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-rw-r--r--trunk/src/sha.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/trunk/src/sha.c b/trunk/src/sha.c
new file mode 100644
index 0000000..cfbc956
--- /dev/null
+++ b/trunk/src/sha.c
@@ -0,0 +1,331 @@
+/* sha.c - Functions to compute the SHA1 hash (message-digest) of files
+ or blocks of memory. Complies to the NIST specification FIPS-180-1.
+
+ Copyright (C) 2000, 2001, 2003 Scott G. Miller
+
+ Credits:
+ Robert Klep <robert@ilse.nl> -- Expansion function fix
+ NOTE: The canonical source of this file is maintained in GNU coreutils.
+*/
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+#include <byteswap.h>
+#include "md5.h"
+#include "sha.h"
+
+/*
+ Not-swap is a macro that does an endian swap on architectures that are
+ big-endian, as SHA needs some data in a little-endian format
+*/
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+# define SWAP(n) bswap_32 (n)
+# define NOTSWAP(n) (n)
+#else
+# define SWAP(n) (n)
+# define NOTSWAP(n) bswap_32 (n)
+#endif
+
+/* This array contains the bytes used to pad the buffer to the next
+ 64-byte boundary. (RFC 1321, 3.1: Step 1) */
+static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ... */ };
+
+
+/*
+ Takes a pointer to a 160 bit block of data (five 32 bit ints) and
+ intializes it to the start constants of the SHA1 algorithm. This
+ must be called before using hash in the call to sha_hash
+*/
+void
+sha_init_ctx (struct sha_ctx *ctx)
+{
+ ctx->A = 0x67452301;
+ ctx->B = 0xefcdab89;
+ ctx->C = 0x98badcfe;
+ ctx->D = 0x10325476;
+ ctx->E = 0xc3d2e1f0;
+
+ ctx->total[0] = ctx->total[1] = 0;
+ ctx->buflen = 0;
+}
+
+/* Put result from CTX in first 20 bytes following RESBUF. The result
+ must be in little endian byte order.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+void *
+sha_read_ctx (const struct sha_ctx *ctx, void *resbuf)
+{
+ ((md5_uint32 *) resbuf)[0] = NOTSWAP (ctx->A);
+ ((md5_uint32 *) resbuf)[1] = NOTSWAP (ctx->B);
+ ((md5_uint32 *) resbuf)[2] = NOTSWAP (ctx->C);
+ ((md5_uint32 *) resbuf)[3] = NOTSWAP (ctx->D);
+ ((md5_uint32 *) resbuf)[4] = NOTSWAP (ctx->E);
+
+ return resbuf;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+ prolog according to the standard and write the result to RESBUF.
+
+ IMPORTANT: On some systems it is required that RESBUF is correctly
+ aligned for a 32 bits value. */
+void *
+sha_finish_ctx (struct sha_ctx *ctx, void *resbuf)
+{
+ /* Take yet unprocessed bytes into account. */
+ md5_uint32 bytes = ctx->buflen;
+ size_t pad;
+
+ /* Now count remaining bytes. */
+ ctx->total[0] += bytes;
+ if (ctx->total[0] < bytes)
+ ++ctx->total[1];
+
+ pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
+ memcpy (&ctx->buffer[bytes], fillbuf, pad);
+
+ /* Put the 64-bit file length in *bits* at the end of the buffer. */
+ *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = NOTSWAP (ctx->total[0] << 3);
+ *(md5_uint32 *) &ctx->buffer[bytes + pad] = NOTSWAP ((ctx->total[1] << 3) |
+ (ctx->total[0] >> 29));
+
+ /* Process last bytes. */
+ sha_process_block (ctx->buffer, bytes + pad + 8, ctx);
+
+ return sha_read_ctx (ctx, resbuf);
+}
+
+/* Compute MD5 message digest for LEN bytes beginning at BUFFER. The
+ result is always in little endian byte order, so that a byte-wise
+ output yields to the wanted ASCII representation of the message
+ digest. */
+void *
+sha_buffer (const char *buffer, size_t len, void *resblock)
+{
+ struct sha_ctx ctx;
+
+ /* Initialize the computation context. */
+ sha_init_ctx (&ctx);
+
+ /* Process whole buffer but last len % 64 bytes. */
+ sha_process_bytes (buffer, len, &ctx);
+
+ /* Put result in desired memory area. */
+ return sha_finish_ctx (&ctx, resblock);
+}
+
+void
+sha_process_bytes (const void *buffer, size_t len, struct sha_ctx *ctx)
+{
+ /* When we already have some bits in our internal buffer concatenate
+ both inputs first. */
+ if (ctx->buflen != 0)
+ {
+ size_t left_over = ctx->buflen;
+ size_t add = 128 - left_over > len ? len : 128 - left_over;
+
+ memcpy (&ctx->buffer[left_over], buffer, add);
+ ctx->buflen += add;
+
+ if (ctx->buflen > 64)
+ {
+ sha_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
+
+ ctx->buflen &= 63;
+ /* The regions in the following copy operation cannot overlap. */
+ memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+ ctx->buflen);
+ }
+
+ buffer = (const char *) buffer + add;
+ len -= add;
+ }
+
+ /* Process available complete blocks. */
+ if (len >= 64)
+ {
+#define UNALIGNED_P(p) (((md5_uintptr) p) % __alignof__ (md5_uint32) != 0)
+ if (UNALIGNED_P (buffer))
+ while (len > 64)
+ {
+ sha_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+ buffer = (const char *) buffer + 64;
+ len -= 64;
+ }
+ else
+ {
+ sha_process_block (buffer, len & ~63, ctx);
+ buffer = (const char *) buffer + (len & ~63);
+ len &= 63;
+ }
+ }
+
+ /* Move remaining bytes in internal buffer. */
+ if (len > 0)
+ {
+ size_t left_over = ctx->buflen;
+
+ memcpy (&ctx->buffer[left_over], buffer, len);
+ left_over += len;
+ if (left_over >= 64)
+ {
+ sha_process_block (ctx->buffer, 64, ctx);
+ left_over -= 64;
+ memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+ }
+ ctx->buflen = left_over;
+ }
+}
+
+/* --- Code below is the primary difference between md5.c and sha.c --- */
+
+/* SHA1 round constants */
+#define K1 0x5a827999L
+#define K2 0x6ed9eba1L
+#define K3 0x8f1bbcdcL
+#define K4 0xca62c1d6L
+
+/* Round functions. Note that F2 is the same as F4. */
+#define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
+#define F2(B,C,D) (B ^ C ^ D)
+#define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
+#define F4(B,C,D) (B ^ C ^ D)
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+ It is assumed that LEN % 64 == 0.
+ Most of this code comes from GnuPG's cipher/sha1.c. */
+
+void
+sha_process_block (const void *buffer, size_t len, struct sha_ctx *ctx)
+{
+ const md5_uint32 *words = buffer;
+ size_t nwords = len / sizeof (md5_uint32);
+ const md5_uint32 *endp = words + nwords;
+ md5_uint32 x[16];
+ md5_uint32 a = ctx->A;
+ md5_uint32 b = ctx->B;
+ md5_uint32 c = ctx->C;
+ md5_uint32 d = ctx->D;
+ md5_uint32 e = ctx->E;
+
+ /* First increment the byte count. RFC 1321 specifies the possible
+ length of the file up to 2^64 bits. Here we only compute the
+ number of bytes. Do a double word increment. */
+ ctx->total[0] += len;
+ if (ctx->total[0] < len)
+ ++ctx->total[1];
+
+#define M(I) ( tm = x[I&0x0f] ^ x[(I-14)&0x0f] \
+ ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
+ , (x[I&0x0f] = rol(tm, 1)) )
+
+#define R(A,B,C,D,E,F,K,M) do { E += rol( A, 5 ) \
+ + F( B, C, D ) \
+ + K \
+ + M; \
+ B = rol( B, 30 ); \
+ } while(0)
+
+ while (words < endp)
+ {
+ md5_uint32 tm;
+ int t;
+ /* FIXME: see sha1.c for a better implementation. */
+ for (t = 0; t < 16; t++)
+ {
+ x[t] = NOTSWAP (*words);
+ words++;
+ }
+
+ R( a, b, c, d, e, F1, K1, x[ 0] );
+ R( e, a, b, c, d, F1, K1, x[ 1] );
+ R( d, e, a, b, c, F1, K1, x[ 2] );
+ R( c, d, e, a, b, F1, K1, x[ 3] );
+ R( b, c, d, e, a, F1, K1, x[ 4] );
+ R( a, b, c, d, e, F1, K1, x[ 5] );
+ R( e, a, b, c, d, F1, K1, x[ 6] );
+ R( d, e, a, b, c, F1, K1, x[ 7] );
+ R( c, d, e, a, b, F1, K1, x[ 8] );
+ R( b, c, d, e, a, F1, K1, x[ 9] );
+ R( a, b, c, d, e, F1, K1, x[10] );
+ R( e, a, b, c, d, F1, K1, x[11] );
+ R( d, e, a, b, c, F1, K1, x[12] );
+ R( c, d, e, a, b, F1, K1, x[13] );
+ R( b, c, d, e, a, F1, K1, x[14] );
+ R( a, b, c, d, e, F1, K1, x[15] );
+ R( e, a, b, c, d, F1, K1, M(16) );
+ R( d, e, a, b, c, F1, K1, M(17) );
+ R( c, d, e, a, b, F1, K1, M(18) );
+ R( b, c, d, e, a, F1, K1, M(19) );
+ R( a, b, c, d, e, F2, K2, M(20) );
+ R( e, a, b, c, d, F2, K2, M(21) );
+ R( d, e, a, b, c, F2, K2, M(22) );
+ R( c, d, e, a, b, F2, K2, M(23) );
+ R( b, c, d, e, a, F2, K2, M(24) );
+ R( a, b, c, d, e, F2, K2, M(25) );
+ R( e, a, b, c, d, F2, K2, M(26) );
+ R( d, e, a, b, c, F2, K2, M(27) );
+ R( c, d, e, a, b, F2, K2, M(28) );
+ R( b, c, d, e, a, F2, K2, M(29) );
+ R( a, b, c, d, e, F2, K2, M(30) );
+ R( e, a, b, c, d, F2, K2, M(31) );
+ R( d, e, a, b, c, F2, K2, M(32) );
+ R( c, d, e, a, b, F2, K2, M(33) );
+ R( b, c, d, e, a, F2, K2, M(34) );
+ R( a, b, c, d, e, F2, K2, M(35) );
+ R( e, a, b, c, d, F2, K2, M(36) );
+ R( d, e, a, b, c, F2, K2, M(37) );
+ R( c, d, e, a, b, F2, K2, M(38) );
+ R( b, c, d, e, a, F2, K2, M(39) );
+ R( a, b, c, d, e, F3, K3, M(40) );
+ R( e, a, b, c, d, F3, K3, M(41) );
+ R( d, e, a, b, c, F3, K3, M(42) );
+ R( c, d, e, a, b, F3, K3, M(43) );
+ R( b, c, d, e, a, F3, K3, M(44) );
+ R( a, b, c, d, e, F3, K3, M(45) );
+ R( e, a, b, c, d, F3, K3, M(46) );
+ R( d, e, a, b, c, F3, K3, M(47) );
+ R( c, d, e, a, b, F3, K3, M(48) );
+ R( b, c, d, e, a, F3, K3, M(49) );
+ R( a, b, c, d, e, F3, K3, M(50) );
+ R( e, a, b, c, d, F3, K3, M(51) );
+ R( d, e, a, b, c, F3, K3, M(52) );
+ R( c, d, e, a, b, F3, K3, M(53) );
+ R( b, c, d, e, a, F3, K3, M(54) );
+ R( a, b, c, d, e, F3, K3, M(55) );
+ R( e, a, b, c, d, F3, K3, M(56) );
+ R( d, e, a, b, c, F3, K3, M(57) );
+ R( c, d, e, a, b, F3, K3, M(58) );
+ R( b, c, d, e, a, F3, K3, M(59) );
+ R( a, b, c, d, e, F4, K4, M(60) );
+ R( e, a, b, c, d, F4, K4, M(61) );
+ R( d, e, a, b, c, F4, K4, M(62) );
+ R( c, d, e, a, b, F4, K4, M(63) );
+ R( b, c, d, e, a, F4, K4, M(64) );
+ R( a, b, c, d, e, F4, K4, M(65) );
+ R( e, a, b, c, d, F4, K4, M(66) );
+ R( d, e, a, b, c, F4, K4, M(67) );
+ R( c, d, e, a, b, F4, K4, M(68) );
+ R( b, c, d, e, a, F4, K4, M(69) );
+ R( a, b, c, d, e, F4, K4, M(70) );
+ R( e, a, b, c, d, F4, K4, M(71) );
+ R( d, e, a, b, c, F4, K4, M(72) );
+ R( c, d, e, a, b, F4, K4, M(73) );
+ R( b, c, d, e, a, F4, K4, M(74) );
+ R( a, b, c, d, e, F4, K4, M(75) );
+ R( e, a, b, c, d, F4, K4, M(76) );
+ R( d, e, a, b, c, F4, K4, M(77) );
+ R( c, d, e, a, b, F4, K4, M(78) );
+ R( b, c, d, e, a, F4, K4, M(79) );
+
+ a = ctx->A += a;
+ b = ctx->B += b;
+ c = ctx->C += c;
+ d = ctx->D += d;
+ e = ctx->E += e;
+ }
+}
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