help: include unsafe SHA-1 build info in version
In 06c92dafb8 (Makefile: allow specifying a SHA-1 for non-cryptographic uses, 2024-09-26), support for unsafe SHA-1 is added. Add the unsafe SHA-1 build info to `git version --build-info` and update corresponding documentation. Signed-off-by: Justin Tobler <jltobler@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Justin Tobler committed
Apr 3, 2025 at 09:05 UTC
6cf65440d39250880e747d2c5281881e95eb9499
3 files changed
+10
-1
Documentation/git-version.adoc
+3
-1
index 913ebf147d..9462043a14 100644
--- a/Documentation/git-version.adoc
+++ b/Documentation/git-version.adoc
@@ -27,7 +27,9 @@ The libraries used to implement the SHA-1 and SHA-256 algorithms are displayed
in the form `SHA-1: <option>` and `SHA-256: <option>`. Note that the SHA-1
options `SHA1_APPLE`, `SHA1_OPENSSL`, and `SHA1_BLK` do not use a collision
detection algorithm and thus may be vulnerable to known SHA-1 collision
-attacks.
+attacks. When a faster SHA-1 implementation without collision detection is used
+for only non-cryptographic purposes, the algorithm is displayed in the form
+`non-collision-detecting-SHA-1: <option>`.
GIT
---
hash.h
+3
index 51cd0ec7b6..72334d3506 100644
--- a/hash.h
+++ b/hash.h
@@ -20,12 +20,14 @@
#endif
#if defined(SHA1_APPLE_UNSAFE)
+# define SHA1_UNSAFE_BACKEND "SHA1_APPLE_UNSAFE"
# include <CommonCrypto/CommonDigest.h>
# define platform_SHA_CTX_unsafe CC_SHA1_CTX
# define platform_SHA1_Init_unsafe CC_SHA1_Init
# define platform_SHA1_Update_unsafe CC_SHA1_Update
# define platform_SHA1_Final_unsafe CC_SHA1_Final
#elif defined(SHA1_OPENSSL_UNSAFE)
+# define SHA1_UNSAFE_BACKEND "SHA1_OPENSSL_UNSAFE"
# include <openssl/sha.h>
# if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3
# define SHA1_NEEDS_CLONE_HELPER_UNSAFE
@@ -42,6 +44,7 @@
# define platform_SHA1_Final_unsafe SHA1_Final
# endif
#elif defined(SHA1_BLK_UNSAFE)
+# define SHA1_UNSAFE_BACKEND "SHA1_BLK_UNSAFE"
# include "block-sha1/sha1.h"
# define platform_SHA_CTX_unsafe blk_SHA_CTX
# define platform_SHA1_Init_unsafe blk_SHA1_Init
help.c
+4
index 991a9525db..6ef90838f1 100644
--- a/help.c
+++ b/help.c
@@ -805,6 +805,10 @@ void get_version_info(struct strbuf *buf, int show_build_options)
strbuf_addf(buf, "zlib: %s\n", ZLIB_VERSION);
#endif
strbuf_addf(buf, "SHA-1: %s\n", SHA1_BACKEND);
+#if defined SHA1_UNSAFE_BACKEND
+ strbuf_addf(buf, "non-collision-detecting-SHA-1: %s\n",
+ SHA1_UNSAFE_BACKEND);
+#endif
strbuf_addf(buf, "SHA-256: %s\n", SHA256_BACKEND);
}
}