1 files changed, 1013 insertions, 0 deletions

diff --git a/md5sum.c b/md5sum.c
new file mode 100644
index 000000000..ffa9e6bce
--- /dev/null
+++ b/md5sum.c
@@ -0,0 +1,1013 @@
+/* md5sum.c - Compute MD5 checksum of files or strings according to the
+ *            definition of MD5 in RFC 1321 from April 1992.
+ * Copyright (C) 1995-1999 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 2, 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, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu> */
+/* Hacked to work with BusyBox by Alfred M. Szmidt <ams@trillian.itslinux.org> */
+
+#include "internal.h"
+#include <stdio.h>
+#include <errno.h>
+#include <ctype.h>
+
+//----------------------------------------------------------------------------
+//--------md5.c
+//----------------------------------------------------------------------------
+
+/* md5.c - Functions to compute MD5 message digest of files or memory blocks
+ *         according to the definition of MD5 in RFC 1321 from April 1992.
+ * Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+ *
+ * NOTE: The canonical source of this file is maintained with the GNU C
+ * Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+ *
+ * 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 2, 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, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
+
+#include <sys/types.h>
+#include <stdlib.h>
+#include <string.h>
+#include <endian.h>
+
+#include "internal.h"
+//----------------------------------------------------------------------------
+//--------md5.h
+//----------------------------------------------------------------------------
+
+/* md5.h - Declaration of functions and data types used for MD5 sum
+   computing library functions.
+   Copyright (C) 1995, 1996 Free Software Foundation, Inc.
+   NOTE: The canonical source of this file is maintained with the GNU C
+   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+
+   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 2, 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, write to the Free Software Foundation,
+   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifndef _MD5_H
+#define _MD5_H 1
+
+#include <stdio.h>
+
+#if defined HAVE_LIMITS_H || _LIBC
+# include <limits.h>
+#endif
+
+/* The following contortions are an attempt to use the C preprocessor
+   to determine an unsigned integral type that is 32 bits wide.  An
+   alternative approach is to use autoconf's AC_CHECK_SIZEOF macro, but
+   doing that would require that the configure script compile and *run*
+   the resulting executable.  Locally running cross-compiled executables
+   is usually not possible.  */
+
+#ifdef _LIBC
+# include <sys/types.h>
+typedef u_int32_t md5_uint32;
+#else
+# if defined __STDC__ && __STDC__
+#  define UINT_MAX_32_BITS 4294967295U
+# else
+#  define UINT_MAX_32_BITS 0xFFFFFFFF
+# endif
+
+/* If UINT_MAX isn't defined, assume it's a 32-bit type.
+   This should be valid for all systems GNU cares about because
+   that doesn't include 16-bit systems, and only modern systems
+   (that certainly have <limits.h>) have 64+-bit integral types.  */
+
+# ifndef UINT_MAX
+#  define UINT_MAX UINT_MAX_32_BITS
+# endif
+
+# if UINT_MAX == UINT_MAX_32_BITS
+   typedef unsigned int md5_uint32;
+# else
+#  if USHRT_MAX == UINT_MAX_32_BITS
+    typedef unsigned short md5_uint32;
+#  else
+#   if ULONG_MAX == UINT_MAX_32_BITS
+     typedef unsigned long md5_uint32;
+#   else
+     /* The following line is intended to evoke an error.
+        Using #error is not portable enough.  */
+     "Cannot determine unsigned 32-bit data type."
+#   endif
+#  endif
+# endif
+#endif
+
+#undef __P
+#if defined (__STDC__) && __STDC__
+#define __P(x) x
+#else
+#define __P(x) ()
+#endif
+
+/* Structure to save state of computation between the single steps.  */
+struct md5_ctx
+{
+  md5_uint32 A;
+  md5_uint32 B;
+  md5_uint32 C;
+  md5_uint32 D;
+
+  md5_uint32 total[2];
+  md5_uint32 buflen;
+  char buffer[128];
+};
+
+/*
+ * The following three functions are build up the low level used in
+ * the functions `md5_stream' and `md5_buffer'.
+ */
+
+/* Initialize structure containing state of computation.
+   (RFC 1321, 3.3: Step 3)  */
+extern void md5_init_ctx __P ((struct md5_ctx *ctx));
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is necessary that LEN is a multiple of 64!!! */
+extern void md5_process_block __P ((const void *buffer, size_t len,
+                                    struct md5_ctx *ctx));
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is NOT required that LEN is a multiple of 64.  */
+extern void md5_process_bytes __P ((const void *buffer, size_t len,
+                                    struct md5_ctx *ctx));
+
+/* Process the remaining bytes in the buffer and put result from CTX
+   in first 16 bytes following RESBUF.  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.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+extern void *md5_finish_ctx __P ((struct md5_ctx *ctx, void *resbuf));
+
+
+/* Put result from CTX in first 16 bytes following RESBUF.  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.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+extern void *md5_read_ctx __P ((const struct md5_ctx *ctx, void *resbuf));
+
+
+/* Compute MD5 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+extern int md5_stream __P ((FILE *stream, void *resblock));
+
+/* 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.  */
+extern void *md5_buffer __P ((const char *buffer, size_t len, void *resblock));
+
+#endif
+
+//----------------------------------------------------------------------------
+//--------end of md5.h
+//----------------------------------------------------------------------------
+
+#define SWAP(n) (n)
+
+/* 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, ...  */  };
+
+/* Initialize structure containing state of computation.
+   (RFC 1321, 3.3: Step 3)  */
+void md5_init_ctx(struct md5_ctx *ctx)
+{
+  ctx->A = 0x67452301;
+  ctx->B = 0xefcdab89;
+  ctx->C = 0x98badcfe;
+  ctx->D = 0x10325476;
+
+  ctx->total[0] = ctx->total[1] = 0;
+  ctx->buflen = 0;
+}
+
+/* Put result from CTX in first 16 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 *md5_read_ctx(const struct md5_ctx *ctx, void *resbuf)
+{
+  ((md5_uint32 *) resbuf)[0] = SWAP(ctx->A);
+  ((md5_uint32 *) resbuf)[1] = SWAP(ctx->B);
+  ((md5_uint32 *) resbuf)[2] = SWAP(ctx->C);
+  ((md5_uint32 *) resbuf)[3] = 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.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+void *md5_finish_ctx(struct md5_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] = SWAP(ctx->total[0] << 3);
+  *(md5_uint32 *) & ctx->buffer[bytes + pad + 4] =
+    SWAP((ctx->total[1] << 3) | (ctx->total[0] >> 29));
+
+  /* Process last bytes.  */
+  md5_process_block(ctx->buffer, bytes + pad + 8, ctx);
+
+  return md5_read_ctx(ctx, resbuf);
+}
+
+/* Compute MD5 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+int md5_stream(FILE *stream, void *resblock)
+{
+  /* Important: BLOCKSIZE must be a multiple of 64.  */
+#define BLOCKSIZE 4096
+  struct md5_ctx ctx;
+  char buffer[BLOCKSIZE + 72];
+  size_t sum;
+
+  /* Initialize the computation context.  */
+  md5_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
+    */
+    md5_process_block(buffer, BLOCKSIZE, &ctx);
+  }
+
+  /* Add the last bytes if necessary.  */
+  if (sum > 0)
+    md5_process_bytes(buffer, sum, &ctx);
+
+  /* Construct result in desired memory.  */
+  md5_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 *md5_buffer(const char *buffer, size_t len, void *resblock)
+{
+  struct md5_ctx ctx;
+
+  /* Initialize the computation context.  */
+  md5_init_ctx(&ctx);
+
+  /* Process whole buffer but last len % 64 bytes.  */
+  md5_process_bytes(buffer, len, &ctx);
+
+  /* Put result in desired memory area.  */
+  return md5_finish_ctx(&ctx, resblock);
+}
+
+void md5_process_bytes(const void *buffer, size_t len, struct md5_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) {
+      md5_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) {
+    md5_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;
+  }
+}
+
+/* These are the four functions used in the four steps of the MD5 algorithm
+   and defined in the RFC 1321.  The first function is a little bit optimized
+   (as found in Colin Plumbs public domain implementation).  */
+/* #define FF(b, c, d) ((b & c) | (~b & d)) */
+#define FF(b, c, d) (d ^ (b & (c ^ d)))
+#define FG(b, c, d) FF (d, b, c)
+#define FH(b, c, d) (b ^ c ^ d)
+#define FI(b, c, d) (c ^ (b | ~d))
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.  */
+void md5_process_block(const void *buffer, size_t len, struct md5_ctx *ctx)
+{
+  md5_uint32 correct_words[16];
+  const md5_uint32 *words = buffer;
+  size_t nwords = len / sizeof(md5_uint32);
+  const md5_uint32 *endp = words + nwords;
+  md5_uint32 A = ctx->A;
+  md5_uint32 B = ctx->B;
+  md5_uint32 C = ctx->C;
+  md5_uint32 D = ctx->D;
+
+  /* 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];
+
+  /* Process all bytes in the buffer with 64 bytes in each round of
+     the loop.  */
+  while (words < endp) {
+    md5_uint32 *cwp = correct_words;
+    md5_uint32 A_save = A;
+    md5_uint32 B_save = B;
+    md5_uint32 C_save = C;
+    md5_uint32 D_save = D;
+
+    /* First round: using the given function, the context and a constant
+       the next context is computed.  Because the algorithms processing
+       unit is a 32-bit word and it is determined to work on words in
+       little endian byte order we perhaps have to change the byte order
+       before the computation.  To reduce the work for the next steps
+       we store the swapped words in the array CORRECT_WORDS.  */
+
+#define OP(a, b, c, d, s, T)                                            \
+      do                                                                \
+        {                                                               \
+          a += FF (b, c, d) + (*cwp++ = SWAP (*words)) + T;             \
+          ++words;                                                      \
+          CYCLIC (a, s);                                                \
+          a += b;                                                       \
+        }                                                               \
+      while (0)
+
+    /* It is unfortunate that C does not provide an operator for
+       cyclic rotation.  Hope the C compiler is smart enough.  */
+#define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
+
+    /* Before we start, one word to the strange constants.
+       They are defined in RFC 1321 as
+
+       T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
+    */
+
+    /* Round 1.  */
+    OP(A, B, C, D, 7, 0xd76aa478);
+    OP(D, A, B, C, 12, 0xe8c7b756);
+    OP(C, D, A, B, 17, 0x242070db);
+    OP(B, C, D, A, 22, 0xc1bdceee);
+    OP(A, B, C, D, 7, 0xf57c0faf);
+    OP(D, A, B, C, 12, 0x4787c62a);
+    OP(C, D, A, B, 17, 0xa8304613);
+    OP(B, C, D, A, 22, 0xfd469501);
+    OP(A, B, C, D, 7, 0x698098d8);
+    OP(D, A, B, C, 12, 0x8b44f7af);
+    OP(C, D, A, B, 17, 0xffff5bb1);
+    OP(B, C, D, A, 22, 0x895cd7be);
+    OP(A, B, C, D, 7, 0x6b901122);
+    OP(D, A, B, C, 12, 0xfd987193);
+    OP(C, D, A, B, 17, 0xa679438e);
+    OP(B, C, D, A, 22, 0x49b40821);
+
+    /* For the second to fourth round we have the possibly swapped words
+       in CORRECT_WORDS.  Redefine the macro to take an additional first
+       argument specifying the function to use.  */
+#undef OP
+#define OP(f, a, b, c, d, k, s, T)                                      \
+      do                                                                \
+        {                                                               \
+          a += f (b, c, d) + correct_words[k] + T;                      \
+          CYCLIC (a, s);                                                \
+          a += b;                                                       \
+        }                                                               \
+      while (0)
+
+    /* Round 2.  */
+    OP(FG, A, B, C, D, 1, 5, 0xf61e2562);
+    OP(FG, D, A, B, C, 6, 9, 0xc040b340);
+    OP(FG, C, D, A, B, 11, 14, 0x265e5a51);
+    OP(FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
+    OP(FG, A, B, C, D, 5, 5, 0xd62f105d);
+    OP(FG, D, A, B, C, 10, 9, 0x02441453);
+    OP(FG, C, D, A, B, 15, 14, 0xd8a1e681);
+    OP(FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
+    OP(FG, A, B, C, D, 9, 5, 0x21e1cde6);
+    OP(FG, D, A, B, C, 14, 9, 0xc33707d6);
+    OP(FG, C, D, A, B, 3, 14, 0xf4d50d87);
+    OP(FG, B, C, D, A, 8, 20, 0x455a14ed);
+    OP(FG, A, B, C, D, 13, 5, 0xa9e3e905);
+    OP(FG, D, A, B, C, 2, 9, 0xfcefa3f8);
+    OP(FG, C, D, A, B, 7, 14, 0x676f02d9);
+    OP(FG, B, C, D, A, 12, 20, 0x8d2a4c8a);
+
+    /* Round 3.  */
+    OP(FH, A, B, C, D, 5, 4, 0xfffa3942);
+    OP(FH, D, A, B, C, 8, 11, 0x8771f681);
+    OP(FH, C, D, A, B, 11, 16, 0x6d9d6122);
+    OP(FH, B, C, D, A, 14, 23, 0xfde5380c);
+    OP(FH, A, B, C, D, 1, 4, 0xa4beea44);
+    OP(FH, D, A, B, C, 4, 11, 0x4bdecfa9);
+    OP(FH, C, D, A, B, 7, 16, 0xf6bb4b60);
+    OP(FH, B, C, D, A, 10, 23, 0xbebfbc70);
+    OP(FH, A, B, C, D, 13, 4, 0x289b7ec6);
+    OP(FH, D, A, B, C, 0, 11, 0xeaa127fa);
+    OP(FH, C, D, A, B, 3, 16, 0xd4ef3085);
+    OP(FH, B, C, D, A, 6, 23, 0x04881d05);
+    OP(FH, A, B, C, D, 9, 4, 0xd9d4d039);
+    OP(FH, D, A, B, C, 12, 11, 0xe6db99e5);
+    OP(FH, C, D, A, B, 15, 16, 0x1fa27cf8);
+    OP(FH, B, C, D, A, 2, 23, 0xc4ac5665);
+
+    /* Round 4.  */
+    OP(FI, A, B, C, D, 0, 6, 0xf4292244);
+    OP(FI, D, A, B, C, 7, 10, 0x432aff97);
+    OP(FI, C, D, A, B, 14, 15, 0xab9423a7);
+    OP(FI, B, C, D, A, 5, 21, 0xfc93a039);
+    OP(FI, A, B, C, D, 12, 6, 0x655b59c3);
+    OP(FI, D, A, B, C, 3, 10, 0x8f0ccc92);
+    OP(FI, C, D, A, B, 10, 15, 0xffeff47d);
+    OP(FI, B, C, D, A, 1, 21, 0x85845dd1);
+    OP(FI, A, B, C, D, 8, 6, 0x6fa87e4f);
+    OP(FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
+    OP(FI, C, D, A, B, 6, 15, 0xa3014314);
+    OP(FI, B, C, D, A, 13, 21, 0x4e0811a1);
+    OP(FI, A, B, C, D, 4, 6, 0xf7537e82);
+    OP(FI, D, A, B, C, 11, 10, 0xbd3af235);
+    OP(FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
+    OP(FI, B, C, D, A, 9, 21, 0xeb86d391);
+
+    /* Add the starting values of the context.  */
+    A += A_save;
+    B += B_save;
+    C += C_save;
+    D += D_save;
+  }
+
+  /* Put checksum in context given as argument.  */
+  ctx->A = A;
+  ctx->B = B;
+  ctx->C = C;
+  ctx->D = D;
+}
+
+//----------------------------------------------------------------------------
+//--------end of md5.c
+//----------------------------------------------------------------------------
+
+#define ISWHITE(c) ((c) == ' ' || (c) == '\t')
+#define IN_CTYPE_DOMAIN(c) 1
+#define ISXDIGIT(c) (IN_CTYPE_DOMAIN (c) && isxdigit (c))
+#define STREQ(a, b) (strcmp ((a), (b)) == 0)
+#define TOLOWER(Ch) tolower (Ch)
+#define OPENOPTS(BINARY) "r"
+
+/* The minimum length of a valid digest line in a file produced
+   by `md5sum FILE' and read by `md5sum -c'.  This length does
+   not include any newline character at the end of a line.  */
+#define MIN_DIGEST_LINE_LENGTH 35 /* 32 - message digest length
+                                      2 - blank and binary indicator
+                                      1 - minimum filename length */
+
+static int have_read_stdin; /* Nonzero if any of the files read were
+                               the standard input. */
+
+static int status_only = 0; /* With -c, don't generate any output.
+                               The exit code indicates success or failure */
+static int warn = 0; /* With -w, print a message to standard error warning
+                        about each improperly formatted MD5 checksum line */
+
+static const char md5sum_usage[] =
+    "md5sum [OPTION] [FILE]...\n"
+    "or:    md5sum [OPTION] -c [FILE]\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+    "\nPrint or check MD5 checksums.\n\n"
+    "Options:\n"
+    "With no FILE, or when FILE is -, read standard input.\n\n"
+    "\t-b\tread files in binary mode\n"
+    "\t-c\tcheck MD5 sums against given list\n"
+    "\t-t\tread files in text mode (default)\n"
+    "\t-g\tread a string\n"
+    "\nThe following two options are useful only when verifying checksums:\n"
+    "\t-s,\tdon't output anything, status code shows success\n"
+    "\t-w,\twarn about improperly formated MD5 checksum lines\n"
+#endif
+;
+
+static int split_3(char *s,
+                   size_t s_len,
+                   unsigned char **u,
+                   int *binary,
+                   char **w)
+{
+  size_t i = 0;
+  int escaped_filename = 0;
+
+  while (ISWHITE(s[i]))
+    ++i;
+
+  /* The line must have at least 35 (36 if the first is a backslash)
+     more characters to contain correct message digest information.
+     Ignore this line if it is too short.  */
+  if (!(s_len - i >= MIN_DIGEST_LINE_LENGTH
+        || (s[i] == '\\' && s_len - i >= 1 + MIN_DIGEST_LINE_LENGTH)))
+    return FALSE;
+
+  if (s[i] == '\\') {
+    ++i;
+    escaped_filename = 1;
+  }
+  *u = (unsigned char *) &s[i];
+
+  /* The first field has to be the 32-character hexadecimal
+     representation of the message digest.  If it is not followed
+     immediately by a white space it's an error.  */
+  i += 32;
+  if (!ISWHITE(s[i]))
+    return FALSE;
+
+  s[i++] = '\0';
+
+  if (s[i] != ' ' && s[i] != '*')
+    return FALSE;
+  *binary = (s[i++] == '*');
+
+  /* All characters between the type indicator and end of line are
+     significant -- that includes leading and trailing white space.  */
+  *w = &s[i];
+
+  if (escaped_filename) {
+    /* Translate each `\n' string in the file name to a NEWLINE,
+       and each `\\' string to a backslash.  */
+
+    char *dst = &s[i];
+
+    while (i < s_len) {
+      switch (s[i]) {
+       case '\\':
+        if (i == s_len - 1) {
+          /* A valid line does not end with a backslash.  */
+          return FALSE;
+        }
+        ++i;
+        switch (s[i++]) {
+         case 'n':
+          *dst++ = '\n';
+          break;
+         case '\\':
+          *dst++ = '\\';
+          break;
+         default:
+          /* Only `\' or `n' may follow a backslash.  */
+          return FALSE;
+        }
+        break;
+
+       case '\0':
+        /* The file name may not contain a NUL.  */
+        return FALSE;
+        break;
+
+       default:
+        *dst++ = s[i++];
+        break;
+      }
+    }
+    *dst = '\0';
+  }
+  return TRUE;
+}
+
+static int hex_digits(unsigned char const *s)
+{
+  while (*s) {
+    if (!ISXDIGIT(*s))
+      return TRUE;
+    ++s;
+  }
+  return FALSE;
+}
+
+/* An interface to md5_stream.  Operate on FILENAME (it may be "-") and
+   put the result in *MD5_RESULT.  Return non-zero upon failure, zero
+   to indicate success.  */
+static int md5_file(const char *filename,
+                    int binary,
+                    unsigned char *md5_result)
+{
+  FILE *fp;
+
+  if (STREQ(filename, "-")) {
+    have_read_stdin = 1;
+    fp = stdin;
+  } else {
+    fp = fopen(filename, OPENOPTS(binary));
+    if (fp == NULL) {
+      errorMsg("md5sum: %s: %s\n", filename, strerror(errno));
+      return FALSE;
+    }
+  }
+
+  if (md5_stream(fp, md5_result)) {
+    errorMsg("md5sum: %s: %s\n", filename, strerror(errno));
+
+    if (fp != stdin)
+      fclose(fp);
+    return FALSE;
+  }
+
+  if (fp != stdin && fclose(fp) == EOF) {
+    errorMsg("md5sum: %s: %s\n", filename, strerror(errno));
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+static int md5_check(const char *checkfile_name)
+{
+  FILE *checkfile_stream;
+  int n_properly_formated_lines = 0;
+  int n_mismatched_checksums = 0;
+  int n_open_or_read_failures = 0;
+  unsigned char md5buffer[16];
+  size_t line_number;
+  char *line;
+  size_t line_chars_allocated;
+
+  if (STREQ(checkfile_name, "-")) {
+    have_read_stdin = 1;
+    checkfile_stream = stdin;
+  } else {
+    checkfile_stream = fopen(checkfile_name, "r");
+    if (checkfile_stream == NULL) {
+      errorMsg("md5sum: %s: %s\n", checkfile_name, strerror(errno));
+      return FALSE;
+    }
+  }
+
+  line_number = 0;
+  line = 0;
+  line_chars_allocated = 0;
+
+  do {
+    char *filename;
+    int binary;
+    unsigned char *md5num;
+    int line_length;
+
+    ++line_number;
+
+    line_length = getline(&line, &line_chars_allocated, checkfile_stream);
+
+    if (line_length <= 0)
+      break;
+
+    /* Ignore comment lines, which begin with a '#' character.  */
+    if (line[0] == '#')
+      continue;
+
+    /* Remove any trailing newline.  */
+    if (line[line_length - 1] == '\n')
+      line[--line_length] = '\0';
+
+    if (split_3(line, line_length, &md5num, &binary, &filename)
+        || !hex_digits(md5num)) {
+      if (warn) {
+        errorMsg("%s: %lu: improperly formatted MD5 checksum line\n",
+                 checkfile_name, (unsigned long) line_number);
+      }
+    } else {
+      static const char bin2hex[] = {
+        '0', '1', '2', '3',
+        '4', '5', '6', '7',
+        '8', '9', 'a', 'b',
+        'c', 'd', 'e', 'f'
+      };
+
+      ++n_properly_formated_lines;
+
+      if (md5_file(filename, binary, md5buffer)) {
+        ++n_open_or_read_failures;
+        if (!status_only) {
+          printf("%s: FAILED open or read\n", filename);
+          fflush(stdout);
+        }
+      } else {
+        size_t cnt;
+        /* Compare generated binary number with text representation
+           in check file.  Ignore case of hex digits.  */
+        for (cnt = 0; cnt < 16; ++cnt) {
+          if (TOLOWER(md5num[2 * cnt])
+              != bin2hex[md5buffer[cnt] >> 4]
+              || (TOLOWER(md5num[2 * cnt + 1])
+                  != (bin2hex[md5buffer[cnt] & 0xf])))
+            break;
+        }
+        if (cnt != 16)
+          ++n_mismatched_checksums;
+
+        if (!status_only) {
+          printf("%s: %s\n", filename,
+                 (cnt != 16 ? "FAILED" : "OK"));
+          fflush(stdout);
+        }
+      }
+    }
+  }
+
+  while (!feof(checkfile_stream) && !ferror(checkfile_stream));
+
+  if (line)
+    free(line);
+
+  if (ferror(checkfile_stream)) {
+    errorMsg("%s: read error", checkfile_name); /* */
+    return FALSE;
+  }
+
+  if (checkfile_stream != stdin && fclose(checkfile_stream) == EOF) {
+    errorMsg("md5sum: %s: %s\n", checkfile_name, strerror(errno));
+    return FALSE;
+  }
+
+  if (n_properly_formated_lines == 0) {
+    /* Warn if no tests are found.  */
+    errorMsg("%s: no properly formatted MD5 checksum lines found\n",
+             checkfile_name);
+    return FALSE;
+  } else {
+    if (!status_only) {
+      int n_computed_checkums = (n_properly_formated_lines
+                                 - n_open_or_read_failures);
+
+      if (n_open_or_read_failures > 0) {
+        errorMsg("WARNING: %d of %d listed files could not be read\n",
+                 n_open_or_read_failures, n_properly_formated_lines);
+        return FALSE;
+      }
+
+      if (n_mismatched_checksums > 0) {
+        errorMsg("WARNING: %d of %d computed checksums did NOT match\n",
+                 n_mismatched_checksums, n_computed_checkums);
+        return FALSE;
+      }
+    }
+  }
+
+  return ((n_properly_formated_lines > 0 && n_mismatched_checksums == 0
+           && n_open_or_read_failures == 0) ? 0 : 1);
+}
+
+int md5sum_main(int argc,
+                char **argv)
+{
+  unsigned char md5buffer[16];
+  int do_check = 0;
+  int opt;
+  char **string = NULL;
+  size_t n_strings = 0;
+  size_t err = 0;
+  int file_type_specified = 0;
+  int binary = 0;
+
+  while ((opt = getopt(argc, argv, "g:bcstw")) != -1) {
+    switch (opt) {
+     case 'g': { /* read a string */
+       if (string == NULL)
+         string = (char **) xmalloc ((argc - 1) * sizeof (char *));
+
+       if (optarg == NULL)
+         optarg = "";
+       string[n_strings++] = optarg;
+       break;
+     }
+
+     case 'b': /* read files in binary mode */
+      file_type_specified = 1;
+      binary = 1;
+      break;
+
+     case 'c': /* check MD5 sums against given list */
+      do_check = 1;
+      break;
+
+     case 's':  /* don't output anything, status code shows success */
+      status_only = 1;
+      warn = 0;
+      break;
+
+     case 't': /* read files in text mode (default) */
+      file_type_specified = 1;
+      binary = 0;
+      break;
+
+     case 'w': /* warn about improperly formated MD5 checksum lines */
+      status_only = 0;
+      warn = 1;
+      break;
+
+     default:
+      usage(md5sum_usage);
+    }
+  }
+
+  if (file_type_specified && do_check) {
+    errorMsg("the -b and -t options are meaningless when verifying checksums\n");
+    exit FALSE;
+  }
+
+  if (n_strings > 0 && do_check) {
+    errorMsg("the -g and -c options are mutually exclusive\n");
+    exit FALSE;
+  }
+
+  if (status_only && !do_check) {
+    errorMsg("the -s option is meaningful only when verifying checksums\n");
+    exit FALSE;
+  }
+
+  if (warn && !do_check) {
+    errorMsg("the -w option is meaningful only when verifying checksums\n");
+    exit FALSE;
+  }
+
+  if (n_strings > 0) {
+    size_t i;
+
+    if (optind < argc) {
+      errorMsg("no files may be specified when using -g\n");
+      exit FALSE;
+    }
+    for (i = 0; i < n_strings; ++i) {
+      size_t cnt;
+      md5_buffer (string[i], strlen (string[i]), md5buffer);
+
+      for (cnt = 0; cnt < 16; ++cnt)
+        printf ("%02x", md5buffer[cnt]);
+
+      printf ("  \"%s\"\n", string[i]);
+    }
+  } else if (do_check) {
+    if (optind + 1 < argc) {
+      errorMsg("only one argument may be specified when using -c\n");
+    }
+
+    err = md5_check ((optind == argc) ? "-" : argv[optind]);
+  } else {
+    if (optind == argc)
+      argv[argc++] = "-";
+
+    for (; optind < argc; ++optind) {
+      int fail;
+      char *file = argv[optind];
+
+      fail = md5_file (file, binary, md5buffer);
+      err |= fail;
+      if (!fail) {
+        size_t i;
+        /* Output a leading backslash if the file name contains
+           a newline or backslash.  */
+        if (strchr (file, '\n') || strchr (file, '\\'))
+          putchar ('\\');
+
+        for (i = 0; i < 16; ++i)
+          printf ("%02x", md5buffer[i]);
+
+        putchar (' ');
+        if (binary)
+          putchar ('*');
+        else
+          putchar (' ');
+
+        /* Translate each NEWLINE byte to the string, "\\n",
+           and each backslash to "\\\\".  */
+        for (i = 0; i < strlen (file); ++i) {
+          switch (file[i]) {
+           case '\n':
+            fputs ("\\n", stdout);
+            break;
+
+           case '\\':
+            fputs ("\\\\", stdout);
+            break;
+
+           default:
+            putchar (file[i]);
+            break;
+          }
+        }
+        putchar ('\n');
+      }
+    }
+  }
+
+  if (fclose (stdout) == EOF) {
+    errorMsg("write error");
+    exit FALSE;
+  }
+
+  if (have_read_stdin && fclose (stdin) == EOF) {
+    errorMsg("standard input");
+    exit FALSE;
+  }
+
+  exit (err == 0 ? TRUE : FALSE);
+}