+/*
+ * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
+ *
+ * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
+ * rights reserved.
+ *
+ * License to copy and use this software is granted provided that it
+ * is identified as the "RSA Data Security, Inc. MD5 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. MD5 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.
+ *
+ * This code is the same as the code published by RSA Inc. It has been
+ * edited for clarity and style only.
+ */
+
+#include <string.h>
+#include <endian.h>
+#include <md5.h>
+
+static void MD5Transform(uint32_t [4], const unsigned char [64]);
+
+#define Encode memcpy
+#define Decode memcpy
+
+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) + (uint32_t)(ac); \
+ (a) = ROTATE_LEFT ((a), (s)); \
+ (a) += (b); \
+ }
+#define GG(a, b, c, d, x, s, ac) { \
+ (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
+ (a) = ROTATE_LEFT ((a), (s)); \
+ (a) += (b); \
+ }
+#define HH(a, b, c, d, x, s, ac) { \
+ (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
+ (a) = ROTATE_LEFT ((a), (s)); \
+ (a) += (b); \
+ }
+#define II(a, b, c, d, x, s, ac) { \
+ (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
+ (a) = ROTATE_LEFT ((a), (s)); \
+ (a) += (b); \
+ }
+
+/* MD5 initialization. Begins an MD5 operation, writing a new context. */
+
+void
+MD5Init (MD5_CTX *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 (MD5_CTX *context, const void *in, size_t inputLen)
+{
+ unsigned int i, idx, partLen;
+ const unsigned char *input = in;
+
+ /* Compute number of bytes mod 64 */
+ idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
+
+ /* Update number of bits */
+ if ((context->count[0] += ((uint32_t)inputLen << 3))
+ < ((uint32_t)inputLen << 3))
+ context->count[1]++;
+ context->count[1] += ((uint32_t)inputLen >> 29);
+
+ partLen = 64 - idx;
+
+ /* Transform as many times as possible. */
+ if (inputLen >= partLen) {
+ memcpy((void *)&context->buffer[idx], (const void *)input,
+ partLen);
+ MD5Transform (context->state, context->buffer);
+
+ for (i = partLen; i + 63 < inputLen; i += 64)
+ MD5Transform (context->state, &input[i]);
+
+ idx = 0;
+ }
+ else
+ i = 0;
+
+ /* Buffer remaining input */
+ memcpy ((void *)&context->buffer[idx], (const void *)&input[i],
+ inputLen-i);
+}
+
+/*
+ * MD5 padding. Adds padding followed by original length.
+ */
+
+static void
+MD5Pad (MD5_CTX *context)
+{
+ unsigned char bits[8];
+ unsigned int idx, padLen;
+
+ /* 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);
+ MD5Update (context, PADDING, padLen);
+
+ /* Append length (before padding) */
+ MD5Update (context, bits, 8);
+}
+
+/*
+ * MD5 finalization. Ends an MD5 message-digest operation, writing the
+ * the message digest and zeroizing the context.
+ */
+
+void
+MD5Final (unsigned char digest[16], MD5_CTX *context)
+{
+ /* Do padding. */
+ MD5Pad (context);
+
+ /* Store state in digest */
+ Encode (digest, context->state, 16);
+
+ /* Zeroize sensitive information. */
+ memset ((void *)context, 0, sizeof (*context));
+}
+
+/* MD5 basic transformation. Transforms state based on block. */
+
+static void
+MD5Transform (state, block)
+ uint32_t state[4];
+ const unsigned char block[64];
+{
+ uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
+
+ Decode (x, block, 64);
+
+ /* Round 1 */
+#define S11 7
+#define S12 12
+#define S13 17
+#define S14 22
+ 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 */
+#define S21 5
+#define S22 9
+#define S23 14
+#define S24 20
+ 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 */
+#define S31 4
+#define S32 11
+#define S33 16
+#define S34 23
+ 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 */
+#define S41 6
+#define S42 10
+#define S43 15
+#define S44 21
+ 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. */
+ memset ((void *)x, 0, sizeof (x));
+}