// Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include <openssl/digest.h>

#include <string.h>

#include <openssl/blake2.h>

#include <openssl/bytestring.h>

#include <openssl/evp_errors.h>

#include <openssl/md4.h>

#include <openssl/md5.h>

#include <openssl/nid.h>

#include <openssl/obj.h>

#include <openssl/sha.h>

#include <openssl/span.h>

#include "../asn1/internal.h"

#include "../fipsmodule/digest/internal.h"

#include "../internal.h"

struct nid_to_digest {

  int nid;

  const EVP_MD *(*md_func)();

  const char *short_name;

  const char *long_name;

};

static const struct nid_to_digest nid_to_digest_mapping[] = {

    {NID_md4, EVP_md4, SN_md4, LN_md4},

    {NID_md5, EVP_md5, SN_md5, LN_md5},

    {NID_sha1, EVP_sha1, SN_sha1, LN_sha1},

    {NID_sha224, EVP_sha224, SN_sha224, LN_sha224},

    {NID_sha256, EVP_sha256, SN_sha256, LN_sha256},

    {NID_sha384, EVP_sha384, SN_sha384, LN_sha384},

    {NID_sha512, EVP_sha512, SN_sha512, LN_sha512},

    {NID_sha512_256, EVP_sha512_256, SN_sha512_256, LN_sha512_256},

    {NID_md5_sha1, EVP_md5_sha1, SN_md5_sha1, LN_md5_sha1},

    // As a remnant of signing |EVP_MD|s, OpenSSL returned the corresponding

    // hash function when given a signature OID. To avoid unintended lax parsing

    // of hash OIDs, this is no longer supported for lookup by OID or NID.

    // Node.js, however, exposes |EVP_get_digestbyname|'s full behavior to

    // consumers so we retain it there.

    {NID_undef, EVP_sha1, SN_dsaWithSHA, LN_dsaWithSHA},

    {NID_undef, EVP_sha1, SN_dsaWithSHA1, LN_dsaWithSHA1},

    {NID_undef, EVP_sha1, SN_ecdsa_with_SHA1, nullptr},

    {NID_undef, EVP_md5, SN_md5WithRSAEncryption, LN_md5WithRSAEncryption},

    {NID_undef, EVP_sha1, SN_sha1WithRSAEncryption, LN_sha1WithRSAEncryption},

    {NID_undef, EVP_sha224, SN_sha224WithRSAEncryption,

     LN_sha224WithRSAEncryption},

    {NID_undef, EVP_sha256, SN_sha256WithRSAEncryption,

     LN_sha256WithRSAEncryption},

    {NID_undef, EVP_sha384, SN_sha384WithRSAEncryption,

     LN_sha384WithRSAEncryption},

    {NID_undef, EVP_sha512, SN_sha512WithRSAEncryption,

     LN_sha512WithRSAEncryption},

};

const EVP_MD *EVP_get_digestbynid(int nid) {

  if (nid == NID_undef) {

    // Skip the |NID_undef| entries in |nid_to_digest_mapping|.

    return nullptr;

  }

  for (const auto &mapping : nid_to_digest_mapping) {

    if (mapping.nid == nid) {

      return mapping.md_func();

    }

  }

  return nullptr;

}

static const struct {

  uint8_t oid[9];

  uint8_t oid_len;

  int nid;

} kMDOIDs[] = {

    // 1.2.840.113549.2.4

    {{0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x04}, 8, NID_md4},

    // 1.2.840.113549.2.5

    {{0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05}, 8, NID_md5},

    // 1.3.14.3.2.26

    {{0x2b, 0x0e, 0x03, 0x02, 0x1a}, 5, NID_sha1},

    // 2.16.840.1.101.3.4.2.1

    {{0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01}, 9, NID_sha256},

    // 2.16.840.1.101.3.4.2.2

    {{0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02}, 9, NID_sha384},

    // 2.16.840.1.101.3.4.2.3

    {{0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03}, 9, NID_sha512},

    // 2.16.840.1.101.3.4.2.4

    {{0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04}, 9, NID_sha224},

};

static int cbs_to_digest_nid(const CBS *cbs) {

  for (const auto &md : kMDOIDs) {

    if (bssl::Span<const uint8_t>(*cbs) ==

        bssl::Span(md.oid).first(md.oid_len)) {

      return md.nid;

    }

  }

  return NID_undef;

}

const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *obj) {

  int nid = obj->nid;

  if (nid == NID_undef) {

    // Handle objects with no saved NID. Note we don't use |OBJ_obj2nid| here to

    // avoid pulling in the OID table.

    CBS cbs;

    CBS_init(&cbs, OBJ_get0_data(obj), OBJ_length(obj));

    nid = cbs_to_digest_nid(&cbs);

  }

  return nid == NID_undef ? nullptr : EVP_get_digestbynid(nid);

}

int EVP_parse_digest_algorithm_nid(CBS *cbs) {

  CBS algorithm, oid;

  if (!CBS_get_asn1(cbs, &algorithm, CBS_ASN1_SEQUENCE) ||

      !CBS_get_asn1(&algorithm, &oid, CBS_ASN1_OBJECT)) {

    OPENSSL_PUT_ERROR(DIGEST, DIGEST_R_DECODE_ERROR);

    return NID_undef;

  }

  int ret = cbs_to_digest_nid(&oid);

  if (ret == NID_undef) {

    OPENSSL_PUT_ERROR(DIGEST, DIGEST_R_UNKNOWN_HASH);

    return NID_undef;

  }

  // The parameters, if present, must be NULL. Historically, whether the NULL

  // was included or omitted was not well-specified. When parsing an

  // AlgorithmIdentifier, we allow both. (Note this code is not used when

  // verifying RSASSA-PKCS1-v1_5 signatures.)

  if (CBS_len(&algorithm) > 0) {

    CBS param;

    if (!CBS_get_asn1(&algorithm, &param, CBS_ASN1_NULL) ||

        CBS_len(&param) != 0 ||  //

        CBS_len(&algorithm) != 0) {

      OPENSSL_PUT_ERROR(DIGEST, DIGEST_R_DECODE_ERROR);

      return NID_undef;

    }

  }

  return ret;

}

const EVP_MD *EVP_parse_digest_algorithm(CBS *cbs) {

  int nid = EVP_parse_digest_algorithm_nid(cbs);

  if (nid == NID_undef) {

    return nullptr;

  }

  return EVP_get_digestbynid(nid);

}

static int marshal_digest_algorithm(CBB *cbb, const EVP_MD *md,

                                    bool with_null) {

  CBB algorithm, oid, null;

  if (!CBB_add_asn1(cbb, &algorithm, CBS_ASN1_SEQUENCE) ||

      !CBB_add_asn1(&algorithm, &oid, CBS_ASN1_OBJECT)) {

    return 0;

  }

  bool found = false;

  int nid = EVP_MD_type(md);

  for (const auto &mdoid : kMDOIDs) {

    if (nid == mdoid.nid) {

      if (!CBB_add_bytes(&oid, mdoid.oid, mdoid.oid_len)) {

        return 0;

      }

      found = true;

      break;

    }

  }

  if (!found) {

    OPENSSL_PUT_ERROR(DIGEST, DIGEST_R_UNKNOWN_HASH);

    return 0;

  }

  if ((with_null && !CBB_add_asn1(&algorithm, &null, CBS_ASN1_NULL)) ||  //

      !CBB_flush(cbb)) {

    return 0;

  }

  return 1;

}

int EVP_marshal_digest_algorithm(CBB *cbb, const EVP_MD *md) {

  return marshal_digest_algorithm(cbb, md, /*with_null=*/true);

}

int EVP_marshal_digest_algorithm_no_params(CBB *cbb, const EVP_MD *md) {

  return marshal_digest_algorithm(cbb, md, /*with_null=*/false);

}

const EVP_MD *EVP_get_digestbyname(const char *name) {

  for (const auto &mapping : nid_to_digest_mapping) {

    const char *short_name = mapping.short_name;

    const char *long_name = mapping.long_name;

    if ((short_name && strcmp(short_name, name) == 0) ||

        (long_name && strcmp(long_name, name) == 0)) {

      return mapping.md_func();

    }

  }

  return nullptr;

}

EVP_MD *EVP_MD_fetch(OSSL_LIB_CTX *libctx, const char *name,

                     const char *propq) {

  EVP_MD *ret = const_cast<EVP_MD *>(EVP_get_digestbyname(name));

  if (ret == nullptr) {

    OPENSSL_PUT_ERROR(EVP, EVP_R_UNSUPPORTED_ALGORITHM);

  }

  return ret;

}

int EVP_MD_up_ref(EVP_MD *md) { return 1; }

void EVP_MD_free(EVP_MD *md) {}

int EVP_Q_digest(OSSL_LIB_CTX *libctx, const char *name, const char *propq,

                 const void *in, size_t in_len, uint8_t *out, size_t *out_len) {

  const EVP_MD *md = EVP_MD_fetch(libctx, name, propq);

  if (md == nullptr) {

    return 0;

  }

  unsigned len_u;

  if (!EVP_Digest(in, in_len, out, &len_u, md, nullptr)) {

    return 0;

  }

  *out_len = len_u;

  return 1;

}

static void blake2b256_init(EVP_MD_CTX *ctx) {

  BLAKE2B256_Init(reinterpret_cast<BLAKE2B_CTX *>(ctx->md_data));

}

static void blake2b256_update(EVP_MD_CTX *ctx, const void *data, size_t len) {

  BLAKE2B256_Update(reinterpret_cast<BLAKE2B_CTX *>(ctx->md_data), data, len);

}

static void blake2b256_final(EVP_MD_CTX *ctx, uint8_t *md) {

  BLAKE2B256_Final(md, reinterpret_cast<BLAKE2B_CTX *>(ctx->md_data));

}

static const EVP_MD evp_md_blake2b256 = {

    NID_undef,       BLAKE2B256_DIGEST_LENGTH, 0,

    blake2b256_init, blake2b256_update,        blake2b256_final,

    BLAKE2B_CBLOCK,  sizeof(BLAKE2B_CTX),

};

const EVP_MD *EVP_blake2b256() { return &evp_md_blake2b256; }

static_assert(sizeof(BLAKE2B_CTX) <= EVP_MAX_MD_DATA_SIZE);

static void md4_init(EVP_MD_CTX *ctx) {

  BSSL_CHECK(MD4_Init(reinterpret_cast<MD4_CTX *>(ctx->md_data)));

}

static void md4_update(EVP_MD_CTX *ctx, const void *data, size_t count) {

  BSSL_CHECK(

      MD4_Update(reinterpret_cast<MD4_CTX *>(ctx->md_data), data, count));

}

static void md4_final(EVP_MD_CTX *ctx, uint8_t *out) {

  BSSL_CHECK(MD4_Final(out, reinterpret_cast<MD4_CTX *>(ctx->md_data)));

}

static const EVP_MD evp_md_md4 = {

    NID_md4,            //

    MD4_DIGEST_LENGTH,  //

    0,

    md4_init,

    md4_update,

    md4_final,

    64,

    sizeof(MD4_CTX),

};

const EVP_MD *EVP_md4() { return &evp_md_md4; }

static_assert(sizeof(MD4_CTX) <= EVP_MAX_MD_DATA_SIZE);

static void md5_init(EVP_MD_CTX *ctx) {

  BSSL_CHECK(MD5_Init(reinterpret_cast<MD5_CTX *>(ctx->md_data)));

}

static void md5_update(EVP_MD_CTX *ctx, const void *data, size_t count) {

  BSSL_CHECK(

      MD5_Update(reinterpret_cast<MD5_CTX *>(ctx->md_data), data, count));

}

static void md5_final(EVP_MD_CTX *ctx, uint8_t *out) {

  BSSL_CHECK(MD5_Final(out, reinterpret_cast<MD5_CTX *>(ctx->md_data)));

}

static const EVP_MD evp_md_md5 = {

    NID_md5,    MD5_DIGEST_LENGTH, 0,  md5_init,

    md5_update, md5_final,         64, sizeof(MD5_CTX),

};

const EVP_MD *EVP_md5() { return &evp_md_md5; }

static_assert(sizeof(MD5_CTX) <= EVP_MAX_MD_DATA_SIZE);

typedef struct {

  MD5_CTX md5;

  SHA_CTX sha1;

} MD5_SHA1_CTX;

static void md5_sha1_init(EVP_MD_CTX *md_ctx) {

  MD5_SHA1_CTX *ctx = reinterpret_cast<MD5_SHA1_CTX *>(md_ctx->md_data);

  BSSL_CHECK(MD5_Init(&ctx->md5) && SHA1_Init(&ctx->sha1));

}

static void md5_sha1_update(EVP_MD_CTX *md_ctx, const void *data,

                            size_t count) {

  MD5_SHA1_CTX *ctx = reinterpret_cast<MD5_SHA1_CTX *>(md_ctx->md_data);

  BSSL_CHECK(MD5_Update(&ctx->md5, data, count) &&

             SHA1_Update(&ctx->sha1, data, count));

}

static void md5_sha1_final(EVP_MD_CTX *md_ctx, uint8_t *out) {

  MD5_SHA1_CTX *ctx = reinterpret_cast<MD5_SHA1_CTX *>(md_ctx->md_data);

  BSSL_CHECK(MD5_Final(out, &ctx->md5) &&

             SHA1_Final(out + MD5_DIGEST_LENGTH, &ctx->sha1));

}

const EVP_MD evp_md_md5_sha1 = {

    NID_md5_sha1,

    MD5_DIGEST_LENGTH + SHA_DIGEST_LENGTH,

    0,

    md5_sha1_init,

    md5_sha1_update,

    md5_sha1_final,

    64,

    sizeof(MD5_SHA1_CTX),

};

const EVP_MD *EVP_md5_sha1() { return &evp_md_md5_sha1; }

static_assert(sizeof(MD5_SHA1_CTX) <= EVP_MAX_MD_DATA_SIZE);