kernel/linux.git/lib/crypto/sha256.c, branch v6.6.131

crypto: lib/sha256 - Use generic code from sha256_base

2023-05-19T08:45:43+00:00

Instead of duplicating the sha256 block processing code, reuse the common code from crypto/sha256_base.h. Signed-off-by: Herbert Xu

crypto: lib/sha256 - Remove redundant and unused sha224_update

2023-05-19T08:45:43+00:00

The function sha224_update is exactly the same as sha256_update. Moreover it's not even used in the kernel so it can be removed. Signed-off-by: Herbert Xu

crypto: sha - split sha.h into sha1.h and sha2.h

2020-11-20T03:45:33+00:00

Currently contains declarations for both SHA-1 and SHA-2, and contains declarations for SHA-3. This organization is inconsistent, but more importantly SHA-1 is no longer considered to be cryptographically secure. So to the extent possible, SHA-1 shouldn't be grouped together with any of the other SHA versions, and usage of it should be phased out. Therefore, split into two headers and , and make everyone explicitly specify whether they want the declarations for SHA-1, SHA-2, or both. This avoids making the SHA-1 declarations visible to files that don't want anything to do with SHA-1. It also prepares for potentially moving sha1.h into a new insecure/ or dangerous/ directory. Signed-off-by: Eric Biggers Acked-by: Ard Biesheuvel Acked-by: Jason A. Donenfeld Signed-off-by: Herbert Xu

crypto: lib/sha256 - Unroll LOAD and BLEND loops

2020-10-30T06:35:04+00:00

Unrolling the LOAD and BLEND loops improves performance by ~8% on x86_64 (tested on Broadwell Xeon) while not increasing code size too much. Signed-off-by: Arvind Sankar Reviewed-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

crypto: lib/sha256 - Unroll SHA256 loop 8 times intead of 64

2020-10-30T06:35:03+00:00

This reduces code size substantially (on x86_64 with gcc-10 the size of sha256_update() goes from 7593 bytes to 1952 bytes including the new SHA256_K array), and on x86 is slightly faster than the full unroll (tested on Broadwell Xeon). Signed-off-by: Arvind Sankar Reviewed-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

crypto: lib/sha256 - Clear W[] in sha256_update() instead of sha256_transform()

2020-10-30T06:35:03+00:00

The temporary W[] array is currently zeroed out once every call to sha256_transform(), i.e. once every 64 bytes of input data. Moving it to sha256_update() instead so that it is cleared only once per update can save about 2-3% of the total time taken to compute the digest, with a reasonable memset() implementation, and considerably more (~20%) with a bad one (eg the x86 purgatory currently uses a memset() coded in C). Signed-off-by: Arvind Sankar Reviewed-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

crypto: lib/sha256 - Don't clear temporary variables

2020-10-30T06:35:03+00:00

The assignments to clear a through h and t1/t2 are optimized out by the compiler because they are unused after the assignments. Clearing individual scalar variables is unlikely to be useful, as they may have been assigned to registers, and even if stack spilling was required, there may be compiler-generated temporaries that are impossible to clear in any case. So drop the clearing of a through h and t1/t2. Signed-off-by: Arvind Sankar Reviewed-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

crypto: lib/sha256 - Use memzero_explicit() for clearing state

2020-10-30T06:35:03+00:00

Without the barrier_data() inside memzero_explicit(), the compiler may optimize away the state-clearing if it can tell that the state is not used afterwards. At least in lib/crypto/sha256.c:__sha256_final(), the function can get inlined into sha256(), in which case the memset is optimized away. Signed-off-by: Arvind Sankar Reviewed-by: Eric Biggers Acked-by: Ard Biesheuvel Signed-off-by: Herbert Xu

crypto: lib/sha256 - add sha256() function

2020-07-16T11:49:05+00:00

Add a function sha256() which computes a SHA-256 digest in one step, combining sha256_init() + sha256_update() + sha256_final(). This is similar to how we also have blake2s(). Reviewed-by: Ard Biesheuvel Tested-by: Hans de Goede Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu

crypto: lib/sha256 - return void

2020-05-08T05:32:12+00:00

The SHA-256 / SHA-224 library functions can't fail, so remove the useless return value. Also long as the declarations are being changed anyway, also fix some parameter names in the declarations to match the definitions. Signed-off-by: Eric Biggers Reviewed-by: Jason A. Donenfeld Signed-off-by: Herbert Xu