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1 files changed, 337 insertions, 0 deletions

diff --git a/lib/sha.c b/lib/sha.c
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+++ b/lib/sha.c
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+/* 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 Scott G. Miller
+
+   Credits:
+      Robert Klep <robert@ilse.nl>  -- Expansion function fix
+*/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <sys/types.h>
+
+#if STDC_HEADERS || defined _LIBC
+# include <stdlib.h>
+# include <string.h>
+#else
+# ifndef HAVE_MEMCPY
+#  define memcpy(d, s, n) bcopy ((s), (d), (n))
+# endif
+#endif
+
+#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
+*/
+
+#ifdef WORDS_BIGENDIAN
+# define NOTSWAP(n) (n)
+# define SWAP(n)							\
+    (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+#else
+# define NOTSWAP(n)                                                         \
+    (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+# define SWAP(n) (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 SHA1 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+int
+sha_stream (FILE *stream, void *resblock)
+{
+  /* Important: BLOCKSIZE must be a multiple of 64.  */
+#define BLOCKSIZE 4096
+  struct sha_ctx ctx;
+  char buffer[BLOCKSIZE + 72];
+  size_t sum;
+
+  /* Initialize the computation context.  */
+  sha_init_ctx (&ctx);
+
+  /* Iterate over full file contents.  */
+  while (1)
+    {
+      /* We read the file in blocks of BLOCKSIZE bytes.  One call of the
+	 computation function processes the whole buffer so that with the
+	 next round of the loop another block can be read.  */
+      size_t n;
+      sum = 0;
+
+      /* Read block.  Take care for partial reads.  */
+      do
+	{
+	  n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
+
+	  sum += n;
+	}
+      while (sum < BLOCKSIZE && n != 0);
+      if (n == 0 && ferror (stream))
+        return 1;
+
+      /* If end of file is reached, end the loop.  */
+      if (n == 0)
+	break;
+
+      /* Process buffer with BLOCKSIZE bytes.  Note that
+			BLOCKSIZE % 64 == 0
+       */
+      sha_process_block (buffer, BLOCKSIZE, &ctx);
+    }
+
+  /* Add the last bytes if necessary.  */
+  if (sum > 0)
+    sha_process_bytes (buffer, sum, &ctx);
+
+  /* Construct result in desired memory.  */
+  sha_finish_ctx (&ctx, resblock);
+  return 0;
+}
+
+/* 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 (left_over + add > 64)
+	{
+	  sha_process_block (ctx->buffer, (left_over + add) & ~63, ctx);
+	  /* The regions in the following copy operation cannot overlap.  */
+	  memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+		  (left_over + add) & 63);
+	  ctx->buflen = (left_over + add) & 63;
+	}
+
+      buffer = (const char *) buffer + add;
+      len -= add;
+    }
+
+  /* Process available complete blocks.  */
+  if (len > 64)
+    {
+      sha_process_block (buffer, len & ~63, ctx);
+      buffer = (const char *) buffer + (len & ~63);
+      len &= 63;
+    }
+
+  /* Move remaining bytes in internal buffer.  */
+  if (len > 0)
+    {
+      memcpy (ctx->buffer, buffer, len);
+      ctx->buflen = len;
+    }
+}
+
+/* --- 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 used in both rounds 2 and 4 */
+#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 ) ) )
+
+#if SHA_DEBUG
+char bin2hex[16]={'0','1','2','3','4','5','6','7',
+		  '8','9','a','b','c','d','e','f'};
+# define BH(x) bin2hex[x]
+# define PH(x) \
+      printf("%c%c%c%c%c%c%c%c\t", BH((x>>28)&0xf), \
+	     BH((x>>24)&0xf), BH((x>>20)&0xf), BH((x>>16)&0xf),\
+	     BH((x>>12)&0xf), BH((x>>8)&0xf), BH((x>>4)&0xf),\
+	     BH(x&0xf));
+#endif
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.  */
+
+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 W[80];
+  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];
+
+  while (words < endp)
+    {
+      int t;
+      for (t = 0; t < 16; t++)
+	{
+	  W[t] = NOTSWAP (*words);
+	  words++;
+	}
+
+      /* SHA1 Data expansion */
+      for (t = 16; t < 80; t++)
+	{
+	  md5_uint32 x = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
+	  W[t] = rol (x, 1);
+	}
+
+      /* SHA1 main loop (t=0 to 79)
+         This is broken down into four subloops in order to use
+         the correct round function and constant */
+      for (t = 0; t < 20; t++)
+	{
+	  md5_uint32 tmp = rol (A, 5) + f1 (B, C, D) + E + W[t] + K1;
+	  E = D;
+	  D = C;
+	  C = rol (B, 30);
+	  B = A;
+	  A = tmp;
+	}
+      for (; t < 40; t++)
+	{
+	  md5_uint32 tmp = rol (A, 5) + f2 (B, C, D) + E + W[t] + K2;
+	  E = D;
+	  D = C;
+	  C = rol (B, 30);
+	  B = A;
+	  A = tmp;
+	}
+      for (; t < 60; t++)
+	{
+	  md5_uint32 tmp = rol (A, 5) + f3 (B, C, D) + E + W[t] + K3;
+	  E = D;
+	  D = C;
+	  C = rol (B, 30);
+	  B = A;
+	  A = tmp;
+	}
+      for (; t < 80; t++)
+	{
+	  md5_uint32 tmp = rol (A, 5) + f2 (B, C, D) + E + W[t] + K4;
+	  E = D;
+	  D = C;
+	  C = rol (B, 30);
+	  B = A;
+	  A = tmp;
+	}
+      A = ctx->A += A;
+      B = ctx->B += B;
+      C = ctx->C += C;
+      D = ctx->D += D;
+      E = ctx->E += E;
+    }
+}