STATUS_BUF_SIZE] = "";
/* Check if everything went fine. */
if (status == 0 || status == 1) return 1;
/* There was an error, get the description in status_text. */
if (0 <= status && status < (long)TS_STATUS_TEXT_SIZE)
status_text = TS_status_text[status];
else
status_text = "unknown code";
/* Set the embedded_status_text to the returned description. */
if (sk_ASN1_UTF8STRING_num(info->text) > 0
&& !(embedded_status_text = TS_get_status_text(info->text)))
return 0;
/* Filling in failure_text with the failure information. */
if (info->failure_info)
{
int i;
int first = 1;
for (i = 0; i < (int)TS_FAILURE_INFO_SIZE; ++i)
{
if (ASN1_BIT_STRING_get_bit(info->failure_info,
TS_failure_info[i].code))
{
if (!first)
strcpy(failure_text, ",");
else
first = 0;
strcat(failure_text, TS_failure_info[i].text);
}
}
}
if (failure_text[0] == '\0')
strcpy(failure_text, "unspecified");
/* Making up the error string. */
TSerr(TS_F_TS_CHECK_STATUS_INFO, TS_R_NO_TIME_STAMP_TOKEN);
ERR_add_error_data(6,
"status code: ", status_text,
", status text: ", embedded_status_text ?
embedded_status_text : "unspecified",
", failure codes: ", failure_text);
OPENSSL_free(embedded_status_text);
return 0;
}
static char *TS_get_status_text(STACK_OF(ASN1_UTF8STRING) *text)
{
int i;
unsigned int length = 0;
char *result = NULL;
char *p;
/* Determine length first. */
for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i)
{
ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
length += ASN1_STRING_length(current);
length += 1; /* separator character */
}
/* Allocate memory (closing '\0' included). */
if (!(result = OPENSSL_malloc(length)))
{
TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE);
return NULL;
}
/* Concatenate the descriptions. */
for (i = 0, p = result; i < sk_ASN1_UTF8STRING_num(text); ++i)
{
ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i);
length = ASN1_STRING_length(current);
if (i > 0) *p++ = '/';
strncpy(p, (const char *)ASN1_STRING_data(current), length);
p += length;
}
/* We do have space for this, too. */
*p = '\0';
return result;
}
static int TS_check_policy(ASN1_OBJECT *req_oid, TS_TST_INFO *tst_info)
{
ASN1_OBJECT *resp_oid = TS_TST_INFO_get_policy_id(tst_info);
if (OBJ_cmp(req_oid, resp_oid) != 0)
{
TSerr(TS_F_TS_CHECK_POLICY, TS_R_POLICY_MISMATCH);
return 0;
}
return 1;
}
static int TS_compute_imprint(BIO *data, TS_TST_INFO *tst_info,
X509_ALGOR **md_alg,
unsigned char **imprint, unsigned *imprint_len)
{
TS_MSG_IMPRINT *msg_imprint = TS_TST_INFO_get_msg_imprint(tst_info);
X509_ALGOR *md_alg_resp = TS_MSG_IMPRINT_get_algo(msg_imprint);
const EVP_MD *md;
EVP_MD_CTX md_ctx;
unsigned char buffer[4096];
int length;
*md_alg = NULL;
*imprint = NULL;
/* Return the MD algorithm of the response. */
if (!(*md_alg = X509_ALGOR_dup(md_alg_resp))) goto err;
/* Getting the MD object. */
if (!(md = EVP_get_digestbyobj((*md_alg)->algorithm)))
{
TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM);
goto err;
}
/* Compute message digest. */
length = EVP_MD_size(md);
if (length < 0)
goto err;
*imprint_len = length;
if (!(*imprint = OPENSSL_malloc(*imprint_len)))
{
TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE);
goto err;
}
EVP_DigestInit(&md_ctx, md);
while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0)
{
EVP_DigestUpdate(&md_ctx, buffer, length);
}
EVP_DigestFinal(&md_ctx, *imprint, NULL);
return 1;
err:
X509_ALGOR_free(*md_alg);
OPENSSL_free(*imprint);
*imprint_len = 0;
return 0;
}
static int TS_check_imprints(X509_ALGOR *algor_a,
unsigned char *imprint_a, unsigned len_a,
TS_TST_INFO *tst_info)
{
TS_MSG_IMPRINT *b = TS_TST_INFO_get_msg_imprint(tst_info);
X509_ALGOR *algor_b = TS_MSG_IMPRINT_get_algo(b);
int ret = 0;
/* algor_a is optional. */
if (algor_a)
{
/* Compare algorithm OIDs. */
if (OBJ_cmp(algor_a->algorithm, algor_b->algorithm)) goto err;
/* The parameter must be NULL in both. */
if ((algor_a->parameter
&& ASN1_TYPE_get(algor_a->parameter) != V_ASN1_NULL)
|| (algor_b->parameter
&& ASN1_TYPE_get(algor_b->parameter) != V_ASN1_NULL))
goto err;
}
/* Compare octet strings. */
ret = len_a == (unsigned) ASN1_STRING_length(b->hashed_msg) &&
memcmp(imprint_a, ASN1_STRING_data(b->hashed_msg), len_a) == 0;
err:
if (!ret)
TSerr(TS_F_TS_CHECK_IMPRINTS, TS_R_MESSAGE_IMPRINT_MISMATCH);
return ret;
}
static int TS_check_nonces(const ASN1_INTEGER *a, TS_TST_INFO *tst_info)
{
const ASN1_INTEGER *b = TS_TST_INFO_get_nonce(tst_info);
/* Error if nonce is missing. */
if (!b)
{
TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_NOT_RETURNED);
return 0;
}
/* No error if a nonce is returned without being requested. */
if (ASN1_INTEGER_cmp(a, b) != 0)
{
TSerr(TS_F_TS_CHECK_NONCES, TS_R_NONCE_MISMATCH);
return 0;
}
return 1;
}
/* Check if the specified TSA name matches either the subject
or one of the subject alternative names of the TSA certificate. */
static int TS_check_signer_name(GENERAL_NAME *tsa_name, X509 *signer)
{
STACK_OF(GENERAL_NAME) *gen_names = NULL;
int idx = -1;
int found = 0;
/* Check the subject name first. */
if (tsa_name->type == GEN_DIRNAME
&& X509_name_cmp(tsa_name->d.dirn, signer->cert_info->subject) == 0)
return 1;
/* Check all the alternative names. */
gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
NULL, &idx);
while (gen_names != NULL
&& !(found = TS_find_name(gen_names, tsa_name) >= 0))
{
/* Get the next subject alternative name,
although there should be no more than one. */
GENERAL_NAMES_free(gen_names);
gen_names = X509_get_ext_d2i(signer, NID_subject_alt_name,
NULL, &idx);
}
if (gen_names) GENERAL_NAMES_free(gen_names);
return found;
}
/* Returns 1 if name is in gen_names, 0 otherwise. */
static int TS_find_name(STACK_OF(GENERAL_NAME) *gen_names, GENERAL_NAME *name)
{
int i, found;
for (i = 0, found = 0; !found && i < sk_GENERAL_NAME_num(gen_names);
++i)
{
GENERAL_NAME *current = sk_GENERAL_NAME_value(gen_names, i);
found = GENERAL_NAME_cmp(current, name) == 0;
}
return found ? i - 1 : -1;
}