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 #include <string.h>
  24
  25 #include "ustream-ssl.h"
  26 #include "ustream-internal.h"
  27
  28 static int urandom_fd = -1;
  29
  30 static int s_ustream_read(void *ctx, unsigned char *buf, size_t len)
  31 {
  32         struct ustream *s = ctx;
  33         char *sbuf;
  34         int slen;
  35
  36         if (s->eof)
  37                 return 0;
  38
  39         sbuf = ustream_get_read_buf(s, &slen);
  40         if (slen > len)
  41                 slen = len;
  42
  43         if (!slen)
  44                 return POLARSSL_ERR_NET_WANT_READ;
  45
  46         memcpy(buf, sbuf, slen);
  47         ustream_consume(s, slen);
  48
  49         return slen;
  50 }
  51
  52 static int s_ustream_write(void *ctx, const unsigned char *buf, size_t len)
  53 {
  54         struct ustream *s = ctx;
  55         int ret;
  56
  57         ret = ustream_write(s, (const char *) buf, len, false);
  58         if (ret < 0 || s->write_error)
  59                 return POLARSSL_ERR_NET_SEND_FAILED;
  60
  61         return ret;
  62 }
  63
  64 __hidden void ustream_set_io(struct ustream_ssl_ctx *ctx, void *ssl, struct ustream *conn)
  65 {
  66         ssl_set_bio(ssl, s_ustream_read, conn, s_ustream_write, conn);
  67 }
  68
  69 static bool urandom_init(void)
  70 {
  71         if (urandom_fd > -1)
  72                 return true;
  73
  74         urandom_fd = open("/dev/urandom", O_RDONLY);
  75         if (urandom_fd < 0)
  76                 return false;
  77
  78         return true;
  79 }
  80
  81 static int _urandom(void *ctx, unsigned char *out, size_t len)
  82 {
  83         if (read(urandom_fd, out, len) < 0)
  84                 return POLARSSL_ERR_ENTROPY_SOURCE_FAILED;
  85
  86         return 0;
  87 }
  88
  89 __hidden struct ustream_ssl_ctx *
  90 __ustream_ssl_context_new(bool server)
  91 {
  92         struct ustream_ssl_ctx *ctx;
  93
  94         if (!urandom_init())
  95                 return NULL;
  96
  97         ctx = calloc(1, sizeof(*ctx));
  98         if (!ctx)
  99                 return NULL;
 100
 101         ctx->server = server;
 102 #ifdef USE_VERSION_1_3
 103         pk_init(&ctx->key);
 104 #else
 105         rsa_init(&ctx->key, RSA_PKCS_V15, 0);
 106 #endif
 107
 108         return ctx;
 109 }
 110
 111 __hidden int __ustream_ssl_add_ca_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 112 {
 113         int ret;
 114
 115 #ifdef USE_VERSION_1_3
 116         ret = x509_crt_parse_file(&ctx->ca_cert, file);
 117 #else
 118         ret = x509parse_crtfile(&ctx->ca_cert, file);
 119 #endif
 120         if (ret)
 121                 return -1;
 122
 123         return 0;
 124 }
 125
 126 __hidden int __ustream_ssl_set_crt_file(struct ustream_ssl_ctx *ctx, const char *file)
 127 {
 128         int ret;
 129
 130 #ifdef USE_VERSION_1_3
 131         ret = x509_crt_parse_file(&ctx->cert, file);
 132 #else
 133         ret = x509parse_crtfile(&ctx->cert, file);
 134 #endif
 135         if (ret)
 136                 return -1;
 137
 138         return 0;
 139 }
 140
 141 __hidden int __ustream_ssl_set_key_file(struct ustream_ssl_ctx *ctx, const char *file)
 142 {
 143         int ret;
 144
 145 #ifdef USE_VERSION_1_3
 146         ret = pk_parse_keyfile(&ctx->key, file, NULL);
 147 #else
 148         ret = x509parse_keyfile(&ctx->key, file, NULL);
 149 #endif
 150         if (ret)
 151                 return -1;
 152
 153         return 0;
 154 }
 155
 156 __hidden void __ustream_ssl_context_free(struct ustream_ssl_ctx *ctx)
 157 {
 158 #ifdef USE_VERSION_1_3
 159         pk_free(&ctx->key);
 160         x509_crt_free(&ctx->cert);
 161 #else
 162         rsa_free(&ctx->key);
 163         x509_free(&ctx->cert);
 164 #endif
 165         free(ctx);
 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 static bool ssl_do_wait(int ret)
 175 {
 176         switch(ret) {
 177         case POLARSSL_ERR_NET_WANT_READ:
 178         case POLARSSL_ERR_NET_WANT_WRITE:
 179                 return true;
 180         default:
 181                 return false;
 182         }
 183 }
 184
 185 static void ustream_ssl_verify_cert(struct ustream_ssl *us)
 186 {
 187         void *ssl = us->ssl;
 188         const char *msg = NULL;
 189         bool cn_mismatch;
 190         int r;
 191
 192         r = ssl_get_verify_result(ssl);
 193         cn_mismatch = r & BADCERT_CN_MISMATCH;
 194         r &= ~BADCERT_CN_MISMATCH;
 195
 196         if (r & BADCERT_EXPIRED)
 197                 msg = "certificate has expired";
 198         else if (r & BADCERT_REVOKED)
 199                 msg = "certificate has been revoked";
 200         else if (r & BADCERT_NOT_TRUSTED)
 201                 msg = "certificate is self-signed or not signed by a trusted CA";
 202         else
 203                 msg = "unknown error";
 204
 205         if (r) {
 206                 if (us->notify_verify_error)
 207                         us->notify_verify_error(us, r, msg);
 208                 return;
 209         }
 210
 211         if (!cn_mismatch)
 212                 us->valid_cn = true;
 213 }
 214
 215 __hidden enum ssl_conn_status __ustream_ssl_connect(struct ustream_ssl *us)
 216 {
 217         void *ssl = us->ssl;
 218         int r;
 219
 220         r = ssl_handshake(ssl);
 221         if (r == 0) {
 222                 ustream_ssl_verify_cert(us);
 223                 return U_SSL_OK;
 224         }
 225
 226         if (ssl_do_wait(r))
 227                 return U_SSL_PENDING;
 228
 229         ustream_ssl_error(us, r);
 230         return U_SSL_ERROR;
 231 }
 232
 233 __hidden int __ustream_ssl_write(struct ustream_ssl *us, const char *buf, int len)
 234 {
 235         void *ssl = us->ssl;
 236         int done = 0, ret = 0;
 237
 238         while (done != len) {
 239                 ret = ssl_write(ssl, (const unsigned char *) buf + done, len - done);
 240
 241                 if (ret < 0) {
 242                         if (ssl_do_wait(ret))
 243                                 return done;
 244
 245                         ustream_ssl_error(us, ret);
 246                         return -1;
 247                 }
 248
 249                 done += ret;
 250         }
 251
 252         return done;
 253 }
 254
 255 __hidden int __ustream_ssl_read(struct ustream_ssl *us, char *buf, int len)
 256 {
 257         int ret = ssl_read(us->ssl, (unsigned char *) buf, len);
 258
 259         if (ret < 0) {
 260                 if (ssl_do_wait(ret))
 261                         return U_SSL_PENDING;
 262
 263                 ustream_ssl_error(us, ret);
 264                 return U_SSL_ERROR;
 265         }
 266
 267         return ret;
 268 }
 269
 270 static const int default_ciphersuites[] =
 271 {
 272 #if defined(POLARSSL_AES_C)
 273 #if defined(POLARSSL_SHA2_C)
 274     TLS_RSA_WITH_AES_256_CBC_SHA256,
 275 #endif /* POLARSSL_SHA2_C */
 276 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA4_C)
 277     TLS_RSA_WITH_AES_256_GCM_SHA384,
 278 #endif /* POLARSSL_SHA2_C */
 279     TLS_RSA_WITH_AES_256_CBC_SHA,
 280 #endif
 281 #if defined(POLARSSL_CAMELLIA_C)
 282 #if defined(POLARSSL_SHA2_C)
 283     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256,
 284 #endif /* POLARSSL_SHA2_C */
 285     TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,
 286 #endif
 287 #if defined(POLARSSL_AES_C)
 288 #if defined(POLARSSL_SHA2_C)
 289     TLS_RSA_WITH_AES_128_CBC_SHA256,
 290 #endif /* POLARSSL_SHA2_C */
 291 #if defined(POLARSSL_GCM_C) && defined(POLARSSL_SHA2_C)
 292     TLS_RSA_WITH_AES_128_GCM_SHA256,
 293 #endif /* POLARSSL_SHA2_C */
 294     TLS_RSA_WITH_AES_128_CBC_SHA,
 295 #endif
 296 #if defined(POLARSSL_CAMELLIA_C)
 297 #if defined(POLARSSL_SHA2_C)
 298     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256,
 299 #endif /* POLARSSL_SHA2_C */
 300     TLS_RSA_WITH_CAMELLIA_128_CBC_SHA,
 301 #endif
 302 #if defined(POLARSSL_DES_C)
 303     TLS_RSA_WITH_3DES_EDE_CBC_SHA,
 304 #endif
 305 #if defined(POLARSSL_ARC4_C)
 306     TLS_RSA_WITH_RC4_128_SHA,
 307     TLS_RSA_WITH_RC4_128_MD5,
 308 #endif
 309     0
 310 };
 311
 312 __hidden void *__ustream_ssl_session_new(struct ustream_ssl_ctx *ctx)
 313 {
 314         ssl_context *ssl;
 315         int auth;
 316         int ep;
 317
 318         ssl = calloc(1, sizeof(ssl_context));
 319         if (!ssl)
 320                 return NULL;
 321
 322         if (ssl_init(ssl)) {
 323                 free(ssl);
 324                 return NULL;
 325         }
 326
 327         if (ctx->server) {
 328                 ep = SSL_IS_SERVER;
 329                 auth = SSL_VERIFY_NONE;
 330         } else {
 331                 ep = SSL_IS_CLIENT;
 332                 auth = SSL_VERIFY_OPTIONAL;
 333         }
 334
 335         ssl_set_ciphersuites(ssl, default_ciphersuites);
 336         ssl_set_endpoint(ssl, ep);
 337         ssl_set_authmode(ssl, auth);
 338         ssl_set_rng(ssl, _urandom, NULL);
 339
 340         if (ctx->server) {
 341                 if (ctx->cert.next)
 342                         ssl_set_ca_chain(ssl, ctx->cert.next, NULL, NULL);
 343                 ssl_set_own_cert(ssl, &ctx->cert, &ctx->key);
 344         } else {
 345                 ssl_set_ca_chain(ssl, &ctx->cert, NULL, NULL);
 346         }
 347
 348         ssl_session_reset(ssl);
 349
 350         return ssl;
 351 }
 352
 353 __hidden void __ustream_ssl_session_free(void *ssl)
 354 {
 355         ssl_free(ssl);
 356         free(ssl);
 357 }
 358
 359 __hidden void __ustream_ssl_update_peer_cn(struct ustream_ssl *us)
 360 {
 361         struct ustream_ssl_ctx *ctx = us->ctx;
 362
 363         ssl_set_ca_chain(us->ssl, &ctx->ca_cert, NULL, us->peer_cn);
 364 }