Add comment about what various Operating Systems are known to have and

what is supported.

SVN-Revision: 1113

diff --git a/libarchive/archive_hash.h b/libarchive/archive_hash.h
index 3bd0090427cceda3232e53625af6a54435f0f440..df87854ab52a9f85906a0fdef1837774cca5d54c 100644 (file)
--- a/libarchive/archive_hash.h
+++ b/libarchive/archive_hash.h
@@ -23,6 +23,25 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+/*
+ * Hash function support in various Operating Systems:
+ *
+ * NetBSD:
+ * - MD5 and SHA1 in libc: without _ after algorithm name
+ * - SHA2 in libc: with _ after algorithm name
+ *
+ * OpenBSD:
+ * - MD5, SHA1 and SHA2 in libc: without _ after algorithm name
+ * - OpenBSD 4.4 and earlier have SHA2 in libc with _ after algorithm name
+ *
+ * DragonFly and FreeBSD (XXX not used yet):
+ * - MD5 and SHA1 in libmd: without _ after algorithm name
+ * - SHA256: with _ after algorithm name
+ *
+ * OpenSSL:
+ * - MD5, SHA1 and SHA2 in libcrypto: with _ after algorithm name
+ */
+
 #if defined(HAVE_MD5_H) && defined(HAVE_MD5INIT)
 #  include <md5.h>
 #  define ARCHIVE_HAS_MD5