crypto: x86/chacha - add XChaCha12 support

Now that the x86_64 SIMD implementations of ChaCha20 and XChaCha20 have
been refactored to support varying the number of rounds, add support for
XChaCha12.  This is identical to XChaCha20 except for the number of
rounds, which is 12 instead of 20.  This can be used by Adiantum.

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

diff --git a/arch/x86/crypto/chacha_glue.c b/arch/x86/crypto/chacha_glue.c
index 35fd02b..d19c290 100644 (file)
--- a/arch/x86/crypto/chacha_glue.c
+++ b/arch/x86/crypto/chacha_glue.c
@@ -232,6 +232,21 @@ static struct skcipher_alg algs[] = {
                .setkey                 = crypto_chacha20_setkey,
                .encrypt                = xchacha_simd,
                .decrypt                = xchacha_simd,
+       }, {
+               .base.cra_name          = "xchacha12",
+               .base.cra_driver_name   = "xchacha12-simd",
+               .base.cra_priority      = 300,
+               .base.cra_blocksize     = 1,
+               .base.cra_ctxsize       = sizeof(struct chacha_ctx),
+               .base.cra_module        = THIS_MODULE,
+
+               .min_keysize            = CHACHA_KEY_SIZE,
+               .max_keysize            = CHACHA_KEY_SIZE,
+               .ivsize                 = XCHACHA_IV_SIZE,
+               .chunksize              = CHACHA_BLOCK_SIZE,
+               .setkey                 = crypto_chacha12_setkey,
+               .encrypt                = xchacha_simd,
+               .decrypt                = xchacha_simd,
        },
 };
 
@@ -268,3 +283,5 @@ MODULE_ALIAS_CRYPTO("chacha20");
 MODULE_ALIAS_CRYPTO("chacha20-simd");
 MODULE_ALIAS_CRYPTO("xchacha20");
 MODULE_ALIAS_CRYPTO("xchacha20-simd");
+MODULE_ALIAS_CRYPTO("xchacha12");
+MODULE_ALIAS_CRYPTO("xchacha12-simd");

diff --git a/crypto/Kconfig b/crypto/Kconfig
index dc3a0e3..045af6e 100644 (file)
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1473,8 +1473,8 @@ config CRYPTO_CHACHA20_X86_64
        select CRYPTO_BLKCIPHER
        select CRYPTO_CHACHA20
        help
-         SSSE3, AVX2, and AVX-512VL optimized implementations of the ChaCha20
-         and XChaCha20 stream ciphers.
+         SSSE3, AVX2, and AVX-512VL optimized implementations of the ChaCha20,
+         XChaCha20, and XChaCha12 stream ciphers.
 
 config CRYPTO_SEED
        tristate "SEED cipher algorithm"