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- // Copyright (c) 2011 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #include "base/hash/sha1.h"
- #include <stddef.h>
- #include <stdint.h>
- #include <string.h>
- #include "base/sys_byteorder.h"
- namespace base {
- // Implementation of SHA-1. Only handles data in byte-sized blocks,
- // which simplifies the code a fair bit.
- // Identifier names follow notation in FIPS PUB 180-3, where you'll
- // also find a description of the algorithm:
- // http://csrc.nist.gov/publications/fips/fips180-3/fips180-3_final.pdf
- // Usage example:
- //
- // SecureHashAlgorithm sha;
- // while(there is data to hash)
- // sha.Update(moredata, size of data);
- // sha.Final();
- // memcpy(somewhere, sha.Digest(), 20);
- //
- // to reuse the instance of sha, call sha.Init();
- static inline uint32_t f(uint32_t t, uint32_t B, uint32_t C, uint32_t D) {
- if (t < 20)
- return (B & C) | ((~B) & D);
- if (t < 40)
- return B ^ C ^ D;
- if (t < 60)
- return (B & C) | (B & D) | (C & D);
- return B ^ C ^ D;
- }
- static inline uint32_t S(uint32_t n, uint32_t X) {
- return (X << n) | (X >> (32 - n));
- }
- static inline uint32_t K(uint32_t t) {
- if (t < 20)
- return 0x5a827999;
- if (t < 40)
- return 0x6ed9eba1;
- if (t < 60)
- return 0x8f1bbcdc;
- return 0xca62c1d6;
- }
- void SHA1Context::Init() {
- A = 0;
- B = 0;
- C = 0;
- D = 0;
- E = 0;
- cursor = 0;
- l = 0;
- H[0] = 0x67452301;
- H[1] = 0xefcdab89;
- H[2] = 0x98badcfe;
- H[3] = 0x10325476;
- H[4] = 0xc3d2e1f0;
- }
- void SHA1Context::Update(const void* data, size_t nbytes) {
- const uint8_t* d = reinterpret_cast<const uint8_t*>(data);
- while (nbytes--) {
- M[cursor++] = *d++;
- if (cursor >= 64) {
- Process();
- }
- l += 8;
- }
- }
- void SHA1Context::Final() {
- Pad();
- Process();
- for (auto& t : H) {
- t = ByteSwap(t);
- }
- }
- const unsigned char* SHA1Context::GetDigest() const {
- return reinterpret_cast<const unsigned char*>(H);
- }
- void SHA1Context::Pad() {
- M[cursor++] = 0x80;
- if (cursor > 64 - 8) {
- // pad out to next block
- while (cursor < 64) {
- M[cursor++] = 0;
- }
- Process();
- }
- while (cursor < 64 - 8) {
- M[cursor++] = 0;
- }
- M[cursor++] = (l >> 56) & 0xff;
- M[cursor++] = (l >> 48) & 0xff;
- M[cursor++] = (l >> 40) & 0xff;
- M[cursor++] = (l >> 32) & 0xff;
- M[cursor++] = (l >> 24) & 0xff;
- M[cursor++] = (l >> 16) & 0xff;
- M[cursor++] = (l >> 8) & 0xff;
- M[cursor++] = l & 0xff;
- }
- void SHA1Context::Process() {
- uint32_t t;
- // Each a...e corresponds to a section in the FIPS 180-3 algorithm.
- // a.
- //
- // W and M are in a union, so no need to memcpy.
- // memcpy(W, M, sizeof(M));
- for (t = 0; t < 16; ++t) {
- W[t] = ByteSwap(W[t]);
- }
- // b.
- for (t = 16; t < 80; ++t) {
- W[t] = S(1, W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16]);
- }
- // c.
- A = H[0];
- B = H[1];
- C = H[2];
- D = H[3];
- E = H[4];
- // d.
- for (t = 0; t < 80; ++t) {
- uint32_t TEMP = S(5, A) + f(t, B, C, D) + E + W[t] + K(t);
- E = D;
- D = C;
- C = S(30, B);
- B = A;
- A = TEMP;
- }
- // e.
- H[0] += A;
- H[1] += B;
- H[2] += C;
- H[3] += D;
- H[4] += E;
- cursor = 0;
- }
- // These functions allow streaming SHA-1 operations.
- void SHA1Init(SHA1Context& context) {
- context.Init();
- }
- void SHA1Update(const StringPiece data, SHA1Context& context) {
- context.Update(data.data(), data.size());
- }
- void SHA1Final(SHA1Context& context, SHA1Digest& digest) {
- context.Final();
- memcpy(digest.data(), context.GetDigest(), kSHA1Length);
- }
- SHA1Digest SHA1HashSpan(span<const uint8_t> data) {
- SHA1Digest hash;
- SHA1HashBytes(data.data(), data.size(), hash.data());
- return hash;
- }
- std::string SHA1HashString(StringPiece str) {
- char hash[kSHA1Length];
- SHA1HashBytes(reinterpret_cast<const unsigned char*>(str.data()),
- str.length(), reinterpret_cast<unsigned char*>(hash));
- return std::string(hash, kSHA1Length);
- }
- void SHA1HashBytes(const unsigned char* data, size_t len, unsigned char* hash) {
- SHA1Context context;
- context.Update(data, len);
- context.Final();
- memcpy(hash, context.GetDigest(), kSHA1Length);
- }
- } // namespace base
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