ustream-polarssl.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 <sys/types.h>
  20 #include <fcntl.h>
  21 #include <unistd.h>
  22 #include <stdlib.h>
  23
  24 #include "ustream-ssl.h"
  25 #include "ustream-internal.h"
  26
  27 static int urandom_fd = -1;
  28
  29 static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
  30 {
  31         struct ustream *s = ctx;
  32         char *sbuf;
  33         int slen;
  34
  35         if (s->eof)
  36                 return 0;
  37
  38         sbuf = ustream_get_read_buf(s, &slen);
  39         if (slen > len)
  40                 slen = len;
  41
  42         if (!slen)
  43                 return POLARSSL_ERR_NET_WANT_READ;
  44
  45         memcpy(buf, sbuf, slen);
  46         ustream_consume(s, slen);
  47
  48         return slen;
  49 }
  50
  51 static int s_ustream_write(void *ctx, const unsigned char *buf, size_t len)
  52 {
  53         struct ustream *s = ctx;
  54         int ret;
  55
  56         ret = ustream_write(s, (const char *) buf, len, false);
  57         if (ret < 0 || s->write_error)
  58                 return POLARSSL_ERR_NET_SEND_FAILED;
  59
  60         return ret;
  61 }
  62
  63 __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx, void *ssl, struct ustream *conn)
  64 {
  65         ssl_set_bio(ssl, s_ustream_read, conn, s_ustream_write, conn);
  66 }
  67
  68 static bool urandom_init(void)
  69 {
  70         if (urandom_fd > -1)
  71                 return true;
  72
  73         urandom_fd = open("/dev/urandom", O_RDONLY);
  74         if (urandom_fd < 0)
  75                 return false;
  76
  77         return true;
  78 }
  79
  80 static int _urandom(void *ctx, unsigned char *out, size_t len)
  81 {
  82         if (read(urandom_fd, out, len) < 0)
  83                 return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
  84
  85         return 0;
  86 }
  87
  88 __hidden struct ustream_ssl_ctx *
  89 __ustream_ssl_context_new(bool server)
  90 {
  91         struct ustream_ssl_ctx *ctx;
  92
  93         if (!urandom_init())
  94                 return NULL;
  95
  96         ctx = calloc(1, sizeof(*ctx));
  97         if (!ctx)
  98                 return NULL;
  99
 100         ctx->server = server;
 101 #ifdef USE_VERSION_1_3
 102         pk_init(&ctx->key);
 103 #else
 104         rsa_init(&ctx->key, RSA_PKCS_V15, 0);
 105 #endif
 106
 107         return ctx;
 108 }
 109
 110 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 111 {
 112         int ret;
 113
 114 #ifdef USE_VERSION_1_3
 115         ret = x509_crt_parse_file(&ctx->ca_cert, file);
 116 #else
 117         ret = x509parse_crtfile(&ctx->ca_cert, file);
 118 #endif
 119         if (ret)
 120                 return -1;
 121
 122         return 0;
 123 }
 124
 125 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 126 {
 127         int ret;
 128
 129 #ifdef USE_VERSION_1_3
 130         ret = x509_crt_parse_file(&ctx->cert, file);
 131 #else
 132         ret = x509parse_crtfile(&ctx->cert, file);
 133 #endif
 134         if (ret)
 135                 return -1;
 136
 137         return 0;
 138 }
 139
 140 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 141 {
 142         int ret;
 143
 144 #ifdef USE_VERSION_1_3
 145         ret = pk_parse_keyfile(&ctx->key, file, NULL);
 146 #else
 147         ret = x509parse_keyfile(&ctx->key, file, NULL);
 148 #endif
 149         if (ret)
 150                 return -1;
 151
 152         return 0;
 153 }
 154
 155 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 156 {
 157 #ifdef USE_VERSION_1_3
 158         pk_free(&ctx->key);
 159         x509_crt_free(&ctx->cert);
 160 #else
 161         rsa_free(&ctx->key);
 162         x509_free(&ctx->cert);
 163 #endif
 164         free(ctx);
 165 }
 166
 167 static void ustream_ssl_error(struct ustream_ssl *us, int ret)
 168 {
 169         us->error = ret;
 170         uloop_timeout_set(&us->error_timer, 0);
 171 }
 172
 173 static bool ssl_do_wait(int ret)
 174 {
 175         switch(ret) {
 176         case POLARSSL_ERR_NET_WANT_READ:
 177         case POLARSSL_ERR_NET_WANT_WRITE:
 178                 return true;
 179         default:
 180                 return false;
 181         }
 182 }
 183
 184 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 185 {
 186         void *ssl = us->ssl;
 187         const char *msg = NULL;
 188         bool cn_mismatch;
 189         int r;
 190
 191         r = ssl_get_verify_result(ssl);
 192         cn_mismatch = r & BADCERT_CN_MISMATCH;
 193         r &= ~BADCERT_CN_MISMATCH;
 194
 195         if (r & BADCERT_EXPIRED)
 196                 msg = "certificate has expired";
 197         else if (r & BADCERT_REVOKED)
 198                 msg = "certificate has been revoked";
 199         else if (r & BADCERT_NOT_TRUSTED)
 200                 msg = "certificate is self-signed or not signed by a trusted CA";
 201         else
 202                 msg = "unknown error";
 203
 204         if (r) {
 205                 if (us->notify_verify_error)
 206                         us->notify_verify_error(us, r, msg);
 207                 return;
 208         }
 209
 210         if (!cn_mismatch)
 211                 us->valid_cn = true;
 212 }
 213
 214 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 215 {
 216         void *ssl = us->ssl;
 217         int r;
 218
 219         r = ssl_handshake(ssl);
 220         if (r == 0) {
 221                 ustream_ssl_verify_cert(us);
 222                 return U_SSL_OK;
 223         }
 224
 225         if (ssl_do_wait(r))
 226                 return U_SSL_PENDING;
 227
 228         ustream_ssl_error(us, r);
 229         return U_SSL_ERROR;
 230 }
 231
 232 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 233 {
 234         void *ssl = us->ssl;
 235         int done = 0, ret = 0;
 236
 237         while (done != len) {
 238                 ret = ssl_write(ssl, (const unsigned char *) buf + done, len - done);
 239
 240                 if (ret < 0) {
 241                         if (ssl_do_wait(ret))
 242                                 return done;
 243
 244                         ustream_ssl_error(us, ret);
 245                         return -1;
 246                 }
 247
 248                 done += ret;
 249         }
 250
 251         return done;
 252 }
 253
 254 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 255 {
 256         int ret = ssl_read(us->ssl, (unsigned char *) buf, len);
 257
 258         if (ret < 0) {
 259                 if (ssl_do_wait(ret))
 260                         return U_SSL_PENDING;
 261
 262                 ustream_ssl_error(us, ret);
 263                 return U_SSL_ERROR;
 264         }
 265
 266         return ret;
 267 }
 268
 269 static const int default_ciphersuites[] =
 270 {
 271 #if defined(POLARSSL_AES_C)
 272 #if defined(POLARSSL_SHA2_C)
 273     TLS_RSA_WITH_AES_256_CBC_SHA256,
 274 #endif /* POLARSSL_SHA2_C */
 275 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA4_C)
 276     TLS_RSA_WITH_AES_256_GCM_SHA384,
 277 #endif /* POLARSSL_SHA2_C */
 278     TLS_RSA_WITH_AES_256_CBC_SHA,
 279 #endif
 280 #if defined(POLARSSL_CAMELLIA_C)
 281 #if defined(POLARSSL_SHA2_C)
 282     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256,
 283 #endif /* POLARSSL_SHA2_C */
 284     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,
 285 #endif
 286 #if defined(POLARSSL_AES_C)
 287 #if defined(POLARSSL_SHA2_C)
 288     TLS_RSA_WITH_AES_128_CBC_SHA256,
 289 #endif /* POLARSSL_SHA2_C */
 290 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA2_C)
 291     TLS_RSA_WITH_AES_128_GCM_SHA256,
 292 #endif /* POLARSSL_SHA2_C */
 293     TLS_RSA_WITH_AES_128_CBC_SHA,
 294 #endif
 295 #if defined(POLARSSL_CAMELLIA_C)
 296 #if defined(POLARSSL_SHA2_C)
 297     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256,
 298 #endif /* POLARSSL_SHA2_C */
 299     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA,
 300 #endif
 301 #if defined(POLARSSL_DES_C)
 302     TLS_RSA_WITH_3DES_EDE_CBC_SHA,
 303 #endif
 304 #if defined(POLARSSL_ARC4_C)
 305     TLS_RSA_WITH_RC4_128_SHA,
 306     TLS_RSA_WITH_RC4_128_MD5,
 307 #endif
 308     0
 309 };
 310
 311 __hidden void *__ustream_ssl_session_new(struct ustream_ssl_ctx *ctx)
 312 {
 313         ssl_context *ssl;
 314         int auth;
 315         int ep;
 316
 317         ssl = calloc(1, sizeof(ssl_context));
 318         if (!ssl)
 319                 return NULL;
 320
 321         if (ssl_init(ssl)) {
 322                 free(ssl);
 323                 return NULL;
 324         }
 325
 326         if (ctx->server) {
 327                 ep = SSL_IS_SERVER;
 328                 auth = SSL_VERIFY_NONE;
 329         } else {
 330                 ep = SSL_IS_CLIENT;
 331                 auth = SSL_VERIFY_OPTIONAL;
 332         }
 333
 334         ssl_set_ciphersuites(ssl, default_ciphersuites);
 335         ssl_set_endpoint(ssl, ep);
 336         ssl_set_authmode(ssl, auth);
 337         ssl_set_rng(ssl, _urandom, NULL);
 338
 339         if (ctx->server) {
 340                 if (ctx->cert.next)
 341                         ssl_set_ca_chain(ssl, ctx->cert.next, NULL, NULL);
 342                 ssl_set_own_cert(ssl, &ctx->cert, &ctx->key);
 343         } else {
 344                 ssl_set_ca_chain(ssl, &ctx->cert, NULL, NULL);
 345         }
 346
 347         ssl_session_reset(ssl);
 348
 349         return ssl;
 350 }
 351
 352 __hidden void __ustream_ssl_session_free(void *ssl)
 353 {
 354         ssl_free(ssl);
 355         free(ssl);
 356 }
 357
 358 __hidden void __ustream_ssl_update_peer_cn(struct ustream_ssl *us)
 359 {
 360         struct ustream_ssl_ctx *ctx = us->ctx;
 361
 362         ssl_set_ca_chain(us->ssl, &ctx->ca_cert, NULL, us->peer_cn);
 363 }