/* $OpenBSD: ssl_asn1.c,v 1.69 2024/07/22 14:47:15 jsing Exp $ */

/*

 * Copyright (c) 2016 Joel Sing <jsing@openbsd.org>

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

#include <limits.h>

#include <openssl/ssl.h>

#include <openssl/x509.h>

#include "bytestring.h"

#include "ssl_local.h"

#define SSLASN1_TAG (CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC)

#define SSLASN1_TIME_TAG    (SSLASN1_TAG | 1)

#define SSLASN1_TIMEOUT_TAG   (SSLASN1_TAG | 2)

#define SSLASN1_PEER_CERT_TAG   (SSLASN1_TAG | 3)

#define SSLASN1_SESSION_ID_CTX_TAG  (SSLASN1_TAG | 4)

#define SSLASN1_VERIFY_RESULT_TAG (SSLASN1_TAG | 5)

#define SSLASN1_HOSTNAME_TAG    (SSLASN1_TAG | 6)

#define SSLASN1_LIFETIME_TAG    (SSLASN1_TAG | 9)

#define SSLASN1_TICKET_TAG    (SSLASN1_TAG | 10)

static uint64_t

time_max(void)

{

  if (sizeof(time_t) == sizeof(int32_t))

    return INT32_MAX;

  if (sizeof(time_t) == sizeof(int64_t))

    return INT64_MAX;

  return 0;

}

static int

SSL_SESSION_encode(SSL_SESSION *s, unsigned char **out, size_t *out_len,

    int ticket_encoding)

{

  CBB cbb, session, cipher_suite, session_id, master_key, time, timeout;

  CBB peer_cert, sidctx, verify_result, hostname, lifetime, ticket, value;

  unsigned char *peer_cert_bytes = NULL;

  int len, rv = 0;

  if (!CBB_init(&cbb, 0))

    goto err;

  if (!CBB_add_asn1(&cbb, &session, CBS_ASN1_SEQUENCE))

    goto err;

  /* Session ASN1 version. */

  if (!CBB_add_asn1_uint64(&session, SSL_SESSION_ASN1_VERSION))

    goto err;

  /* TLS/SSL protocol version. */

  if (s->ssl_version < 0)

    goto err;

  if (!CBB_add_asn1_uint64(&session, s->ssl_version))

    goto err;

  /* Cipher suite value. */

  if (!CBB_add_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBB_add_u16(&cipher_suite, s->cipher_value))

    goto err;

  /* Session ID - zero length for a ticket. */

  if (!CBB_add_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBB_add_bytes(&session_id, s->session_id,

      ticket_encoding ? 0 : s->session_id_length))

    goto err;

  /* Master key. */

  if (!CBB_add_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBB_add_bytes(&master_key, s->master_key, s->master_key_length))

    goto err;

  /* Time [1]. */

  if (s->time != 0) {

    if (s->time < 0)

      goto err;

    if (!CBB_add_asn1(&session, &time, SSLASN1_TIME_TAG))

      goto err;

    if (!CBB_add_asn1_uint64(&time, s->time))

      goto err;

  }

  /* Timeout [2]. */

  if (s->timeout != 0) {

    if (s->timeout < 0)

      goto err;

    if (!CBB_add_asn1(&session, &timeout, SSLASN1_TIMEOUT_TAG))

      goto err;

    if (!CBB_add_asn1_uint64(&timeout, s->timeout))

      goto err;

  }

  /* Peer certificate [3]. */

  if (s->peer_cert != NULL) {

    if ((len = i2d_X509(s->peer_cert, &peer_cert_bytes)) <= 0)

      goto err;

    if (!CBB_add_asn1(&session, &peer_cert, SSLASN1_PEER_CERT_TAG))

      goto err;

    if (!CBB_add_bytes(&peer_cert, peer_cert_bytes, len))

      goto err;

  }

  /* Session ID context [4]. */

  /* XXX - Actually handle this as optional? */

  if (!CBB_add_asn1(&session, &sidctx, SSLASN1_SESSION_ID_CTX_TAG))

    goto err;

  if (!CBB_add_asn1(&sidctx, &value, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBB_add_bytes(&value, s->sid_ctx, s->sid_ctx_length))

    goto err;

  /* Verify result [5]. */

  if (s->verify_result != X509_V_OK) {

    if (s->verify_result < 0)

      goto err;

    if (!CBB_add_asn1(&session, &verify_result,

        SSLASN1_VERIFY_RESULT_TAG))

      goto err;

    if (!CBB_add_asn1_uint64(&verify_result, s->verify_result))

      goto err;

  }

  /* Hostname [6]. */

  if (s->tlsext_hostname != NULL) {

    if (!CBB_add_asn1(&session, &hostname, SSLASN1_HOSTNAME_TAG))

      goto err;

    if (!CBB_add_asn1(&hostname, &value, CBS_ASN1_OCTETSTRING))

      goto err;

    if (!CBB_add_bytes(&value, (const uint8_t *)s->tlsext_hostname,

        strlen(s->tlsext_hostname)))

      goto err;

  }

  /* PSK identity hint [7]. */

  /* PSK identity [8]. */

  /* Ticket lifetime hint [9]. */

  if (s->tlsext_tick_lifetime_hint > 0) {

    if (!CBB_add_asn1(&session, &lifetime, SSLASN1_LIFETIME_TAG))

      goto err;

    if (!CBB_add_asn1_uint64(&lifetime,

        s->tlsext_tick_lifetime_hint))

      goto err;

  }

  /* Ticket [10]. */

  if (s->tlsext_tick != NULL) {

    if (!CBB_add_asn1(&session, &ticket, SSLASN1_TICKET_TAG))

      goto err;

    if (!CBB_add_asn1(&ticket, &value, CBS_ASN1_OCTETSTRING))

      goto err;

    if (!CBB_add_bytes(&value, s->tlsext_tick, s->tlsext_ticklen))

      goto err;

  }

  /* Compression method [11]. */

  /* SRP username [12]. */

  if (!CBB_finish(&cbb, out, out_len))

    goto err;

  rv = 1;

 err:

  CBB_cleanup(&cbb);

  free(peer_cert_bytes);

  return rv;

}

int

SSL_SESSION_ticket(SSL_SESSION *ss, unsigned char **out, size_t *out_len)

{

  if (ss == NULL)

    return 0;

  if (ss->cipher_value == 0)

    return 0;

  return SSL_SESSION_encode(ss, out, out_len, 1);

}

int

i2d_SSL_SESSION(SSL_SESSION *ss, unsigned char **pp)

{

  unsigned char *data = NULL;

  size_t data_len = 0;

  int rv = -1;

  if (ss == NULL)

    return 0;

  if (ss->cipher_value == 0)

    return 0;

  if (!SSL_SESSION_encode(ss, &data, &data_len, 0))

    goto err;

  if (data_len > INT_MAX)

    goto err;

  if (pp != NULL) {

    if (*pp == NULL) {

      *pp = data;

      data = NULL;

    } else {

      memcpy(*pp, data, data_len);

      *pp += data_len;

    }

  }

  rv = (int)data_len;

 err:

  freezero(data, data_len);

  return rv;

}

LSSL_ALIAS(i2d_SSL_SESSION);

SSL_SESSION *

d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length)

{

  CBS cbs, session, cipher_suite, session_id, master_key, peer_cert;

  CBS hostname, ticket;

  uint64_t version, tls_version, stime, timeout, verify_result, lifetime;

  const unsigned char *peer_cert_bytes;

  SSL_SESSION *s = NULL;

  size_t data_len;

  int present;

  if (a != NULL)

    s = *a;

  if (s == NULL) {

    if ((s = SSL_SESSION_new()) == NULL) {

      SSLerrorx(ERR_R_MALLOC_FAILURE);

      return (NULL);

    }

  }

  CBS_init(&cbs, *pp, length);

  if (!CBS_get_asn1(&cbs, &session, CBS_ASN1_SEQUENCE))

    goto err;

  /* Session ASN1 version. */

  if (!CBS_get_asn1_uint64(&session, &version))

    goto err;

  if (version != SSL_SESSION_ASN1_VERSION)

    goto err;

  /* TLS/SSL Protocol Version. */

  if (!CBS_get_asn1_uint64(&session, &tls_version))

    goto err;

  if (tls_version > INT_MAX)

    goto err;

  s->ssl_version = (int)tls_version;

  /* Cipher suite value. */

  if (!CBS_get_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBS_get_u16(&cipher_suite, &s->cipher_value))

    goto err;

  if (CBS_len(&cipher_suite) != 0)

    goto err;

  /* Session ID. */

  if (!CBS_get_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBS_write_bytes(&session_id, s->session_id, sizeof(s->session_id),

      &s->session_id_length))

    goto err;

  /* Master key. */

  if (!CBS_get_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING))

    goto err;

  if (!CBS_write_bytes(&master_key, s->master_key, sizeof(s->master_key),

      &s->master_key_length))

    goto err;

  /* Time [1]. */

  s->time = time(NULL);

  if (!CBS_get_optional_asn1_uint64(&session, &stime, SSLASN1_TIME_TAG,

      0))

    goto err;

  if (stime > time_max())

    goto err;

  if (stime != 0)

    s->time = (time_t)stime;

  /* Timeout [2]. */

  s->timeout = 3;

  if (!CBS_get_optional_asn1_uint64(&session, &timeout,

      SSLASN1_TIMEOUT_TAG, 0))

    goto err;

  if (timeout > LONG_MAX)

    goto err;

  if (timeout != 0)

    s->timeout = (long)timeout;

  /* Peer certificate [3]. */

  X509_free(s->peer_cert);

  s->peer_cert = NULL;

  if (!CBS_get_optional_asn1(&session, &peer_cert, &present,

      SSLASN1_PEER_CERT_TAG))

    goto err;

  if (present) {

    data_len = CBS_len(&peer_cert);

    if (data_len > LONG_MAX)

      goto err;

    peer_cert_bytes = CBS_data(&peer_cert);

    if (d2i_X509(&s->peer_cert, &peer_cert_bytes,

        (long)data_len) == NULL)

      goto err;

  }

  /* Session ID context [4]. */

  s->sid_ctx_length = 0;

  if (!CBS_get_optional_asn1_octet_string(&session, &session_id, &present,

      SSLASN1_SESSION_ID_CTX_TAG))

    goto err;

  if (present) {

    if (!CBS_write_bytes(&session_id, (uint8_t *)&s->sid_ctx,

        sizeof(s->sid_ctx), &s->sid_ctx_length))

      goto err;

  }

  /* Verify result [5]. */

  s->verify_result = X509_V_OK;

  if (!CBS_get_optional_asn1_uint64(&session, &verify_result,

      SSLASN1_VERIFY_RESULT_TAG, X509_V_OK))

    goto err;

  if (verify_result > LONG_MAX)

    goto err;

  s->verify_result = (long)verify_result;

  /* Hostname [6]. */

  free(s->tlsext_hostname);

  s->tlsext_hostname = NULL;

  if (!CBS_get_optional_asn1_octet_string(&session, &hostname, &present,

      SSLASN1_HOSTNAME_TAG))

    goto err;

  if (present) {

    if (CBS_contains_zero_byte(&hostname))

      goto err;

    if (!CBS_strdup(&hostname, &s->tlsext_hostname))

      goto err;

  }

  /* PSK identity hint [7]. */

  /* PSK identity [8]. */

  /* Ticket lifetime [9]. */

  s->tlsext_tick_lifetime_hint = 0;

  if (!CBS_get_optional_asn1_uint64(&session, &lifetime,

      SSLASN1_LIFETIME_TAG, 0))

    goto err;

  if (lifetime > UINT32_MAX)

    goto err;

  if (lifetime > 0)

    s->tlsext_tick_lifetime_hint = (uint32_t)lifetime;

  /* Ticket [10]. */

  free(s->tlsext_tick);

  s->tlsext_tick = NULL;

  if (!CBS_get_optional_asn1_octet_string(&session, &ticket, &present,

      SSLASN1_TICKET_TAG))

    goto err;

  if (present) {

    if (!CBS_stow(&ticket, &s->tlsext_tick, &s->tlsext_ticklen))

      goto err;

  }

  /* Compression method [11]. */

  /* SRP username [12]. */

  *pp = CBS_data(&cbs);

  if (a != NULL)

    *a = s;

  return (s);

 err:

  ERR_asprintf_error_data("offset=%d", (int)(CBS_data(&cbs) - *pp));

  if (s != NULL && (a == NULL || *a != s))

    SSL_SESSION_free(s);

  return (NULL);

}

LSSL_ALIAS(d2i_SSL_SESSION);