From c6da2325e39600995ac5b586be986dc553543060 Mon Sep 17 00:00:00 2001
From: Moinak Ghosh <moinakg@gmail.com>
Date: Sat, 4 May 2013 15:59:29 +0530
Subject: [PATCH] Allow SKEIN to be used as a Global Dedupe chunk lookup hash.

---
 rabin/global/dedupe_config.c | 18 ++++++++++++++++--
 rabin/rabin_dedup.c          |  2 +-
 utils/utils.h                |  3 +++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/rabin/global/dedupe_config.c b/rabin/global/dedupe_config.c
index b0368c5..29bc70b 100644
--- a/rabin/global/dedupe_config.c
+++ b/rabin/global/dedupe_config.c
@@ -128,6 +128,12 @@ get_cksum_type(char *cksum_name)
 
 	} else if (strcmp(cksum_name, "KECCAK512") == 0) {
 		return (CKSUM_KECCAK512);
+
+	} else if (strcmp(cksum_name, "SKEIN256") == 0) {
+		return (CKSUM_SKEIN256);
+
+	} else if (strcmp(cksum_name, "SKEIN512") == 0) {
+		return (CKSUM_SKEIN512);
 	}
 	return (CKSUM_INVALID);
 }
@@ -155,6 +161,12 @@ get_cksum_str(cksum_t ck)
 
 	} else if (ck == CKSUM_KECCAK512) {
 		return ("KECCAK512");
+
+	} else if (ck == CKSUM_SKEIN256) {
+		return ("SKEIN256");
+
+	} else if (ck == CKSUM_SKEIN512) {
+		return ("SKEIN512");
 	}
 	return ("INVALID");
 }
@@ -165,10 +177,12 @@ get_cksum_sz(cksum_t ck)
 	if (ck == CKSUM_CRC64) {
 		return (8);
 
-	} else if (ck == CKSUM_SHA256 || ck == CKSUM_BLAKE256 || ck == CKSUM_KECCAK256) {
+	} else if (ck == CKSUM_SHA256 || ck == CKSUM_BLAKE256 || ck == CKSUM_KECCAK256 ||
+	    ck == CKSUM_SKEIN256) {
 		return (32);
 
-	} else if (ck == CKSUM_SHA512 || ck == CKSUM_BLAKE512 || ck == CKSUM_KECCAK512) {
+	} else if (ck == CKSUM_SHA512 || ck == CKSUM_BLAKE512 || ck == CKSUM_KECCAK512 ||
+	    ck == CKSUM_SKEIN512) {
 		return (64);
 	}
 	return (0);
diff --git a/rabin/rabin_dedup.c b/rabin/rabin_dedup.c
index bcc6322..d0fa12d 100755
--- a/rabin/rabin_dedup.c
+++ b/rabin/rabin_dedup.c
@@ -221,7 +221,7 @@ create_dedupe_context(uint64_t chunksize, uint64_t real_chunksize, int rab_blk_s
 
 			chunk_cksum = 0;
 			if ((ck = getenv("PCOMPRESS_CHUNK_HASH_GLOBAL")) != NULL) {
-				if (get_checksum_props(ck, &chunk_cksum, &cksum_bytes, &mac_bytes, 0) != 0 ||
+				if (get_checksum_props(ck, &chunk_cksum, &cksum_bytes, &mac_bytes, 1) != 0 ||
 				    strcmp(ck, "CRC64") == 0) {
 					fprintf(stderr, "Invalid PCOMPRESS_CHUNK_HASH_GLOBAL. Reverting to default.\n");
 					chunk_cksum = -1;
diff --git a/utils/utils.h b/utils/utils.h
index f6c9720..ce62866 100644
--- a/utils/utils.h
+++ b/utils/utils.h
@@ -160,6 +160,9 @@ typedef enum {
  * Backwards compatibility options. SKEIN in release 1.2 was replaced with
  * Blake2 from 1.3 onwards (for sheer speed of Blake2). We want to be able
  * to decode archives created with 1.2. New archives do not use SKEIN.
+ * 
+ * However SKEIN can be used as a chunk/block hash for Global Deduplication.
+ * So it will not be removed.
  */
 	CKSUM_SKEIN256 = 0x800,
 	CKSUM_SKEIN512 = 0x900,