/*  $OpenBSD: ct_oct.c,v 1.8 2021/12/20 17:23:07 jsing Exp $ */

/*

 * Written by Rob Stradling (rob@comodo.com) and Stephen Henson

 * (steve@openssl.org) for the OpenSSL project 2014.

 */

/* ====================================================================

 * Copyright (c) 2014 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#ifdef OPENSSL_NO_CT

# error "CT is disabled"

#endif

#include <limits.h>

#include <string.h>

#include <openssl/asn1.h>

#include <openssl/buffer.h>

#include <openssl/ct.h>

#include <openssl/err.h>

#include "bytestring.h"

#include "ct_local.h"

int

o2i_SCT_signature(SCT *sct, CBS *cbs)

{

  uint8_t hash_alg, sig_alg;

  CBS signature;

  if (sct->version != SCT_VERSION_V1) {

    CTerror(CT_R_UNSUPPORTED_VERSION);

    return 0;

  }

  /*

   * Parse a digitally-signed element - see RFC 6962 section 3.2 and

   * RFC 5246 sections 4.7 and 7.4.1.4.1.

   */

  if (!CBS_get_u8(cbs, &hash_alg))

    goto err_invalid;

  if (!CBS_get_u8(cbs, &sig_alg))

    goto err_invalid;

  if (!CBS_get_u16_length_prefixed(cbs, &signature))

    goto err_invalid;

  if (CBS_len(cbs) != 0)

    goto err_invalid;

  /*

   * Reject empty signatures since they are invalid for all supported

   * algorithms (this really should be done by SCT_set1_signature()).

   */

  if (CBS_len(&signature) == 0)

    goto err_invalid;

  sct->hash_alg = hash_alg;

  sct->sig_alg = sig_alg;

  if (SCT_get_signature_nid(sct) == NID_undef)

    goto err_invalid;

  if (!SCT_set1_signature(sct, CBS_data(&signature), CBS_len(&signature)))

    return 0;

  return 1;

 err_invalid:

  CTerror(CT_R_SCT_INVALID_SIGNATURE);

  return 0;

}

static int

o2i_SCT_internal(SCT **out_sct, CBS *cbs)

{

  SCT *sct = NULL;

  uint8_t version;

  *out_sct = NULL;

  if ((sct = SCT_new()) == NULL)

    goto err;

  if (CBS_len(cbs) > MAX_SCT_SIZE)

    goto err_invalid;

  if (!CBS_peek_u8(cbs, &version))

    goto err_invalid;

  sct->version = version;

  if (version == SCT_VERSION_V1) {

    CBS extensions, log_id;

    uint64_t timestamp;

    /*

     * Parse a v1 SignedCertificateTimestamp - see RFC 6962

     * section 3.2.

     */

    if (!CBS_get_u8(cbs, &version))

      goto err_invalid;

    if (!CBS_get_bytes(cbs, &log_id, CT_V1_LOG_ID_LEN))

      goto err_invalid;

    if (!CBS_get_u64(cbs, &timestamp))

      goto err_invalid;

    if (!CBS_get_u16_length_prefixed(cbs, &extensions))

      goto err_invalid;

    if (!CBS_stow(&log_id, &sct->log_id, &sct->log_id_len))

      goto err;

    sct->timestamp = timestamp;

    if (!CBS_stow(&extensions, &sct->ext, &sct->ext_len))

      goto err;

    if (!o2i_SCT_signature(sct, cbs))

      goto err;

    if (CBS_len(cbs) != 0)

      goto err_invalid;

  } else {

    /* If not V1 just cache encoding. */

    if (!CBS_stow(cbs, &sct->sct, &sct->sct_len))

      goto err;

  }

  *out_sct = sct;

  return 1;

 err_invalid:

  CTerror(CT_R_SCT_INVALID);

 err:

  SCT_free(sct);

  return 0;

}

SCT *

o2i_SCT(SCT **psct, const unsigned char **in, size_t len)

{

  SCT *sct;

  CBS cbs;

  CBS_init(&cbs, *in, len);

  if (psct != NULL) {

    SCT_free(*psct);

    *psct = NULL;

  }

  if (!o2i_SCT_internal(&sct, &cbs))

    return NULL;

  if (psct != NULL)

    *psct = sct;

  *in = CBS_data(&cbs);

  return sct;

}

int

i2o_SCT_signature(const SCT *sct, unsigned char **out)

{

  size_t len;

  unsigned char *p = NULL, *pstart = NULL;

  if (!SCT_signature_is_complete(sct)) {

    CTerror(CT_R_SCT_INVALID_SIGNATURE);

    goto err;

  }

  if (sct->version != SCT_VERSION_V1) {

    CTerror(CT_R_UNSUPPORTED_VERSION);

    goto err;

  }

  /*

   * (1 byte) Hash algorithm

   * (1 byte) Signature algorithm

   * (2 bytes + ?) Signature

   */

  len = 4 + sct->sig_len;

  if (out != NULL) {

    if (*out != NULL) {

      p = *out;

      *out += len;

    } else {

      pstart = p = malloc(len);

      if (p == NULL) {

        CTerror(ERR_R_MALLOC_FAILURE);

        goto err;

      }

      *out = p;

    }

    *p++ = sct->hash_alg;

    *p++ = sct->sig_alg;

    s2n(sct->sig_len, p);

    memcpy(p, sct->sig, sct->sig_len);

  }

  return len;

 err:

  free(pstart);

  return -1;

}

int

i2o_SCT(const SCT *sct, unsigned char **out)

{

  size_t len;

  unsigned char *p = NULL, *pstart = NULL;

  if (!SCT_is_complete(sct)) {

    CTerror(CT_R_SCT_NOT_SET);

    goto err;

  }

  /*

   * Fixed-length header: struct { (1 byte) Version sct_version; (32 bytes)

   * log_id id; (8 bytes) uint64 timestamp; (2 bytes + ?) CtExtensions

   * extensions; (1 byte) Hash algorithm (1 byte) Signature algorithm (2

   * bytes + ?) Signature

   */

  if (sct->version == SCT_VERSION_V1)

    len = 43 + sct->ext_len + 4 + sct->sig_len;

  else

    len = sct->sct_len;

  if (out == NULL)

    return len;

  if (*out != NULL) {

    p = *out;

    *out += len;

  } else {

    pstart = p = malloc(len);

    if (p == NULL) {

      CTerror(ERR_R_MALLOC_FAILURE);

      goto err;

    }

    *out = p;

  }

  if (sct->version == SCT_VERSION_V1) {

    *p++ = sct->version;

    memcpy(p, sct->log_id, CT_V1_HASHLEN);

    p += CT_V1_HASHLEN;

    l2n8(sct->timestamp, p);

    s2n(sct->ext_len, p);

    if (sct->ext_len > 0) {

      memcpy(p, sct->ext, sct->ext_len);

      p += sct->ext_len;

    }

    if (i2o_SCT_signature(sct, &p) <= 0)

      goto err;

  } else {

    memcpy(p, sct->sct, len);

  }

  return len;

 err:

  free(pstart);

  return -1;

}

STACK_OF(SCT) *

o2i_SCT_LIST(STACK_OF(SCT) **out_scts, const unsigned char **pp, size_t len)

{

  CBS cbs, cbs_scts, cbs_sct;

  STACK_OF(SCT) *scts = NULL;

  CBS_init(&cbs, *pp, len);

  if (CBS_len(&cbs) > MAX_SCT_LIST_SIZE)

    goto err_invalid;

  if (!CBS_get_u16_length_prefixed(&cbs, &cbs_scts))

    goto err_invalid;

  if (CBS_len(&cbs) != 0)

    goto err_invalid;

  if (out_scts != NULL) {

    SCT_LIST_free(*out_scts);

    *out_scts = NULL;

  }

  if ((scts = sk_SCT_new_null()) == NULL)

    return NULL;

  while (CBS_len(&cbs_scts) > 0) {

    SCT *sct;

    if (!CBS_get_u16_length_prefixed(&cbs_scts, &cbs_sct))

      goto err_invalid;

    if (!o2i_SCT_internal(&sct, &cbs_sct))

      goto err;

    if (!sk_SCT_push(scts, sct)) {

      SCT_free(sct);

      goto err;

    }

  }

  if (out_scts != NULL)

    *out_scts = scts;

  *pp = CBS_data(&cbs);

  return scts;

 err_invalid:

  CTerror(CT_R_SCT_LIST_INVALID);

 err:

  SCT_LIST_free(scts);

  return NULL;

}

int

i2o_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **pp)

{

  int len, sct_len, i, is_pp_new = 0;

  size_t len2;

  unsigned char *p = NULL, *p2;

  if (pp != NULL) {

    if (*pp == NULL) {

      if ((len = i2o_SCT_LIST(a, NULL)) == -1) {

        CTerror(CT_R_SCT_LIST_INVALID);

        return -1;

      }

      if ((*pp = malloc(len)) == NULL) {

        CTerror(ERR_R_MALLOC_FAILURE);

        return -1;

      }

      is_pp_new = 1;

    }

    p = *pp + 2;

  }

  len2 = 2;

  for (i = 0; i < sk_SCT_num(a); i++) {

    if (pp != NULL) {

      p2 = p;

      p += 2;

      if ((sct_len = i2o_SCT(sk_SCT_value(a, i), &p)) == -1)

        goto err;

      s2n(sct_len, p2);

    } else {

      if ((sct_len = i2o_SCT(sk_SCT_value(a, i), NULL)) == -1)

        goto err;

    }

    len2 += 2 + sct_len;

  }

  if (len2 > MAX_SCT_LIST_SIZE)

    goto err;

  if (pp != NULL) {

    p = *pp;

    s2n(len2 - 2, p);

    if (!is_pp_new)

      *pp += len2;

  }

  return len2;

 err:

  if (is_pp_new) {

    free(*pp);

    *pp = NULL;

  }

  return -1;

}

STACK_OF(SCT) *

d2i_SCT_LIST(STACK_OF(SCT) **a, const unsigned char **pp, long len)

{

  ASN1_OCTET_STRING *oct = NULL;

  STACK_OF(SCT) *sk = NULL;

  const unsigned char *p;

  p = *pp;

  if (d2i_ASN1_OCTET_STRING(&oct, &p, len) == NULL)

    return NULL;

  p = oct->data;

  if ((sk = o2i_SCT_LIST(a, &p, oct->length)) != NULL)

    *pp += len;

  ASN1_OCTET_STRING_free(oct);

  return sk;

}

int

i2d_SCT_LIST(const STACK_OF(SCT) *a, unsigned char **out)

{

  ASN1_OCTET_STRING oct;

  int len;

  oct.data = NULL;

  if ((oct.length = i2o_SCT_LIST(a, &oct.data)) == -1)

    return -1;

  len = i2d_ASN1_OCTET_STRING(&oct, out);

  free(oct.data);

  return len;

}