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 "ustream-ssl.h"
  22 #include "ustream-internal.h"
  23
  24 #if !defined(HAVE_WOLFSSL)
  25 #include <openssl/x509v3.h>
  26 #endif
  27
  28 #if defined(HAVE_WOLFSSL) && defined(DEBUG)
  29 #include <wolfssl/test.h>
  30 #endif
  31
  32 /* Ciphersuite preference:
  33  * - for server, no weak ciphers are used if you use an ECDSA key.
  34  * - forward-secret (pfs), authenticated (AEAD) ciphers are at the top:
  35  *      chacha20-poly1305, the fastest in software, 256-bits
  36  *      aes128-gcm, 128-bits
  37  *      aes256-gcm, 256-bits
  38  * - key exchange: prefer ECDHE, then DHE (client only)
  39  * - forward-secret ECDSA CBC ciphers (client-only)
  40  * - forward-secret RSA CBC ciphers
  41  * - non-pfs ciphers
  42  *      aes128, aes256, 3DES(client only)
  43  */
  44
  45 #ifdef WOLFSSL_SSL_H
  46 # define top_ciphers                                                    \
  47                                 "TLS13-CHACHA20-POLY1305-SHA256:"       \
  48                                 "TLS13-AES128-GCM-SHA256:"              \
  49                                 "TLS13-AES256-GCM-SHA384:"              \
  50                                 ecdhe_aead_ciphers
  51 #else
  52 # define tls13_ciphersuites     "TLS_CHACHA20_POLY1305_SHA256:"         \
  53                                 "TLS_AES_128_GCM_SHA256:"               \
  54                                 "TLS_AES_256_GCM_SHA384"
  55
  56 # define top_ciphers                                                    \
  57                                 ecdhe_aead_ciphers
  58 #endif
  59
  60 #define ecdhe_aead_ciphers                                              \
  61                                 "ECDHE-ECDSA-CHACHA20-POLY1305:"        \
  62                                 "ECDHE-ECDSA-AES128-GCM-SHA256:"        \
  63                                 "ECDHE-ECDSA-AES256-GCM-SHA384:"        \
  64                                 "ECDHE-RSA-CHACHA20-POLY1305:"          \
  65                                 "ECDHE-RSA-AES128-GCM-SHA256:"          \
  66                                 "ECDHE-RSA-AES256-GCM-SHA384"
  67
  68 #define dhe_aead_ciphers                                                \
  69                                 "DHE-RSA-CHACHA20-POLY1305:"            \
  70                                 "DHE-RSA-AES128-GCM-SHA256:"            \
  71                                 "DHE-RSA-AES256-GCM-SHA384"
  72
  73 #define ecdhe_ecdsa_cbc_ciphers                                         \
  74                                 "ECDHE-ECDSA-AES128-SHA:"               \
  75                                 "ECDHE-ECDSA-AES256-SHA"
  76
  77 #define ecdhe_rsa_cbc_ciphers                                           \
  78                                 "ECDHE-RSA-AES128-SHA:"                 \
  79                                 "ECDHE-RSA-AES256-SHA"
  80
  81 #define dhe_cbc_ciphers                                                 \
  82                                 "DHE-RSA-AES128-SHA:"                   \
  83                                 "DHE-RSA-AES256-SHA:"                   \
  84                                 "DHE-DES-CBC3-SHA"
  85
  86 #define non_pfs_aes                                                     \
  87                                 "AES128-GCM-SHA256:"                    \
  88                                 "AES256-GCM-SHA384:"                    \
  89                                 "AES128-SHA:"                           \
  90                                 "AES256-SHA"
  91
  92 #define server_cipher_list                                              \
  93                                 top_ciphers ":"                         \
  94                                 ecdhe_rsa_cbc_ciphers ":"               \
  95                                 non_pfs_aes
  96
  97 #define client_cipher_list                                              \
  98                                 top_ciphers ":"                         \
  99                                 dhe_aead_ciphers ":"                    \
 100                                 ecdhe_ecdsa_cbc_ciphers ":"             \
 101                                 ecdhe_rsa_cbc_ciphers ":"               \
 102                                 dhe_cbc_ciphers ":"                     \
 103                                 non_pfs_aes ":"                         \
 104                                 "DES-CBC3-SHA"
 105
 106 __hidden struct ustream_ssl_ctx *
 107 __ustream_ssl_context_new(bool server)
 108 {
 109         const void *m;
 110         SSL_CTX *c;
 111
 112 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 113         static bool _init = false;
 114
 115         if (!_init) {
 116                 SSL_load_error_strings();
 117                 SSL_library_init();
 118                 _init = true;
 119         }
 120 # ifndef TLS_server_method
 121 #  define TLS_server_method SSLv23_server_method
 122 # endif
 123 # ifndef TLS_client_method
 124 #  define TLS_client_method SSLv23_client_method
 125 # endif
 126 #endif
 127
 128         if (server) {
 129                 m = TLS_server_method();
 130         } else
 131                 m = TLS_client_method();
 132
 133         c = SSL_CTX_new((void *) m);
 134         if (!c)
 135                 return NULL;
 136
 137 #if defined(HAVE_WOLFSSL)
 138         if (server)
 139                 SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 140         else
 141                 SSL_CTX_set_verify(c, SSL_VERIFY_PEER, NULL);
 142 #else
 143         SSL_CTX_set_verify(c, SSL_VERIFY_NONE, NULL);
 144 #endif
 145
 146         SSL_CTX_set_options(c, SSL_OP_NO_COMPRESSION | SSL_OP_SINGLE_ECDH_USE |
 147                                SSL_OP_CIPHER_SERVER_PREFERENCE);
 148 #if defined(SSL_CTX_set_ecdh_auto) && OPENSSL_VERSION_NUMBER < 0x10100000L
 149         SSL_CTX_set_ecdh_auto(c, 1);
 150 #elif OPENSSL_VERSION_NUMBER >= 0x10101000L
 151         SSL_CTX_set_ciphersuites(c, tls13_ciphersuites);
 152 #endif
 153         if (server) {
 154 #if OPENSSL_VERSION_NUMBER >= 0x10100000L
 155                 SSL_CTX_set_min_proto_version(c, TLS1_2_VERSION);
 156 #else
 157                 SSL_CTX_set_options(c, SSL_OP_NO_SSLv3 | SSL_OP_NO_TLSv1 |
 158                                        SSL_OP_NO_TLSv1_1);
 159 #endif
 160                 SSL_CTX_set_cipher_list(c, server_cipher_list);
 161         } else {
 162                 SSL_CTX_set_cipher_list(c, client_cipher_list);
 163         }
 164         SSL_CTX_set_quiet_shutdown(c, 1);
 165
 166         return (void *) c;
 167 }
 168
 169 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 170 {
 171         int ret;
 172
 173         ret = SSL_CTX_load_verify_locations((void *) ctx, file, NULL);
 174         if (ret < 1)
 175                 return -1;
 176
 177         return 0;
 178 }
 179
 180 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 181 {
 182         int ret;
 183
 184         ret = SSL_CTX_use_certificate_chain_file((void *) ctx, file);
 185         if (ret < 1)
 186                 ret = SSL_CTX_use_certificate_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 187
 188         if (ret < 1)
 189                 return -1;
 190
 191         return 0;
 192 }
 193
 194 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 195 {
 196         int ret;
 197
 198         ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_PEM);
 199         if (ret < 1)
 200                 ret = SSL_CTX_use_PrivateKey_file((void *) ctx, file, SSL_FILETYPE_ASN1);
 201
 202         if (ret < 1)
 203                 return -1;
 204
 205         return 0;
 206 }
 207
 208 __hidden int __ustream_ssl_set_ciphers(struct ustream_ssl_ctx *ctx, const char *ciphers)
 209 {
 210         int ret = SSL_CTX_set_cipher_list((void *) ctx, ciphers);
 211
 212         if (ret == 0)
 213                 return -1;
 214
 215         return 0;
 216 }
 217
 218 __hidden int __ustream_ssl_set_require_validation(struct ustream_ssl_ctx *ctx, bool require)
 219 {
 220         int mode = SSL_VERIFY_PEER;
 221
 222         if (!require)
 223                 mode = SSL_VERIFY_NONE;
 224
 225         SSL_CTX_set_verify((void *) ctx, mode, NULL);
 226
 227         return 0;
 228 }
 229
 230 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 231 {
 232         SSL_CTX_free((void *) ctx);
 233 }
 234
 235 void __ustream_ssl_session_free(void *ssl)
 236 {
 237         BIO *bio = SSL_get_wbio(ssl);
 238         struct bio_ctx *ctx = BIO_get_data(bio);
 239
 240         SSL_shutdown(ssl);
 241         SSL_free(ssl);
 242         if (ctx) {
 243                 BIO_meth_free(ctx->meth);
 244                 free(ctx);
 245         }
 246 }
 247
 248 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 249 {
 250         us->error = ret;
 251         uloop_timeout_set(&us->error_timer, 0);
 252 }
 253
 254 static bool ustream_ssl_verify_cn(struct ustream_ssl *us, X509 *cert)
 255 {
 256         int ret;
 257
 258         if (!us->peer_cn)
 259                 return false;
 260
 261 # ifndef WOLFSSL_OPENSSL_H_
 262         ret = X509_check_host(cert, us->peer_cn, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS, NULL);
 263 # else
 264         ret = wolfSSL_X509_check_host(cert, us->peer_cn, 0, 0, NULL);
 265 # endif
 266         return ret == 1;
 267 }
 268
 269 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 270 {
 271         void *ssl = us->ssl;
 272         X509 *cert;
 273         int res;
 274
 275 #if defined(HAVE_WOLFSSL) && defined(DEBUG)
 276         showPeer(ssl);
 277 #endif
 278
 279         res = SSL_get_verify_result(ssl);
 280         if (res != X509_V_OK) {
 281                 if (us->notify_verify_error)
 282                         us->notify_verify_error(us, res, X509_verify_cert_error_string(res));
 283                 return;
 284         }
 285
 286         cert = SSL_get_peer_certificate(ssl);
 287         if (!cert)
 288                 return;
 289
 290         us->valid_cert = true;
 291         us->valid_cn = ustream_ssl_verify_cn(us, cert);
 292
 293         X509_free(cert);
 294 }
 295
 296 #ifdef WOLFSSL_SSL_H
 297 static bool handle_wolfssl_asn_error(struct ustream_ssl *us, int r)
 298 {
 299         switch (r) {
 300         case ASN_PARSE_E:
 301         case ASN_VERSION_E:
 302         case ASN_GETINT_E:
 303         case ASN_RSA_KEY_E:
 304         case ASN_OBJECT_ID_E:
 305         case ASN_TAG_NULL_E:
 306         case ASN_EXPECT_0_E:
 307         case ASN_BITSTR_E:
 308         case ASN_UNKNOWN_OID_E:
 309         case ASN_DATE_SZ_E:
 310         case ASN_BEFORE_DATE_E:
 311         case ASN_AFTER_DATE_E:
 312         case ASN_SIG_OID_E:
 313         case ASN_TIME_E:
 314         case ASN_INPUT_E:
 315         case ASN_SIG_CONFIRM_E:
 316         case ASN_SIG_HASH_E:
 317         case ASN_SIG_KEY_E:
 318         case ASN_DH_KEY_E:
 319 #if LIBWOLFSSL_VERSION_HEX < 0x05000000
 320         case ASN_NTRU_KEY_E:
 321 #endif
 322         case ASN_CRIT_EXT_E:
 323         case ASN_ALT_NAME_E:
 324         case ASN_NO_PEM_HEADER:
 325         case ASN_ECC_KEY_E:
 326         case ASN_NO_SIGNER_E:
 327         case ASN_CRL_CONFIRM_E:
 328         case ASN_CRL_NO_SIGNER_E:
 329         case ASN_OCSP_CONFIRM_E:
 330         case ASN_NAME_INVALID_E:
 331         case ASN_NO_SKID:
 332         case ASN_NO_AKID:
 333         case ASN_NO_KEYUSAGE:
 334         case ASN_COUNTRY_SIZE_E:
 335         case ASN_PATHLEN_SIZE_E:
 336         case ASN_PATHLEN_INV_E:
 337         case ASN_SELF_SIGNED_E:
 338                 if (us->notify_verify_error)
 339                         us->notify_verify_error(us, r, wc_GetErrorString(r));
 340                 return true;
 341         }
 342
 343         return false;
 344 }
 345 #endif
 346
 347 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 348 {
 349         void *ssl = us->ssl;
 350         int r;
 351
 352         ERR_clear_error();
 353
 354         if (us->server)
 355                 r = SSL_accept(ssl);
 356         else
 357                 r = SSL_connect(ssl);
 358
 359         if (r == 1) {
 360                 ustream_ssl_verify_cert(us);
 361                 return U_SSL_OK;
 362         }
 363
 364         r = SSL_get_error(ssl, r);
 365         if (r == SSL_ERROR_WANT_READ || r == SSL_ERROR_WANT_WRITE)
 366                 return U_SSL_PENDING;
 367
 368 #ifdef WOLFSSL_SSL_H
 369         if (handle_wolfssl_asn_error(us, r))
 370                 return U_SSL_OK;
 371 #endif
 372
 373         ustream_ssl_error(us, r);
 374         return U_SSL_ERROR;
 375 }
 376
 377 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 378 {
 379         void *ssl = us->ssl;
 380         int ret;
 381
 382         ERR_clear_error();
 383
 384         ret = SSL_write(ssl, buf, len);
 385
 386         if (ret < 0) {
 387                 int err = SSL_get_error(ssl, ret);
 388                 if (err == SSL_ERROR_WANT_WRITE)
 389                         return 0;
 390
 391                 ustream_ssl_error(us, err);
 392                 return -1;
 393         }
 394
 395         return ret;
 396 }
 397
 398 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 399 {
 400         int ret;
 401
 402         ERR_clear_error();
 403
 404         ret = SSL_read(us->ssl, buf, len);
 405
 406         if (ret < 0) {
 407                 ret = SSL_get_error(us->ssl, ret);
 408                 if (ret == SSL_ERROR_WANT_READ)
 409                         return U_SSL_PENDING;
 410
 411                 ustream_ssl_error(us, ret);
 412                 return U_SSL_ERROR;
 413         }
 414
 415         return ret;
 416 }