Introduce _FAST variants of the OPENSSL_SHA1, BLK_SHA1, and APPLE_COMMON_CRYPTO_SHA1 compile-time knobs which indicate which SHA-1 implementation is to be used for non-cryptographic uses. There are a couple of small implementation notes worth mentioning: - There is no way to select the collision detecting SHA-1 as the "fast" fallback, since the fast fallback is only for non-cryptographic uses, and is meant to be faster than our collision-detecting implementation. - There are no similar knobs for SHA-256, since no collision attacks are presently known and thus no collision-detecting implementations actually exist. Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx> --- Makefile | 25 +++++++++++++++++++++++++ hash.h | 30 ++++++++++++++++++++++++++++++ 2 files changed, 55 insertions(+) diff --git a/Makefile b/Makefile index e298c8b55ec..d24f9088802 100644 --- a/Makefile +++ b/Makefile @@ -517,6 +517,10 @@ include shared.mak # Define APPLE_COMMON_CRYPTO_SHA1 to use Apple's CommonCrypto for # SHA-1. # +# Define the same Makefile knobs as above, but suffixed with _FAST to +# use the corresponding implementations for "fast" SHA-1 hashing for +# non-cryptographic purposes. +# # If don't enable any of the *_SHA1 settings in this section, Git will # default to its built-in sha1collisiondetection library, which is a # collision-detecting sha1 This is slower, but may detect attempted @@ -1982,6 +1986,27 @@ endif endif endif +ifdef OPENSSL_SHA1_FAST +ifndef OPENSSL_SHA1 + EXTLIBS += $(LIB_4_CRYPTO) + BASIC_CFLAGS += -DSHA1_OPENSSL_FAST +endif +else +ifdef BLK_SHA1_FAST +ifndef BLK_SHA1 + LIB_OBJS += block-sha1/sha1.o + BASIC_CFLAGS += -DSHA1_BLK_FAST +endif +else +ifdef APPLE_COMMON_CRYPTO_SHA1_FAST +ifndef APPLE_COMMON_CRYPTO_SHA1 + COMPAT_CFLAGS += -DCOMMON_DIGEST_FOR_OPENSSL + BASIC_CFLAGS += -DSHA1_APPLE_FAST +endif +endif +endif +endif + ifdef OPENSSL_SHA256 EXTLIBS += $(LIB_4_CRYPTO) BASIC_CFLAGS += -DSHA256_OPENSSL diff --git a/hash.h b/hash.h index 5e5b8205b58..6ea0d968017 100644 --- a/hash.h +++ b/hash.h @@ -15,6 +15,36 @@ #include "block-sha1/sha1.h" #endif +#if defined(SHA1_APPLE_FAST) +# include <CommonCrypto/CommonDigest.h> +# define platform_SHA_CTX_fast CC_SHA1_CTX +# define platform_SHA1_Init_fast CC_SHA1_Init +# define platform_SHA1_Update_fast CC_SHA1_Update +# define platform_SHA1_Final_fast CC_SHA1_Final +#elif defined(SHA1_OPENSSL_FAST) +# include <openssl/sha.h> +# if defined(OPENSSL_API_LEVEL) && OPENSSL_API_LEVEL >= 3 +# define SHA1_NEEDS_CLONE_HELPER_FAST +# include "sha1/openssl.h" +# define platform_SHA_CTX_fast openssl_SHA1_CTX +# define platform_SHA1_Init_fast openssl_SHA1_Init +# define platform_SHA1_Clone_fast openssl_SHA1_Clone +# define platform_SHA1_Update_fast openssl_SHA1_Update +# define platform_SHA1_Final_fast openssl_SHA1_Final +# else +# define platform_SHA_CTX_fast SHA_CTX +# define platform_SHA1_Init_fast SHA1_Init +# define platform_SHA1_Update_fast SHA1_Update +# define platform_SHA1_Final_fast SHA1_Final +# endif +#elif defined(SHA1_BLK_FAST) +# include "block-sha1/sha1.h" +# define platform_SHA_CTX_fast blk_SHA_CTX +# define platform_SHA1_Init_fast blk_SHA1_Init +# define platform_SHA1_Update_fast blk_SHA1_Update +# define platform_SHA1_Final_fast blk_SHA1_Final +#endif + #if defined(SHA256_NETTLE) #include "sha256/nettle.h" #elif defined(SHA256_GCRYPT) -- 2.46.0.426.g82754d92509.dirty