New state-object-based sha256 and md5 digesting.

* chksum.c (sha256_ctx_s, md5_ctx_s): New symbol variables.
(sha256_ops, md5_ops): New static structs.
(sha256_begin, sha256_hash, sha256_end, md5_begin, md5_hash,
md5_end): New functions.
(chksum_init): New symbol variables initialized; sha256-begin,
sha256-hash, sha256-end, md5-begin, md5-hash, md5-end
intrinsics registered.

* chksum.h (sha256_begin, sha256_hash, sha256_end, md5_begin,
md5_hash, md5_end): Declared.

* txr.1: Documented.

1 files changed, 6 insertions, 0 deletions

diff --git a/chksum.h b/chksum.h
index 089d784e..6c5f1312 100644
--- a/chksum.h
+++ b/chksum.h
@@ -27,8 +27,14 @@
 
 val sha256_stream(val stream, val nbytes, val buf);
 val sha256(val obj, val buf);
+val sha256_begin(void);
+val sha256_hash(val ctx, val obj);
+val sha256_end(val ctx, val buf);
 val crc32_stream(val stream, val nbytes);
 val crc32(val obj);
 val md5_stream(val stream, val nbytes, val buf);
 val md5(val obj, val buf_in);
+val md5_begin(void);
+val md5_hash(val ctx, val obj);
+val md5_end(val ctx, val buf);
 void chksum_init(void);