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authorVincent Ambo <Vincent Ambo>2020-01-11T23·36+0000
committerVincent Ambo <Vincent Ambo>2020-01-11T23·40+0000
commit7ef0d62730840ded097b524104cc0a0904591a63 (patch)
treea670f96103667aeca4789a95d94ca0dff550c4ce /third_party/git/sha1dc_git.c
parent6a2a3007077818e24a3d56fc492ada9206a10cf0 (diff)
parent1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 (diff)
merge(third_party/git): Merge squashed git subtree at v2.23.0 r/373
Merge commit '1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5' as 'third_party/git'
Diffstat (limited to 'third_party/git/sha1dc_git.c')
-rw-r--r--third_party/git/sha1dc_git.c38
1 files changed, 38 insertions, 0 deletions
diff --git a/third_party/git/sha1dc_git.c b/third_party/git/sha1dc_git.c
new file mode 100644
index 000000000000..e0cc9d988c70
--- /dev/null
+++ b/third_party/git/sha1dc_git.c
@@ -0,0 +1,38 @@
+#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);
+}