libexec/dma/crypto.c

   1 /*
   2  * Copyright (c) 2008 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
   6  * Germany.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in
  16  *    the documentation and/or other materials provided with the
  17  *    distribution.
  18  * 3. Neither the name of The DragonFly Project nor the names of its
  19  *    contributors may be used to endorse or promote products derived
  20  *    from this software without specific, prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  * $DragonFly: src/libexec/dma/crypto.c,v 1.2 2008/03/04 11:36:08 matthias Exp $
  36  */
  37
  38 #ifdef HAVE_CRYPTO
  39
  40 #include <openssl/x509.h>
  41 #include <openssl/ssl.h>
  42 #include <openssl/err.h>
  43 #include <openssl/pem.h>
  44 #include <openssl/rand.h>
  45
  46 #include <syslog.h>
  47
  48 #include "dma.h"
  49
  50 extern struct config *config;
  51
  52 static int
  53 init_cert_file(struct qitem *it, SSL_CTX *ctx, const char *path)
  54 {
  55         int error;
  56
  57         /* Load certificate into ctx */
  58         error = SSL_CTX_use_certificate_chain_file(ctx, path);
  59         if (error < 1) {
  60                 syslog(LOG_ERR, "%s: SSL: Cannot load certificate: %s",
  61                         it->queueid, path);
  62                 return (-1);
  63         }
  64
  65         /* Add private key to ctx */
  66         error = SSL_CTX_use_PrivateKey_file(ctx, path, SSL_FILETYPE_PEM);
  67         if (error < 1) {
  68                 syslog(LOG_ERR, "%s: SSL: Cannot load private key: %s",
  69                         it->queueid, path);
  70                 return (-1);
  71         }
  72
  73         /*
  74          * Check the consistency of a private key with the corresponding
  75          * certificate
  76          */
  77         error = SSL_CTX_check_private_key(ctx);
  78         if (error < 1) {
  79                 syslog(LOG_ERR, "%s: SSL: Cannot check private key: %s",
  80                         it->queueid, path);
  81                 return (-1);
  82         }
  83
  84         return (0);
  85 }
  86
  87 int
  88 smtp_init_crypto(struct qitem *it, int fd, int feature)
  89 {
  90         SSL_CTX *ctx = NULL;
  91         SSL_METHOD *meth = NULL;
  92         X509 *cert;
  93         char buf[2048];
  94         int error;
  95
  96         /* Init SSL library */
  97         SSL_library_init();
  98
  99         meth = TLSv1_client_method();
 100
 101         ctx = SSL_CTX_new(meth);
 102         if (ctx == NULL) {
 103                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 104                        " SSL init failed: %m", it->queueid);
 105                 return (2);
 106         }
 107
 108         /* User supplied a certificate */
 109         if (config->certfile != NULL)
 110                 init_cert_file(it, ctx, config->certfile);
 111
 112         /*
 113          * If the user wants STARTTLS, we have to send EHLO here
 114          */
 115         if (((feature & SECURETRANS) != 0) &&
 116              (feature & STARTTLS) != 0) {
 117                 /* TLS init phase, disable SSL_write */
 118                 config->features |= NOSSL;
 119
 120                 send_remote_command(fd, "EHLO %s", hostname());
 121                 if (read_remote(fd) == 2) {
 122                         send_remote_command(fd, "STARTTLS");
 123                         if (read_remote(fd) != 2) {
 124                                 syslog(LOG_ERR, "%s: remote delivery failed:"
 125                                   " STARTTLS not available: %m", it->queueid);
 126                                 config->features &= ~NOSSL;
 127                                 return (-1);
 128                         }
 129                 }
 130                 /* End of TLS init phase, enable SSL_write/read */
 131                 config->features &= ~NOSSL;
 132         }
 133
 134         config->ssl = SSL_new(ctx);
 135         if (config->ssl == NULL) {
 136                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 137                        " SSL struct creation failed:", it->queueid);
 138                 return (2);
 139         }
 140
 141         /* Set ssl to work in client mode */
 142         SSL_set_connect_state(config->ssl);
 143
 144         /* Set fd for SSL in/output */
 145         error = SSL_set_fd(config->ssl, fd);
 146         if (error == 0) {
 147                 error = SSL_get_error(config->ssl, error);
 148                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 149                        " SSL set fd failed (%d): %m", it->queueid, error);
 150                 return (2);
 151         }
 152
 153         /* Open SSL connection */
 154         error = SSL_connect(config->ssl);
 155         if (error < 0) {
 156                 syslog(LOG_ERR, "%s: remote delivery failed:"
 157                        " SSL handshake fataly failed: %m", it->queueid);
 158                 return (-1);
 159         }
 160
 161         /* Get peer certificate */
 162         cert = SSL_get_peer_certificate(config->ssl);
 163         if (cert == NULL) {
 164                 syslog(LOG_ERR, "%s: remote delivery deferred:"
 165                        " Peer did not provied certificate: %m", it->queueid);
 166         }
 167         X509_free(cert);
 168
 169         return (0);
 170 }
 171
 172 #if 0
 173 /*
 174  * CRAM-MD5 authentication
 175  *
 176  * XXX TODO implement me, I don't have a mail server with CRAM-MD5 available
 177  */
 178 int
 179 smtp_auth_md5(int fd, char *login, char *password)
 180 {
 181 }
 182 #endif /* 0 */
 183
 184 #endif /* HAVE_CRYPTO */