Commit Graph

15 Commits

Author SHA1 Message Date
Eric Biggers
a24d22b225 crypto: sha - split sha.h into sha1.h and sha2.h
Currently <crypto/sha.h> contains declarations for both SHA-1 and SHA-2,
and <crypto/sha3.h> 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 <crypto/sha.h> into two headers <crypto/sha1.h> and
<crypto/sha2.h>, 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 <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-11-20 14:45:33 +11:00
Arvind Sankar
18d05ca448 crypto: lib/sha256 - Unroll LOAD and BLEND loops
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 <nivedita@alum.mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:04 +11:00
Arvind Sankar
63642d5c14 crypto: lib/sha256 - Unroll SHA256 loop 8 times intead of 64
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 <nivedita@alum.mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:03 +11:00
Arvind Sankar
b8399819b2 crypto: lib/sha256 - Clear W[] in sha256_update() instead of sha256_transform()
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 <nivedita@alum.mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:03 +11:00
Arvind Sankar
7a4295f6c9 crypto: lib/sha256 - Don't clear temporary variables
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 <nivedita@alum.mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:03 +11:00
Arvind Sankar
1762818f25 crypto: lib/sha256 - Use memzero_explicit() for clearing state
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 <nivedita@alum.mit.edu>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-10-30 17:35:03 +11:00
Eric Biggers
9ea9c58b40 crypto: lib/sha256 - add sha256() function
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 <ardb@kernel.org>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-07-16 21:49:05 +10:00
Eric Biggers
13855fd8ce crypto: lib/sha256 - return void
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 <ebiggers@google.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-05-08 15:32:12 +10:00
Hans de Goede
c75c66bbaa crypto: sha256 - Remove sha256/224_init code duplication
lib/crypto/sha256.c and include/crypto/sha256_base.h define
99% identical functions to init a sha256_state struct for sha224 or
sha256 use.

This commit moves the functions from lib/crypto/sha256.c to
include/crypto/sha.h (making them static inline) and makes the
sha224/256_base_init static inline functions from
include/crypto/sha256_base.h wrappers around the now also
static inline include/crypto/sha.h functions.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-09-05 14:54:54 +10:00
Hans de Goede
34d6245fbc crypto: sha256 - Merge crypto/sha256.h into crypto/sha.h
The generic sha256 implementation from lib/crypto/sha256.c uses data
structs defined in crypto/sha.h, so lets move the function prototypes
there too.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-09-05 14:54:54 +10:00
Hans de Goede
9ecf5ad522 crypto: sha256 - Add missing MODULE_LICENSE() to lib/crypto/sha256.c
lib/crypto/sha256.c / lib/crypto/libsha256.o may end up being a module,
so it needs a MODULE_LICENSE() line, add this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-30 18:05:31 +10:00
Hans de Goede
7d2f5b0c43 crypto: sha256 - Add sha224 support to sha256 library code
Add sha224 support to the lib/crypto/sha256 library code. This will allow
us to replace both the sha256 and sha224 parts of crypto/sha256_generic.c
when we remove the code duplication in further patches in this series.

Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:57:35 +10:00
Hans de Goede
01d3aee866 crypto: sha256 - Make lib/crypto/sha256.c suitable for generic use
Before this commit lib/crypto/sha256.c has only been used in the s390 and
x86 purgatory code, make it suitable for generic use:

* Export interesting symbols
* Add  -D__DISABLE_EXPORTS to CFLAGS_sha256.o for purgatory builds to
  avoid the exports for the purgatory builds
* Add to lib/crypto/Makefile and crypto/Kconfig

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:57:35 +10:00
Hans de Goede
906a4bb97f crypto: sha256 - Use get/put_unaligned_be32 to get input, memzero_explicit
Use get/put_unaligned_be32 in lib/crypto/sha256.c to load / store data
so that it can be used with unaligned buffers too, making it more generic.

And use memzero_explicit for better clearing of sensitive data.

Note unlike other patches in this series this commit actually makes
functional changes to the sha256 code as used by the purgatory code.

This fully aligns the lib/crypto/sha256.c sha256 implementation with the
one from crypto/sha256_generic.c allowing us to remove the latter in
further patches in this series.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:57:35 +10:00
Hans de Goede
ad767ee858 crypto: sha256 - Move lib/sha256.c to lib/crypto
Generic crypto implementations belong under lib/crypto not directly in
lib, likewise the header should be in include/crypto, not include/linux.

Note that the code in lib/crypto/sha256.c is not yet available for
generic use after this commit, it is still only used by the s390 and x86
purgatory code. Making it suitable for generic use is done in further
patches in this series.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-08-22 14:57:35 +10:00