/*

 * This code is derived from (original license follows):

 *

 * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.

 * MD5 Message-Digest Algorithm (RFC 1321).

 *

 * Homepage:

 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5

 *

 * Author:

 * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>

 *

 * This software was written by Alexander Peslyak in 2001.  No copyright is

 * claimed, and the software is hereby placed in the public domain.

 * In case this attempt to disclaim copyright and place the software in the

 * public domain is deemed null and void, then the software is

 * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the

 * general public under the following terms:

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted.

 *

 * There's ABSOLUTELY NO WARRANTY, express or implied.

 *

 * (This is a heavily cut-down "BSD license".)

 *

 * This differs from Colin Plumb's older public domain implementation in that

 * no exactly 32-bit integer data type is required (any 32-bit or wider

 * unsigned integer data type will do), there's no compile-time endianness

 * configuration, and the function prototypes match OpenSSL's.  No code from

 * Colin Plumb's implementation has been reused; this comment merely compares

 * the properties of the two independent implementations.

 *

 * The primary goals of this implementation are portability and ease of use.

 * It is meant to be fast, but not as fast as possible.  Some known

 * optimizations are not included to reduce source code size and avoid

 * compile-time configuration.

 */

#include "llvm/Support/MD5.h"

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/Endian.h"

#include "llvm/Support/Format.h"

#include "llvm/Support/raw_ostream.h"

#include <array>

#include <cstdint>

#include <cstring>

// The basic MD5 functions.

// F and G are optimized compared to their RFC 1321 definitions for

// architectures that lack an AND-NOT instruction, just like in Colin Plumb's

// implementation.

#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))

#define G(x, y, z) ((y) ^ ((z) & ((x) ^ (y))))

#define H(x, y, z) ((x) ^ (y) ^ (z))

#define I(x, y, z) ((y) ^ ((x) | ~(z)))

// The MD5 transformation for all four rounds.

#define STEP(f, a, b, c, d, x, t, s)                                           \

  (a) += f((b), (c), (d)) + (x) + (t);                                         \

  (a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s))));                   \

  (a) += (b);

// SET reads 4 input bytes in little-endian byte order and stores them

// in a properly aligned word in host byte order.

#define SET(n)                                                                 \

  (block[(n)] =                                                                \

       (MD5_u32plus) ptr[(n) * 4] | ((MD5_u32plus) ptr[(n) * 4 + 1] << 8) |    \

       ((MD5_u32plus) ptr[(n) * 4 + 2] << 16) |                                \

       ((MD5_u32plus) ptr[(n) * 4 + 3] << 24))

#define GET(n) (block[(n)])

using namespace llvm;

/// This processes one or more 64-byte data blocks, but does NOT update

///the bit counters.  There are no alignment requirements.

const uint8_t *MD5::body(ArrayRef<uint8_t> Data) {

  const uint8_t *ptr;

  MD5_u32plus a, b, c, d;

  MD5_u32plus saved_a, saved_b, saved_c, saved_d;

  unsigned long Size = Data.size();

  ptr = Data.data();

  a = this->a;

  b = this->b;

  c = this->c;

  d = this->d;

  do {

    saved_a = a;

    saved_b = b;

    saved_c = c;

    saved_d = d;

    // Round 1

    STEP(F, a, b, c, d, SET(0), 0xd76aa478, 7)

    STEP(F, d, a, b, c, SET(1), 0xe8c7b756, 12)

    STEP(F, c, d, a, b, SET(2), 0x242070db, 17)

    STEP(F, b, c, d, a, SET(3), 0xc1bdceee, 22)

    STEP(F, a, b, c, d, SET(4), 0xf57c0faf, 7)

    STEP(F, d, a, b, c, SET(5), 0x4787c62a, 12)

    STEP(F, c, d, a, b, SET(6), 0xa8304613, 17)

    STEP(F, b, c, d, a, SET(7), 0xfd469501, 22)

    STEP(F, a, b, c, d, SET(8), 0x698098d8, 7)

    STEP(F, d, a, b, c, SET(9), 0x8b44f7af, 12)

    STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17)

    STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22)

    STEP(F, a, b, c, d, SET(12), 0x6b901122, 7)

    STEP(F, d, a, b, c, SET(13), 0xfd987193, 12)

    STEP(F, c, d, a, b, SET(14), 0xa679438e, 17)

    STEP(F, b, c, d, a, SET(15), 0x49b40821, 22)

    // Round 2

    STEP(G, a, b, c, d, GET(1), 0xf61e2562, 5)

    STEP(G, d, a, b, c, GET(6), 0xc040b340, 9)

    STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14)

    STEP(G, b, c, d, a, GET(0), 0xe9b6c7aa, 20)

    STEP(G, a, b, c, d, GET(5), 0xd62f105d, 5)

    STEP(G, d, a, b, c, GET(10), 0x02441453, 9)

    STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14)

    STEP(G, b, c, d, a, GET(4), 0xe7d3fbc8, 20)

    STEP(G, a, b, c, d, GET(9), 0x21e1cde6, 5)

    STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9)

    STEP(G, c, d, a, b, GET(3), 0xf4d50d87, 14)

    STEP(G, b, c, d, a, GET(8), 0x455a14ed, 20)

    STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5)

    STEP(G, d, a, b, c, GET(2), 0xfcefa3f8, 9)

    STEP(G, c, d, a, b, GET(7), 0x676f02d9, 14)

    STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20)

    // Round 3

    STEP(H, a, b, c, d, GET(5), 0xfffa3942, 4)

    STEP(H, d, a, b, c, GET(8), 0x8771f681, 11)

    STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16)

    STEP(H, b, c, d, a, GET(14), 0xfde5380c, 23)

    STEP(H, a, b, c, d, GET(1), 0xa4beea44, 4)

    STEP(H, d, a, b, c, GET(4), 0x4bdecfa9, 11)

    STEP(H, c, d, a, b, GET(7), 0xf6bb4b60, 16)

    STEP(H, b, c, d, a, GET(10), 0xbebfbc70, 23)

    STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4)

    STEP(H, d, a, b, c, GET(0), 0xeaa127fa, 11)

    STEP(H, c, d, a, b, GET(3), 0xd4ef3085, 16)

    STEP(H, b, c, d, a, GET(6), 0x04881d05, 23)

    STEP(H, a, b, c, d, GET(9), 0xd9d4d039, 4)

    STEP(H, d, a, b, c, GET(12), 0xe6db99e5, 11)

    STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16)

    STEP(H, b, c, d, a, GET(2), 0xc4ac5665, 23)

    // Round 4

    STEP(I, a, b, c, d, GET(0), 0xf4292244, 6)

    STEP(I, d, a, b, c, GET(7), 0x432aff97, 10)

    STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15)

    STEP(I, b, c, d, a, GET(5), 0xfc93a039, 21)

    STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6)

    STEP(I, d, a, b, c, GET(3), 0x8f0ccc92, 10)

    STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15)

    STEP(I, b, c, d, a, GET(1), 0x85845dd1, 21)

    STEP(I, a, b, c, d, GET(8), 0x6fa87e4f, 6)

    STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10)

    STEP(I, c, d, a, b, GET(6), 0xa3014314, 15)

    STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21)

    STEP(I, a, b, c, d, GET(4), 0xf7537e82, 6)

    STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10)

    STEP(I, c, d, a, b, GET(2), 0x2ad7d2bb, 15)

    STEP(I, b, c, d, a, GET(9), 0xeb86d391, 21)

    a += saved_a;

    b += saved_b;

    c += saved_c;

    d += saved_d;

    ptr += 64;

  } while (Size -= 64);

  this->a = a;

  this->b = b;

  this->c = c;

  this->d = d;

  return ptr;

}

MD5::MD5() = default;

/// Incrementally add the bytes in \p Data to the hash.

void MD5::update(ArrayRef<uint8_t> Data) {

  MD5_u32plus saved_lo;

  unsigned long used, free;

  const uint8_t *Ptr = Data.data();

  unsigned long Size = Data.size();

  saved_lo = lo;

  if ((lo = (saved_lo + Size) & 0x1fffffff) < saved_lo)

    hi++;

  hi += Size >> 29;

  used = saved_lo & 0x3f;

  if (used) {

    free = 64 - used;

    if (Size < free) {

      memcpy(&buffer[used], Ptr, Size);

      return;

    }

    memcpy(&buffer[used], Ptr, free);

    Ptr = Ptr + free;

    Size -= free;

    body(makeArrayRef(buffer, 64));

  }

  if (Size >= 64) {

    Ptr = body(makeArrayRef(Ptr, Size & ~(unsigned long) 0x3f));

    Size &= 0x3f;

  }

  memcpy(buffer, Ptr, Size);

}

/// Add the bytes in the StringRef \p Str to the hash.

// Note that this isn't a string and so this won't include any trailing NULL

// bytes.

void MD5::update(StringRef Str) {

  ArrayRef<uint8_t> SVal((const uint8_t *)Str.data(), Str.size());

  update(SVal);

}

/// Finish the hash and place the resulting hash into \p result.

/// \param Result is assumed to be a minimum of 16-bytes in size.

void MD5::final(MD5Result &Result) {

  unsigned long used, free;

  used = lo & 0x3f;

  buffer[used++] = 0x80;

  free = 64 - used;

  if (free < 8) {

    memset(&buffer[used], 0, free);

    body(makeArrayRef(buffer, 64));

    used = 0;

    free = 64;

  }

  memset(&buffer[used], 0, free - 8);

  lo <<= 3;

  support::endian::write32le(&buffer[56], lo);

  support::endian::write32le(&buffer[60], hi);

  body(makeArrayRef(buffer, 64));

  support::endian::write32le(&Result[0], a);

  support::endian::write32le(&Result[4], b);

  support::endian::write32le(&Result[8], c);

  support::endian::write32le(&Result[12], d);

}

SmallString<32> MD5::MD5Result::digest() const {

  SmallString<32> Str;

  raw_svector_ostream Res(Str);

  for (int i = 0; i < 16; ++i)

    Res << format("%.2x", Bytes[i]);

  return Str;

}

void MD5::stringifyResult(MD5Result &Result, SmallString<32> &Str) {

  Str = Result.digest();

}

std::array<uint8_t, 16> MD5::hash(ArrayRef<uint8_t> Data) {

  MD5 Hash;

  Hash.update(Data);

  MD5::MD5Result Res;

  Hash.final(Res);

  return Res;

}