Fix compilation of uuid-ossp

This module had a dependency on pgcrypto's md5.c that got removed by
b67b57a9.  Instead of the code from pgcrypto, this code can just use the
new cryptohash routines for MD5 as a drop-in replacement, so let's just
do this switch.  This has also the merit to simplify a bit the
compilation of uuid-ossp.

This requires --with-uuid to be reproduced, and I have used e2fs as a
way to reproduce the failure, then test this commit.

Per reports from buildfarm members longfin, florican and sifaka.

Discussion: https://postgr.es/m/X9GToVd3QmWeNvj8@paquier.xyz

configure

@@ -8307,12 +8307,12 @@ if test "$with_uuid" = bsd ; then
 
 $as_echo "#define HAVE_UUID_BSD 1" >>confdefs.h
 
-  UUID_EXTRA_OBJS="md5.o sha1.o"
+  UUID_EXTRA_OBJS="sha1.o"
 elif test "$with_uuid" = e2fs ; then
 
 $as_echo "#define HAVE_UUID_E2FS 1" >>confdefs.h
 
-  UUID_EXTRA_OBJS="md5.o sha1.o"
+  UUID_EXTRA_OBJS="sha1.o"
 elif test "$with_uuid" = ossp ; then
 
 $as_echo "#define HAVE_UUID_OSSP 1" >>confdefs.h

configure.ac

@@ -921,10 +921,10 @@ fi
 
 if test "$with_uuid" = bsd ; then
   AC_DEFINE([HAVE_UUID_BSD], 1, [Define to 1 if you have BSD UUID support.])
-  UUID_EXTRA_OBJS="md5.o sha1.o"
+  UUID_EXTRA_OBJS="sha1.o"
 elif test "$with_uuid" = e2fs ; then
   AC_DEFINE([HAVE_UUID_E2FS], 1, [Define to 1 if you have E2FS UUID support.])
-  UUID_EXTRA_OBJS="md5.o sha1.o"
+  UUID_EXTRA_OBJS="sha1.o"
 elif test "$with_uuid" = ossp ; then
   AC_DEFINE([HAVE_UUID_OSSP], 1, [Define to 1 if you have OSSP UUID support.])
   UUID_EXTRA_OBJS=""

contrib/uuid-ossp/Makefile

@@ -19,7 +19,7 @@ pgcrypto_src = $(top_srcdir)/contrib/pgcrypto
 
 PG_CPPFLAGS = -I$(pgcrypto_src)
 
-EXTRA_CLEAN = md5.c sha1.c
+EXTRA_CLEAN = sha1.c
 
 ifdef USE_PGXS
 PG_CONFIG = pg_config
@@ -32,5 +32,5 @@ include $(top_builddir)/src/Makefile.global
 include $(top_srcdir)/contrib/contrib-global.mk
 endif
 
-md5.c sha1.c: % : $(pgcrypto_src)/%
+sha1.c: % : $(pgcrypto_src)/%
 	rm -f $@ && $(LN_S) $< .

contrib/uuid-ossp/uuid-ossp.c

@@ -14,6 +14,7 @@
 #include "postgres.h"
 
 #include "fmgr.h"
+#include "common/cryptohash.h"
 #include "port/pg_bswap.h"
 #include "utils/builtins.h"
 #include "utils/uuid.h"
@@ -44,7 +45,6 @@
  * so we use a copy of the ones from pgcrypto.  Not needed with OSSP, though.
  */
 #ifndef HAVE_UUID_OSSP
-#include "md5.h"
 #include "sha1.h"
 #endif
 
@@ -324,13 +324,17 @@ uuid_generate_internal(int v, unsigned char *ns, const char *ptr, int len)
 
 				if (v == 3)
 				{
-					MD5_CTX		ctx;
+					pg_cryptohash_ctx *ctx = pg_cryptohash_create(PG_MD5);
 
-					MD5Init(&ctx);
-					MD5Update(&ctx, ns, sizeof(uu));
-					MD5Update(&ctx, (unsigned char *) ptr, len);
+					if (pg_cryptohash_init(ctx) < 0)
+						elog(ERROR, "could not initialize %s context", "MD5");
+					if (pg_cryptohash_update(ctx, ns, sizeof(uu)) < 0 ||
+						pg_cryptohash_update(ctx, (unsigned char *) ptr, len) < 0)
+						elog(ERROR, "could not update %s context", "MD5");
 					/* we assume sizeof MD5 result is 16, same as UUID size */
-					MD5Final((unsigned char *) &uu, &ctx);
+					if (pg_cryptohash_final(ctx, (unsigned char *) &uu) < 0)
+						elog(ERROR, "could not finalize %s context", "MD5");
+					pg_cryptohash_free(ctx);
 				}
 				else
 				{