Merge branch 'ab/sha1dc-maint'

The "collision detecting" SHA-1 implementation shipped with 2.13
was quite broken on some big-endian platforms and/or platforms that
do not like unaligned fetches.  Update to the upstream code which
has already fixed these issues.

* ab/sha1dc-maint:
  sha1dc: update from upstream

1 files changed, 60 insertions, 31 deletions

diff --git a/sha1dc/sha1.c b/sha1dc/sha1.c
index 35e9dd5bf4..3dff80ac72 100644
--- a/sha1dc/sha1.c
+++ b/sha1dc/sha1.c
@@ -5,9 +5,23 @@
 * https://opensource.org/licenses/MIT
 ***/
 
-#include "cache.h"
-#include "sha1dc/sha1.h"
-#include "sha1dc/ubc_check.h"
+#ifndef SHA1DC_NO_STANDARD_INCLUDES
+#include <string.h>
+#include <memory.h>
+#include <stdio.h>
+#include <stdlib.h>
+#endif
+
+#ifdef SHA1DC_CUSTOM_INCLUDE_SHA1_C
+#include SHA1DC_CUSTOM_INCLUDE_SHA1_C
+#endif
+
+#ifndef SHA1DC_INIT_SAFE_HASH_DEFAULT
+#define SHA1DC_INIT_SAFE_HASH_DEFAULT 1
+#endif
+
+#include "sha1.h"
+#include "ubc_check.h"
 
 
 /*
@@ -18,16 +32,31 @@
    If you are compiling on a big endian platform and your compiler does not define one of these,
    you will have to add whatever macros your tool chain defines to indicate Big-Endianness.
  */
-#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || \
+#ifdef SHA1DC_BIGENDIAN
+#undef SHA1DC_BIGENDIAN
+#endif
+#if (!defined SHA1DC_FORCE_LITTLEENDIAN) && \
+    ((defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || \
     (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __BIG_ENDIAN__)) || \
-    defined(__BIG_ENDIAN__) || defined(__ARMEB__) || defined(__THUMBEB__) ||  defined(__AARCH64EB__) || \
-    defined(_MIPSEB) || defined(__MIPSEB) || defined(__MIPSEB__)
+    defined(_BIG_ENDIAN) || defined(__BIG_ENDIAN__) || defined(__ARMEB__) || defined(__THUMBEB__) ||  defined(__AARCH64EB__) || \
+    defined(_MIPSEB) || defined(__MIPSEB) || defined(__MIPSEB__) || defined(SHA1DC_FORCE_BIGENDIAN))
+
+#define SHA1DC_BIGENDIAN
 
-#define SHA1DC_BIGENDIAN	1
-#else
-#undef SHA1DC_BIGENDIAN
 #endif /*ENDIANNESS SELECTION*/
 
+#if (defined SHA1DC_FORCE_UNALIGNED_ACCESS || \
+     defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64) || \
+     defined(i386) || defined(__i386) || defined(__i386__) || defined(__i486__)  || \
+     defined(__i586__) || defined(__i686__) || defined(_M_IX86) || defined(__X86__) || \
+     defined(_X86_) || defined(__THW_INTEL__) || defined(__I86__) || defined(__INTEL__) || \
+     defined(__386) || defined(_M_X64) || defined(_M_AMD64))
+
+#define SHA1DC_ALLOW_UNALIGNED_ACCESS
+
+#endif /*UNALIGNMENT DETECTION*/
+
+
 #define rotate_right(x,n) (((x)>>(n))|((x)<<(32-(n))))
 #define rotate_left(x,n)  (((x)<<(n))|((x)>>(32-(n))))
 
@@ -36,11 +65,11 @@
 
 #define sha1_mix(W, t)  (rotate_left(W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16], 1))
 
-#if defined(SHA1DC_BIGENDIAN)
+#ifdef SHA1DC_BIGENDIAN
 	#define sha1_load(m, t, temp)  { temp = m[t]; }
 #else
 	#define sha1_load(m, t, temp)  { temp = m[t]; sha1_bswap32(temp); }
-#endif /* !defined(SHA1DC_BIGENDIAN) */
+#endif
 
 #define sha1_store(W, t, x)	*(volatile uint32_t *)&W[t] = x
 
@@ -869,6 +898,11 @@ static void sha1recompress_fast_ ## t (uint32_t ihvin[5], uint32_t ihvout[5], co
 	ihvout[0] = ihvin[0] + a; ihvout[1] = ihvin[1] + b; ihvout[2] = ihvin[2] + c; ihvout[3] = ihvin[3] + d; ihvout[4] = ihvin[4] + e; \
 }
 
+#ifdef _MSC_VER
+#pragma warning(push)
+#pragma warning(disable: 4127)  /* Complier complains about the checks in the above macro being constant. */
+#endif
+
 #ifdef DOSTORESTATE0
 SHA1_RECOMPRESS(0)
 #endif
@@ -1189,6 +1223,10 @@ SHA1_RECOMPRESS(78)
 SHA1_RECOMPRESS(79)
 #endif
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
 static void sha1_recompression_step(uint32_t step, uint32_t ihvin[5], uint32_t ihvout[5], const uint32_t me2[80], const uint32_t state[5])
 {
 	switch (step)
@@ -1662,7 +1700,7 @@ void SHA1DCInit(SHA1_CTX* ctx)
 	ctx->ihv[3] = 0x10325476;
 	ctx->ihv[4] = 0xC3D2E1F0;
 	ctx->found_collision = 0;
-	ctx->safe_hash = 0;
+	ctx->safe_hash = SHA1DC_INIT_SAFE_HASH_DEFAULT;
 	ctx->ubc_check = 1;
 	ctx->detect_coll = 1;
 	ctx->reduced_round_coll = 0;
@@ -1710,6 +1748,7 @@ void SHA1DCSetCallback(SHA1_CTX* ctx, collision_block_callback callback)
 void SHA1DCUpdate(SHA1_CTX* ctx, const char* buf, size_t len)
 {
 	unsigned left, fill;
+
 	if (len == 0)
 		return;
 
@@ -1728,7 +1767,13 @@ void SHA1DCUpdate(SHA1_CTX* ctx, const char* buf, size_t len)
 	while (len >= 64)
 	{
 		ctx->total += 64;
+
+#if defined(SHA1DC_ALLOW_UNALIGNED_ACCESS)
 		sha1_process(ctx, (uint32_t*)(buf));
+#else
+		memcpy(ctx->buffer, buf, 64);
+		sha1_process(ctx, (uint32_t*)(ctx->buffer));
+#endif /* defined(SHA1DC_ALLOW_UNALIGNED_ACCESS) */
 		buf += 64;
 		len -= 64;
 	}
@@ -1788,22 +1833,6 @@ int SHA1DCFinal(unsigned char output[20], SHA1_CTX *ctx)
 	return ctx->found_collision;
 }
 
-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));
-}
-
-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);
-}
+#ifdef SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_C
+#include SHA1DC_CUSTOM_TRAILING_INCLUDE_SHA1_C
+#endif