/* * Copyright (C) 2000, 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., 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_int.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) { mpi_t g, p; const mpi_t *mpis; int ret = 0, data_size; int bits; 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; } bits = _gnutls_dh_get_allowed_prime_bits(session); /* 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_certificate_get_dh_params(cred, session); mpis = _gnutls_get_dh_params(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); if (ret < 0) { gnutls_assert(); return ret; } data_size = ret; /* Generate the signature. */ ddata.data = *data; ddata.size = data_size; if (apr_pkey != NULL) { 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; 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; 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); if (ret < 0) { gnutls_assert(); return ret; } /* VERIFY SIGNATURE */ vparams.size = ret; vparams.data = data; DECR_LEN(data_size, 2); sigsize = _gnutls_read_uint16(&data[vparams.size]); DECR_LEN(data_size, sigsize); signature.data = &data[vparams.size + 2]; signature.size = sigsize; if ((ret = _gnutls_raw_cert_to_gcert(&peer_cert, session->security_parameters.cert_type, &info->raw_certificate_list[0], CERT_NO_COPY)) < 0) { gnutls_assert(); return ret; } ret = _gnutls_verify_sig_params(session, &peer_cert, &vparams, &signature); _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; mpi_t p, g; const mpi_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_certificate_get_dh_params(cred, session); mpis = _gnutls_get_dh_params(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; }