[llvm/Support] Add SHA256 implementation

[cynecx]

Summary

Adds an *unaudited* SHA-256 implementation to llvm/Support. The ongoing lld-macho effort needs this to emit an adhoc code signature for macho files on macOS Big Sur.

[cynecx]

Cleanup

[smeenai]

Adding some reviewers who've contributed to the SHA1 implementation.

[mehdi_amini]

LGTM

[cynecx]

@mehdi_amini Thanks for the review. I don't have commit rights. I'd be great if someone could commit this!

[mehdi_amini]

I'll wait a couple of days to see if anyone has a concern with this, ping me on Monday if I forget :)

Can you also add the motivation in the description? What are you planning to use this for?

[cynecx]

I'll wait a couple of days to see if anyone has a concern with this, ping me on Monday if I forget :)

Will do :)

Can you also add the motivation in the description? What are you planning to use this for?

SHA-256 hashing is required for https://reviews.llvm.org/D96164 (lld needs this to emit an adhoc code signature for macho files on macOS Big Sur).

[mehdi_amini]

What do you want for author information? Right now I have "cynecx <[e-mail]>"

[cynecx]

@mehdi_amini That's alright. Thank You!

llvm/include/llvm/Support/SHA256.h

+//====- SHA256.cpp - SHA256 implementation ---*- C++ -* ======//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+/*
+ *  The SHA-256 Secure Hash Standard was published by NIST in 2002.
+ *
+ *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
+ *
+ *   The implementation is based on nacl's sha256 implementation [0] and LLVM's
+ *  pre-exsiting SHA1 code [1].
+ *
+ *   [0] https://hyperelliptic.org/nacl/nacl-20110221.tar.bz2 (public domain
+ *       code)
+ *   [1] llvm/lib/Support/SHA1.{h,cpp}
+ */
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_SHA2_H
+#define LLVM_SUPPORT_SHA2_H
+
+#include <array>
+#include <cstdint>
+
+namespace llvm {
+
+template <typename T> class ArrayRef;
+class StringRef;
+
+class SHA256 {
+public:
+  explicit SHA256() { init(); }
+
+  /// Reinitialize the internal state
+  void init();
+
+  /// Digest more data.
+  void update(ArrayRef<uint8_t> Data);
+
+  /// Digest more data.
+  void update(StringRef Str);
+
+  /// Return a reference to the current raw 256-bits SHA256 for the digested
+  /// data since the last call to init(). This call will add data to the
+  /// internal state and as such is not suited for getting an intermediate
+  /// result (see result()).
+  StringRef final();
+
+  /// Return a reference to the current raw 256-bits SHA256 for the digested
+  /// data since the last call to init(). This is suitable for getting the
+  /// SHA256 at any time without invalidating the internal state so that more
+  /// calls can be made into update.
+  StringRef result();
+
+  /// Returns a raw 256-bit SHA256 hash for the given data.
+  static std::array<uint8_t, 32> hash(ArrayRef<uint8_t> Data);
+
+private:
+  /// Define some constants.
+  /// "static constexpr" would be cleaner but MSVC does not support it yet.
+  enum { BLOCK_LENGTH = 64 };
+  enum { HASH_LENGTH = 32 };
+
+  // Internal State
+  struct {
+    union {
+      uint8_t C[BLOCK_LENGTH];
+      uint32_t L[BLOCK_LENGTH / 4];
+    } Buffer;
+    uint32_t State[HASH_LENGTH / 4];
+    uint32_t ByteCount;
+    uint8_t BufferOffset;
+  } InternalState;
+
+  // Internal copy of the hash, populated and accessed on calls to result()
+  uint32_t HashResult[HASH_LENGTH / 4];
+
+  // Helper
+  void writebyte(uint8_t data);
+  void hashBlock();
+  void addUncounted(uint8_t data);
+  void pad();
+};
+
+} // namespace llvm
+
+#endif // LLVM_SUPPORT_SHA2_H

llvm/lib/Support/CMakeLists.txt

add_llvm_component_library(LLVMSupport
   PrettyStackTrace.cpp
   RandomNumberGenerator.cpp
   Regex.cpp
   RISCVAttributes.cpp
   RISCVAttributeParser.cpp
   ScaledNumber.cpp
   ScopedPrinter.cpp
   SHA1.cpp
+  SHA256.cpp
   Signposts.cpp
   SmallPtrSet.cpp
   SmallVector.cpp
   SourceMgr.cpp
   SpecialCaseList.cpp
   Statistic.cpp
   StringExtras.cpp
   StringMap.cpp

llvm/lib/Support/SHA256.cpp

+//====- SHA256.cpp - SHA256 implementation ---*- C++ -* ======//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+/*
+ *  The SHA-256 Secure Hash Standard was published by NIST in 2002.
+ *
+ *  http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf
+ *
+ *   The implementation is based on nacl's sha256 implementation [0] and LLVM's
+ *  pre-exsiting SHA1 code [1].
+ *
+ *   [0] https://hyperelliptic.org/nacl/nacl-20110221.tar.bz2 (public domain
+ *       code)
+ *   [1] llvm/lib/Support/SHA1.{h,cpp}
+ */
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/SHA256.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Host.h"
+#include <string.h>
+
+namespace llvm {
+
+#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
+#define SHA_BIG_ENDIAN
+#endif
+
+#define SHR(x, c) ((x) >> (c))
+#define ROTR(x, n) (((x) >> n) | ((x) << (32 - (n))))
+
+#define CH(x, y, z) (((x) & (y)) ^ (~(x) & (z)))
+#define MAJ(x, y, z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
+
+#define SIGMA_0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define SIGMA_1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+
+#define SIGMA_2(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHR(x, 10))
+#define SIGMA_3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHR(x, 3))
+
+#define F_EXPAND(A, B, C, D, E, F, G, H, M1, M2, M3, M4, k)                    \
+  do {                                                                         \
+    H += SIGMA_1(E) + CH(E, F, G) + M1 + k;                                    \
+    D += H;                                                                    \
+    H += SIGMA_0(A) + MAJ(A, B, C);                                            \
+    M1 += SIGMA_2(M2) + M3 + SIGMA_3(M4);                                      \
+  } while (0);
+
+void SHA256::init() {
+  InternalState.State[0] = 0x6A09E667;
+  InternalState.State[1] = 0xBB67AE85;
+  InternalState.State[2] = 0x3C6EF372;
+  InternalState.State[3] = 0xA54FF53A;
+  InternalState.State[4] = 0x510E527F;
+  InternalState.State[5] = 0x9B05688C;
+  InternalState.State[6] = 0x1F83D9AB;
+  InternalState.State[7] = 0x5BE0CD19;
+  InternalState.ByteCount = 0;
+  InternalState.BufferOffset = 0;
+}
+
+void SHA256::hashBlock() {
+  uint32_t A = InternalState.State[0];
+  uint32_t B = InternalState.State[1];
+  uint32_t C = InternalState.State[2];
+  uint32_t D = InternalState.State[3];
+  uint32_t E = InternalState.State[4];
+  uint32_t F = InternalState.State[5];
+  uint32_t G = InternalState.State[6];
+  uint32_t H = InternalState.State[7];
+
+  uint32_t W00 = InternalState.Buffer.L[0];
+  uint32_t W01 = InternalState.Buffer.L[1];
+  uint32_t W02 = InternalState.Buffer.L[2];
+  uint32_t W03 = InternalState.Buffer.L[3];
+  uint32_t W04 = InternalState.Buffer.L[4];
+  uint32_t W05 = InternalState.Buffer.L[5];
+  uint32_t W06 = InternalState.Buffer.L[6];
+  uint32_t W07 = InternalState.Buffer.L[7];
+  uint32_t W08 = InternalState.Buffer.L[8];
+  uint32_t W09 = InternalState.Buffer.L[9];
+  uint32_t W10 = InternalState.Buffer.L[10];
+  uint32_t W11 = InternalState.Buffer.L[11];
+  uint32_t W12 = InternalState.Buffer.L[12];
+  uint32_t W13 = InternalState.Buffer.L[13];
+  uint32_t W14 = InternalState.Buffer.L[14];
+  uint32_t W15 = InternalState.Buffer.L[15];
+
+  F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x428A2F98);
+  F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x71374491);
+  F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0xB5C0FBCF);
+  F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0xE9B5DBA5);
+  F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x3956C25B);
+  F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x59F111F1);
+  F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x923F82A4);
+  F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0xAB1C5ED5);
+  F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0xD807AA98);
+  F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0x12835B01);
+  F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0x243185BE);
+  F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0x550C7DC3);
+  F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0x72BE5D74);
+  F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0x80DEB1FE);
+  F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0x9BDC06A7);
+  F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0xC19BF174);
+
+  F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0xE49B69C1);
+  F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0xEFBE4786);
+  F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x0FC19DC6);
+  F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x240CA1CC);
+  F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x2DE92C6F);
+  F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x4A7484AA);
+  F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x5CB0A9DC);
+  F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x76F988DA);
+  F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0x983E5152);
+  F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0xA831C66D);
+  F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0xB00327C8);
+  F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0xBF597FC7);
+  F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0xC6E00BF3);
+  F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xD5A79147);
+  F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0x06CA6351);
+  F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0x14292967);
+
+  F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x27B70A85);
+  F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x2E1B2138);
+  F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x4D2C6DFC);
+  F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x53380D13);
+  F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x650A7354);
+  F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x766A0ABB);
+  F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x81C2C92E);
+  F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x92722C85);
+  F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0xA2BFE8A1);
+  F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0xA81A664B);
+  F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0xC24B8B70);
+  F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0xC76C51A3);
+  F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0xD192E819);
+  F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xD6990624);
+  F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0xF40E3585);
+  F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0x106AA070);
+
+  F_EXPAND(A, B, C, D, E, F, G, H, W00, W14, W09, W01, 0x19A4C116);
+  F_EXPAND(H, A, B, C, D, E, F, G, W01, W15, W10, W02, 0x1E376C08);
+  F_EXPAND(G, H, A, B, C, D, E, F, W02, W00, W11, W03, 0x2748774C);
+  F_EXPAND(F, G, H, A, B, C, D, E, W03, W01, W12, W04, 0x34B0BCB5);
+  F_EXPAND(E, F, G, H, A, B, C, D, W04, W02, W13, W05, 0x391C0CB3);
+  F_EXPAND(D, E, F, G, H, A, B, C, W05, W03, W14, W06, 0x4ED8AA4A);
+  F_EXPAND(C, D, E, F, G, H, A, B, W06, W04, W15, W07, 0x5B9CCA4F);
+  F_EXPAND(B, C, D, E, F, G, H, A, W07, W05, W00, W08, 0x682E6FF3);
+  F_EXPAND(A, B, C, D, E, F, G, H, W08, W06, W01, W09, 0x748F82EE);
+  F_EXPAND(H, A, B, C, D, E, F, G, W09, W07, W02, W10, 0x78A5636F);
+  F_EXPAND(G, H, A, B, C, D, E, F, W10, W08, W03, W11, 0x84C87814);
+  F_EXPAND(F, G, H, A, B, C, D, E, W11, W09, W04, W12, 0x8CC70208);
+  F_EXPAND(E, F, G, H, A, B, C, D, W12, W10, W05, W13, 0x90BEFFFA);
+  F_EXPAND(D, E, F, G, H, A, B, C, W13, W11, W06, W14, 0xA4506CEB);
+  F_EXPAND(C, D, E, F, G, H, A, B, W14, W12, W07, W15, 0xBEF9A3F7);
+  F_EXPAND(B, C, D, E, F, G, H, A, W15, W13, W08, W00, 0xC67178F2);
+
+  InternalState.State[0] += A;
+  InternalState.State[1] += B;
+  InternalState.State[2] += C;
+  InternalState.State[3] += D;
+  InternalState.State[4] += E;
+  InternalState.State[5] += F;
+  InternalState.State[6] += G;
+  InternalState.State[7] += H;
+}
+
+void SHA256::addUncounted(uint8_t Data) {
+#ifdef SHA_BIG_ENDIAN
+  InternalState.Buffer.C[InternalState.BufferOffset] = Data;
+#else
+  InternalState.Buffer.C[InternalState.BufferOffset ^ 3] = Data;
+#endif
+
+  InternalState.BufferOffset++;
+  if (InternalState.BufferOffset == BLOCK_LENGTH) {
+    hashBlock();
+    InternalState.BufferOffset = 0;
+  }
+}
+
+void SHA256::writebyte(uint8_t Data) {
+  ++InternalState.ByteCount;
+  addUncounted(Data);
+}
+
+void SHA256::update(ArrayRef<uint8_t> Data) {
+  InternalState.ByteCount += Data.size();
+
+  // Finish the current block.
+  if (InternalState.BufferOffset > 0) {
+    const size_t Remainder = std::min<size_t>(
+        Data.size(), BLOCK_LENGTH - InternalState.BufferOffset);
+    for (size_t I = 0; I < Remainder; ++I)
+      addUncounted(Data[I]);
+    Data = Data.drop_front(Remainder);
+  }
+
+  // Fast buffer filling for large inputs.
+  while (Data.size() >= BLOCK_LENGTH) {
+    assert(InternalState.BufferOffset == 0);
+    assert(BLOCK_LENGTH % 4 == 0);
+    constexpr size_t BLOCK_LENGTH_32 = BLOCK_LENGTH / 4;
+    for (size_t I = 0; I < BLOCK_LENGTH_32; ++I)
+      InternalState.Buffer.L[I] = support::endian::read32be(&Data[I * 4]);
+    hashBlock();
+    Data = Data.drop_front(BLOCK_LENGTH);
+  }
+
+  // Finish the remainder.
+  for (uint8_t C : Data)
+    addUncounted(C);
+}
+
+void SHA256::update(StringRef Str) {
+  update(
+      ArrayRef<uint8_t>((uint8_t *)const_cast<char *>(Str.data()), Str.size()));
+}
+
+void SHA256::pad() {
+  // Implement SHA-2 padding (fips180-2 5.1.1)
+
+  // Pad with 0x80 followed by 0x00 until the end of the block
+  addUncounted(0x80);
+  while (InternalState.BufferOffset != 56)
+    addUncounted(0x00);
+
+  uint64_t len = InternalState.ByteCount << 3; // bit size
+
+  // Append length in the last 8 bytes big edian encoded
+  addUncounted(len >> 56);
+  addUncounted(len >> 48);
+  addUncounted(len >> 40);
+  addUncounted(len >> 32);
+  addUncounted(len >> 24);
+  addUncounted(len >> 16);
+  addUncounted(len >> 8);
+  addUncounted(len);
+}
+
+StringRef SHA256::final() {
+  // Pad to complete the last block
+  pad();
+
+#ifdef SHA_BIG_ENDIAN
+  // Just copy the current state
+  for (int i = 0; i < 8; i++) {
+    HashResult[i] = InternalState.State[i];
+  }
+#else
+  // Swap byte order back
+  for (int i = 0; i < 8; i++) {
+    HashResult[i] = (((InternalState.State[i]) << 24) & 0xff000000) |
+                    (((InternalState.State[i]) << 8) & 0x00ff0000) |
+                    (((InternalState.State[i]) >> 8) & 0x0000ff00) |
+                    (((InternalState.State[i]) >> 24) & 0x000000ff);
+  }
+#endif
+
+  // Return pointer to hash (32 characters)
+  return StringRef((char *)HashResult, HASH_LENGTH);
+}
+
+StringRef SHA256::result() {
+  auto StateToRestore = InternalState;
+
+  auto Hash = final();
+
+  // Restore the state
+  InternalState = StateToRestore;
+
+  // Return pointer to hash (32 characters)
+  return Hash;
+}
+
+std::array<uint8_t, 32> SHA256::hash(ArrayRef<uint8_t> Data) {
+  SHA256 Hash;
+  Hash.update(Data);
+  StringRef S = Hash.final();
+
+  std::array<uint8_t, 32> Arr;
+  memcpy(Arr.data(), S.data(), S.size());
+  return Arr;
+}
+
+} // namespace llvm
 No newline at end of file

llvm/unittests/Support/CMakeLists.txt

add_llvm_unittest(SupportTests
   Path.cpp
   ProcessTest.cpp
   ProgramTest.cpp
   RegexTest.cpp
   ReverseIterationTest.cpp
   ReplaceFileTest.cpp
   RISCVAttributeParserTest.cpp
   ScaledNumberTest.cpp
+  SHA256.cpp
   SourceMgrTest.cpp
   SpecialCaseListTest.cpp
   SuffixTreeTest.cpp
   SwapByteOrderTest.cpp
   SymbolRemappingReaderTest.cpp
   TarWriterTest.cpp
   TargetParserTest.cpp
   TaskQueueTest.cpp

llvm/unittests/Support/SHA256.cpp

+//===- llvm/unittest/Support/SHA256Test.cpp - SHA256 tests
+//----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements unit tests for the SHA256 functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/SHA256.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallString.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace {
+
+static std::string toHex(StringRef Input) {
+  static const char *const LUT = "0123456789abcdef";
+  size_t Length = Input.size();
+
+  std::string Output;
+  Output.reserve(2 * Length);
+  for (size_t i = 0; i < Length; ++i) {
+    const unsigned char c = Input[i];
+    Output.push_back(LUT[c >> 4]);
+    Output.push_back(LUT[c & 15]);
+  }
+  return Output;
+}
+
+/// Tests an arbitrary set of bytes passed as \p Input.
+void TestSHA256Sum(ArrayRef<uint8_t> Input, StringRef Final) {
+  SHA256 Hash;
+  Hash.update(Input);
+  auto hash = Hash.final();
+  auto hashStr = toHex(hash);
+  EXPECT_EQ(hashStr, Final);
+}
+
+using KV = std::pair<const char *, const char *>;
+
+TEST(SHA256Test, SHA256) {
+  std::array<KV, 5> testvectors{
+      KV{"",
+         "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"},
+      KV{"a",
+         "ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb"},
+      KV{"abc",
+         "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"},
+      KV{"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
+         "248d6a61d20638b8e5c026930c3e6039a33ce45964ff2167f6ecedd419db06c1"},
+      KV{"abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmnhijklmnoijklm"
+         "nopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
+         "cf5b16a778af8380036ce59e7b0492370b249b11e8f07a51afac45037afee9d1"}};
+
+  for (auto input_expected : testvectors) {
+    auto str = std::get<0>(input_expected);
+    auto expected = std::get<1>(input_expected);
+    TestSHA256Sum({reinterpret_cast<const uint8_t *>(str), strlen(str)},
+                  expected);
+  }
+
+  std::string rep(1000, 'a');
+  SHA256 Hash;
+  for (int i = 0; i < 1000; ++i) {
+    Hash.update({reinterpret_cast<const uint8_t *>(rep.data()), rep.size()});
+  }
+  auto hash = Hash.final();
+  auto hashStr = toHex(hash);
+  EXPECT_EQ(hashStr,
+            "cdc76e5c9914fb9281a1c7e284d73e67f1809a48a497200e046d39ccc7112cd0");
+}
+
+} // namespace
+
+int main(int argc, char **argv) {
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
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