Rivest                                                          [Page 7]RFC 1321              MD5 Message-Digest Algorithm            April 1992  been defined with C compiler flags. */#ifndef PROTOTYPES#define PROTOTYPES 0#endif/* POINTER defines a generic pointer type */typedef unsigned char *POINTER;/* UINT2 defines a two byte word */typedef unsigned short int UINT2;/* UINT4 defines a four byte word */typedef unsigned long int UINT4;/* PROTO_LIST is defined depending on how PROTOTYPES is defined above.If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it  returns an empty list. */#if PROTOTYPES#define PROTO_LIST(list) list#else#define PROTO_LIST(list) ()#endifA.2 md5.h/* MD5.H - header file for MD5C.C *//* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. Allrights reserved.License to copy and use this software is granted provided that itis identified as the "RSA Data Security, Inc. MD5 Message-DigestAlgorithm" in all material mentioning or referencing this softwareor this function.License is also granted to make and use derivative works providedthat such works are identified as "derived from the RSA DataSecurity, Inc. MD5 Message-Digest Algorithm" in all materialmentioning or referencing the derived work.RSA Data Security, Inc. makes no representations concerning eitherthe merchantability of this software or the suitability of thissoftware for any particular purpose. It is provided "as is"without express or implied warranty of any kind.Rivest                                                          [Page 8]RFC 1321              MD5 Message-Digest Algorithm            April 1992These notices must be retained in any copies of any part of thisdocumentation and/or software. *//* MD5 context. */typedef struct {  UINT4 state[4];                                   /* state (ABCD) */  UINT4 count[2];        /* number of bits, modulo 2^64 (lsb first) */  unsigned char buffer[64];                         /* input buffer */} MD5_CTX;void MD5Init PROTO_LIST ((MD5_CTX *));void MD5Update PROTO_LIST  ((MD5_CTX *, unsigned char *, unsigned int));void MD5Final PROTO_LIST ((unsigned char [16], MD5_CTX *));A.3 md5c.c/* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm *//* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. Allrights reserved.License to copy and use this software is granted provided that itis identified as the "RSA Data Security, Inc. MD5 Message-DigestAlgorithm" in all material mentioning or referencing this softwareor this function.License is also granted to make and use derivative works providedthat such works are identified as "derived from the RSA DataSecurity, Inc. MD5 Message-Digest Algorithm" in all materialmentioning or referencing the derived work.RSA Data Security, Inc. makes no representations concerning eitherthe merchantability of this software or the suitability of thissoftware for any particular purpose. It is provided "as is"without express or implied warranty of any kind.These notices must be retained in any copies of any part of thisdocumentation and/or software. */#include "global.h"#include "md5.h"/* Constants for MD5Transform routine. */Rivest                                                          [Page 9]RFC 1321              MD5 Message-Digest Algorithm            April 1992#define S11 7#define S12 12#define S13 17#define S14 22#define S21 5#define S22 9#define S23 14#define S24 20#define S31 4#define S32 11#define S33 16#define S34 23#define S41 6#define S42 10#define S43 15#define S44 21static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));static void Encode PROTO_LIST  ((unsigned char *, UINT4 *, unsigned int));static void Decode PROTO_LIST  ((UINT4 *, unsigned char *, unsigned int));static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));static unsigned char PADDING[64] = {  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};/* F, G, H and I are basic MD5 functions. */#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))#define H(x, y, z) ((x) ^ (y) ^ (z))#define I(x, y, z) ((y) ^ ((x) | (~z)))/* ROTATE_LEFT rotates x left n bits. */#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.Rotation is separate from addition to prevent recomputation. */#define FF(a, b, c, d, x, s, ac) { \ (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \ (a) = ROTATE_LEFT ((a), (s)); \Rivest                                                         [Page 10]RFC 1321              MD5 Message-Digest Algorithm            April 1992 (a) += (b); \  }#define GG(a, b, c, d, x, s, ac) { \ (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \ (a) = ROTATE_LEFT ((a), (s)); \ (a) += (b); \  }#define HH(a, b, c, d, x, s, ac) { \ (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \ (a) = ROTATE_LEFT ((a), (s)); \ (a) += (b); \  }#define II(a, b, c, d, x, s, ac) { \ (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \ (a) = ROTATE_LEFT ((a), (s)); \ (a) += (b); \  }/* MD5 initialization. Begins an MD5 operation, writing a new context. */void MD5Init (context)MD5_CTX *context;                                        /* context */{  context->count[0] = context->count[1] = 0;  /* Load magic initialization constants.*/  context->state[0] = 0x67452301;  context->state[1] = 0xefcdab89;  context->state[2] = 0x98badcfe;  context->state[3] = 0x10325476;}/* MD5 block update operation. Continues an MD5 message-digest  operation, processing another message block, and updating the  context. */void MD5Update (context, input, inputLen)MD5_CTX *context;                                        /* context */unsigned char *input;                                /* input block */unsigned int inputLen;                     /* length of input block */{  unsigned int i, index, partLen;  /* Compute number of bytes mod 64 */  index = (unsigned int)((context->count[0] >> 3) & 0x3F);  /* Update number of bits */  if ((context->count[0] += ((UINT4)inputLen << 3))Rivest                                                         [Page 11]RFC 1321              MD5 Message-Digest Algorithm            April 1992   < ((UINT4)inputLen << 3)) context->count[1]++;  context->count[1] += ((UINT4)inputLen >> 29);  partLen = 64 - index;  /* Transform as many times as possible.*/  if (inputLen >= partLen) { MD5_memcpy   ((POINTER)&context->buffer[index], (POINTER)input, partLen); MD5Transform (context->state, context->buffer); for (i = partLen; i + 63 < inputLen; i += 64)   MD5Transform (context->state, &input[i]); index = 0;  }  else i = 0;  /* Buffer remaining input */  MD5_memcpy ((POINTER)&context->buffer[index], (POINTER)&input[i],  inputLen-i);}/* MD5 finalization. Ends an MD5 message-digest operation, writing the  the message digest and zeroizing the context. */void MD5Final (digest, context)unsigned char digest[16];                         /* message digest */MD5_CTX *context;                                       /* context */{  unsigned char bits[8];  unsigned int index, padLen;  /* Save number of bits */  Encode (bits, context->count, 8);  /* Pad out to 56 mod 64.*/  index = (unsigned int)((context->count[0] >> 3) & 0x3f);  padLen = (index < 56) ? (56 - index) : (120 - index);  MD5Update (context, PADDING, padLen);  /* Append length (before padding) */  MD5Update (context, bits, 8);Rivest                                                         [Page 12]RFC 1321              MD5 Message-Digest Algorithm            April 1992  /* Store state in digest */  Encode (digest, context->state, 16);  /* Zeroize sensitive information.*/  MD5_memset ((POINTER)context, 0, sizeof (*context));}/* MD5 basic transformation. Transforms state based on block. */static void MD5Transform (state, block)UINT4 state[4];unsigned char block[64];{  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];  Decode (x, block, 64);  /* Round 1 */  FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */  FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */  FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */  FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */  FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */  FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */  FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */  FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */  FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */  FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */  FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */  FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */  FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */  FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */  FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */  FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */ /* Round 2 */  GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */  GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */  GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */  GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */  GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */  GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */  GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */  GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */  GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */  GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */  GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */Rivest                                                         [Page 13]RFC 1321              MD5 Message-Digest Algorithm            April 1992  GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */  GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */  GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */  GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */  GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */  /* Round 3 */  HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */  HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */  HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */  HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */  HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */  HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */  HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */  HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */  HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */  HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */  HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */  HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */  HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */  HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */  HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */  HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */  /* Round 4 */  II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */  II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */  II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */  II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */  II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */  II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */  II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */  II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */  II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */  II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */  II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */  II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */  II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */  II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */  II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */  II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */  state[0] += a;  state[1] += b;  state[2] += c;  state[3] += d;  /* Zeroize sensitive information.Rivest                                                         [Page 14]