X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fsha1.c;h=d15325063d92b6e047ccfb438a7b683d4fb056ab;hb=eb3e3b72db23ecaa7789a807afeb9577962653fe;hp=bd83a413745bd0f8c8bd747517c09cad6c939a2d;hpb=19ce03addb8071555d951a965fa0bd7e3ae7224b;p=wimlib

diff --git a/src/sha1.c b/src/sha1.c
index bd83a413..d1532506 100644
--- a/src/sha1.c
+++ b/src/sha1.c
@@ -1,15 +1,21 @@
 /*
- * sha1.c
+ * sha1.c - implementation of the Secure Hash Algorithm version 1 (FIPS 180-1)
  *
- * Implementation of the Secure Hash Algorithm version 1 (FIPS 180-1).
+ * The following copying information applies to this specific source code file:
  *
- * Author:  Eric Biggers
- * Year:    2014
+ * Written in 2014-2015 by Eric Biggers <ebiggers3@gmail.com>
  *
- * The default SHA-1 transform is based on public domain code by Steve Reid.
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide via the Creative Commons Zero 1.0 Universal Public Domain
+ * Dedication (the "CC0").
  *
- * The author dedicates this file to the public domain.
- * You can do whatever you want with this file.
+ * This software is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the CC0 for more details.
+ *
+ * You should have received a copy of the CC0 along with this software; if not
+ * see <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -18,11 +24,32 @@
 
 #include "wimlib/endianness.h"
 #include "wimlib/sha1.h"
+#include "wimlib/unaligned.h"
 
 /* Dummy SHA-1 message digest of all 0's.  This is used in the WIM format to
  * mean "SHA-1 not specified".  */
 const u8 zero_hash[20];
 
+/*
+ * Builds a hexadecimal string representation of a SHA-1 message digest.
+ *
+ * The output buffer must be at least 41 characters.
+ */
+void
+sprint_hash(const u8 hash[SHA1_HASH_SIZE], tchar strbuf[SHA1_HASH_SIZE * 2 + 1])
+{
+	int i;
+	u8 high, low;
+
+	for (i = 0; i < SHA1_HASH_SIZE; i++) {
+		high = hash[i] >> 4;
+		low = hash[i] & 0xF;
+		strbuf[i * 2 + 0] = (high < 10 ? high + '0' : high - 10 + 'a');
+		strbuf[i * 2 + 1] = (low  < 10 ? low  + '0' : low  - 10 + 'a');
+	}
+	strbuf[i * 2] = 0;
+}
+
 /* If we use libcrypto (e.g. OpenSSL) then we get all the SHA-1 functions for
  * free.  Otherwise we need to implement them ourselves.  */
 
@@ -30,7 +57,7 @@ const u8 zero_hash[20];
 
 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
 
-#define blk0(i) (tmp[i] = be32_to_cpu(((const be32 *)block)[i]))
+#define blk0(i) (tmp[i] = be32_to_cpu(load_be32_unaligned(&(block)[(i) * 4])))
 
 #define blk(i) (tmp[i & 15] = rol(tmp[(i + 13) & 15] ^ \
 				  tmp[(i +  8) & 15] ^ \
@@ -183,13 +210,12 @@ sha1_final(u8 md[20], SHA_CTX *ctx)
 	 * final length is a multiple of the block size.  */
 	static const u8 padding[64] = {0x80, };
 	be64 finalcount = cpu_to_be64(ctx->bytecount << 3);
-	be32 *out = (be32 *)md;
 
 	sha1_update(ctx, padding, 64 - ((ctx->bytecount + 8) & 63));
 	sha1_update(ctx, &finalcount, 8);
 
 	for (int i = 0; i < 5; i++)
-		out[i] = cpu_to_be32(ctx->state[i]);
+		store_be32_unaligned(cpu_to_be32(ctx->state[i]), &md[i * 4]);
 }
 
 /* Calculate the SHA-1 message digest of the specified buffer.