oid 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->
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