Do SHA1 hash _before_ compression.

And add a "convert-cache" program to convert from old-style
to new-style.

1 files changed, 8 insertions, 6 deletions

diff --git a/sha1_file.c b/sha1_file.c
index bb44a01746..40c00b77d0 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -80,12 +80,14 @@ char *sha1_file_name(const unsigned char *sha1)
 	return base;
 }
 
-int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size)
+int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, const char *type)
 {
+	char header[100];
 	unsigned char real_sha1[20];
 	SHA_CTX c;
 
 	SHA1_Init(&c);
+	SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
 	SHA1_Update(&c, map, size);
 	SHA1_Final(real_sha1, &c);
 	return memcmp(sha1, real_sha1, 20) ? -1 : 0;
@@ -172,6 +174,11 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 	unsigned char sha1[20];
 	SHA_CTX c;
 
+	/* Sha1.. */
+	SHA1_Init(&c);
+	SHA1_Update(&c, buf, len);
+	SHA1_Final(sha1, &c);
+
 	/* Set it up */
 	memset(&stream, 0, sizeof(stream));
 	deflateInit(&stream, Z_BEST_COMPRESSION);
@@ -188,11 +195,6 @@ int write_sha1_file(char *buf, unsigned len, unsigned char *returnsha1)
 	deflateEnd(&stream);
 	size = stream.total_out;
 
-	/* Sha1.. */
-	SHA1_Init(&c);
-	SHA1_Update(&c, compressed, size);
-	SHA1_Final(sha1, &c);
-
 	if (write_sha1_buffer(sha1, compressed, size) < 0)
 		return -1;
 	if (returnsha1)