/* * Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation * * Author: Nikos Mavroyanopoulos * * This file is part of GNUTLS. * * The GNUTLS library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * USA * */ /* Some of the stuff needed for Certificate authentication is contained * in this file. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "x509/compat.h" #include "x509/x509.h" #include "x509/mpi.h" /** * gnutls_certificate_free_keys - Used to free all the keys from a gnutls_certificate_credentials_t structure * @sc: is an #gnutls_certificate_credentials_t structure. * * This function will delete all the keys and the certificates associated * with the given credentials. This function must not be called when a * TLS negotiation that uses the credentials is in progress. * **/ void gnutls_certificate_free_keys(gnutls_certificate_credentials_t sc) { uint i, j; for (i = 0; i < sc->ncerts; i++) { for (j = 0; j < sc->cert_list_length[i]; j++) { _gnutls_gcert_deinit(&sc->cert_list[i][j]); } gnutls_free(sc->cert_list[i]); } gnutls_free(sc->cert_list_length); sc->cert_list_length = NULL; gnutls_free(sc->cert_list); sc->cert_list = NULL; for (i = 0; i < sc->ncerts; i++) { _gnutls_gkey_deinit(&sc->pkey[i]); } gnutls_free(sc->pkey); sc->pkey = NULL; sc->ncerts = 0; } /** * gnutls_certificate_free_cas - Used to free all the CAs from a gnutls_certificate_credentials_t structure * @sc: is an #gnutls_certificate_credentials_t structure. * * This function will delete all the CAs associated * with the given credentials. Servers that do not use * gnutls_certificate_verify_peers2() may call this to * save some memory. * **/ void gnutls_certificate_free_cas(gnutls_certificate_credentials_t sc) { uint j; for (j = 0; j < sc->x509_ncas; j++) { gnutls_x509_crt_deinit(sc->x509_ca_list[j]); } sc->x509_ncas = 0; gnutls_free(sc->x509_ca_list); sc->x509_ca_list = NULL; } /** * gnutls_certificate_free_ca_names - Used to free all the CA names from a gnutls_certificate_credentials_t structure * @sc: is an #gnutls_certificate_credentials_t structure. * * This function will delete all the CA name in the * given credentials. Clients may call this to save some memory * since in client side the CA names are not used. * * CA names are used by servers to advertize the CAs they * support to clients. * **/ void gnutls_certificate_free_ca_names(gnutls_certificate_credentials_t sc) { _gnutls_free_datum(&sc->x509_rdn_sequence); } /*- * _gnutls_certificate_get_dh_params - Returns the DH parameters pointer * @sc: is an #gnutls_certificate_credentials_t structure. * * This function will return the dh parameters pointer. This will read the * credentials structure, and cache the output to the session, so later * calls would not examine the credentials (or call a callback). * -*/ gnutls_dh_params_t _gnutls_certificate_get_dh_params(const gnutls_certificate_credentials_t sc, gnutls_session_t session) { gnutls_params_st params; int ret; if (session->internals.params.cert_dh_params) { return session->internals.params.cert_dh_params; } if (sc->dh_params) { session->internals.params.cert_dh_params = sc->dh_params; } else if (sc->params_func) { ret = sc->params_func(session, GNUTLS_PARAMS_DH, ¶ms); if (ret == 0 && params.type == GNUTLS_PARAMS_DH) { session->internals.params.cert_dh_params = params.params.dh; session->internals.params.free_cert_dh_params = params.deinit; } } return session->internals.params.cert_dh_params; } /*- * _gnutls_certificate_get_rsa_params - Returns the RSA parameters pointer * @sc: is an #gnutls_certificate_credentials_t structure. * * This function will return the rsa parameters pointer. * -*/ gnutls_rsa_params_t _gnutls_certificate_get_rsa_params(const gnutls_certificate_credentials_t sc, gnutls_session_t session) { gnutls_params_st params; int ret; if (session->internals.params.rsa_params) { return session->internals.params.rsa_params; } if (sc->rsa_params) { session->internals.params.rsa_params = sc->rsa_params; } else if (sc->params_func) { ret = sc->params_func(session, GNUTLS_PARAMS_RSA_EXPORT, ¶ms); if (ret == 0 && params.type == GNUTLS_PARAMS_RSA_EXPORT) { session->internals.params.rsa_params = params.params.rsa_export; session->internals.params.free_rsa_params = params.deinit; } } return session->internals.params.rsa_params; } /** * gnutls_certificate_free_credentials - Used to free an allocated gnutls_certificate_credentials_t structure * @sc: is an #gnutls_certificate_credentials_t structure. * * This structure is complex enough to manipulate directly thus * this helper function is provided in order to free (deallocate) it. * * This function does not free any temporary parameters associated * with this structure (ie RSA and DH parameters are not freed by * this function). **/ void gnutls_certificate_free_credentials(gnutls_certificate_credentials_t sc) { gnutls_certificate_free_keys(sc); gnutls_certificate_free_cas(sc); gnutls_certificate_free_ca_names(sc); #ifdef ENABLE_PKI gnutls_certificate_free_crls(sc); #endif _gnutls_free_datum(&sc->keyring); gnutls_free(sc); } /** * gnutls_certificate_allocate_credentials - Used to allocate a gnutls_certificate_credentials_t structure * @res: is a pointer to an #gnutls_certificate_credentials_t structure. * * This structure is complex enough to manipulate directly thus * this helper function is provided in order to allocate it. * * Returns 0 on success. **/ int gnutls_certificate_allocate_credentials(gnutls_certificate_credentials_t * res) { *res = gnutls_calloc(1, sizeof(certificate_credentials_st)); if (*res == NULL) return GNUTLS_E_MEMORY_ERROR; (*res)->verify_bits = DEFAULT_VERIFY_BITS; (*res)->verify_depth = DEFAULT_VERIFY_DEPTH; return 0; } /* returns the KX algorithms that are supported by a * certificate. (Eg a certificate with RSA params, supports * GNUTLS_KX_RSA algorithm). * This function also uses the KeyUsage field of the certificate * extensions in order to disable unneded algorithms. */ int _gnutls_selected_cert_supported_kx(gnutls_session_t session, gnutls_kx_algorithm_t ** alg, int *alg_size) { gnutls_kx_algorithm_t kx; gnutls_pk_algorithm_t pk; gnutls_kx_algorithm_t kxlist[MAX_ALGOS]; gnutls_cert *cert; int i; if (session->internals.selected_cert_list_length == 0) { *alg_size = 0; *alg = NULL; return 0; } cert = &session->internals.selected_cert_list[0]; i = 0; for (kx = 0; kx < MAX_ALGOS; kx++) { pk = _gnutls_map_pk_get_pk(kx); if (pk == cert->subject_pk_algorithm) { /* then check key usage */ if (_gnutls_check_key_usage(cert, kx) == 0) { kxlist[i] = kx; i++; } } } if (i == 0) { gnutls_assert(); return GNUTLS_E_INVALID_REQUEST; } *alg = gnutls_calloc(1, sizeof(gnutls_kx_algorithm_t) * i); if (*alg == NULL) return GNUTLS_E_MEMORY_ERROR; *alg_size = i; memcpy(*alg, kxlist, i * sizeof(gnutls_kx_algorithm_t)); return 0; } /** * gnutls_certificate_server_set_request - Used to set whether to request a client certificate * @session: is an #gnutls_session_t structure. * @req: is one of GNUTLS_CERT_REQUEST, GNUTLS_CERT_REQUIRE * * This function specifies if we (in case of a server) are going * to send a certificate request message to the client. If @req * is GNUTLS_CERT_REQUIRE then the server will return an error if * the peer does not provide a certificate. If you do not * call this function then the client will not be asked to * send a certificate. **/ void gnutls_certificate_server_set_request(gnutls_session_t session, gnutls_certificate_request_t req) { session->internals.send_cert_req = req; } /** * gnutls_certificate_client_set_retrieve_function - Used to set a callback to retrieve the certificate * @cred: is a #gnutls_certificate_credentials_t structure. * @func: is the callback function * * This function sets a callback to be called in order to retrieve the certificate * to be used in the handshake. * The callback's function prototype is: * int (*callback)(gnutls_session_t, const gnutls_datum_t* req_ca_dn, int nreqs, * gnutls_pk_algorithm_t* pk_algos, int pk_algos_length, gnutls_retr_st* st); * * @st should contain the certificates and private keys. * * @req_ca_cert, is only used in X.509 certificates. * Contains a list with the CA names that the server considers trusted. * Normally we should send a certificate that is signed * by one of these CAs. These names are DER encoded. To get a more * meaningful value use the function gnutls_x509_rdn_get(). * * @pk_algos, contains a list with server's acceptable signature algorithms. * The certificate returned should support the server's given algorithms. * * If the callback function is provided then gnutls will call it, in the * handshake, after the certificate request message has been received. * * The callback function should set the certificate list to be sent, and * return 0 on success. If no certificate was selected then the number of certificates * should be set to zero. The value (-1) indicates error and the handshake * will be terminated. **/ void gnutls_certificate_client_set_retrieve_function (gnutls_certificate_credentials_t cred, gnutls_certificate_client_retrieve_function * func) { cred->client_get_cert_callback = func; } /** * gnutls_certificate_server_set_retrieve_function - Used to set a callback to retrieve the certificate * @cred: is a #gnutls_certificate_credentials_t structure. * @func: is the callback function * * This function sets a callback to be called in order to retrieve the certificate * to be used in the handshake. * The callback's function prototype is: * int (*callback)(gnutls_session_t, gnutls_retr_st* st); * * @st should contain the certificates and private keys. * * If the callback function is provided then gnutls will call it, in the * handshake, after the certificate request message has been received. * * The callback function should set the certificate list to be sent, and * return 0 on success. The value (-1) indicates error and the handshake * will be terminated. **/ void gnutls_certificate_server_set_retrieve_function (gnutls_certificate_credentials_t cred, gnutls_certificate_server_retrieve_function * func) { cred->server_get_cert_callback = func; } /* These are set by the gnutls_extra library's initialization function. */ OPENPGP_KEY_CREATION_TIME_FUNC _E_gnutls_openpgp_get_raw_key_creation_time = NULL; OPENPGP_KEY_EXPIRATION_TIME_FUNC _E_gnutls_openpgp_get_raw_key_expiration_time = NULL; OPENPGP_VERIFY_KEY_FUNC _E_gnutls_openpgp_verify_key = NULL; /*- * _gnutls_openpgp_cert_verify_peers - This function returns the peer's certificate status * @session: is a gnutls session * * This function will try to verify the peer's certificate and return its status (TRUSTED, INVALID etc.). * Returns a negative error code in case of an error, or GNUTLS_E_NO_CERTIFICATE_FOUND if no certificate was sent. * -*/ int _gnutls_openpgp_cert_verify_peers(gnutls_session_t session, unsigned int *status) { cert_auth_info_t info; gnutls_certificate_credentials_t cred; int peer_certificate_list_size, ret; CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, GNUTLS_E_INVALID_REQUEST); info = _gnutls_get_auth_info(session); if (info == NULL) return GNUTLS_E_INVALID_REQUEST; cred = _gnutls_get_cred(session->key, GNUTLS_CRD_CERTIFICATE, NULL); if (cred == NULL) { gnutls_assert(); return GNUTLS_E_INSUFFICIENT_CREDENTIALS; } if (info->raw_certificate_list == NULL || info->ncerts == 0) { gnutls_assert(); return GNUTLS_E_NO_CERTIFICATE_FOUND; } /* generate a list of gnutls_certs based on the auth info * raw certs. */ peer_certificate_list_size = info->ncerts; if (peer_certificate_list_size != 1) { gnutls_assert(); return GNUTLS_E_INTERNAL_ERROR; } /* Verify certificate */ if (_E_gnutls_openpgp_verify_key == NULL) { gnutls_assert(); return GNUTLS_E_INIT_LIBEXTRA; } ret = _E_gnutls_openpgp_verify_key(cred, &info->raw_certificate_list[0], peer_certificate_list_size, status); if (ret < 0) { gnutls_assert(); return ret; } return 0; } /** * gnutls_certificate_verify_peers2 - This function returns the peer's certificate verification status * @session: is a gnutls session * @status: is the output of the verification * * This function will try to verify the peer's certificate and return its status (trusted, invalid etc.). * The value of @status should be one or more of the gnutls_certificate_status_t * enumerated elements bitwise or'd. To avoid denial of service attacks * some default upper limits regarding the certificate key size and * chain size are set. To override them use gnutls_certificate_set_verify_limits(). * * Note that you must also check the peer's name in order to * check if the verified certificate belongs to the actual peer. * * Returns a negative error code on error and zero on success. * * This is the same as gnutls_x509_verify_certificate() and * uses the loaded CAs in the credentials as trusted CAs. **/ int gnutls_certificate_verify_peers2(gnutls_session_t session, unsigned int *status) { cert_auth_info_t info; CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, GNUTLS_E_INVALID_REQUEST); info = _gnutls_get_auth_info(session); if (info == NULL) { return GNUTLS_E_NO_CERTIFICATE_FOUND; } if (info->raw_certificate_list == NULL || info->ncerts == 0) return GNUTLS_E_NO_CERTIFICATE_FOUND; switch (gnutls_certificate_type_get(session)) { case GNUTLS_CRT_X509: return _gnutls_x509_cert_verify_peers(session, status); case GNUTLS_CRT_OPENPGP: return _gnutls_openpgp_cert_verify_peers(session, status); default: return GNUTLS_E_INVALID_REQUEST; } } /*- * gnutls_certificate_verify_peers - This function returns the peer's certificate verification status * @session: is a gnutls session * * This function will try to verify the peer's certificate and return its status (trusted, invalid etc.). * However you must also check the peer's name in order to check if the verified certificate belongs to the * actual peer. * * The return value should be one or more of the gnutls_certificate_status_t * enumerated elements bitwise or'd, or a negative value on error. * * This is the same as gnutls_x509_verify_certificate(). * -*/ int gnutls_certificate_verify_peers(gnutls_session_t session) { unsigned int status; int ret; ret = gnutls_certificate_verify_peers2(session, &status); if (ret < 0) { gnutls_assert(); return ret; } return status; } /** * gnutls_certificate_expiration_time_peers - This function returns the peer's certificate expiration time * @session: is a gnutls session * * This function will return the peer's certificate expiration time. * * Returns (time_t) -1 on error. * **/ time_t gnutls_certificate_expiration_time_peers(gnutls_session_t session) { cert_auth_info_t info; CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, GNUTLS_E_INVALID_REQUEST); info = _gnutls_get_auth_info(session); if (info == NULL) { return (time_t) - 1; } if (info->raw_certificate_list == NULL || info->ncerts == 0) { gnutls_assert(); return (time_t) - 1; } switch (gnutls_certificate_type_get(session)) { case GNUTLS_CRT_X509: return _gnutls_x509_get_raw_crt_expiration_time(&info-> raw_certificate_list [0]); case GNUTLS_CRT_OPENPGP: if (_E_gnutls_openpgp_get_raw_key_expiration_time == NULL) return (time_t) - 1; return _E_gnutls_openpgp_get_raw_key_expiration_time(&info-> raw_certificate_list [0]); default: return (time_t) - 1; } } /** * gnutls_certificate_activation_time_peers - This function returns the peer's certificate activation time * @session: is a gnutls session * * This function will return the peer's certificate activation time. * This is the creation time for openpgp keys. * * Returns (time_t) -1 on error. * **/ time_t gnutls_certificate_activation_time_peers(gnutls_session_t session) { cert_auth_info_t info; CHECK_AUTH(GNUTLS_CRD_CERTIFICATE, GNUTLS_E_INVALID_REQUEST); info = _gnutls_get_auth_info(session); if (info == NULL) { return (time_t) - 1; } if (info->raw_certificate_list == NULL || info->ncerts == 0) { gnutls_assert(); return (time_t) - 1; } switch (gnutls_certificate_type_get(session)) { case GNUTLS_CRT_X509: return _gnutls_x509_get_raw_crt_activation_time(&info-> raw_certificate_list [0]); case GNUTLS_CRT_OPENPGP: if (_E_gnutls_openpgp_get_raw_key_creation_time == NULL) return (time_t) - 1; return _E_gnutls_openpgp_get_raw_key_creation_time(&info-> raw_certificate_list [0]); default: return (time_t) - 1; } } OPENPGP_RAW_KEY_TO_GCERT _E_gnutls_openpgp_raw_key_to_gcert; OPENPGP_RAW_PRIVKEY_TO_GKEY _E_gnutls_openpgp_raw_privkey_to_gkey; int _gnutls_raw_cert_to_gcert(gnutls_cert * gcert, gnutls_certificate_type_t type, const gnutls_datum_t * raw_cert, int flags /* OR of ConvFlags */ ) { switch (type) { case GNUTLS_CRT_X509: return _gnutls_x509_raw_cert_to_gcert(gcert, raw_cert, flags); case GNUTLS_CRT_OPENPGP: if (_E_gnutls_openpgp_raw_key_to_gcert == NULL) { gnutls_assert(); return GNUTLS_E_INIT_LIBEXTRA; } return _E_gnutls_openpgp_raw_key_to_gcert(gcert, raw_cert); default: gnutls_assert(); return GNUTLS_E_INTERNAL_ERROR; } } int _gnutls_raw_privkey_to_gkey(gnutls_privkey * key, gnutls_certificate_type_t type, const gnutls_datum_t * raw_key, int key_enc /* DER or PEM */ ) { switch (type) { case GNUTLS_CRT_X509: return _gnutls_x509_raw_privkey_to_gkey(key, raw_key, key_enc); case GNUTLS_CRT_OPENPGP: if (_E_gnutls_openpgp_raw_privkey_to_gkey == NULL) { gnutls_assert(); return GNUTLS_E_INIT_LIBEXTRA; } return _E_gnutls_openpgp_raw_privkey_to_gkey(key, raw_key); default: gnutls_assert(); return GNUTLS_E_INTERNAL_ERROR; } } /* This function will convert a der certificate to a format * (structure) that gnutls can understand and use. Actually the * important thing on this function is that it extracts the * certificate's (public key) parameters. * * The noext flag is used to complete the handshake even if the * extensions found in the certificate are unsupported and critical. * The critical extensions will be catched by the verification functions. */ int _gnutls_x509_raw_cert_to_gcert(gnutls_cert * gcert, const gnutls_datum_t * derCert, int flags /* OR of ConvFlags */ ) { int ret; gnutls_x509_crt_t cert; ret = gnutls_x509_crt_init(&cert); if (ret < 0) { gnutls_assert(); return ret; } ret = gnutls_x509_crt_import(cert, derCert, GNUTLS_X509_FMT_DER); if (ret < 0) { gnutls_assert(); gnutls_x509_crt_deinit(cert); return ret; } ret = _gnutls_x509_crt_to_gcert(gcert, cert, flags); gnutls_x509_crt_deinit(cert); return ret; } /* Like above but it accepts a parsed certificate instead. */ int _gnutls_x509_crt_to_gcert(gnutls_cert * gcert, gnutls_x509_crt_t cert, unsigned int flags) { int ret = 0; memset(gcert, 0, sizeof(gnutls_cert)); gcert->cert_type = GNUTLS_CRT_X509; if (!(flags & CERT_NO_COPY)) { #define SMALL_DER 512 opaque *der; size_t der_size = SMALL_DER; /* initially allocate a bogus size, just in case the certificate * fits in it. That way we minimize the DER encodings performed. */ der = gnutls_malloc(SMALL_DER); if (der == NULL) { gnutls_assert(); return GNUTLS_E_MEMORY_ERROR; } ret = gnutls_x509_crt_export(cert, GNUTLS_X509_FMT_DER, der, &der_size); if (ret < 0 && ret != GNUTLS_E_SHORT_MEMORY_BUFFER) { gnutls_assert(); gnutls_free(der); return ret; } if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) { der = gnutls_realloc(der, der_size); if (der == NULL) { gnutls_assert(); return GNUTLS_E_MEMORY_ERROR; } ret = gnutls_x509_crt_export(cert, GNUTLS_X509_FMT_DER, der, &der_size); if (ret < 0) { gnutls_assert(); gnutls_free(der); return ret; } } gcert->raw.data = der; gcert->raw.size = der_size; } else /* now we have 0 or a bitwise or of things to decode */ flags ^= CERT_NO_COPY; if (flags & CERT_ONLY_EXTENSIONS || flags == 0) { gnutls_x509_crt_get_key_usage(cert, &gcert->key_usage, NULL); gcert->version = gnutls_x509_crt_get_version(cert); } gcert->subject_pk_algorithm = gnutls_x509_crt_get_pk_algorithm(cert, NULL); if (flags & CERT_ONLY_PUBKEY || flags == 0) { gcert->params_size = MAX_PUBLIC_PARAMS_SIZE; ret = _gnutls_x509_crt_get_mpis(cert, gcert->params, &gcert->params_size); if (ret < 0) { gnutls_assert(); return ret; } } return 0; } void _gnutls_gcert_deinit(gnutls_cert * cert) { int i; if (cert == NULL) return; for (i = 0; i < cert->params_size; i++) { _gnutls_mpi_release(&cert->params[i]); } _gnutls_free_datum(&cert->raw); }