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git/sha256/gcrypt.h

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sha256: add an SHA-256 implementation using libgcrypt Generally, one gets better performance out of cryptographic routines written in assembly than C, and this is also true for SHA-256. In addition, most Linux distributions cannot distribute Git linked against OpenSSL for licensing reasons. Most systems with GnuPG will also have libgcrypt, since it is a dependency of GnuPG. libgcrypt is also faster than the SHA1DC implementation for messages of a few KiB and larger. For comparison, on a Core i7-6600U, this implementation processes 16 KiB chunks at 355 MiB/s while SHA1DC processes equivalent chunks at 337 MiB/s. In addition, libgcrypt is licensed under the LGPL 2.1, which is compatible with the GPL. Add an implementation of SHA-256 that uses libgcrypt. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 04:09:37 +00:00
#ifndef SHA256_GCRYPT_H
#define SHA256_GCRYPT_H
#include <gcrypt.h>
#define SHA256_DIGEST_SIZE 32
typedef gcry_md_hd_t gcrypt_SHA256_CTX;
inline void gcrypt_SHA256_Init(gcrypt_SHA256_CTX *ctx)
{
gcry_md_open(ctx, GCRY_MD_SHA256, 0);
}
inline void gcrypt_SHA256_Update(gcrypt_SHA256_CTX *ctx, const void *data, size_t len)
{
gcry_md_write(*ctx, data, len);
}
inline void gcrypt_SHA256_Final(unsigned char *digest, gcrypt_SHA256_CTX *ctx)
{
memcpy(digest, gcry_md_read(*ctx, GCRY_MD_SHA256), SHA256_DIGEST_SIZE);
}
hash: implement and use a context cloning function For all of our SHA-1 implementations and most of our SHA-256 implementations, the hash context we use is a real struct. For these implementations, it's possible to copy a hash context by making a copy of the struct. However, for our libgcrypt implementation, our hash context is a pointer. Consequently, copying it does not lead to an independent hash context like we intended. Fortunately, however, libgcrypt provides us with a handy function to copy hash contexts. Let's add a cloning function to the hash algorithm API, and use it in the one place we need to make a hash context copy. With this change, our libgcrypt SHA-256 implementation is fully functional with all of our other hash implementations. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-22 20:17:27 +00:00
inline void gcrypt_SHA256_Clone(gcrypt_SHA256_CTX *dst, const gcrypt_SHA256_CTX *src)
{
gcry_md_copy(dst, *src);
}
sha256: add an SHA-256 implementation using libgcrypt Generally, one gets better performance out of cryptographic routines written in assembly than C, and this is also true for SHA-256. In addition, most Linux distributions cannot distribute Git linked against OpenSSL for licensing reasons. Most systems with GnuPG will also have libgcrypt, since it is a dependency of GnuPG. libgcrypt is also faster than the SHA1DC implementation for messages of a few KiB and larger. For comparison, on a Core i7-6600U, this implementation processes 16 KiB chunks at 355 MiB/s while SHA1DC processes equivalent chunks at 337 MiB/s. In addition, libgcrypt is licensed under the LGPL 2.1, which is compatible with the GPL. Add an implementation of SHA-256 that uses libgcrypt. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 04:09:37 +00:00
#define platform_SHA256_CTX gcrypt_SHA256_CTX
#define platform_SHA256_Init gcrypt_SHA256_Init
hash: implement and use a context cloning function For all of our SHA-1 implementations and most of our SHA-256 implementations, the hash context we use is a real struct. For these implementations, it's possible to copy a hash context by making a copy of the struct. However, for our libgcrypt implementation, our hash context is a pointer. Consequently, copying it does not lead to an independent hash context like we intended. Fortunately, however, libgcrypt provides us with a handy function to copy hash contexts. Let's add a cloning function to the hash algorithm API, and use it in the one place we need to make a hash context copy. With this change, our libgcrypt SHA-256 implementation is fully functional with all of our other hash implementations. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-22 20:17:27 +00:00
#define platform_SHA256_Clone gcrypt_SHA256_Clone
sha256: add an SHA-256 implementation using libgcrypt Generally, one gets better performance out of cryptographic routines written in assembly than C, and this is also true for SHA-256. In addition, most Linux distributions cannot distribute Git linked against OpenSSL for licensing reasons. Most systems with GnuPG will also have libgcrypt, since it is a dependency of GnuPG. libgcrypt is also faster than the SHA1DC implementation for messages of a few KiB and larger. For comparison, on a Core i7-6600U, this implementation processes 16 KiB chunks at 355 MiB/s while SHA1DC processes equivalent chunks at 337 MiB/s. In addition, libgcrypt is licensed under the LGPL 2.1, which is compatible with the GPL. Add an implementation of SHA-256 that uses libgcrypt. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 04:09:37 +00:00
#define platform_SHA256_Update gcrypt_SHA256_Update
#define platform_SHA256_Final gcrypt_SHA256_Final
#endif
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