Patch from Devin Bayer to split up hash_fd.c into md5.c and sha1.c.  (I tweaked
md5_sha1_sum.c to convert some #ifdef CONFIG to if(ENABLE).)
diff --git a/libbb/sha1.c b/libbb/sha1.c
new file mode 100644
index 0000000..f0d952f
--- /dev/null
+++ b/libbb/sha1.c
@@ -0,0 +1,200 @@
+/*
+ *  Based on shasum from http://www.netsw.org/crypto/hash/
+ *  Majorly hacked up to use Dr Brian Gladman's sha1 code
+ *
+ *  Copyright (C) 2002 Dr Brian Gladman <brg@gladman.me.uk>, Worcester, UK.
+ *  Copyright (C) 2003 Glenn L. McGrath
+ *  Copyright (C) 2003 Erik Andersen
+ *  
+ *  LICENSE TERMS
+ *
+ *  The free distribution and use of this software in both source and binary
+ *  form is allowed (with or without changes) provided that:
+ *
+ *    1. distributions of this source code include the above copyright
+ *       notice, this list of conditions and the following disclaimer;
+ *
+ *    2. distributions in binary form include the above copyright
+ *       notice, this list of conditions and the following disclaimer
+ *       in the documentation and/or other associated materials;
+ *
+ *    3. the copyright holder's name is not used to endorse products
+ *       built using this software without specific written permission.
+ *
+ *  ALTERNATIVELY, provided that this notice is retained in full, this product
+ *  may be distributed under the terms of the GNU General Public License (GPL),
+ *  in which case the provisions of the GPL apply INSTEAD OF those given above.
+ *
+ *  DISCLAIMER
+ *
+ *  This software is provided 'as is' with no explicit or implied warranties
+ *  in respect of its properties, including, but not limited to, correctness
+ *  and/or fitness for purpose.
+ *  ---------------------------------------------------------------------------
+ *  Issue Date: 10/11/2002
+ *
+ *  This is a byte oriented version of SHA1 that operates on arrays of bytes
+ *  stored in memory. It runs at 22 cycles per byte on a Pentium P4 processor
+ */
+
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "busybox.h"
+
+# define SHA1_BLOCK_SIZE  64
+# define SHA1_DIGEST_SIZE 20
+# define SHA1_HASH_SIZE   SHA1_DIGEST_SIZE
+# define SHA2_GOOD        0
+# define SHA2_BAD         1
+
+# define rotl32(x,n) (((x) << n) | ((x) >> (32 - n)))
+
+# define SHA1_MASK   (SHA1_BLOCK_SIZE - 1)
+
+/* reverse byte order in 32-bit words   */
+#define ch(x,y,z)       ((z) ^ ((x) & ((y) ^ (z))))
+#define parity(x,y,z)   ((x) ^ (y) ^ (z))
+#define maj(x,y,z)      (((x) & (y)) | ((z) & ((x) | (y))))
+
+/* A normal version as set out in the FIPS. This version uses   */
+/* partial loop unrolling and is optimised for the Pentium 4    */
+# define rnd(f,k)    \
+    t = a; a = rotl32(a,5) + f(b,c,d) + e + k + w[i]; \
+    e = d; d = c; c = rotl32(b, 30); b = t
+
+
+static void sha1_compile(sha1_ctx_t *ctx)
+{
+	uint32_t w[80], i, a, b, c, d, e, t;
+
+	/* note that words are compiled from the buffer into 32-bit */
+	/* words in big-endian order so an order reversal is needed */
+	/* here on little endian machines                           */
+	for (i = 0; i < SHA1_BLOCK_SIZE / 4; ++i)
+		w[i] = htonl(ctx->wbuf[i]);
+
+	for (i = SHA1_BLOCK_SIZE / 4; i < 80; ++i)
+		w[i] = rotl32(w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16], 1);
+
+	a = ctx->hash[0];
+	b = ctx->hash[1];
+	c = ctx->hash[2];
+	d = ctx->hash[3];
+	e = ctx->hash[4];
+
+	for (i = 0; i < 20; ++i) {
+		rnd(ch, 0x5a827999);
+	}
+
+	for (i = 20; i < 40; ++i) {
+		rnd(parity, 0x6ed9eba1);
+	}
+
+	for (i = 40; i < 60; ++i) {
+		rnd(maj, 0x8f1bbcdc);
+	}
+
+	for (i = 60; i < 80; ++i) {
+		rnd(parity, 0xca62c1d6);
+	}
+
+	ctx->hash[0] += a;
+	ctx->hash[1] += b;
+	ctx->hash[2] += c;
+	ctx->hash[3] += d;
+	ctx->hash[4] += e;
+}
+
+void sha1_begin(sha1_ctx_t *ctx)
+{
+	ctx->count[0] = ctx->count[1] = 0;
+	ctx->hash[0] = 0x67452301;
+	ctx->hash[1] = 0xefcdab89;
+	ctx->hash[2] = 0x98badcfe;
+	ctx->hash[3] = 0x10325476;
+	ctx->hash[4] = 0xc3d2e1f0;
+}
+
+/* SHA1 hash data in an array of bytes into hash buffer and call the        */
+/* hash_compile function as required.                                       */
+void sha1_hash(const void *data, size_t length, sha1_ctx_t *ctx)
+{
+	uint32_t pos = (uint32_t) (ctx->count[0] & SHA1_MASK);
+	uint32_t freeb = SHA1_BLOCK_SIZE - pos;
+	const unsigned char *sp = data;
+
+	if ((ctx->count[0] += length) < length)
+		++(ctx->count[1]);
+
+	while (length >= freeb) {	/* tranfer whole blocks while possible  */
+		memcpy(((unsigned char *) ctx->wbuf) + pos, sp, freeb);
+		sp += freeb;
+		length -= freeb;
+		freeb = SHA1_BLOCK_SIZE;
+		pos = 0;
+		sha1_compile(ctx);
+	}
+
+	memcpy(((unsigned char *) ctx->wbuf) + pos, sp, length);
+}
+
+void *sha1_end(void *resbuf, sha1_ctx_t *ctx)
+{
+	/* SHA1 Final padding and digest calculation  */
+	#if BB_BIG_ENDIAN
+		static uint32_t mask[4] = { 0x00000000, 0xff000000, 0xffff0000, 0xffffff00 };
+		static uint32_t bits[4] = { 0x80000000, 0x00800000, 0x00008000, 0x00000080 };
+	#else
+		static uint32_t mask[4] = { 0x00000000, 0x000000ff, 0x0000ffff, 0x00ffffff };
+		static uint32_t bits[4] = { 0x00000080, 0x00008000, 0x00800000, 0x80000000 };
+	#endif /* __BYTE_ORDER */
+
+	uint8_t *hval = resbuf;
+	uint32_t i, cnt = (uint32_t) (ctx->count[0] & SHA1_MASK);
+
+	/* mask out the rest of any partial 32-bit word and then set    */
+	/* the next byte to 0x80. On big-endian machines any bytes in   */
+	/* the buffer will be at the top end of 32 bit words, on little */
+	/* endian machines they will be at the bottom. Hence the AND    */
+	/* and OR masks above are reversed for little endian systems    */
+	ctx->wbuf[cnt >> 2] =
+		(ctx->wbuf[cnt >> 2] & mask[cnt & 3]) | bits[cnt & 3];
+
+	/* we need 9 or more empty positions, one for the padding byte  */
+	/* (above) and eight for the length count.  If there is not     */
+	/* enough space pad and empty the buffer                        */
+	if (cnt > SHA1_BLOCK_SIZE - 9) {
+		if (cnt < 60)
+			ctx->wbuf[15] = 0;
+		sha1_compile(ctx);
+		cnt = 0;
+	} else				/* compute a word index for the empty buffer positions  */
+		cnt = (cnt >> 2) + 1;
+
+	while (cnt < 14)	/* and zero pad all but last two positions      */
+		ctx->wbuf[cnt++] = 0;
+
+	/* assemble the eight byte counter in the buffer in big-endian  */
+	/* format					               */
+
+	ctx->wbuf[14] = htonl((ctx->count[1] << 3) | (ctx->count[0] >> 29));
+	ctx->wbuf[15] = htonl(ctx->count[0] << 3);
+
+	sha1_compile(ctx);
+
+	/* extract the hash value as bytes in case the hash buffer is   */
+	/* misaligned for 32-bit words                                  */
+
+	for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
+		hval[i] = (unsigned char) (ctx->hash[i >> 2] >> 8 * (~i & 3));
+	
+	return resbuf;
+}
+
+