path: root/sha256
diff options
authorbrian m. carlson <>2018-11-14 04:09:37 (GMT)
committerJunio C Hamano <>2018-11-14 07:54:53 (GMT)
commit27dc04c54506967fcaa87b2d560547ee5633040c (patch)
tree488f25ff856706ec8eaf74ea2bcfafa0252c9061 /sha256
parent13eeedb5d17ca3539600b6618d103b652ecc8ab0 (diff)
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 <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'sha256')
1 files changed, 30 insertions, 0 deletions
diff --git a/sha256/gcrypt.h b/sha256/gcrypt.h
new file mode 100644
index 0000000..09bd8bb
--- /dev/null
+++ b/sha256/gcrypt.h
@@ -0,0 +1,30 @@
+#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);
+#define platform_SHA256_CTX gcrypt_SHA256_CTX
+#define platform_SHA256_Init gcrypt_SHA256_Init
+#define platform_SHA256_Update gcrypt_SHA256_Update
+#define platform_SHA256_Final gcrypt_SHA256_Final