md5: Clarify module to source relation.

* lib/md5-stream.c: New file, extracted from lib/md5.c.
* lib/md5.c: Don't include stdlib.h, unlocked-io.h.
(BLOCKSIZE, md5_stream): Moved to md5-stream.c.
* lib/md5.h: Tweak.
* modules/crypto/md5 (Files): Add lib/md5-stream.c.
(configure.ac): Don't define GL_COMPILE_CRYPTO_STREAM.
(Makefile.am): Arrange to compile md5-stream.c.
(Link): Mention $(LIB_CRYPTO).

5 files changed, 162 insertions, 98 deletions

diff --git a/ChangeLog b/ChangeLog
index 312cbb8403..13d6d4dbee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
 2021-09-18  Bruno Haible  <bruno@clisp.org>
 
+	md5: Clarify module to source relation.
+	* lib/md5-stream.c: New file, extracted from lib/md5.c.
+	* lib/md5.c: Don't include stdlib.h, unlocked-io.h.
+	(BLOCKSIZE, md5_stream): Moved to md5-stream.c.
+	* lib/md5.h: Tweak.
+	* modules/crypto/md5 (Files): Add lib/md5-stream.c.
+	(configure.ac): Don't define GL_COMPILE_CRYPTO_STREAM.
+	(Makefile.am): Arrange to compile md5-stream.c.
+	(Link): Mention $(LIB_CRYPTO).
+
+2021-09-18  Bruno Haible  <bruno@clisp.org>
+
 	md4-buffer tests: New module.
 	* tests/test-md4-buffer.c: Renamed from tests/test-md4.c.
 	* modules/crypto/md4-buffer-tests: Renamed from
diff --git a/lib/md5-stream.c b/lib/md5-stream.c
new file mode 100644
index 0000000000..fb483b7334
--- /dev/null
+++ b/lib/md5-stream.c
@@ -0,0 +1,141 @@
+/* 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) 1995-1997, 1999-2001, 2005-2006, 2008-2021 Free Software
+   Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.  */
+
+#include <config.h>
+
+/* Specification.  */
+#if HAVE_OPENSSL_MD5
+# define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
+#endif
+#include "md5.h"
+
+#include <stdlib.h>
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+#include "af_alg.h"
+
+#ifdef _LIBC
+# include <endian.h>
+# if __BYTE_ORDER == __BIG_ENDIAN
+#  define WORDS_BIGENDIAN 1
+# endif
+/* We need to keep the namespace clean so define the MD5 function
+   protected using leading __ .  */
+# define md5_init_ctx __md5_init_ctx
+# define md5_process_block __md5_process_block
+# define md5_process_bytes __md5_process_bytes
+# define md5_finish_ctx __md5_finish_ctx
+# define md5_stream __md5_stream
+#endif
+
+#define BLOCKSIZE 32768
+#if BLOCKSIZE % 64 != 0
+# error "invalid BLOCKSIZE"
+#endif
+
+/* 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)
+{
+  switch (afalg_stream (stream, "md5", resblock, MD5_DIGEST_SIZE))
+    {
+    case 0: return 0;
+    case -EIO: return 1;
+    }
+
+  char *buffer = malloc (BLOCKSIZE + 72);
+  if (!buffer)
+    return 1;
+
+  struct md5_ctx ctx;
+  md5_init_ctx (&ctx);
+  size_t sum;
+
+  /* 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)
+        {
+          /* Either process a partial fread() from this loop,
+             or the fread() in afalg_stream may have gotten EOF.
+             We need to avoid a subsequent fread() as EOF may
+             not be sticky.  For details of such systems, see:
+             https://sourceware.org/bugzilla/show_bug.cgi?id=1190  */
+          if (feof (stream))
+            goto process_partial_block;
+
+          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;
+            }
+        }
+
+      /* Process buffer with BLOCKSIZE bytes.  Note that
+         BLOCKSIZE % 64 == 0
+       */
+      md5_process_block (buffer, BLOCKSIZE, &ctx);
+    }
+
+process_partial_block:
+
+  /* Process any remaining bytes.  */
+  if (sum > 0)
+    md5_process_bytes (buffer, sum, &ctx);
+
+  /* Construct result in desired memory.  */
+  md5_finish_ctx (&ctx, resblock);
+  free (buffer);
+  return 0;
+}
+
+/*
+ * Hey Emacs!
+ * Local Variables:
+ * coding: utf-8
+ * End:
+ */
diff --git a/lib/md5.c b/lib/md5.c
index b1dd452ed2..7955665ccd 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -21,6 +21,7 @@
 
 #include <config.h>
 
+/* Specification.  */
 #if HAVE_OPENSSL_MD5
 # define GL_OPENSSL_INLINE _GL_EXTERN_INLINE
 #endif
@@ -28,14 +29,9 @@
 
 #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 _LIBC
 # include <endian.h>
 # if __BYTE_ORDER == __BIG_ENDIAN
@@ -48,7 +44,6 @@
 # define md5_process_bytes __md5_process_bytes
 # define md5_finish_ctx __md5_finish_ctx
 # define md5_read_ctx __md5_read_ctx
-# define md5_stream __md5_stream
 # define md5_buffer __md5_buffer
 #endif
 
@@ -59,12 +54,8 @@
 # define SWAP(n) (n)
 #endif
 
-#define BLOCKSIZE 32768
-#if BLOCKSIZE % 64 != 0
-# error "invalid BLOCKSIZE"
-#endif
-
 #if ! HAVE_OPENSSL_MD5
+
 /* 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, ...  */ };
@@ -132,93 +123,7 @@ md5_finish_ctx (struct md5_ctx *ctx, void *resbuf)
 
   return md5_read_ctx (ctx, resbuf);
 }
-#endif
-
-#if defined _LIBC || defined GL_COMPILE_CRYPTO_STREAM
-
-#include "af_alg.h"
-
-/* 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)
-{
-  switch (afalg_stream (stream, "md5", resblock, MD5_DIGEST_SIZE))
-    {
-    case 0: return 0;
-    case -EIO: return 1;
-    }
-
-  char *buffer = malloc (BLOCKSIZE + 72);
-  if (!buffer)
-    return 1;
-
-  struct md5_ctx ctx;
-  md5_init_ctx (&ctx);
-  size_t sum;
-
-  /* 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)
-        {
-          /* Either process a partial fread() from this loop,
-             or the fread() in afalg_stream may have gotten EOF.
-             We need to avoid a subsequent fread() as EOF may
-             not be sticky.  For details of such systems, see:
-             https://sourceware.org/bugzilla/show_bug.cgi?id=1190  */
-          if (feof (stream))
-            goto process_partial_block;
-
-          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;
-            }
-        }
-
-      /* Process buffer with BLOCKSIZE bytes.  Note that
-         BLOCKSIZE % 64 == 0
-       */
-      md5_process_block (buffer, BLOCKSIZE, &ctx);
-    }
-
-process_partial_block:
-
-  /* Process any remaining bytes.  */
-  if (sum > 0)
-    md5_process_bytes (buffer, sum, &ctx);
-
-  /* Construct result in desired memory.  */
-  md5_finish_ctx (&ctx, resblock);
-  free (buffer);
-  return 0;
-}
-#endif
 
-#if ! HAVE_OPENSSL_MD5
 /* 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
@@ -479,6 +384,7 @@ md5_process_block (const void *buffer, size_t len, struct md5_ctx *ctx)
   ctx->C = C;
   ctx->D = D;
 }
+
 #endif
 
 /*
diff --git a/lib/md5.h b/lib/md5.h
index ca7c78ed5c..bae5960a8c 100644
--- a/lib/md5.h
+++ b/lib/md5.h
@@ -124,6 +124,7 @@ extern void *__md5_buffer (const char *buffer, size_t len,
                            void *restrict resblock) __THROW;
 
 # endif
+
 /* Compute MD5 message digest for bytes read from STREAM.
    STREAM is an open file stream.  Regular files are handled more efficiently.
    The contents of STREAM from its current position to its end will be read.
diff --git a/modules/crypto/md5 b/modules/crypto/md5
index afcdbc38fa..ea9722ed3b 100644
--- a/modules/crypto/md5
+++ b/modules/crypto/md5
@@ -2,19 +2,23 @@ Description:
 Compute MD5 checksum.
 
 Files:
+lib/md5-stream.c
 
 Depends-on:
 crypto/af_alg
 crypto/md5-buffer
 
 configure.ac:
-AC_DEFINE([GL_COMPILE_CRYPTO_STREAM], 1, [Compile Gnulib crypto stream ops.])
 
 Makefile.am:
+lib_SOURCES += md5-stream.c
 
 Include:
 "md5.h"
 
+Link:
+$(LIB_CRYPTO)
+
 License:
 LGPLv2+