[project @ 1998-06-29 14:13:14 by sof]

Added basic library for computing MD5 message digests

ghc/lib/misc/MD5.lhs

+%
+% (c) The GRASP/AQUA Project, Glasgow University, 1998
+%
+\section[md5]{MD5: Message-digest}
+
+This module provides basic MD5 support for Haskell, using
+Colin Plumb's C implementation of MD5 to do the Hard Work.
+
+\begin{code}
+{-# OPTIONS -#include "cbits/md5.h" #-}
+module MD5 
+	(
+          digest	-- :: String	   -> IO String
+	, digestPS      -- :: PackedString -> IO (ByteArray Int)
+	) where
+
+
+import GlaExts
+import Addr
+import PackedString
+
+\end{code}
+
+\begin{code}
+digest :: String -> IO String
+digest str = do
+  ps   <- stToIO (packStringST str)
+  ba   <- digestPS ps
+  let (ByteArray _ ba#) = ba
+  baToString ba# 16# 0#
+ where
+  baToString ba# n# i#
+    | n# ==# 0# = return []
+    | otherwise = do
+       let ch# = indexCharArray# ba# i#
+       ls <- baToString ba# (n# -# 1#) (i# +# 1#)
+       return ((C# ch#):ls)
+
+digestPS :: PackedString -> IO (ByteArray Int)
+digestPS ps = do
+  ctxt <- stToIO (newCharArray (0::Int,``sizeof(struct MD5Context)''::Int))
+  let len = lengthPS ps
+  _ccall_ MD5Init ctxt
+  (if isCString ps
+    then _ccall_ MD5Update ctxt (psToCString ps) len
+    else _ccall_ MD5Update ctxt (psToByteArray ps) len)
+  dig  <- stToIO (newCharArray (0::Int,16*(``sizeof(unsigned char)''::Int)))
+  _ccall_ MD5Final dig ctxt
+  stToIO (unsafeFreezeByteArray dig)
+
+\end{code}

ghc/lib/misc/cbits/md5.c

+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
+typedef unsigned long word32;
+typedef unsigned char byte;
+
+struct MD5Context {
+	word32 buf[4];
+	word32 bytes[2];
+	word32 in[16];
+};
+
+void MD5Init(struct MD5Context *context);
+void MD5Update(struct MD5Context *context, byte const *buf, int len);
+void MD5Final(byte digest[16], struct MD5Context *context);
+void MD5Transform(word32 buf[4], word32 const in[16]);
+
+
+/*
+ * Shuffle the bytes into little-endian order within words, as per the
+ * MD5 spec.  Note: this code works regardless of the byte order.
+ */
+void
+byteSwap(word32 *buf, unsigned words)
+{
+	byte *p = (byte *)buf;
+
+	do {
+		*buf++ = (word32)((unsigned)p[3] << 8 | p[2]) << 16 |
+			((unsigned)p[1] << 8 | p[0]);
+		p += 4;
+	} while (--words);
+}
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+void
+MD5Init(struct MD5Context *ctx)
+{
+	ctx->buf[0] = 0x67452301;
+	ctx->buf[1] = 0xefcdab89;
+	ctx->buf[2] = 0x98badcfe;
+	ctx->buf[3] = 0x10325476;
+
+	ctx->bytes[0] = 0;
+	ctx->bytes[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+void
+MD5Update(struct MD5Context *ctx, byte const *buf, int len)
+{
+	word32 t;
+
+	/* Update byte count */
+
+	t = ctx->bytes[0];
+	if ((ctx->bytes[0] = t + len) < t)
+		ctx->bytes[1]++;	/* Carry from low to high */
+
+	t = 64 - (t & 0x3f);	/* Space available in ctx->in (at least 1) */
+	if ((unsigned)t > len) {
+		bcopy(buf, (byte *)ctx->in + 64 - (unsigned)t, len);
+		return;
+	}
+	/* First chunk is an odd size */
+	bcopy(buf,(byte *)ctx->in + 64 - (unsigned)t, (unsigned)t);
+	byteSwap(ctx->in, 16);
+	MD5Transform(ctx->buf, ctx->in);
+	buf += (unsigned)t;
+	len -= (unsigned)t;
+
+	/* Process data in 64-byte chunks */
+	while (len >= 64) {
+		bcopy(buf, ctx->in, 64);
+		byteSwap(ctx->in, 16);
+		MD5Transform(ctx->buf, ctx->in);
+		buf += 64;
+		len -= 64;
+	}
+
+	/* Handle any remaining bytes of data. */
+	bcopy(buf, ctx->in, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern 
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+void
+MD5Final(byte digest[16], struct MD5Context *ctx)
+{
+	int count = (int)(ctx->bytes[0] & 0x3f); /* Bytes in ctx->in */
+	byte *p = (byte *)ctx->in + count;	/* First unused byte */
+
+	/* Set the first char of padding to 0x80.  There is always room. */
+	*p++ = 0x80;
+
+	/* Bytes of padding needed to make 56 bytes (-8..55) */
+	count = 56 - 1 - count;
+
+	if (count < 0) {	/* Padding forces an extra block */
+		bzero(p, count+8);
+		byteSwap(ctx->in, 16);
+		MD5Transform(ctx->buf, ctx->in);
+		p = (byte *)ctx->in;
+		count = 56;
+	}
+	bzero(p, count+8);
+	byteSwap(ctx->in, 14);
+
+	/* Append length in bits and transform */
+	ctx->in[14] = ctx->bytes[0] << 3;
+	ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
+	MD5Transform(ctx->buf, ctx->in);
+
+	byteSwap(ctx->buf, 4);
+	bcopy(ctx->buf, digest, 16);
+	bzero(ctx,sizeof(ctx));
+}
+
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f,w,x,y,z,in,s) \
+	 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+
+void
+MD5Transform(word32 buf[4], word32 const in[16])
+{
+	register word32 a, b, c, d;
+
+	a = buf[0];
+	b = buf[1];
+	c = buf[2];
+	d = buf[3];
+
+	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+	buf[0] += a;
+	buf[1] += b;
+	buf[2] += c;
+	buf[3] += d;
+}
+

ghc/lib/misc/cbits/md5.h

+/* MD5 message digest */
+#ifndef _MD5_H
+#define _MD5_H
+
+typedef unsigned long word32;
+typedef unsigned char byte;
+
+struct MD5Context {
+	word32 buf[4];
+	word32 bytes[2];
+	word32 in[16];
+};
+
+void MD5Init(StgByteArray context);
+/*ORIG: void MD5Init(struct MD5Context *context);*/
+void MD5Update(StgByteArray context, void *buf, int len);
+/*ORIG: void MD5Update(struct MD5Context *context, byte const *buf, int len); */
+void MD5Final(StgByteArray digest, StgByteArray context);
+/*ORIG: void MD5Final(byte digest[16], struct MD5Context *context);*/
+
+#endif /* _MD5_H */
+
+
+