/* * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2009 Free Software Foundation * * Author: Nikos Mavrogiannopoulos * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA * */ /* This file contains everything for the Ephemeral Diffie-Hellman * (DHE) key exchange. This is used in the handshake procedure of the * certificate authentication. */ #include "gnutls_int.h" #include "gnutls_auth.h" #include "gnutls_errors.h" #include "gnutls_dh.h" #include "gnutls_num.h" #include "gnutls_sig.h" #include #include #include #include #include #include static int gen_dhe_server_kx (gnutls_session_t, opaque **); static int proc_dhe_server_kx (gnutls_session_t, opaque *, size_t); static int proc_dhe_client_kx (gnutls_session_t, opaque *, size_t); const mod_auth_st dhe_rsa_auth_struct = { "DHE_RSA", _gnutls_gen_cert_server_certificate, _gnutls_gen_cert_client_certificate, gen_dhe_server_kx, _gnutls_gen_dh_common_client_kx, _gnutls_gen_cert_client_cert_vrfy, /* gen client cert vrfy */ _gnutls_gen_cert_server_cert_req, /* server cert request */ _gnutls_proc_cert_server_certificate, _gnutls_proc_cert_client_certificate, proc_dhe_server_kx, proc_dhe_client_kx, _gnutls_proc_cert_client_cert_vrfy, /* proc client cert vrfy */ _gnutls_proc_cert_cert_req /* proc server cert request */ }; const mod_auth_st dhe_dss_auth_struct = { "DHE_DSS", _gnutls_gen_cert_server_certificate, _gnutls_gen_cert_client_certificate, gen_dhe_server_kx, _gnutls_gen_dh_common_client_kx, _gnutls_gen_cert_client_cert_vrfy, /* gen client cert vrfy */ _gnutls_gen_cert_server_cert_req, /* server cert request */ _gnutls_proc_cert_server_certificate, _gnutls_proc_cert_client_certificate, proc_dhe_server_kx, proc_dhe_client_kx, _gnutls_proc_cert_client_cert_vrfy, /* proc client cert vrfy */ _gnutls_proc_cert_cert_req /* proc server cert request */ }; static int gen_dhe_server_kx (gnutls_session_t session, opaque ** data) { bigint_t g, p; const bigint_t *mpis; int ret = 0, data_size; gnutls_cert *apr_cert_list; gnutls_privkey *apr_pkey; int apr_cert_list_length; gnutls_datum_t signature, ddata; gnutls_certificate_credentials_t cred; gnutls_dh_params_t dh_params; cred = (gnutls_certificate_credentials_t) _gnutls_get_cred (session->key, GNUTLS_CRD_CERTIFICATE, NULL); if (cred == NULL) { gnutls_assert (); return GNUTLS_E_INSUFFICIENT_CREDENTIALS; } /* find the appropriate certificate */ if ((ret = _gnutls_get_selected_cert (session, &apr_cert_list, &apr_cert_list_length, &apr_pkey)) < 0) { gnutls_assert (); return ret; } dh_params = _gnutls_get_dh_params (cred->dh_params, cred->params_func, session); mpis = _gnutls_dh_params_to_mpi (dh_params); if (mpis == NULL) { gnutls_assert (); return GNUTLS_E_NO_TEMPORARY_DH_PARAMS; } p = mpis[0]; g = mpis[1]; if ((ret = _gnutls_auth_info_set (session, GNUTLS_CRD_CERTIFICATE, sizeof (cert_auth_info_st), 0)) < 0) { gnutls_assert (); return ret; } _gnutls_dh_set_group (session, g, p); ret = _gnutls_dh_common_print_server_kx (session, g, p, data, 0); if (ret < 0) { gnutls_assert (); return ret; } data_size = ret; /* Generate the signature. */ ddata.data = *data; ddata.size = data_size; if (apr_cert_list_length > 0) { if ((ret = _gnutls_tls_sign_params (session, &apr_cert_list[0], apr_pkey, &ddata, &signature)) < 0) { gnutls_assert (); gnutls_free (*data); return ret; } } else { gnutls_assert (); return data_size; /* do not put a signature - ILLEGAL! */ } *data = gnutls_realloc_fast (*data, data_size + signature.size + 2); if (*data == NULL) { _gnutls_free_datum (&signature); gnutls_assert (); return GNUTLS_E_MEMORY_ERROR; } _gnutls_write_datum16 (&(*data)[data_size], signature); data_size += signature.size + 2; _gnutls_free_datum (&signature); return data_size; } static int proc_dhe_server_kx (gnutls_session_t session, opaque * data, size_t _data_size) { int sigsize; opaque *sigdata; gnutls_datum_t vparams, signature; int ret; cert_auth_info_t info = _gnutls_get_auth_info (session); ssize_t data_size = _data_size; gnutls_cert peer_cert; gnutls_sign_algorithm_t sign_algo = GNUTLS_SIGN_UNKNOWN; gnutls_protocol_t ver = gnutls_protocol_get_version (session); if (info == NULL || info->ncerts == 0) { gnutls_assert (); /* we need this in order to get peer's certificate */ return GNUTLS_E_INTERNAL_ERROR; } ret = _gnutls_proc_dh_common_server_kx (session, data, _data_size, 0); if (ret < 0) { gnutls_assert (); return ret; } /* VERIFY SIGNATURE */ vparams.size = ret; vparams.data = data; sigdata = &data[vparams.size]; if (_gnutls_version_has_selectable_sighash (ver)) { sign_algorithm_st aid; DECR_LEN(data_size, 1); aid.hash_algorithm = *sigdata++; DECR_LEN(data_size, 1); aid.sign_algorithm = *sigdata++; sign_algo = _gnutls_tls_aid_to_sign (aid); if (sign_algo == GNUTLS_SIGN_UNKNOWN) { gnutls_assert (); return GNUTLS_E_UNKNOWN_PK_ALGORITHM; } } DECR_LEN (data_size, 2); sigsize = _gnutls_read_uint16 (sigdata); sigdata += 2; DECR_LEN (data_size, sigsize); signature.data = sigdata; signature.size = sigsize; if ((ret = _gnutls_get_auth_info_gcert (&peer_cert, session->security_parameters.cert_type, info, CERT_NO_COPY)) < 0) { gnutls_assert (); return ret; } ret = _gnutls_verify_sig_params (session, &peer_cert, &vparams, &signature, sign_algo); _gnutls_gcert_deinit (&peer_cert); if (ret < 0) { gnutls_assert (); return ret; } return ret; } static int proc_dhe_client_kx (gnutls_session_t session, opaque * data, size_t _data_size) { gnutls_certificate_credentials_t cred; int ret; bigint_t p, g; const bigint_t *mpis; gnutls_dh_params_t dh_params; cred = (gnutls_certificate_credentials_t) _gnutls_get_cred (session->key, GNUTLS_CRD_CERTIFICATE, NULL); if (cred == NULL) { gnutls_assert (); return GNUTLS_E_INSUFFICIENT_CREDENTIALS; } dh_params = _gnutls_get_dh_params (cred->dh_params, cred->params_func, session); mpis = _gnutls_dh_params_to_mpi (dh_params); if (mpis == NULL) { gnutls_assert (); return GNUTLS_E_NO_TEMPORARY_DH_PARAMS; } p = mpis[0]; g = mpis[1]; ret = _gnutls_proc_dh_common_client_kx (session, data, _data_size, g, p); return ret; }