FreeBSD/Linux Kernel Cross Reference
sys/lib/libkern/md4c.c

     /*      $NetBSD: md4c.c,v 1.3 2003/12/04 12:42:54 keihan Exp $  */
     
     /*
      * This file is derived from the RSA Data Security, Inc. MD4 Message-Digest
      * Algorithm and has been modified by Jason R. Thorpe <thorpej@NetBSD.org>
      * for portability and formatting.
      */
     
     /*
     * Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
     *
     * License to copy and use this software is granted provided that it
     * is identified as the "RSA Data Security, Inc. MD4 Message-Digest
     * Algorithm" in all material mentioning or referencing this software
     * or this function.
     *
     * License is also granted to make and use derivative works provided
     * that such works are identified as "derived from the RSA Data
     * Security, Inc. MD4 Message-Digest Algorithm" in all material
     * mentioning or referencing the derived work.
     *
     * RSA Data Security, Inc. makes no representations concerning either
     * the merchantability of this software or the suitability of this
     * software 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 this
     * documentation and/or software.
     */
    
    #include <sys/param.h>
    #if defined(_KERNEL) || defined(_STANDALONE)
    #include <sys/md4.h>
    #include <lib/libkern/libkern.h>
    #define _DIAGASSERT(x)  (void)0
    #else
    #include <assert.h>
    #include <md4.h>
    #include <string.h>
    #endif /* _KERNEL || _STANDALONE */
    
    typedef unsigned char *POINTER;
    typedef u_int16_t UINT2;
    typedef u_int32_t UINT4;
    
    /*
     * Constants for MD4Transform routine.
     */
    #define S11 3
    #define S12 7
    #define S13 11
    #define S14 19
    #define S21 3
    #define S22 5
    #define S23 9
    #define S24 13
    #define S31 3
    #define S32 9
    #define S33 11
    #define S34 15
    
    static void MD4Transform __P((UINT4 [4], const unsigned char [64]));
    
    static void Encode __P((unsigned char *, UINT4 *, unsigned int));
    static void Decode __P((UINT4 *, const unsigned char *, unsigned int));
    
    static const 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 and H are basic MD4 functions.
     */
    #define F(x, y, z)      (((x) & (y)) | ((~x) & (z)))
    #define G(x, y, z)      (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
    #define H(x, y, z)      ((x) ^ (y) ^ (z))
    
    /*
     * ROTATE_LEFT rotates x left n bits.
     */
    #define ROTATE_LEFT(x, n)       (((x) << (n)) | ((x) >> (32-(n))))
    
    /*
     * FF, GG and HH are transformations for rounds 1, 2 and 3.
     * Rotation is separate from addition to prevent recomputation.
     */
    #define FF(a, b, c, d, x, s) { \
            (a) += F ((b), (c), (d)) + (x); \
            (a) = ROTATE_LEFT ((a), (s)); \
    }
    
    #define GG(a, b, c, d, x, s) { \
            (a) += G ((b), (c), (d)) + (x) + (UINT4)0x5a827999; \
            (a) = ROTATE_LEFT ((a), (s)); \
    }
    
    #define HH(a, b, c, d, x, s) { \
           (a) += H ((b), (c), (d)) + (x) + (UINT4)0x6ed9eba1; \
           (a) = ROTATE_LEFT ((a), (s)); \
   }
   
   #if !defined(_KERNEL) && !defined(_STANDALONE) && defined(__weak_alias)
   __weak_alias(MD4Init,_MD4Init)
   __weak_alias(MD4Update,_MD4Update)
   __weak_alias(MD4Final,_MD4Final)
   #endif
   
   /*
    * MD4 initialization. Begins an MD4 operation, writing a new context.
    */
   void
   MD4Init(context)
           MD4_CTX *context;               /* context */
   {
   
           _DIAGASSERT(context != 0);
   
           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;
   }
   
   /*
    * MD4 block update operation.  Continues an MD4 message-digest
    * operation, processing another message block, and updating the
    * context.
    */
   void
   MD4Update (context, input, inputLen)
           MD4_CTX *context;               /* context */
           const unsigned char *input;     /* input block */
           unsigned int inputLen;          /* length of input block */
   {
           unsigned int i, idx, partLen;
   
           _DIAGASSERT(context != 0);
           _DIAGASSERT(input != 0);
   
           /* Compute number of bytes mod 64 */
           idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
   
           /* Update number of bits */
           if ((context->count[0] += ((UINT4)inputLen << 3))
               < ((UINT4)inputLen << 3))
                   context->count[1]++;
           context->count[1] += ((UINT4)inputLen >> 29);
   
           partLen = 64 - idx;
   
           /* Transform as many times as possible. */
           if (inputLen >= partLen) {
                   memcpy(&context->buffer[idx], input, partLen);
                   MD4Transform(context->state, context->buffer);
   
                   for (i = partLen; i + 63 < inputLen; i += 64)
                           MD4Transform(context->state, &input[i]);
   
                   idx = 0;
           } else
                   i = 0;
   
           /* Buffer remaining input */
           memcpy(&context->buffer[idx], &input[i], inputLen - i);
   }
   
   /*
    * MD4 finalization.  Ends an MD4 message-digest operation, writing the
    * message digest and zeroing the context.
    */
   void
   MD4Final (digest, context)
           unsigned char digest[16];       /* message digest */
           MD4_CTX *context;               /* context */
   {
           unsigned char bits[8];
           unsigned int idx, padLen;
   
           _DIAGASSERT(digest != 0);
           _DIAGASSERT(context != 0);
   
           /* Save number of bits */
           Encode(bits, context->count, 8);
   
           /* Pad out to 56 mod 64. */
           idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
           padLen = (idx < 56) ? (56 - idx) : (120 - idx);
           MD4Update(context, PADDING, padLen);
   
           /* Append length (before padding) */
           MD4Update(context, bits, 8);
   
           /* Store state in digest */
           Encode(digest, context->state, 16);
   
           /* Zeroize sensitive information. */
           memset(context, 0, sizeof(*context));
   }
   
   /*
    * MD4 basic transformation.  Transforms state based on block.
    */
   static void
   MD4Transform (state, block)
           UINT4 state[4];
           const 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); /* 1 */
           FF (d, a, b, c, x[ 1], S12); /* 2 */
           FF (c, d, a, b, x[ 2], S13); /* 3 */
           FF (b, c, d, a, x[ 3], S14); /* 4 */
           FF (a, b, c, d, x[ 4], S11); /* 5 */
           FF (d, a, b, c, x[ 5], S12); /* 6 */
           FF (c, d, a, b, x[ 6], S13); /* 7 */
           FF (b, c, d, a, x[ 7], S14); /* 8 */
           FF (a, b, c, d, x[ 8], S11); /* 9 */
           FF (d, a, b, c, x[ 9], S12); /* 10 */
           FF (c, d, a, b, x[10], S13); /* 11 */
           FF (b, c, d, a, x[11], S14); /* 12 */
           FF (a, b, c, d, x[12], S11); /* 13 */
           FF (d, a, b, c, x[13], S12); /* 14 */
           FF (c, d, a, b, x[14], S13); /* 15 */
           FF (b, c, d, a, x[15], S14); /* 16 */
   
           /* Round 2 */
           GG (a, b, c, d, x[ 0], S21); /* 17 */
           GG (d, a, b, c, x[ 4], S22); /* 18 */
           GG (c, d, a, b, x[ 8], S23); /* 19 */
           GG (b, c, d, a, x[12], S24); /* 20 */
           GG (a, b, c, d, x[ 1], S21); /* 21 */
           GG (d, a, b, c, x[ 5], S22); /* 22 */
           GG (c, d, a, b, x[ 9], S23); /* 23 */
           GG (b, c, d, a, x[13], S24); /* 24 */
           GG (a, b, c, d, x[ 2], S21); /* 25 */
           GG (d, a, b, c, x[ 6], S22); /* 26 */
           GG (c, d, a, b, x[10], S23); /* 27 */
           GG (b, c, d, a, x[14], S24); /* 28 */
           GG (a, b, c, d, x[ 3], S21); /* 29 */
           GG (d, a, b, c, x[ 7], S22); /* 30 */
           GG (c, d, a, b, x[11], S23); /* 31 */
           GG (b, c, d, a, x[15], S24); /* 32 */
   
           /* Round 3 */
           HH (a, b, c, d, x[ 0], S31); /* 33 */
           HH (d, a, b, c, x[ 8], S32); /* 34 */
           HH (c, d, a, b, x[ 4], S33); /* 35 */
           HH (b, c, d, a, x[12], S34); /* 36 */
           HH (a, b, c, d, x[ 2], S31); /* 37 */
           HH (d, a, b, c, x[10], S32); /* 38 */
           HH (c, d, a, b, x[ 6], S33); /* 39 */
           HH (b, c, d, a, x[14], S34); /* 40 */
           HH (a, b, c, d, x[ 1], S31); /* 41 */
           HH (d, a, b, c, x[ 9], S32); /* 42 */
           HH (c, d, a, b, x[ 5], S33); /* 43 */
           HH (b, c, d, a, x[13], S34); /* 44 */
           HH (a, b, c, d, x[ 3], S31); /* 45 */
           HH (d, a, b, c, x[11], S32); /* 46 */
           HH (c, d, a, b, x[ 7], S33); /* 47 */
           HH (b, c, d, a, x[15], S34); /* 48 */
   
           state[0] += a;
           state[1] += b;
           state[2] += c;
           state[3] += d;
   
           /* Zeroize sensitive information. */
           memset(x, 0, sizeof (x));
   }
   
   /*
    * Encodes input (UINT4) into output (unsigned char). Assumes len is
    * a multiple of 4.
    */
   static void
   Encode(output, input, len)
           unsigned char *output;
           UINT4 *input;
           unsigned int len;
   {
           unsigned int i, j;
   
           for (i = 0, j = 0; j < len; i++, j += 4) {
                   output[j] = (unsigned char)(input[i] & 0xff);
                   output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
                   output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
                   output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
           }
   }
   
   /*
    * Decodes input (unsigned char) into output (UINT4). Assumes len is
    * a multiple of 4.
    */
   static void
   Decode(output, input, len)
           UINT4 *output;
           const unsigned char *input;
           unsigned int len;
   {
           unsigned int i, j;
   
           for (i = 0, j = 0; j < len; i++, j += 4)
                   output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
                       (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
   }

Cache object: f60b2074a1f31ea6ec991a420d99fcd1