aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/git-version.adoc8
-rw-r--r--hash.h11
-rw-r--r--help.c7
3 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/git-version.adoc b/Documentation/git-version.adoc
index 80fa7754a6..9462043a14 100644
--- a/Documentation/git-version.adoc
+++ b/Documentation/git-version.adoc
@@ -22,6 +22,14 @@ OPTIONS
--build-options::
Include additional information about how git was built for diagnostic
purposes.
++
+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. 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
---
diff --git a/hash.h b/hash.h
index 23b7f92bd3..d6422ddf45 100644
--- a/hash.h
+++ b/hash.h
@@ -2,26 +2,32 @@
#define HASH_H
#if defined(SHA1_APPLE)
+#define SHA1_BACKEND "SHA1_APPLE (No collision detection)"
#include <CommonCrypto/CommonDigest.h>
#elif defined(SHA1_OPENSSL)
+# define SHA1_BACKEND "SHA1_OPENSSL (No collision detection)"
# include <openssl/sha.h>
# if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3
# define SHA1_NEEDS_CLONE_HELPER
# include "sha1/openssl.h"
# endif
#elif defined(SHA1_DC)
+#define SHA1_BACKEND "SHA1_DC"
#include "sha1dc_git.h"
#else /* SHA1_BLK */
+#define SHA1_BACKEND "SHA1_BLK (No collision detection)"
#include "block-sha1/sha1.h"
#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
@@ -38,6 +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
@@ -46,17 +53,21 @@
#endif
#if defined(SHA256_NETTLE)
+#define SHA256_BACKEND "SHA256_NETTLE"
#include "sha256/nettle.h"
#elif defined(SHA256_GCRYPT)
+#define SHA256_BACKEND "SHA256_GCRYPT"
#define SHA256_NEEDS_CLONE_HELPER
#include "sha256/gcrypt.h"
#elif defined(SHA256_OPENSSL)
+# define SHA256_BACKEND "SHA256_OPENSSL"
# include <openssl/sha.h>
# if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3
# define SHA256_NEEDS_CLONE_HELPER
# include "sha256/openssl.h"
# endif
#else
+#define SHA256_BACKEND "SHA256_BLK"
#include "sha256/block/sha256.h"
#endif
diff --git a/help.c b/help.c
index c54bd9918a..6ef90838f1 100644
--- a/help.c
+++ b/help.c
@@ -9,6 +9,7 @@
#include "run-command.h"
#include "levenshtein.h"
#include "gettext.h"
+#include "hash.h"
#include "help.h"
#include "command-list.h"
#include "string-list.h"
@@ -803,6 +804,12 @@ void get_version_info(struct strbuf *buf, int show_build_options)
#elif defined ZLIB_VERSION
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);
}
}