crypto: x86/salsa20 - cleanup and convert to skcipher API

Convert salsa20-asm from the deprecated "blkcipher" API to the
"skcipher" API, in the process fixing it up to use the generic helpers.
This allows removing the salsa20_keysetup() and salsa20_ivsetup()
assembly functions, which aren't performance critical; the C versions do
just fine.

This also fixes the same bug that salsa20-generic had, where the state
array was being maintained directly in the transform context rather than
on the stack or in the request context.  Thus, if multiple threads used
the same Salsa20 transform concurrently they produced the wrong results.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 0 deletions

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 9327fbfccf5a..b44c0ae04eb2 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1339,6 +1339,7 @@ config CRYPTO_SALSA20_586
         tristate "Salsa20 stream cipher algorithm (i586)"
         depends on (X86 || UML_X86) && !64BIT
         select CRYPTO_BLKCIPHER
+        select CRYPTO_SALSA20
         help
           Salsa20 stream cipher algorithm.
 
@@ -1352,6 +1353,7 @@ config CRYPTO_SALSA20_X86_64
         tristate "Salsa20 stream cipher algorithm (x86_64)"
         depends on (X86 || UML_X86) && 64BIT
         select CRYPTO_BLKCIPHER
+        select CRYPTO_SALSA20
         help
           Salsa20 stream cipher algorithm.