 3964cbbb5c
			
		
	
	3964cbbb5c
	
	
	
		
			
			Some distros provide SHA1 collision-detect code as a shared library. It's the same code as we have in git tree (but may be with a different init default for hash), and git can link with it as well; at least, it may make maintenance easier, according to our security guys. This patch allows user to build git linking with the external sha1dc library instead of the built-in code. User needs to define DC_SHA1_EXTERNAL explicitly. As default without it, the built-in sha1dc code is used like before. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
		
			
				
	
	
		
			39 lines
		
	
	
		
			855 B
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			39 lines
		
	
	
		
			855 B
		
	
	
	
		
			C
		
	
	
	
	
	
| #include "cache.h"
 | |
| 
 | |
| #ifdef DC_SHA1_EXTERNAL
 | |
| /*
 | |
|  * Same as SHA1DCInit, but with default save_hash=0
 | |
|  */
 | |
| void git_SHA1DCInit(SHA1_CTX *ctx)
 | |
| {
 | |
| 	SHA1DCInit(ctx);
 | |
| 	SHA1DCSetSafeHash(ctx, 0);
 | |
| }
 | |
| #endif
 | |
| 
 | |
| /*
 | |
|  * Same as SHA1DCFinal, but convert collision attack case into a verbose die().
 | |
|  */
 | |
| void git_SHA1DCFinal(unsigned char hash[20], SHA1_CTX *ctx)
 | |
| {
 | |
| 	if (!SHA1DCFinal(hash, ctx))
 | |
| 		return;
 | |
| 	die("SHA-1 appears to be part of a collision attack: %s",
 | |
| 	    sha1_to_hex(hash));
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * Same as SHA1DCUpdate, but adjust types to match git's usual interface.
 | |
|  */
 | |
| void git_SHA1DCUpdate(SHA1_CTX *ctx, const void *vdata, unsigned long len)
 | |
| {
 | |
| 	const char *data = vdata;
 | |
| 	/* We expect an unsigned long, but sha1dc only takes an int */
 | |
| 	while (len > INT_MAX) {
 | |
| 		SHA1DCUpdate(ctx, data, INT_MAX);
 | |
| 		data += INT_MAX;
 | |
| 		len -= INT_MAX;
 | |
| 	}
 | |
| 	SHA1DCUpdate(ctx, data, len);
 | |
| }
 |