lib/libssl/ssl_asn1.c

   1 /* $OpenBSD: ssl_asn1.c,v 1.55 2017/05/06 16:18:36 jsing Exp $ */
   2 /*
   3  * Copyright (c) 2016 Joel Sing <jsing@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 #include <limits.h>
  19
  20 #include <openssl/ssl.h>
  21 #include <openssl/x509.h>
  22
  23 #include "ssl_locl.h"
  24
  25 #include "bytestring.h"
  26
  27 #define SSLASN1_TAG     (CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC)
  28 #define SSLASN1_TIME_TAG                (SSLASN1_TAG | 1)
  29 #define SSLASN1_TIMEOUT_TAG             (SSLASN1_TAG | 2)
  30 #define SSLASN1_PEER_CERT_TAG           (SSLASN1_TAG | 3)
  31 #define SSLASN1_SESSION_ID_CTX_TAG      (SSLASN1_TAG | 4)
  32 #define SSLASN1_VERIFY_RESULT_TAG       (SSLASN1_TAG | 5)
  33 #define SSLASN1_HOSTNAME_TAG            (SSLASN1_TAG | 6)
  34 #define SSLASN1_LIFETIME_TAG            (SSLASN1_TAG | 9)
  35 #define SSLASN1_TICKET_TAG              (SSLASN1_TAG | 10)
  36
  37 static uint64_t
  38 time_max(void)
  39 {
  40         if (sizeof(time_t) == sizeof(int32_t))
  41                 return INT32_MAX;
  42         if (sizeof(time_t) == sizeof(int64_t))
  43                 return INT64_MAX;
  44         return 0;
  45 }
  46
  47 int
  48 i2d_SSL_SESSION(SSL_SESSION *s, unsigned char **pp)
  49 {
  50         CBB cbb, session, cipher_suite, session_id, master_key, time, timeout;
  51         CBB peer_cert, sidctx, verify_result, hostname, lifetime, ticket;
  52         CBB value;
  53         unsigned char *data = NULL, *peer_cert_bytes = NULL;
  54         size_t data_len = 0;
  55         int len, rv = -1;
  56         uint16_t cid;
  57
  58         if (s == NULL)
  59                 return (0);
  60
  61         if (s->cipher == NULL && s->cipher_id == 0)
  62                 return (0);
  63
  64         if (!CBB_init(&cbb, 0))
  65                 goto err;
  66
  67         if (!CBB_add_asn1(&cbb, &session, CBS_ASN1_SEQUENCE))
  68                 goto err;
  69
  70         /* Session ASN1 version. */
  71         if (!CBB_add_asn1_uint64(&session, SSL_SESSION_ASN1_VERSION))
  72                 goto err;
  73
  74         /* TLS/SSL protocol version. */
  75         if (s->ssl_version < 0)
  76                 goto err;
  77         if (!CBB_add_asn1_uint64(&session, s->ssl_version))
  78                 goto err;
  79
  80         /* Cipher suite ID. */
  81         /* XXX - require cipher to be non-NULL or always/only use cipher_id. */
  82         cid = (uint16_t)(s->cipher_id & 0xffff);
  83         if (s->cipher != NULL)
  84                 cid = ssl3_cipher_get_value(s->cipher);
  85         if (!CBB_add_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))
  86                 goto err;
  87         if (!CBB_add_u16(&cipher_suite, cid))
  88                 goto err;
  89
  90         /* Session ID. */
  91         if (!CBB_add_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))
  92                 goto err;
  93         if (!CBB_add_bytes(&session_id, s->session_id, s->session_id_length))
  94                 goto err;
  95
  96         /* Master key. */
  97         if (!CBB_add_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))
  98                 goto err;
  99         if (!CBB_add_bytes(&master_key, s->master_key, s->master_key_length))
 100                 goto err;
 101
 102         /* Time [1]. */
 103         if (s->time != 0) {
 104                 if (s->time < 0)
 105                         goto err;
 106                 if (!CBB_add_asn1(&session, &time, SSLASN1_TIME_TAG))
 107                         goto err;
 108                 if (!CBB_add_asn1_uint64(&time, s->time))
 109                         goto err;
 110         }
 111
 112         /* Timeout [2]. */
 113         if (s->timeout != 0) {
 114                 if (s->timeout < 0)
 115                         goto err;
 116                 if (!CBB_add_asn1(&session, &timeout, SSLASN1_TIMEOUT_TAG))
 117                         goto err;
 118                 if (!CBB_add_asn1_uint64(&timeout, s->timeout))
 119                         goto err;
 120         }
 121
 122         /* Peer certificate [3]. */
 123         if (s->peer != NULL) {
 124                 if ((len = i2d_X509(s->peer, &peer_cert_bytes)) <= 0)
 125                         goto err;
 126                 if (!CBB_add_asn1(&session, &peer_cert, SSLASN1_PEER_CERT_TAG))
 127                         goto err;
 128                 if (!CBB_add_bytes(&peer_cert, peer_cert_bytes, len))
 129                         goto err;
 130         }
 131
 132         /* Session ID context [4]. */
 133         /* XXX - Actually handle this as optional? */
 134         if (!CBB_add_asn1(&session, &sidctx, SSLASN1_SESSION_ID_CTX_TAG))
 135                 goto err;
 136         if (!CBB_add_asn1(&sidctx, &value, CBS_ASN1_OCTETSTRING))
 137                 goto err;
 138         if (!CBB_add_bytes(&value, s->sid_ctx, s->sid_ctx_length))
 139                 goto err;
 140
 141         /* Verify result [5]. */
 142         if (s->verify_result != X509_V_OK) {
 143                 if (s->verify_result < 0)
 144                         goto err;
 145                 if (!CBB_add_asn1(&session, &verify_result,
 146                     SSLASN1_VERIFY_RESULT_TAG))
 147                         goto err;
 148                 if (!CBB_add_asn1_uint64(&verify_result, s->verify_result))
 149                         goto err;
 150         }
 151
 152         /* Hostname [6]. */
 153         if (s->tlsext_hostname != NULL) {
 154                 if (!CBB_add_asn1(&session, &hostname, SSLASN1_HOSTNAME_TAG))
 155                         goto err;
 156                 if (!CBB_add_asn1(&hostname, &value, CBS_ASN1_OCTETSTRING))
 157                         goto err;
 158                 if (!CBB_add_bytes(&value, (const uint8_t *)s->tlsext_hostname,
 159                     strlen(s->tlsext_hostname)))
 160                         goto err;
 161         }
 162
 163         /* PSK identity hint [7]. */
 164         /* PSK identity [8]. */
 165
 166         /* Ticket lifetime hint [9]. */
 167         if (s->tlsext_tick_lifetime_hint > 0) {
 168                 if (!CBB_add_asn1(&session, &lifetime, SSLASN1_LIFETIME_TAG))
 169                         goto err;
 170                 if (!CBB_add_asn1_uint64(&lifetime,
 171                     s->tlsext_tick_lifetime_hint))
 172                         goto err;
 173         }
 174
 175         /* Ticket [10]. */
 176         if (s->tlsext_tick) {
 177                 if (!CBB_add_asn1(&session, &ticket, SSLASN1_TICKET_TAG))
 178                         goto err;
 179                 if (!CBB_add_asn1(&ticket, &value, CBS_ASN1_OCTETSTRING))
 180                         goto err;
 181                 if (!CBB_add_bytes(&value, s->tlsext_tick, s->tlsext_ticklen))
 182                         goto err;
 183         }
 184
 185         /* Compression method [11]. */
 186         /* SRP username [12]. */
 187
 188         if (!CBB_finish(&cbb, &data, &data_len))
 189                 goto err;
 190
 191         if (data_len > INT_MAX)
 192                 goto err;
 193
 194         if (pp != NULL) {
 195                 if (*pp == NULL) {
 196                         *pp = data;
 197                         data = NULL;
 198                 } else {
 199                         memcpy(*pp, data, data_len);
 200                         *pp += data_len;
 201                 }
 202         }
 203
 204         rv = (int)data_len;
 205
 206  err:
 207         CBB_cleanup(&session);
 208         freezero(data, data_len);
 209         free(peer_cert_bytes);
 210
 211         return rv;
 212 }
 213
 214 SSL_SESSION *
 215 d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length)
 216 {
 217         CBS cbs, session, cipher_suite, session_id, master_key, peer_cert;
 218         CBS hostname, ticket;
 219         uint64_t version, tls_version, stime, timeout, verify_result, lifetime;
 220         const unsigned char *peer_cert_bytes;
 221         uint16_t cipher_value;
 222         SSL_SESSION *s = NULL;
 223         size_t data_len;
 224         int present;
 225
 226         if (a != NULL)
 227                 s = *a;
 228
 229         if (s == NULL) {
 230                 if ((s = SSL_SESSION_new()) == NULL) {
 231                         SSLerrorx(ERR_R_MALLOC_FAILURE);
 232                         return (NULL);
 233                 }
 234         }
 235
 236         CBS_init(&cbs, *pp, length);
 237
 238         if (!CBS_get_asn1(&cbs, &session, CBS_ASN1_SEQUENCE))
 239                 goto err;
 240
 241         /* Session ASN1 version. */
 242         if (!CBS_get_asn1_uint64(&session, &version))
 243                 goto err;
 244         if (version != SSL_SESSION_ASN1_VERSION)
 245                 goto err;
 246
 247         /* TLS/SSL Protocol Version. */
 248         if (!CBS_get_asn1_uint64(&session, &tls_version))
 249                 goto err;
 250         if (tls_version > INT_MAX)
 251                 goto err;
 252         s->ssl_version = (int)tls_version;
 253
 254         /* Cipher suite. */
 255         if (!CBS_get_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))
 256                 goto err;
 257         if (!CBS_get_u16(&cipher_suite, &cipher_value))
 258                 goto err;
 259         if (CBS_len(&cipher_suite) != 0)
 260                 goto err;
 261
 262         /* XXX - populate cipher instead? */
 263         s->cipher = NULL;
 264         s->cipher_id = SSL3_CK_ID | cipher_value;
 265
 266         /* Session ID. */
 267         if (!CBS_get_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))
 268                 goto err;
 269         if (!CBS_write_bytes(&session_id, s->session_id, sizeof(s->session_id),
 270             &data_len))
 271                 goto err;
 272         if (data_len > UINT_MAX)
 273                 goto err;
 274         s->session_id_length = (unsigned int)data_len;
 275
 276         /* Master key. */
 277         if (!CBS_get_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))
 278                 goto err;
 279         if (!CBS_write_bytes(&master_key, s->master_key, sizeof(s->master_key),
 280             &data_len))
 281                 goto err;
 282         if (data_len > INT_MAX)
 283                 goto err;
 284         s->master_key_length = (int)data_len;
 285
 286         /* Time [1]. */
 287         s->time = time(NULL);
 288         if (!CBS_get_optional_asn1_uint64(&session, &stime, SSLASN1_TIME_TAG,
 289             0))
 290                 goto err;
 291         if (stime > time_max())
 292                 goto err;
 293         if (stime != 0)
 294                 s->time = (time_t)stime;
 295
 296         /* Timeout [2]. */
 297         s->timeout = 3;
 298         if (!CBS_get_optional_asn1_uint64(&session, &timeout,
 299             SSLASN1_TIMEOUT_TAG, 0))
 300                 goto err;
 301         if (timeout > LONG_MAX)
 302                 goto err;
 303         if (timeout != 0)
 304                 s->timeout = (long)timeout;
 305
 306         /* Peer certificate [3]. */
 307         X509_free(s->peer);
 308         s->peer = NULL;
 309         if (!CBS_get_optional_asn1(&session, &peer_cert, &present,
 310             SSLASN1_PEER_CERT_TAG))
 311                 goto err;
 312         if (present) {
 313                 data_len = CBS_len(&peer_cert);
 314                 if (data_len > LONG_MAX)
 315                         goto err;
 316                 peer_cert_bytes = CBS_data(&peer_cert);
 317                 if (d2i_X509(&s->peer, &peer_cert_bytes,
 318                     (long)data_len) == NULL)
 319                         goto err;
 320         }
 321
 322         /* Session ID context [4]. */
 323         s->sid_ctx_length = 0;
 324         if (!CBS_get_optional_asn1_octet_string(&session, &session_id, &present,
 325             SSLASN1_SESSION_ID_CTX_TAG))
 326                 goto err;
 327         if (present) {
 328                 if (!CBS_write_bytes(&session_id, (uint8_t *)&s->sid_ctx,
 329                     sizeof(s->sid_ctx), &data_len))
 330                         goto err;
 331                 if (data_len > UINT_MAX)
 332                         goto err;
 333                 s->sid_ctx_length = (unsigned int)data_len;
 334         }
 335
 336         /* Verify result [5]. */
 337         s->verify_result = X509_V_OK;
 338         if (!CBS_get_optional_asn1_uint64(&session, &verify_result,
 339             SSLASN1_VERIFY_RESULT_TAG, X509_V_OK))
 340                 goto err;
 341         if (verify_result > LONG_MAX)
 342                 goto err;
 343         s->verify_result = (long)verify_result;
 344
 345         /* Hostname [6]. */
 346         free(s->tlsext_hostname);
 347         s->tlsext_hostname = NULL;
 348         if (!CBS_get_optional_asn1_octet_string(&session, &hostname, &present,
 349             SSLASN1_HOSTNAME_TAG))
 350                 goto err;
 351         if (present) {
 352                 if (CBS_contains_zero_byte(&hostname))
 353                         goto err;
 354                 if (!CBS_strdup(&hostname, &s->tlsext_hostname))
 355                         goto err;
 356         }
 357
 358         /* PSK identity hint [7]. */
 359         /* PSK identity [8]. */
 360
 361         /* Ticket lifetime [9]. */
 362         s->tlsext_tick_lifetime_hint = 0;
 363         /* XXX - tlsext_ticklen is not yet set... */
 364         if (s->tlsext_ticklen > 0 && s->session_id_length > 0)
 365                 s->tlsext_tick_lifetime_hint = -1;
 366         if (!CBS_get_optional_asn1_uint64(&session, &lifetime,
 367             SSLASN1_LIFETIME_TAG, 0))
 368                 goto err;
 369         if (lifetime > LONG_MAX)
 370                 goto err;
 371         if (lifetime > 0)
 372                 s->tlsext_tick_lifetime_hint = (long)lifetime;
 373
 374         /* Ticket [10]. */
 375         free(s->tlsext_tick);
 376         s->tlsext_tick = NULL;
 377         if (!CBS_get_optional_asn1_octet_string(&session, &ticket, &present,
 378             SSLASN1_TICKET_TAG))
 379                 goto err;
 380         if (present) {
 381                 if (!CBS_stow(&ticket, &s->tlsext_tick, &s->tlsext_ticklen))
 382                         goto err;
 383         }
 384
 385         /* Compression method [11]. */
 386         /* SRP username [12]. */
 387
 388         *pp = CBS_data(&cbs);
 389
 390         if (a != NULL)
 391                 *a = s;
 392
 393         return (s);
 394
 395 err:
 396         ERR_asprintf_error_data("offset=%d", (int)(CBS_data(&cbs) - *pp));
 397
 398         if (s != NULL && (a == NULL || *a != s))
 399                 SSL_SESSION_free(s);
 400
 401         return (NULL);
 402 }