/src/md5.cpp
C++ | 323 lines | 209 code | 47 blank | 67 comment | 15 complexity | 1ce6c873bbaa96a1d34b6363bcbd8a8d MD5 | raw file
Possible License(s): GPL-2.0
- /**
- * This code implements the MD5 message-digest algorithm.
- * The algorithm is due to Ron Rivest. This code was
- * written by Colin Plumb in 1993, no copyright is claimed.
- * This code is in the public domain; do with it what you wish.
- *
- * Equivalent code is available from RSA Data Security, Inc.
- * This code has been tested against that, and is equivalent,
- * except that you don't need to include two pages of legalese
- * with every copy.
- *
- * To compute the message digest of a chunk of bytes, declare an
- * MD5Context structure, pass it to MD5Init, call MD5Update as
- * needed on buffers full of bytes, and then call MD5Final, which
- * will fill a supplied 16-byte array with the digest.
- *
- * @license Public Domain / GPL v2+
- */
- #include "md5.h"
- #include <string.h> /* memcpy, memset */
- /**
- * Reverse the bytes in 32-bit chunks.
- * 'buf' might not be word-aligned.
- *
- * @param buf The byte array to reverse
- * @param n_u32 The number of UINT32's in the data
- */
- void MD5::reverse_u32(UINT8 *buf, int n_u32)
- {
- UINT8 tmp;
- if (m_big_endian)
- {
- /* change { 4, 3, 2, 1 } => { 1, 2, 3, 4 } */
- while (n_u32-- > 0)
- {
- tmp = buf[0];
- buf[0] = buf[3];
- buf[3] = tmp;
- tmp = buf[1];
- buf[1] = buf[2];
- buf[2] = tmp;
- buf += 4;
- }
- }
- else
- {
- /* change { 4, 3, 2, 1 } => { 3, 4, 1, 2 } */
- while (n_u32-- > 0)
- {
- tmp = buf[0];
- buf[0] = buf[1];
- buf[1] = tmp;
- tmp = buf[2];
- buf[2] = buf[3];
- buf[3] = tmp;
- buf += 4;
- }
- }
- }
- MD5::MD5()
- {
- m_buf[0] = 0x01020304;
- /*
- * Little endian = { 4, 3, 2, 1 }
- * Big endian = { 1, 2, 3, 4 }
- * PDP endian = { 3, 4, 1, 2 }
- *
- * The MD5 stuff is written for little endian.
- */
- m_need_byteswap = *(UINT8 *)m_buf != 4;
- m_big_endian = *(UINT8 *)m_buf == 1;
- }
- /**
- * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
- * initialization constants.
- */
- void MD5::Init()
- {
- m_buf[0] = 0x67452301;
- m_buf[1] = 0xefcdab89;
- m_buf[2] = 0x98badcfe;
- m_buf[3] = 0x10325476;
- m_bits[0] = 0;
- m_bits[1] = 0;
- }
- /**
- * Update context to reflect the concatenation of another buffer full
- * of bytes.
- */
- void MD5::Update(const void *data, UINT32 len)
- {
- const UINT8 *buf = (const UINT8 *)data;
- /* Update bitcount */
- UINT32 t = m_bits[0];
- if ((m_bits[0] = t + ((UINT32)len << 3)) < t)
- {
- m_bits[1]++; /* Carry from low to high */
- }
- m_bits[1] += len >> 29;
- t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
- /* Handle any leading odd-sized chunks */
- if (t)
- {
- UINT8 *p = (UINT8 *)m_in + t;
- t = 64 - t;
- if (len < t)
- {
- memcpy(p, buf, len);
- return;
- }
- memcpy(p, buf, t);
- if (m_need_byteswap)
- {
- reverse_u32(m_in, 16);
- }
- Transform(m_buf, (UINT32 *)m_in);
- buf += t;
- len -= t;
- }
- /* Process data in 64-byte chunks */
- while (len >= 64)
- {
- memcpy(m_in, buf, 64);
- if (m_need_byteswap)
- {
- reverse_u32(m_in, 16);
- }
- Transform(m_buf, (UINT32 *)m_in);
- buf += 64;
- len -= 64;
- }
- /* Save off any remaining bytes of data */
- memcpy(m_in, buf, len);
- } // MD5::Update
- /**
- * Final wrapup - pad to 64-byte boundary with the bit pattern
- * 1 0* (64-bit count of bits processed, MSB-first)
- */
- void MD5::Final(UINT8 digest[16])
- {
- /* Compute number of bytes mod 64 */
- UINT32 count = (m_bits[0] >> 3) & 0x3F;
- /* Set the first char of padding to 0x80. This is safe since there is
- * always at least one byte free */
- UINT8 *p = m_in + count;
- *p++ = 0x80;
- /* Bytes of padding needed to make 64 bytes */
- count = 64 - 1 - count;
- /* Pad out to 56 mod 64 */
- if (count < 8)
- {
- /* Two lots of padding: Pad the first block to 64 bytes */
- memset(p, 0, count);
- if (m_need_byteswap)
- {
- reverse_u32(m_in, 16);
- }
- Transform(m_buf, (UINT32 *)m_in);
- /* Now fill the next block with 56 bytes */
- memset(m_in, 0, 56);
- }
- else
- {
- /* Pad block to 56 bytes */
- memset(p, 0, count - 8);
- }
- if (m_need_byteswap)
- {
- reverse_u32(m_in, 14);
- }
- /* Append length in bits and transform */
- memcpy(m_in + 56, &m_bits[0], 4);
- memcpy(m_in + 60, &m_bits[1], 4);
- Transform(m_buf, (UINT32 *)m_in);
- if (m_need_byteswap)
- {
- reverse_u32((UINT8 *)m_buf, 4);
- }
- memcpy(digest, m_buf, 16);
- } // MD5::Final
- /* The four core functions - F1 is optimized somewhat */
- /* #define F1(x, y, z) (x & y | ~x & z) */
- #define F1(x, y, z) (z ^ (x & (y ^ z)))
- #define F2(x, y, z) F1(z, x, y)
- #define F3(x, y, z) (x ^ y ^ z)
- #define F4(x, y, z) (y ^ (x | ~z))
- /* This is the central step in the MD5 algorithm. */
- #define MD5STEP(f, w, x, y, z, data, s) \
- (w += f(x, y, z) + data, w = w << s | w >> (32 - s), w += x)
- /*
- * The core of the MD5 algorithm, this alters an existing MD5 hash to
- * reflect the addition of 16 longwords of new data. MD5::Update blocks
- * the data and converts bytes into longwords for this routine.
- */
- void MD5::Transform(UINT32 buf[4], UINT32 in_data[16])
- {
- UINT32 a = buf[0];
- UINT32 b = buf[1];
- UINT32 c = buf[2];
- UINT32 d = buf[3];
- MD5STEP(F1, a, b, c, d, in_data[0] + 0xd76aa478, 7);
- MD5STEP(F1, d, a, b, c, in_data[1] + 0xe8c7b756, 12);
- MD5STEP(F1, c, d, a, b, in_data[2] + 0x242070db, 17);
- MD5STEP(F1, b, c, d, a, in_data[3] + 0xc1bdceee, 22);
- MD5STEP(F1, a, b, c, d, in_data[4] + 0xf57c0faf, 7);
- MD5STEP(F1, d, a, b, c, in_data[5] + 0x4787c62a, 12);
- MD5STEP(F1, c, d, a, b, in_data[6] + 0xa8304613, 17);
- MD5STEP(F1, b, c, d, a, in_data[7] + 0xfd469501, 22);
- MD5STEP(F1, a, b, c, d, in_data[8] + 0x698098d8, 7);
- MD5STEP(F1, d, a, b, c, in_data[9] + 0x8b44f7af, 12);
- MD5STEP(F1, c, d, a, b, in_data[10] + 0xffff5bb1, 17);
- MD5STEP(F1, b, c, d, a, in_data[11] + 0x895cd7be, 22);
- MD5STEP(F1, a, b, c, d, in_data[12] + 0x6b901122, 7);
- MD5STEP(F1, d, a, b, c, in_data[13] + 0xfd987193, 12);
- MD5STEP(F1, c, d, a, b, in_data[14] + 0xa679438e, 17);
- MD5STEP(F1, b, c, d, a, in_data[15] + 0x49b40821, 22);
- MD5STEP(F2, a, b, c, d, in_data[1] + 0xf61e2562, 5);
- MD5STEP(F2, d, a, b, c, in_data[6] + 0xc040b340, 9);
- MD5STEP(F2, c, d, a, b, in_data[11] + 0x265e5a51, 14);
- MD5STEP(F2, b, c, d, a, in_data[0] + 0xe9b6c7aa, 20);
- MD5STEP(F2, a, b, c, d, in_data[5] + 0xd62f105d, 5);
- MD5STEP(F2, d, a, b, c, in_data[10] + 0x02441453, 9);
- MD5STEP(F2, c, d, a, b, in_data[15] + 0xd8a1e681, 14);
- MD5STEP(F2, b, c, d, a, in_data[4] + 0xe7d3fbc8, 20);
- MD5STEP(F2, a, b, c, d, in_data[9] + 0x21e1cde6, 5);
- MD5STEP(F2, d, a, b, c, in_data[14] + 0xc33707d6, 9);
- MD5STEP(F2, c, d, a, b, in_data[3] + 0xf4d50d87, 14);
- MD5STEP(F2, b, c, d, a, in_data[8] + 0x455a14ed, 20);
- MD5STEP(F2, a, b, c, d, in_data[13] + 0xa9e3e905, 5);
- MD5STEP(F2, d, a, b, c, in_data[2] + 0xfcefa3f8, 9);
- MD5STEP(F2, c, d, a, b, in_data[7] + 0x676f02d9, 14);
- MD5STEP(F2, b, c, d, a, in_data[12] + 0x8d2a4c8a, 20);
- MD5STEP(F3, a, b, c, d, in_data[5] + 0xfffa3942, 4);
- MD5STEP(F3, d, a, b, c, in_data[8] + 0x8771f681, 11);
- MD5STEP(F3, c, d, a, b, in_data[11] + 0x6d9d6122, 16);
- MD5STEP(F3, b, c, d, a, in_data[14] + 0xfde5380c, 23);
- MD5STEP(F3, a, b, c, d, in_data[1] + 0xa4beea44, 4);
- MD5STEP(F3, d, a, b, c, in_data[4] + 0x4bdecfa9, 11);
- MD5STEP(F3, c, d, a, b, in_data[7] + 0xf6bb4b60, 16);
- MD5STEP(F3, b, c, d, a, in_data[10] + 0xbebfbc70, 23);
- MD5STEP(F3, a, b, c, d, in_data[13] + 0x289b7ec6, 4);
- MD5STEP(F3, d, a, b, c, in_data[0] + 0xeaa127fa, 11);
- MD5STEP(F3, c, d, a, b, in_data[3] + 0xd4ef3085, 16);
- MD5STEP(F3, b, c, d, a, in_data[6] + 0x04881d05, 23);
- MD5STEP(F3, a, b, c, d, in_data[9] + 0xd9d4d039, 4);
- MD5STEP(F3, d, a, b, c, in_data[12] + 0xe6db99e5, 11);
- MD5STEP(F3, c, d, a, b, in_data[15] + 0x1fa27cf8, 16);
- MD5STEP(F3, b, c, d, a, in_data[2] + 0xc4ac5665, 23);
- MD5STEP(F4, a, b, c, d, in_data[0] + 0xf4292244, 6);
- MD5STEP(F4, d, a, b, c, in_data[7] + 0x432aff97, 10);
- MD5STEP(F4, c, d, a, b, in_data[14] + 0xab9423a7, 15);
- MD5STEP(F4, b, c, d, a, in_data[5] + 0xfc93a039, 21);
- MD5STEP(F4, a, b, c, d, in_data[12] + 0x655b59c3, 6);
- MD5STEP(F4, d, a, b, c, in_data[3] + 0x8f0ccc92, 10);
- MD5STEP(F4, c, d, a, b, in_data[10] + 0xffeff47d, 15);
- MD5STEP(F4, b, c, d, a, in_data[1] + 0x85845dd1, 21);
- MD5STEP(F4, a, b, c, d, in_data[8] + 0x6fa87e4f, 6);
- MD5STEP(F4, d, a, b, c, in_data[15] + 0xfe2ce6e0, 10);
- MD5STEP(F4, c, d, a, b, in_data[6] + 0xa3014314, 15);
- MD5STEP(F4, b, c, d, a, in_data[13] + 0x4e0811a1, 21);
- MD5STEP(F4, a, b, c, d, in_data[4] + 0xf7537e82, 6);
- MD5STEP(F4, d, a, b, c, in_data[11] + 0xbd3af235, 10);
- MD5STEP(F4, c, d, a, b, in_data[2] + 0x2ad7d2bb, 15);
- MD5STEP(F4, b, c, d, a, in_data[9] + 0xeb86d391, 21);
- buf[0] += a;
- buf[1] += b;
- buf[2] += c;
- buf[3] += d;
- } // MD5::Transform
- void MD5::Calc(const void *data, UINT32 length, UINT8 digest[16])
- {
- MD5 md5;
- md5.Init();
- md5.Update(data, length);
- md5.Final(digest);
- }