diff options
Diffstat (limited to 'openssl-1.1.0h/crypto/ts/ts_rsp_verify.c')
| -rw-r--r-- | openssl-1.1.0h/crypto/ts/ts_rsp_verify.c | 635 |
1 files changed, 635 insertions, 0 deletions
diff --git a/openssl-1.1.0h/crypto/ts/ts_rsp_verify.c b/openssl-1.1.0h/crypto/ts/ts_rsp_verify.c new file mode 100644 index 0000000..2755dd0 --- /dev/null +++ b/openssl-1.1.0h/crypto/ts/ts_rsp_verify.c @@ -0,0 +1,635 @@ +/* + * Copyright 2006-2016 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 "internal/cryptlib.h" +#include <openssl/objects.h> +#include <openssl/ts.h> +#include <openssl/pkcs7.h> +#include "ts_lcl.h" + +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 *cert); +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(const ASN1_OBJECT *req_oid, + const 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, + const 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); + +/* + * This must be large enough to hold all values in ts_status_text (with + * comma separator) or all text fields in ts_failure_info (also with comma). + */ +#define TS_STATUS_BUF_SIZE 256 + +/* + * Local mapping between response codes and descriptions. + */ +static const char *ts_status_text[] = { + "granted", + "grantedWithMods", + "rejection", + "waiting", + "revocationWarning", + "revocationNotification" +}; + +#define TS_STATUS_TEXT_SIZE OSSL_NELEM(ts_status_text) + +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"} +}; + + +/*- + * 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; + } + if (!PKCS7_type_is_signed(token)) { + TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_WRONG_CONTENT_TYPE); + goto err; + } + 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); + 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); + + if (!ts_verify_cert(store, certs, signer, &chain)) + goto err; + if (!ts_check_signing_certs(si, chain)) + goto err; + 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) + continue; + + j = PKCS7_signatureVerify(p7bio, token, si, signer); + if (j <= 0) { + TSerr(TS_F_TS_RESP_VERIFY_SIGNATURE, TS_R_SIGNATURE_FAILURE); + goto err; + } + + if (signer_out) { + *signer_out = signer; + X509_up_ref(signer); + } + 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 = NULL; + int i; + int ret = 0; + + *chain = NULL; + cert_ctx = X509_STORE_CTX_new(); + if (cert_ctx == NULL) { + TSerr(TS_F_TS_VERIFY_CERT, ERR_R_MALLOC_FAILURE); + goto err; + } + if (!X509_STORE_CTX_init(cert_ctx, store, signer, untrusted)) + goto end; + 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)); + goto err; + } + *chain = X509_STORE_CTX_get1_chain(cert_ctx); + ret = 1; + goto end; + +err: + ret = 0; + +end: + X509_STORE_CTX_free(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; + 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) { + 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; + unsigned char cert_sha1[SHA_DIGEST_LENGTH]; + + if (!cert_ids || !cert) + return -1; + + X509_digest(cert, EVP_sha1(), cert_sha1, NULL); + + /* 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); + + if (cid->hash->length == SHA_DIGEST_LENGTH + && memcmp(cid->hash->data, cert_sha1, SHA_DIGEST_LENGTH) == 0) { + ESS_ISSUER_SERIAL *is = cid->issuer_serial; + if (!is || !ts_issuer_serial_cmp(is, cert)) + return i; + } + } + + return -1; +} + +static int ts_issuer_serial_cmp(ESS_ISSUER_SERIAL *is, X509 *cert) +{ + GENERAL_NAME *issuer; + + if (!is || !cert || sk_GENERAL_NAME_num(is->issuer) != 1) + return -1; + + issuer = sk_GENERAL_NAME_value(is->issuer, 0); + if (issuer->type != GEN_DIRNAME + || X509_NAME_cmp(issuer->d.dirn, X509_get_issuer_name(cert))) + return -1; + + if (ASN1_INTEGER_cmp(is->serial, X509_get_serialNumber(cert))) + 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 = response->token; + TS_TST_INFO *tst_info = response->tst_info; + int ret = 0; + + if (!ts_check_status_info(response)) + goto err; + 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 = tst_info->tsa; + X509_ALGOR *md_alg = NULL; + unsigned char *imprint = NULL; + unsigned imprint_len = 0; + int ret = 0; + int flags = ctx->flags; + + /* Some options require us to also check the signature */ + if (((flags & TS_VFY_SIGNER) && tsa_name != NULL) + || (flags & TS_VFY_TSA_NAME)) { + flags |= TS_VFY_SIGNATURE; + } + + if ((flags & TS_VFY_SIGNATURE) + && !TS_RESP_verify_signature(token, ctx->certs, ctx->store, &signer)) + goto err; + if ((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; + } + if ((flags & TS_VFY_POLICY) + && !ts_check_policy(ctx->policy, tst_info)) + goto err; + if ((flags & TS_VFY_IMPRINT) + && !ts_check_imprints(ctx->md_alg, ctx->imprint, ctx->imprint_len, + tst_info)) + goto err; + if ((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; + if ((flags & TS_VFY_NONCE) + && !ts_check_nonces(ctx->nonce, tst_info)) + goto err; + if ((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; + } + if ((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 = response->status_info; + long status = ASN1_INTEGER_get(info->status); + const char *status_text = NULL; + char *embedded_status_text = NULL; + char failure_text[TS_STATUS_BUF_SIZE] = ""; + + if (status == 0 || status == 1) + return 1; + + /* There was an error, get the description in status_text. */ + if (0 <= status && status < (long) OSSL_NELEM(ts_status_text)) + status_text = ts_status_text[status]; + else + status_text = "unknown code"; + + if (sk_ASN1_UTF8STRING_num(info->text) > 0 + && (embedded_status_text = ts_get_status_text(info->text)) == NULL) + return 0; + + /* Fill in failure_text with the failure information. */ + if (info->failure_info) { + int i; + int first = 1; + for (i = 0; i < (int)OSSL_NELEM(ts_failure_info); ++i) { + if (ASN1_BIT_STRING_get_bit(info->failure_info, + ts_failure_info[i].code)) { + if (!first) + strcat(failure_text, ","); + else + first = 0; + strcat(failure_text, ts_failure_info[i].text); + } + } + } + if (failure_text[0] == '\0') + strcpy(failure_text, "unspecified"); + + 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; + int length = 0; + char *result = NULL; + char *p; + + for (i = 0; i < sk_ASN1_UTF8STRING_num(text); ++i) { + ASN1_UTF8STRING *current = sk_ASN1_UTF8STRING_value(text, i); + if (ASN1_STRING_length(current) > TS_MAX_STATUS_LENGTH - length - 1) + return NULL; + length += ASN1_STRING_length(current); + length += 1; /* separator character */ + } + if ((result = OPENSSL_malloc(length)) == NULL) { + TSerr(TS_F_TS_GET_STATUS_TEXT, ERR_R_MALLOC_FAILURE); + return NULL; + } + + 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_get0_data(current), length); + p += length; + } + *p = '\0'; + + return result; +} + +static int ts_check_policy(const ASN1_OBJECT *req_oid, + const TS_TST_INFO *tst_info) +{ + const ASN1_OBJECT *resp_oid = tst_info->policy_id; + + 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 = tst_info->msg_imprint; + X509_ALGOR *md_alg_resp = msg_imprint->hash_algo; + const EVP_MD *md; + EVP_MD_CTX *md_ctx = NULL; + unsigned char buffer[4096]; + int length; + + *md_alg = NULL; + *imprint = NULL; + + if ((*md_alg = X509_ALGOR_dup(md_alg_resp)) == NULL) + goto err; + if ((md = EVP_get_digestbyobj((*md_alg)->algorithm)) == NULL) { + TSerr(TS_F_TS_COMPUTE_IMPRINT, TS_R_UNSUPPORTED_MD_ALGORITHM); + goto err; + } + length = EVP_MD_size(md); + if (length < 0) + goto err; + *imprint_len = length; + if ((*imprint = OPENSSL_malloc(*imprint_len)) == NULL) { + TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); + goto err; + } + + md_ctx = EVP_MD_CTX_new(); + if (md_ctx == NULL) { + TSerr(TS_F_TS_COMPUTE_IMPRINT, ERR_R_MALLOC_FAILURE); + goto err; + } + if (!EVP_DigestInit(md_ctx, md)) + goto err; + while ((length = BIO_read(data, buffer, sizeof(buffer))) > 0) { + if (!EVP_DigestUpdate(md_ctx, buffer, length)) + goto err; + } + if (!EVP_DigestFinal(md_ctx, *imprint, NULL)) + goto err; + EVP_MD_CTX_free(md_ctx); + + return 1; + err: + EVP_MD_CTX_free(md_ctx); + X509_ALGOR_free(*md_alg); + OPENSSL_free(*imprint); + *imprint_len = 0; + *imprint = 0; + return 0; +} + +static int ts_check_imprints(X509_ALGOR *algor_a, + const unsigned char *imprint_a, unsigned len_a, + TS_TST_INFO *tst_info) +{ + TS_MSG_IMPRINT *b = tst_info->msg_imprint; + X509_ALGOR *algor_b = b->hash_algo; + int ret = 0; + + if (algor_a) { + 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; + } + + ret = len_a == (unsigned)ASN1_STRING_length(b->hashed_msg) && + memcmp(imprint_a, ASN1_STRING_get0_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 = tst_info->nonce; + + 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; + + if (tsa_name->type == GEN_DIRNAME + && X509_name_cmp(tsa_name->d.dirn, X509_get_subject_name(signer)) == 0) + return 1; + 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; + if (found) + break; + /* + * 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); + } + 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; +} |