/* $OpenBSD: ssl_transcript.c,v 1.9 2022/11/26 16:08:56 tb Exp $ */

/*

 * Copyright (c) 2017 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 <openssl/ssl.h>

#include "ssl_local.h"

#include "tls_internal.h"

int

tls1_transcript_hash_init(SSL *s)

{

  const unsigned char *data;

  const EVP_MD *md;

  size_t len;

  tls1_transcript_hash_free(s);

  if (!ssl_get_handshake_evp_md(s, &md)) {

    SSLerrorx(ERR_R_INTERNAL_ERROR);

    goto err;

  }

  if ((s->s3->handshake_hash = EVP_MD_CTX_new()) == NULL) {

    SSLerror(s, ERR_R_MALLOC_FAILURE);

    goto err;

  }

  if (!EVP_DigestInit_ex(s->s3->handshake_hash, md, NULL)) {

    SSLerror(s, ERR_R_EVP_LIB);

    goto err;

  }

  if (!tls1_transcript_data(s, &data, &len)) {

    SSLerror(s, SSL_R_BAD_HANDSHAKE_LENGTH);

    goto err;

  }

  if (!tls1_transcript_hash_update(s, data, len)) {

    SSLerror(s, ERR_R_EVP_LIB);

    goto err;

  }

  return 1;

 err:

  tls1_transcript_hash_free(s);

  return 0;

}

int

tls1_transcript_hash_update(SSL *s, const unsigned char *buf, size_t len)

{

  if (s->s3->handshake_hash == NULL)

    return 1;

  return EVP_DigestUpdate(s->s3->handshake_hash, buf, len);

}

int

tls1_transcript_hash_value(SSL *s, unsigned char *out, size_t len,

    size_t *outlen)

{

  EVP_MD_CTX *mdctx = NULL;

  unsigned int mdlen;

  int ret = 0;

  if (s->s3->handshake_hash == NULL)

    goto err;

  if (EVP_MD_CTX_size(s->s3->handshake_hash) > len)

    goto err;

  if ((mdctx = EVP_MD_CTX_new()) == NULL) {

    SSLerror(s, ERR_R_MALLOC_FAILURE);

    goto err;

  }

  if (!EVP_MD_CTX_copy_ex(mdctx, s->s3->handshake_hash)) {

    SSLerror(s, ERR_R_EVP_LIB);

    goto err;

  }

  if (!EVP_DigestFinal_ex(mdctx, out, &mdlen)) {

    SSLerror(s, ERR_R_EVP_LIB);

    goto err;

  }

  if (outlen != NULL)

    *outlen = mdlen;

  ret = 1;

 err:

  EVP_MD_CTX_free(mdctx);

  return (ret);

}

void

tls1_transcript_hash_free(SSL *s)

{

  EVP_MD_CTX_free(s->s3->handshake_hash);

  s->s3->handshake_hash = NULL;

}

int

tls1_transcript_init(SSL *s)

{

  if (s->s3->handshake_transcript != NULL)

    return 0;

  if ((s->s3->handshake_transcript = tls_buffer_new(0)) == NULL)

    return 0;

  tls1_transcript_reset(s);

  return 1;

}

void

tls1_transcript_free(SSL *s)

{

  tls_buffer_free(s->s3->handshake_transcript);

  s->s3->handshake_transcript = NULL;

}

void

tls1_transcript_reset(SSL *s)

{

  tls_buffer_clear(s->s3->handshake_transcript);

  tls1_transcript_unfreeze(s);

}

int

tls1_transcript_append(SSL *s, const unsigned char *buf, size_t len)

{

  if (s->s3->handshake_transcript == NULL)

    return 1;

  if (s->s3->flags & TLS1_FLAGS_FREEZE_TRANSCRIPT)

    return 1;

  return tls_buffer_append(s->s3->handshake_transcript, buf, len);

}

int

tls1_transcript_data(SSL *s, const unsigned char **data, size_t *len)

{

  CBS cbs;

  if (s->s3->handshake_transcript == NULL)

    return 0;

  if (!tls_buffer_data(s->s3->handshake_transcript, &cbs))

    return 0;

  /* XXX - change to caller providing a CBS argument. */

  *data = CBS_data(&cbs);

  *len = CBS_len(&cbs);

  return 1;

}

void

tls1_transcript_freeze(SSL *s)

{

  s->s3->flags |= TLS1_FLAGS_FREEZE_TRANSCRIPT;

}

void

tls1_transcript_unfreeze(SSL *s)

{

  s->s3->flags &= ~TLS1_FLAGS_FREEZE_TRANSCRIPT;

}

int

tls1_transcript_record(SSL *s, const unsigned char *buf, size_t len)

{

  if (!tls1_transcript_hash_update(s, buf, len))

    return 0;

  if (!tls1_transcript_append(s, buf, len))

    return 0;

  return 1;

}