Re: [PATCH] Limit the size of the data block passed to SHA1_Update()

From: Atousa Duprat <atousa.p@gmail.com>
Date: Nov 2, 2015, 20:52 UTC
Message-ID: <CA+izobvbDYLvShT8TdDhe9UiYHVWw+Le+Yy4yOnvCYOWE0bhQQ@mail.gmail.com>
In-Reply-To: <xmqqh9l5h8g3.fsf@gitster.mtv.corp.google.com>

In the Makefile there is the following:

ifdef BLK_SHA1
        SHA1_HEADER = "block-sha1/sha1.h"
        LIB_OBJS += block-sha1/sha1.o
else
ifdef PPC_SHA1
        SHA1_HEADER = "ppc/sha1.h"
        LIB_OBJS += ppc/sha1.o ppc/sha1ppc.o
else
ifdef APPLE_COMMON_CRYPTO
        COMPAT_CFLAGS += -DCOMMON_DIGEST_FOR_OPENSSL
        SHA1_HEADER = <CommonCrypto/CommonDigest.h>
        SHA1_MAX_BLOCK_SIZE = 1024L*1024L*1024L
else
        SHA1_HEADER = <openssl/sha.h>
        EXTLIBS += $(LIB_4_CRYPTO)
endif

which seems to imply that BLK_SHA1 and APPLE_COMMON_CRYPTO are mutually exclusive?

On Sun, Nov 1, 2015 at 10:37 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 29 quoted lines

> atousa.p@gmail.com writes:
>
>> diff --git a/cache.h b/cache.h
>> index 79066e5..ec84b16 100644
>> --- a/cache.h
>> +++ b/cache.h
>> @@ -14,7 +14,12 @@
>>  #ifndef git_SHA_CTX
>>  #define git_SHA_CTX  SHA_CTX
>>  #define git_SHA1_Init        SHA1_Init
>> -#define git_SHA1_Update      SHA1_Update
>> +#ifdef SHA1_MAX_BLOCK_SIZE
>> +extern int SHA1_Update_Chunked(SHA_CTX *, const void *, size_t);
>> +#define git_SHA1_Update SHA1_Update_Chunked
>> +#else
>> +#define git_SHA1_Update SHA1_Update
>> +#endif
>>  #define git_SHA1_Final       SHA1_Final
>>  #endif
>
> Hmm, I admit that this mess is my creation, but unfortunately it
> does not allow us to say:
>
>         make SHA1_MAX_BLOCK_SIZE='1024L*1024L*1024L'
>
> when using other SHA-1 implementations (e.g. blk_SHA1_Update()).
>
> Ideas for cleaning it up, anybody?
>

-- 
Atousa Pahlevan, PhD
M.Math. University of Waterloo, Canada
Ph.D. Department of Computer Science, University of Victoria, Canada
Voice: 415-341-6206
Email: apahlevan@ieee.org
Website: www.apahlevan.org