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/*
* Copyright 2011 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "rtc_base/message_digest.h"
#include <string.h>
#include <cstdint>
#include <memory>
#include "absl/strings/string_view.h"
#include "rtc_base/openssl_digest.h"
#include "rtc_base/string_encode.h"
namespace rtc {
// From RFC 4572.
const char DIGEST_MD5[] = "md5";
const char DIGEST_SHA_1[] = "sha-1";
const char DIGEST_SHA_224[] = "sha-224";
const char DIGEST_SHA_256[] = "sha-256";
const char DIGEST_SHA_384[] = "sha-384";
const char DIGEST_SHA_512[] = "sha-512";
static const size_t kBlockSize = 64; // valid for SHA-256 and down
MessageDigest* MessageDigestFactory::Create(absl::string_view alg) {
MessageDigest* digest = new OpenSSLDigest(alg);
if (digest->Size() == 0) { // invalid algorithm
delete digest;
digest = nullptr;
}
return digest;
}
bool IsFips180DigestAlgorithm(absl::string_view alg) {
// These are the FIPS 180 algorithms. According to RFC 4572 Section 5,
// "Self-signed certificates (for which legacy certificates are not a
// consideration) MUST use one of the FIPS 180 algorithms (SHA-1,
// SHA-224, SHA-256, SHA-384, or SHA-512) as their signature algorithm,
// and thus also MUST use it to calculate certificate fingerprints."
return alg == DIGEST_SHA_1 || alg == DIGEST_SHA_224 ||
alg == DIGEST_SHA_256 || alg == DIGEST_SHA_384 ||
alg == DIGEST_SHA_512;
}
size_t ComputeDigest(MessageDigest* digest,
const void* input,
size_t in_len,
void* output,
size_t out_len) {
digest->Update(input, in_len);
return digest->Finish(output, out_len);
}
size_t ComputeDigest(absl::string_view alg,
const void* input,
size_t in_len,
void* output,
size_t out_len) {
std::unique_ptr<MessageDigest> digest(MessageDigestFactory::Create(alg));
return (digest) ? ComputeDigest(digest.get(), input, in_len, output, out_len)
: 0;
}
std::string ComputeDigest(MessageDigest* digest, absl::string_view input) {
std::unique_ptr<char[]> output(new char[digest->Size()]);
ComputeDigest(digest, input.data(), input.size(), output.get(),
digest->Size());
return hex_encode(absl::string_view(output.get(), digest->Size()));
}
bool ComputeDigest(absl::string_view alg,
absl::string_view input,
std::string* output) {
std::unique_ptr<MessageDigest> digest(MessageDigestFactory::Create(alg));
if (!digest) {
return false;
}
*output = ComputeDigest(digest.get(), input);
return true;
}
std::string ComputeDigest(absl::string_view alg, absl::string_view input) {
std::string output;
ComputeDigest(alg, input, &output);
return output;
}
// Compute a RFC 2104 HMAC: H(K XOR opad, H(K XOR ipad, text))
size_t ComputeHmac(MessageDigest* digest,
const void* key,
size_t key_len,
const void* input,
size_t in_len,
void* output,
size_t out_len) {
// We only handle algorithms with a 64-byte blocksize.
// TODO: Add BlockSize() method to MessageDigest.
size_t block_len = kBlockSize;
if (digest->Size() > 32) {
return 0;
}
// Copy the key to a block-sized buffer to simplify padding.
// If the key is longer than a block, hash it and use the result instead.
std::unique_ptr<uint8_t[]> new_key(new uint8_t[block_len]);
if (key_len > block_len) {
ComputeDigest(digest, key, key_len, new_key.get(), block_len);
memset(new_key.get() + digest->Size(), 0, block_len - digest->Size());
} else {
memcpy(new_key.get(), key, key_len);
memset(new_key.get() + key_len, 0, block_len - key_len);
}
// Set up the padding from the key, salting appropriately for each padding.
std::unique_ptr<uint8_t[]> o_pad(new uint8_t[block_len]);
std::unique_ptr<uint8_t[]> i_pad(new uint8_t[block_len]);
for (size_t i = 0; i < block_len; ++i) {
o_pad[i] = 0x5c ^ new_key[i];
i_pad[i] = 0x36 ^ new_key[i];
}
// Inner hash; hash the inner padding, and then the input buffer.
std::unique_ptr<uint8_t[]> inner(new uint8_t[digest->Size()]);
digest->Update(i_pad.get(), block_len);
digest->Update(input, in_len);
digest->Finish(inner.get(), digest->Size());
// Outer hash; hash the outer padding, and then the result of the inner hash.
digest->Update(o_pad.get(), block_len);
digest->Update(inner.get(), digest->Size());
return digest->Finish(output, out_len);
}
size_t ComputeHmac(absl::string_view alg,
const void* key,
size_t key_len,
const void* input,
size_t in_len,
void* output,
size_t out_len) {
std::unique_ptr<MessageDigest> digest(MessageDigestFactory::Create(alg));
if (!digest) {
return 0;
}
return ComputeHmac(digest.get(), key, key_len, input, in_len, output,
out_len);
}
std::string ComputeHmac(MessageDigest* digest,
absl::string_view key,
absl::string_view input) {
std::unique_ptr<char[]> output(new char[digest->Size()]);
ComputeHmac(digest, key.data(), key.size(), input.data(), input.size(),
output.get(), digest->Size());
return hex_encode(absl::string_view(output.get(), digest->Size()));
}
bool ComputeHmac(absl::string_view alg,
absl::string_view key,
absl::string_view input,
std::string* output) {
std::unique_ptr<MessageDigest> digest(MessageDigestFactory::Create(alg));
if (!digest) {
return false;
}
*output = ComputeHmac(digest.get(), key, input);
return true;
}
std::string ComputeHmac(absl::string_view alg,
absl::string_view key,
absl::string_view input) {
std::string output;
ComputeHmac(alg, key, input, &output);
return output;
}
} // namespace rtc
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