crypto: chacha20-generic - refactor to allow varying number of rounds

In preparation for adding XChaCha12 support, rename/refactor
chacha20-generic to support different numbers of rounds.  The
justification for needing XChaCha12 support is explained in more detail
in the patch "crypto: chacha - add XChaCha12 support".

The only difference between ChaCha{8,12,20} are the number of rounds
itself; all other parts of the algorithm are the same.  Therefore,
remove the "20" from all definitions, structures, functions, files, etc.
that will be shared by all ChaCha versions.

Also make ->setkey() store the round count in the chacha_ctx (previously
chacha20_ctx).  The generic code then passes the round count through to
chacha_block().  There will be a ->setkey() function for each explicitly
allowed round count; the encrypt/decrypt functions will be the same.  I
decided not to do it the opposite way (same ->setkey() function for all
round counts, with different encrypt/decrypt functions) because that
would have required more boilerplate code in architecture-specific
implementations of ChaCha and XChaCha.

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

3 files changed, 6 insertions, 6 deletions

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 523565ce0060..92e593e2069a 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -559,7 +559,7 @@ static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
         unsigned int ivsize = crypto_aead_ivsize(aead);
         unsigned int saltlen = CHACHAPOLY_IV_SIZE - ivsize;
 
-        if (keylen != CHACHA20_KEY_SIZE + saltlen) {
+        if (keylen != CHACHA_KEY_SIZE + saltlen) {
                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
                 return -EINVAL;
         }
diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 2598640aa98b..425d5d974613 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -591,7 +591,7 @@ static int chachapoly_setkey(struct crypto_aead *aead, const u8 *key,
         unsigned int ivsize = crypto_aead_ivsize(aead);
         unsigned int saltlen = CHACHAPOLY_IV_SIZE - ivsize;
 
-        if (keylen != CHACHA20_KEY_SIZE + saltlen) {
+        if (keylen != CHACHA_KEY_SIZE + saltlen) {
                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
                 return -EINVAL;
         }
@@ -1577,9 +1577,9 @@ static struct caam_skcipher_alg driver_algs[] = {
                         .setkey = skcipher_setkey,
                         .encrypt = skcipher_encrypt,
                         .decrypt = skcipher_decrypt,
-                        .min_keysize = CHACHA20_KEY_SIZE,
-                        .max_keysize = CHACHA20_KEY_SIZE,
-                        .ivsize = CHACHA20_IV_SIZE,
+                        .min_keysize = CHACHA_KEY_SIZE,
+                        .max_keysize = CHACHA_KEY_SIZE,
+                        .ivsize = CHACHA_IV_SIZE,
                 },
                 .caam.class1_alg_type = OP_ALG_ALGSEL_CHACHA20,
         },
diff --git a/drivers/crypto/caam/compat.h b/drivers/crypto/caam/compat.h
index 8bde903f9f4a..87d9efe4c7aa 100644
--- a/drivers/crypto/caam/compat.h
+++ b/drivers/crypto/caam/compat.h
@@ -36,7 +36,7 @@
 #include <crypto/gcm.h>
 #include <crypto/sha.h>
 #include <crypto/md5.h>
-#include <crypto/chacha20.h>
+#include <crypto/chacha.h>
 #include <crypto/poly1305.h>
 #include <crypto/internal/aead.h>
 #include <crypto/authenc.h>