ustream-openssl.c

   1 /*
   2  * ustream-ssl - library for SSL over ustream
   3  *
   4  * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <string.h>
  20 #include <ctype.h>
  21 #include <openssl/x509v3.h>
  22 #include "ustream-ssl.h"
  23 #include "ustream-internal.h"
  24
  25
  26 /* Ciphersuite preference:
  27  * - key exchange: prefer ECDHE, then DHE(client only), then RSA
  28  * - prefer AEAD ciphers:
  29  *      chacha20-poly1305, the fastest in software, 256-bits
  30  *      aes128-gcm, 128-bits
  31  *      aes256-gcm, 256-bits
  32  * - CBC ciphers
  33  *      aes128, aes256, 3DES(client only)
  34  */
  35
  36 #define ecdhe_ciphers                                                   \
  37                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"        \
  38                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"        \
  39                                 "ECDHE-ECDSA-AES256-GCM-SHA384:"        \
  40                                 "ECDHE-ECDSA-AES128-SHA:"               \
  41                                 "ECDHE-ECDSA-AES256-SHA:"               \
  42                                 "ECDHE-RSA-CHACHA20-POLY1305:"          \
  43                                 "ECDHE-RSA-AES128-GCM-SHA256:"          \
  44                                 "ECDHE-RSA-AES256-GCM-SHA384:"          \
  45                                 "ECDHE-RSA-AES128-SHA:"                 \
  46                                 "ECDHE-RSA-AES256-SHA"
  47
  48 #define dhe_ciphers                                                     \
  49                                 "DHE-RSA-CHACHA20-POLY1305:"            \
  50                                 "DHE-RSA-AES128-GCM-SHA256:"            \
  51                                 "DHE-RSA-AES256-GCM-SHA384:"            \
  52                                 "DHE-RSA-AES128-SHA:"                   \
  53                                 "DHE-RSA-AES256-SHA:"                   \
  54                                 "DHE-DES-CBC3-SHA"
  55
  56 #define non_pfs_aes                                                     \
  57                                 "AES128-GCM-SHA256:"                    \
  58                                 "AES256-GCM-SHA384:"                    \
  59                                 "AES128-SHA:"                           \
  60                                 "AES256-SHA"
  61
  62 #define server_cipher_list                                              \
  63                                 ecdhe_ciphers ":"                       \
  64                                 non_pfs_aes
  65
  66 #define client_cipher_list                                              \
  67                                 ecdhe_ciphers ":"                       \
  68                                 dhe_ciphers ":"                         \
  69                                 non_pfs_aes ":"                         \
  70                                 "DES-CBC3-SHA"
  71
  72 __hidden struct ustream_ssl_ctx *
  73 __ustream_ssl_context_new(bool server)
  74 {
  75         const void *m;
  76         SSL_CTX *c;
  77
  78 #if OPENSSL_VERSION_NUMBER < 0x10100000L
  79         static bool _init = false;
  80
  81         if (!_init) {
  82                 SSL_load_error_strings();
  83                 SSL_library_init();
  84                 _init = true;
  85         }
  86 # define TLS_server_method TLSv1_2_server_method
  87 # define TLS_client_method SSLv23_client_method
  88 #endif
  89
  90         if (server) {
  91                 m = TLS_server_method();
  92         } else
  93                 m = TLS_client_method();
  94
  95         c = SSL_CTX_new((void *) m);
  96         if (!c)
  97                 return NULL;
  98
  99         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 100         SSL_CTX_set_options(c, SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_ECDH_USE |
 101                                SSL_OP_CIPHER_SERVER_PREFERENCE);
 102 #if defined(SSL_CTX_set_ecdh_auto) && OPENSSL_VERSION_NUMBER < 0x10100000L
 103         SSL_CTX_set_ecdh_auto(c, 1);
 104 #endif
 105         if (server) {
 106 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
 107                 SSL_CTX_set_min_proto_version(c, TLS1_2_VERSION);
 108 #endif
 109                 SSL_CTX_set_cipher_list(c, server_cipher_list);
 110         } else {
 111                 SSL_CTX_set_cipher_list(c, client_cipher_list);
 112         }
 113         SSL_CTX_set_quiet_shutdown(c, 1);
 114
 115         return (void *) c;
 116 }
 117
 118 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 119 {
 120         int ret;
 121
 122         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
 123         if (ret < 1)
 124                 return -1;
 125
 126         return 0;
 127 }
 128
 129 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 130 {
 131         int ret;
 132
 133         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
 134         if (ret < 1)
 135                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 136
 137         if (ret < 1)
 138                 return -1;
 139
 140         return 0;
 141 }
 142
 143 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 144 {
 145         int ret;
 146
 147         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
 148         if (ret < 1)
 149                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 150
 151         if (ret < 1)
 152                 return -1;
 153
 154         return 0;
 155 }
 156
 157 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 158 {
 159         SSL_CTX_free((void *) ctx);
 160 }
 161
 162 void __ustream_ssl_session_free(void *ssl)
 163 {
 164         SSL_shutdown(ssl);
 165         SSL_free(ssl);
 166 }
 167
 168 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 169 {
 170         us->error = ret;
 171         uloop_timeout_set(&us->error_timer, 0);
 172 }
 173
 174 #ifndef CYASSL_OPENSSL_H_
 175
 176 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 177 {
 178         int ret;
 179
 180         if (!us->peer_cn)
 181                 return false;
 182
 183         ret = X509_check_host(cert, us->peer_cn, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS, NULL);
 184         return ret == 1;
 185 }
 186
 187
 188 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 189 {
 190         void *ssl = us->ssl;
 191         X509 *cert;
 192         int res;
 193
 194         res = SSL_get_verify_result(ssl);
 195         if (res != X509_V_OK) {
 196                 if (us->notify_verify_error)
 197                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 198                 return;
 199         }
 200
 201         cert = SSL_get_peer_certificate(ssl);
 202         if (!cert)
 203                 return;
 204
 205         us->valid_cert = true;
 206         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 207         X509_free(cert);
 208 }
 209
 210 #endif
 211
 212 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 213 {
 214         void *ssl = us->ssl;
 215         int r;
 216
 217         if (us->server)
 218                 r = SSL_accept(ssl);
 219         else
 220                 r = SSL_connect(ssl);
 221
 222         if (r == 1) {
 223 #ifndef CYASSL_OPENSSL_H_
 224                 ustream_ssl_verify_cert(us);
 225 #endif
 226                 return U_SSL_OK;
 227         }
 228
 229         r = SSL_get_error(ssl, r);
 230         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 231                 return U_SSL_PENDING;
 232
 233         ustream_ssl_error(us, r);
 234         return U_SSL_ERROR;
 235 }
 236
 237 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 238 {
 239         void *ssl = us->ssl;
 240         int ret = SSL_write(ssl, buf, len);
 241
 242         if (ret < 0) {
 243                 int err = SSL_get_error(ssl, ret);
 244                 if (err == SSL_ERROR_WANT_WRITE)
 245                         return 0;
 246
 247                 ustream_ssl_error(us, err);
 248                 return -1;
 249         }
 250
 251         return ret;
 252 }
 253
 254 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 255 {
 256         int ret = SSL_read(us->ssl, buf, len);
 257
 258         if (ret < 0) {
 259                 ret = SSL_get_error(us->ssl, ret);
 260                 if (ret == SSL_ERROR_WANT_READ)
 261                         return U_SSL_PENDING;
 262
 263                 ustream_ssl_error(us, ret);
 264                 return U_SSL_ERROR;
 265         }
 266
 267         return ret;
 268 }
 269