From 3bc72fde3f35b988c902abf5a0bc027f2e54d0c1 Mon Sep 17 00:00:00 2001 From: Atousa Pahlevan Duprat Date: Wed, 4 Nov 2015 22:38:41 -0800 Subject: sha1: provide another level of indirection for the SHA-1 functions The git source uses git_SHA1_Update() and friends to call into the code that computes the hashes. Traditionally, we used to map these directly to underlying implementation of the SHA-1 hash (e.g. SHA1_Update() from OpenSSL or blk_SHA1_Update() from block-sha1/). This arrangement however makes it hard to tweak behaviour of the underlying implementation without fully replacing. If we want to introduce a tweaked_SHA1_Update() wrapper to implement the "Update" in a slightly different way, for example, the implementation of the wrapper still would want to call into the underlying implementation, but tweaked_SHA1_Update() cannot call git_SHA1_Update() to get to the underlying implementation (often but not always SHA1_Update()). Add another level of indirection that maps platform_SHA1_Update() and friends to their underlying implementations, and by default make git_SHA1_Update() and friends map to platform_SHA1_* functions. Doing it this way will later allow us to map git_SHA1_Update() to tweaked_SHA1_Update(), and the latter can use platform_SHA1_Update() in its implementation. Signed-off-by: Atousa Pahlevan Duprat Signed-off-by: Junio C Hamano --- block-sha1/sha1.h | 8 ++++---- cache.h | 22 +++++++++++++++++----- ppc/sha1.h | 8 ++++---- 3 files changed, 25 insertions(+), 13 deletions(-) diff --git a/block-sha1/sha1.h b/block-sha1/sha1.h index b864df623e..4df6747752 100644 --- a/block-sha1/sha1.h +++ b/block-sha1/sha1.h @@ -16,7 +16,7 @@ void blk_SHA1_Init(blk_SHA_CTX *ctx); void blk_SHA1_Update(blk_SHA_CTX *ctx, const void *dataIn, unsigned long len); void blk_SHA1_Final(unsigned char hashout[20], blk_SHA_CTX *ctx); -#define git_SHA_CTX blk_SHA_CTX -#define git_SHA1_Init blk_SHA1_Init -#define git_SHA1_Update blk_SHA1_Update -#define git_SHA1_Final blk_SHA1_Final +#define platform_SHA_CTX blk_SHA_CTX +#define platform_SHA1_Init blk_SHA1_Init +#define platform_SHA1_Update blk_SHA1_Update +#define platform_SHA1_Final blk_SHA1_Final diff --git a/cache.h b/cache.h index 22b7b81290..0d89ad8a3a 100644 --- a/cache.h +++ b/cache.h @@ -11,13 +11,25 @@ #include "string-list.h" #include SHA1_HEADER -#ifndef git_SHA_CTX -#define git_SHA_CTX SHA_CTX -#define git_SHA1_Init SHA1_Init -#define git_SHA1_Update SHA1_Update -#define git_SHA1_Final SHA1_Final +#ifndef platform_SHA_CTX +/* + * platform's underlying implementation of SHA-1; could be OpenSSL, + * blk_SHA, Apple CommonCrypto, etc... Note that including + * SHA1_HEADER may have already defined platform_SHA_CTX for our + * own implementations like block-sha1 and ppc-sha1, so we list + * the default for OpenSSL compatible SHA-1 implementations here. + */ +#define platform_SHA_CTX SHA_CTX +#define platform_SHA1_Init SHA1_Init +#define platform_SHA1_Update SHA1_Update +#define platform_SHA1_Final SHA1_Final #endif +#define git_SHA_CTX platform_SHA_CTX +#define git_SHA1_Init platform_SHA1_Init +#define git_SHA1_Update platform_SHA1_Update +#define git_SHA1_Final platform_SHA1_Final + #include typedef struct git_zstream { z_stream z; diff --git a/ppc/sha1.h b/ppc/sha1.h index c405f734c2..9b24b32615 100644 --- a/ppc/sha1.h +++ b/ppc/sha1.h @@ -19,7 +19,7 @@ int ppc_SHA1_Init(ppc_SHA_CTX *c); int ppc_SHA1_Update(ppc_SHA_CTX *c, const void *p, unsigned long n); int ppc_SHA1_Final(unsigned char *hash, ppc_SHA_CTX *c); -#define git_SHA_CTX ppc_SHA_CTX -#define git_SHA1_Init ppc_SHA1_Init -#define git_SHA1_Update ppc_SHA1_Update -#define git_SHA1_Final ppc_SHA1_Final +#define platform_SHA_CTX ppc_SHA_CTX +#define platform_SHA1_Init ppc_SHA1_Init +#define platform_SHA1_Update ppc_SHA1_Update +#define platform_SHA1_Final ppc_SHA1_Final -- cgit v1.2.3 From 001fd7a90b5851f62e700510729a5e09706f9b63 Mon Sep 17 00:00:00 2001 From: Atousa Pahlevan Duprat Date: Wed, 4 Nov 2015 22:38:42 -0800 Subject: sha1: allow limiting the size of the data passed to SHA1_Update() Using the previous commit's inredirection mechanism for SHA1, support a chunked implementation of SHA1_Update() that limits the amount of data in the chunk passed to SHA1_Update(). This is enabled by using the Makefile variable SHA1_MAX_BLOCK_SIZE to specify chunk size. When using Apple's CommonCrypto library this is set to 1GiB (the implementation cannot handle more 4GiB). Signed-off-by: Atousa Pahlevan Duprat Signed-off-by: Junio C Hamano --- Makefile | 13 +++++++++++++ cache.h | 6 ++++++ compat/apple-common-crypto.h | 4 ++++ compat/sha1-chunked.c | 19 +++++++++++++++++++ compat/sha1-chunked.h | 2 ++ 5 files changed, 44 insertions(+) create mode 100644 compat/sha1-chunked.c create mode 100644 compat/sha1-chunked.h diff --git a/Makefile b/Makefile index 7482a4dbab..8ffcf37d5f 100644 --- a/Makefile +++ b/Makefile @@ -141,6 +141,10 @@ all:: # Define PPC_SHA1 environment variable when running make to make use of # a bundled SHA1 routine optimized for PowerPC. # +# Define SHA1_MAX_BLOCK_SIZE to limit the amount of data that will be hashed +# in one call to the platform's SHA1_Update(). e.g. APPLE_COMMON_CRYPTO +# wants 'SHA1_MAX_BLOCK_SIZE=1024L*1024L*1024L' defined. +# # Define NEEDS_CRYPTO_WITH_SSL if you need -lcrypto when using -lssl (Darwin). # # Define NEEDS_SSL_WITH_CRYPTO if you need -lssl when using -lcrypto (Darwin). @@ -1276,6 +1280,11 @@ ifdef NO_POSIX_GOODIES BASIC_CFLAGS += -DNO_POSIX_GOODIES endif +ifdef APPLE_COMMON_CRYPTO + # Apple CommonCrypto requires chunking + SHA1_MAX_BLOCK_SIZE = 1024L*1024L*1024L +endif + ifdef BLK_SHA1 SHA1_HEADER = "block-sha1/sha1.h" LIB_OBJS += block-sha1/sha1.o @@ -1294,6 +1303,10 @@ endif endif endif +ifdef SHA1_MAX_BLOCK_SIZE + LIB_OBJS += compat/sha1-chunked.o + BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)" +endif ifdef NO_PERL_MAKEMAKER export NO_PERL_MAKEMAKER endif diff --git a/cache.h b/cache.h index 0d89ad8a3a..0adc7ef7f7 100644 --- a/cache.h +++ b/cache.h @@ -30,6 +30,12 @@ #define git_SHA1_Update platform_SHA1_Update #define git_SHA1_Final platform_SHA1_Final +#ifdef SHA1_MAX_BLOCK_SIZE +#include "compat/sha1-chunked.h" +#undef git_SHA1_Update +#define git_SHA1_Update git_SHA1_Update_Chunked +#endif + #include typedef struct git_zstream { z_stream z; diff --git a/compat/apple-common-crypto.h b/compat/apple-common-crypto.h index c8b9b0e1a6..d3fb264181 100644 --- a/compat/apple-common-crypto.h +++ b/compat/apple-common-crypto.h @@ -16,6 +16,10 @@ #undef TYPE_BOOL #endif +#ifndef SHA1_MAX_BLOCK_SIZE +#error Using Apple Common Crypto library requires setting SHA1_MAX_BLOCK_SIZE +#endif + #ifdef APPLE_LION_OR_NEWER #define git_CC_error_check(pattern, err) \ do { \ diff --git a/compat/sha1-chunked.c b/compat/sha1-chunked.c new file mode 100644 index 0000000000..6adfcfd540 --- /dev/null +++ b/compat/sha1-chunked.c @@ -0,0 +1,19 @@ +#include "cache.h" + +int git_SHA1_Update_Chunked(platform_SHA_CTX *c, const void *data, size_t len) +{ + size_t nr; + size_t total = 0; + const char *cdata = (const char*)data; + + while (len) { + nr = len; + if (nr > SHA1_MAX_BLOCK_SIZE) + nr = SHA1_MAX_BLOCK_SIZE; + platform_SHA1_Update(c, cdata, nr); + total += nr; + cdata += nr; + len -= nr; + } + return total; +} diff --git a/compat/sha1-chunked.h b/compat/sha1-chunked.h new file mode 100644 index 0000000000..7b2df28eec --- /dev/null +++ b/compat/sha1-chunked.h @@ -0,0 +1,2 @@ + +int git_SHA1_Update_Chunked(platform_SHA_CTX *c, const void *data, size_t len); -- cgit v1.2.3