1 files changed, 382 insertions, 0 deletions
diff --git a/lib/md4.c b/lib/md4.c
new file mode 100644
index 0000000..05855f6
--- /dev/null
+++ b/lib/md4.c
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+/* Functions to compute MD4 message digest of files or memory blocks.
+   according to the definition of MD4 in RFC 1320 from April 1992.
+   Copyright (C) 1995-1997, 1999-2003, 2005-2006, 2008-2017 Free Software
+   Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by the
+   Free Software Foundation; either version 3, or (at your option) any
+   later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+/* Adapted by Simon Josefsson from gnulib md5.? and Libgcrypt
+   cipher/md4.c . */
+
+#include <config.h>
+
+#include "md4.h"
+
+#include <stdalign.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+#ifdef WORDS_BIGENDIAN
+# define SWAP(n)                                                        \
+  (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+#else
+# define SWAP(n) (n)
+#endif
+
+#define BLOCKSIZE 32768
+#if BLOCKSIZE % 64 != 0
+# error "invalid BLOCKSIZE"
+#endif
+
+/* This array contains the bytes used to pad the buffer to the next
+   64-byte boundary.  (RFC 1320, 3.1: Step 1)  */
+static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ...  */  };
+
+
+/* Initialize structure containing state of computation.
+   (RFC 1320, 3.3: Step 3)  */
+void
+md4_init_ctx (struct md4_ctx *ctx)
+{
+  ctx->A = 0x67452301;
+  ctx->B = 0xefcdab89;
+  ctx->C = 0x98badcfe;
+  ctx->D = 0x10325476;
+
+  ctx->total[0] = ctx->total[1] = 0;
+  ctx->buflen = 0;
+}
+
+/* Copy the 4 byte value from v into the memory location pointed to by *cp,
+   If your architecture allows unaligned access this is equivalent to
+   * (uint32_t *) cp = v  */
+static void
+set_uint32 (char *cp, uint32_t v)
+{
+  memcpy (cp, &v, sizeof v);
+}
+
+/* Put result from CTX in first 16 bytes following RESBUF.  The result
+   must be in little endian byte order.  */
+void *
+md4_read_ctx (const struct md4_ctx *ctx, void *resbuf)
+{
+  char *r = resbuf;
+  set_uint32 (r + 0 * sizeof ctx->A, SWAP (ctx->A));
+  set_uint32 (r + 1 * sizeof ctx->B, SWAP (ctx->B));
+  set_uint32 (r + 2 * sizeof ctx->C, SWAP (ctx->C));
+  set_uint32 (r + 3 * sizeof ctx->D, SWAP (ctx->D));
+
+  return resbuf;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+   prolog according to the standard and write the result to RESBUF.  */
+void *
+md4_finish_ctx (struct md4_ctx *ctx, void *resbuf)
+{
+  /* Take yet unprocessed bytes into account.  */
+  uint32_t 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 (&((char*)ctx->buffer)[bytes], fillbuf, pad);
+
+  /* Put the 64-bit file length in *bits* at the end of the buffer.  */
+  ctx->buffer[(bytes + pad) / 4] = SWAP (ctx->total[0] << 3);
+  ctx->buffer[(bytes + pad) / 4 + 1] = SWAP ((ctx->total[1] << 3) |
+                                             (ctx->total[0] >> 29));
+
+  /* Process last bytes.  */
+  md4_process_block (ctx->buffer, bytes + pad + 8, ctx);
+
+  return md4_read_ctx (ctx, resbuf);
+}
+
+/* Compute MD4 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+int
+md4_stream (FILE * stream, void *resblock)
+{
+  struct md4_ctx ctx;
+  size_t sum;
+
+  char *buffer = malloc (BLOCKSIZE + 72);
+  if (!buffer)
+    return 1;
+
+  /* Initialize the computation context.  */
+  md4_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.  */
+      while (1)
+        {
+          n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
+
+          sum += n;
+
+          if (sum == BLOCKSIZE)
+            break;
+
+          if (n == 0)
+            {
+              /* Check for the error flag IFF N == 0, so that we don't
+                 exit the loop after a partial read due to e.g., EAGAIN
+                 or EWOULDBLOCK.  */
+              if (ferror (stream))
+                {
+                  free (buffer);
+                  return 1;
+                }
+              goto process_partial_block;
+            }
+
+          /* We've read at least one byte, so ignore errors.  But always
+             check for EOF, since feof may be true even though N > 0.
+             Otherwise, we could end up calling fread after EOF.  */
+          if (feof (stream))
+            goto process_partial_block;
+        }
+
+      /* Process buffer with BLOCKSIZE bytes.  Note that
+         BLOCKSIZE % 64 == 0
+       */
+      md4_process_block (buffer, BLOCKSIZE, &ctx);
+    }
+
+process_partial_block:;
+
+  /* Process any remaining bytes.  */
+  if (sum > 0)
+    md4_process_bytes (buffer, sum, &ctx);
+
+  /* Construct result in desired memory.  */
+  md4_finish_ctx (&ctx, resblock);
+  free (buffer);
+  return 0;
+}
+
+/* Compute MD4 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 *
+md4_buffer (const char *buffer, size_t len, void *resblock)
+{
+  struct md4_ctx ctx;
+
+  /* Initialize the computation context.  */
+  md4_init_ctx (&ctx);
+
+  /* Process whole buffer but last len % 64 bytes.  */
+  md4_process_bytes (buffer, len, &ctx);
+
+  /* Put result in desired memory area.  */
+  return md4_finish_ctx (&ctx, resblock);
+}
+
+void
+md4_process_bytes (const void *buffer, size_t len, struct md4_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 (&((char*)ctx->buffer)[left_over], buffer, add);
+      ctx->buflen += add;
+
+      if (ctx->buflen > 64)
+        {
+          md4_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
+
+          ctx->buflen &= 63;
+          /* The regions in the following copy operation cannot overlap.  */
+          memcpy (ctx->buffer, &((char*)ctx->buffer)[(left_over + add) & ~63],
+                  ctx->buflen);
+        }
+
+      buffer = (const char *) buffer + add;
+      len -= add;
+    }
+
+  /* Process available complete blocks.  */
+  if (len >= 64)
+    {
+#if !(_STRING_ARCH_unaligned || _STRING_INLINE_unaligned)
+# define UNALIGNED_P(p) ((uintptr_t) (p) % alignof (uint32_t) != 0)
+      if (UNALIGNED_P (buffer))
+        while (len > 64)
+          {
+            md4_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+            buffer = (const char *) buffer + 64;
+            len -= 64;
+          }
+      else
+#endif
+        {
+          md4_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 (&((char*)ctx->buffer)[left_over], buffer, len);
+      left_over += len;
+      if (left_over >= 64)
+        {
+          md4_process_block (ctx->buffer, 64, ctx);
+          left_over -= 64;
+          memcpy (ctx->buffer, &ctx->buffer[16], left_over);
+        }
+      ctx->buflen = left_over;
+    }
+}
+
+/* --- Code below is the primary difference between md5.c and md4.c --- */
+
+/* MD4 round constants */
+#define K1 0x5a827999
+#define K2 0x6ed9eba1
+
+/* Round functions.  */
+#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
+#define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
+#define H(x, y, z) ((x) ^ (y) ^ (z))
+#define rol(x, n) (((x) << (n)) | ((uint32_t) (x) >> (32 - (n))))
+#define R1(a,b,c,d,k,s) a=rol(a+F(b,c,d)+x[k],s);
+#define R2(a,b,c,d,k,s) a=rol(a+G(b,c,d)+x[k]+K1,s);
+#define R3(a,b,c,d,k,s) a=rol(a+H(b,c,d)+x[k]+K2,s);
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.  */
+
+void
+md4_process_block (const void *buffer, size_t len, struct md4_ctx *ctx)
+{
+  const uint32_t *words = buffer;
+  size_t nwords = len / sizeof (uint32_t);
+  const uint32_t *endp = words + nwords;
+  uint32_t x[16];
+  uint32_t A = ctx->A;
+  uint32_t B = ctx->B;
+  uint32_t C = ctx->C;
+  uint32_t D = ctx->D;
+  uint32_t lolen = len;
+
+  /* First increment the byte count.  RFC 1320 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] += lolen;
+  ctx->total[1] += (len >> 31 >> 1) + (ctx->total[0] < lolen);
+
+  /* Process all bytes in the buffer with 64 bytes in each round of
+     the loop.  */
+  while (words < endp)
+    {
+      int t;
+      for (t = 0; t < 16; t++)
+        {
+          x[t] = SWAP (*words);
+          words++;
+        }
+
+      /* Round 1.  */
+      R1 (A, B, C, D, 0, 3);
+      R1 (D, A, B, C, 1, 7);
+      R1 (C, D, A, B, 2, 11);
+      R1 (B, C, D, A, 3, 19);
+      R1 (A, B, C, D, 4, 3);
+      R1 (D, A, B, C, 5, 7);
+      R1 (C, D, A, B, 6, 11);
+      R1 (B, C, D, A, 7, 19);
+      R1 (A, B, C, D, 8, 3);
+      R1 (D, A, B, C, 9, 7);
+      R1 (C, D, A, B, 10, 11);
+      R1 (B, C, D, A, 11, 19);
+      R1 (A, B, C, D, 12, 3);
+      R1 (D, A, B, C, 13, 7);
+      R1 (C, D, A, B, 14, 11);
+      R1 (B, C, D, A, 15, 19);
+
+      /* Round 2.  */
+      R2 (A, B, C, D, 0, 3);
+      R2 (D, A, B, C, 4, 5);
+      R2 (C, D, A, B, 8, 9);
+      R2 (B, C, D, A, 12, 13);
+      R2 (A, B, C, D, 1, 3);
+      R2 (D, A, B, C, 5, 5);
+      R2 (C, D, A, B, 9, 9);
+      R2 (B, C, D, A, 13, 13);
+      R2 (A, B, C, D, 2, 3);
+      R2 (D, A, B, C, 6, 5);
+      R2 (C, D, A, B, 10, 9);
+      R2 (B, C, D, A, 14, 13);
+      R2 (A, B, C, D, 3, 3);
+      R2 (D, A, B, C, 7, 5);
+      R2 (C, D, A, B, 11, 9);
+      R2 (B, C, D, A, 15, 13);
+
+      /* Round 3.  */
+      R3 (A, B, C, D, 0, 3);
+      R3 (D, A, B, C, 8, 9);
+      R3 (C, D, A, B, 4, 11);
+      R3 (B, C, D, A, 12, 15);
+      R3 (A, B, C, D, 2, 3);
+      R3 (D, A, B, C, 10, 9);
+      R3 (C, D, A, B, 6, 11);
+      R3 (B, C, D, A, 14, 15);
+      R3 (A, B, C, D, 1, 3);
+      R3 (D, A, B, C, 9, 9);
+      R3 (C, D, A, B, 5, 11);
+      R3 (B, C, D, A, 13, 15);
+      R3 (A, B, C, D, 3, 3);
+      R3 (D, A, B, C, 11, 9);
+      R3 (C, D, A, B, 7, 11);
+      R3 (B, C, D, A, 15, 15);
+
+      A = ctx->A += A;
+      B = ctx->B += B;
+      C = ctx->C += C;
+      D = ctx->D += D;
+    }
+}