ut_md5.c

一个包含MD5加密

#define MODULE_NAME "UT_MD5"

/******************************************************************************
 * Include Files
 *****************************************************************************/

#include    <system.h>
#include    <string.h>
#include    <ut_md5.h>

/******************************************************************************
 * Manifest Constants
 *****************************************************************************/

#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 21

/******************************************************************************
 * Macros
 *****************************************************************************/

/*
 * 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) + (Int32) (ac);     \
 (a) = ROTATE_LEFT ((a), (s));                      \
 (a) += (b);                                        \
  }
#define GG(a, b, c, d, x, s, ac) {                  \
 (a) += G ((b), (c), (d)) + (x) + (Int32) (ac);     \
 (a) = ROTATE_LEFT ((a), (s));                      \
 (a) += (b);                                        \
  }
#define HH(a, b, c, d, x, s, ac) {                  \
 (a) += H ((b), (c), (d)) + (x) + (Int32) (ac);     \
 (a) = ROTATE_LEFT ((a), (s));                      \
 (a) += (b);                                        \
  }
#define II(a, b, c, d, x, s, ac) {                  \
 (a) += I ((b), (c), (d)) + (x) + (Int32) (ac);     \
 (a) = ROTATE_LEFT ((a), (s));                      \
 (a) += (b);                                        \
  }

/******************************************************************************
 * Constants
 *****************************************************************************/

static Int8 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
};

/******************************************************************************
 * Local Function Prototypes
 *****************************************************************************/

static void Md5Transform (Int32 *state, Int8 *block);
static void Md5Encode    (Int8 *output, Int32 *input, Int16 length);
static void Md5Decode    (Int32 *output, Int8 *input, Int16 length);

/***************************************************************************
 * Global Functions
 ***************************************************************************/

/************************************************************************
 * Function: Md5Init
 * MD5 initialization. Begins an MD5 operation, writing a new context
 ************************************************************************/
void Md5Init (Md5Context *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;
}

/************************************************************************
 * Function: Md5Update
 * MD5 block update operation. Continues an MD5 message-digest
 * operation, processing another message block, and updating the
 * context.
 ************************************************************************/
void Md5Update (Md5Context *context, Int8 *input, Int16 inputLength)
{
    Int16 i, index, partLength;

    /* Compute number of bytes mod 64 */
    index = (Int16)((context->count[0] >> 3) & 0x3F);

    /* Update number of bits */
    if ((context->count[0] += ((Int16) inputLength << 3))
        < ((Int32) inputLength << 3))
    {
        context->count[1]++;
    }

    context->count[1] += ((Int32) inputLength >> 29);

    partLength = (Int16)(64 - index);

    /* Transform as many times as possible */
    if (inputLength >= partLength)
    {
        memcpy ((Int8 *) &context->buffer[index], (Int8 *) input, partLength);

        Md5Transform (context->state, context->buffer);

        for (i = partLength; i + 63 < inputLength; i = (Int16)(i + 64))
        {
            Md5Transform (context->state, &input[i]);
        }

        index = 0;
    }
    else
    {
        i = 0;
    }

    if(inputLength > i)
    {    
      /* Buffer remaining input */
      memcpy ((Int8 *) &context->buffer[index], (Int8 *) &input[i], inputLength - i);
    }
}

/************************************************************************
 * Function: Md5Final
 * MD5 finalization. Ends an MD5 message-digest operation, writing the
 * the message digest and zeroing the context.
 ************************************************************************/
void Md5Final (Int8 *digest, Md5Context *context)
{
    Int8  bits[8];
    Int16 index, padLength;

    /* Save number of bits */
    Md5Encode (bits, context->count, 8);

    /* Pad out to 56 mod 64 */
    index = (Int16) ((context->count[0] >> 3) & 0x3f);
    padLength = (index < 56) ? (Int16)(56 - index) : (Int16)(120 - index);
    Md5Update (context, PADDING, padLength);

    /* Append length (before padding) */
    Md5Update (context, bits, 8);

    /* Store state in digest */
    Md5Encode (digest, context->state, MD5_DIGEST_LENGTH);

    /* Zero sensitive information */
    memset ((Int8 *) context, 0, sizeof (*context));
}

/***************************************************************************
 * Local Functions
 ***************************************************************************/

/************************************************************************
 * Function: Md5Transform
 * MD5 basic transformation. Transforms state based on block.
 ************************************************************************/
static void Md5Transform (Int32 *state, Int8 *block)
{
    Int32 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

    Md5Decode (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 */
    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;

    /* Zero sensitive information */
    memset ((Int8 *) x, 0, sizeof (x));
}

/************************************************************************
 * Function: Md5Encode
 * Encodes input (Int32) into output (Int8). Assumes length is
 * a multiple of 4.
 ************************************************************************/
static void Md5Encode (Int8 *output, Int32 *input, Int16 length)
{
    Int16 i, j;

    for (i = 0, j = 0; j < length; i++, j = (Int16)(j+4))
    {
        output[j] = (Int8)   (input[i] & 0xff);
        output[j+1] = (Int8) ((input[i] >> 8) & 0xff);
        output[j+2] = (Int8) ((input[i] >> 16) & 0xff);
        output[j+3] = (Int8) ((input[i] >> 24) & 0xff);
    }
}

/************************************************************************
 * Function: Md5Decode
 * Decodes input (Int8) into output (Int32). Assumes length is
 * a multiple of 4.
 ************************************************************************/
static void Md5Decode (Int32 *output, Int8 *input, Int16 length)
{
    Int16 i, j;

    for (i = 0, j = 0; j < length; i++, j = (Int16)(j+4))
    {
        output[i] = ((Int32) input[j]) | (((Int32) input[j+1]) << 8) |
        (((Int32) input[j+2]) << 16) | (((Int32) input[j+3]) << 24);
    }
}

/************************************************************************/
/************************************************************************/
/************************************************************************/
/************************************************************************/

/************************************************************************
 * Function: sd_md5
 * Decodes data (Int8 *) with length datalen (Int16) into result 
 * (unsigned char *). 
 ************************************************************************/
void sd_md5(Int8 *data, Int16 datalen, unsigned char *result)
{
  Md5Context context;
  
  Md5Init(&context);
  Md5Update(&context, data, datalen);
  Md5Final(result, &context);
}