Use libcrypto's checksum implementations if available, for speed.

On commonly used platform libcrypto uses architecture-specific
assembly code, which is significantly faster than the C code we
were using.  See Pádraig Brady's note in
<http://lists.gnu.org/archive/html/bug-gnulib/2013-12/msg00000.html>.
Merge from gnulib, incorporating:
2013-12-07 md5, sha1, sha256, sha512: add gl_SET_CRYPTO_CHECK_DEFAULT
2013-12-07 md5, sha1, sha256, sha512: add 'auto', and set-default method
2013-12-04 include_next: minimize code duplication
2013-12-03 md5, sha1, sha256, sha512: support mandating use of openssl
2013-12-02 md5, sha1, sha256, sha512: use openssl routines if available
* configure.ac (--without-all): Set with_openssl_default too.
Use gl_SET_CRYPTO_CHECK_DEFAULT to default to 'auto'.
(HAVE_LIB_CRYPTO): New var.
Say whether Emacs is configured to use a crypto library.
* lib/gl_openssl.h, m4/absolute-header.m4, m4/gl-openssl.m4:
New files, copied from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib/md5.c, lib/md5.h, lib/sha1.c, lib/sha1.h:
* lib/sha256.c, lib/sha256.h, lib/sha512.c, lib/sha512.h:
* m4/include_next.m4, m4/md5.m4, m4/sha1.m4, m4/sha256.m4, m4/sha512.m4:
Update from gnulib.
* src/Makefile.in (LIB_CRYPTO): New macro.
(LIBES): Use it.

1 files changed, 21 insertions, 9 deletions

diff --git a/lib/sha256.h b/lib/sha256.h
index 7e6252285bb..6ee326b0466 100644
--- a/lib/sha256.h
+++ b/lib/sha256.h
@@ -21,10 +21,23 @@
 # include <stdio.h>
 # include <stdint.h>
 
+# if HAVE_OPENSSL_SHA256
+#  include <openssl/sha.h>
+# endif
+
 # ifdef __cplusplus
 extern "C" {
 # endif
 
+enum { SHA224_DIGEST_SIZE = 224 / 8 };
+enum { SHA256_DIGEST_SIZE = 256 / 8 };
+
+# if HAVE_OPENSSL_SHA256
+#  define GL_OPENSSL_NAME 224
+#  include "gl_openssl.h"
+#  define GL_OPENSSL_NAME 256
+#  include "gl_openssl.h"
+# else
 /* Structure to save state of computation between the single steps.  */
 struct sha256_ctx
 {
@@ -35,9 +48,6 @@ struct sha256_ctx
   uint32_t buffer[32];
 };
 
-enum { SHA224_DIGEST_SIZE = 224 / 8 };
-enum { SHA256_DIGEST_SIZE = 256 / 8 };
-
 /* Initialize structure containing state of computation. */
 extern void sha256_init_ctx (struct sha256_ctx *ctx);
 extern void sha224_init_ctx (struct sha256_ctx *ctx);
@@ -71,12 +81,6 @@ extern void *sha256_read_ctx (const struct sha256_ctx *ctx, void *resbuf);
 extern void *sha224_read_ctx (const struct sha256_ctx *ctx, void *resbuf);
 
 
-/* Compute SHA256 (SHA224) message digest for bytes read from STREAM.  The
-   resulting message digest number will be written into the 32 (28) bytes
-   beginning at RESBLOCK.  */
-extern int sha256_stream (FILE *stream, void *resblock);
-extern int sha224_stream (FILE *stream, void *resblock);
-
 /* Compute SHA256 (SHA224) 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
@@ -84,6 +88,14 @@ extern int sha224_stream (FILE *stream, void *resblock);
 extern void *sha256_buffer (const char *buffer, size_t len, void *resblock);
 extern void *sha224_buffer (const char *buffer, size_t len, void *resblock);
 
+# endif
+/* Compute SHA256 (SHA224) message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 32 (28) bytes
+   beginning at RESBLOCK.  */
+extern int sha256_stream (FILE *stream, void *resblock);
+extern int sha224_stream (FILE *stream, void *resblock);
+
+
 # ifdef __cplusplus
 }
 # endif