From 3aa316cbcf696304c13f295e70b40c94ac75d17d Mon Sep 17 00:00:00 2001
From: Thomas Adam <thomas@xteddy.org>
Date: Sun, 26 Feb 2023 19:22:52 +0000
Subject: [PATCH] portable: improve SHA detection

Original patch from Omar Polo.  Tweak by me.
---
 configure.ac         | 31 +++++++++++++------------------
 include/got_compat.h |  2 +-
 2 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/configure.ac b/configure.ac
index 613855f1..35053180 100644
--- a/configure.ac
+++ b/configure.ac
@@ -88,24 +88,19 @@ fi
 AM_CONDITIONAL([HAVE_SHA2], [test "x$ac_cv_header_sha2_h" = xyes])
 
 # Check for SHA1_DIGEST_LENGTH
-if test "x$ac_cv_header_sha_h" = xyes; then
-AC_CHECK_DECL([SHA_DIGEST_LENGTH],
-	      [AC_DEFINE(HAVE_SHA_AS_SHA1)],
-	      [AC_DEFINE(NEEDS_SHA1_DEFS)],
-	      [#include <sha.h>])
-fi
-
-if test "x$ac_cv_header_sha1_h" = xyes; then
-AC_CHECK_DECL([SHA_DIGEST_LENGTH],
-	      [AC_DEFINE(HAVE_SHA1_AS_SHA1)],
-	      [AC_DEFINE(NEEDS_SHA1_DEFS)],
-	      [#include <sha1.h>])
-fi
-
-if test "x$ac_cv_header_sha_h" = xno || test "x$ac_cv_header_sha1_h" = xno
-then
-	AC_DEFINE(NEEDS_SHA1_DEFS)
-fi
+AC_CHECK_DECL([SHA1_DIGEST_LENGTH],
+	[AC_DEFINE(HAVE_SHA1_AS_SHA1)],
+	[
+		dnl maybe sha.h is available
+		AC_CHECK_DECL([SHA_DIGEST_LENGTH],
+			[AC_DEFINE(HAVE_SHA_AS_SHA1)],
+			[],
+			[#include <sha.h>])
+	],
+	[
+	#include <sys/types.h>
+	#include <sha1.h>
+	])
 
 # Checks for typ edefs, structures, and compiler characteristics.
 AC_CHECK_HEADER_STDBOOL
diff --git a/include/got_compat.h b/include/got_compat.h
index 1ca8f7f5..847c7695 100644
--- a/include/got_compat.h
+++ b/include/got_compat.h
@@ -240,7 +240,7 @@ typedef struct _SHA2_CTX {
 #include <openssl/sha.h>
 #endif
 
-#ifdef NEEDS_SHA1_DEFS
+#ifndef SHA1_DIGEST_LENGTH
 #define SHA1_DIGEST_LENGTH		SHA_DIGEST_LENGTH
 #define SHA1_DIGEST_STRING_LENGTH	(SHA1_DIGEST_LENGTH * 2 + 1)
 
-- 
2.11.4.GIT