crypto: speck - export common helpers

Export the Speck constants and transform context and the ->setkey(),
->encrypt(), and ->decrypt() functions so that they can be reused by the
ARM NEON implementation of Speck-XTS.  The generic key expansion code
will be reused because it is not performance-critical and is not
vectorizable, while the generic encryption and decryption functions are
needed as fallbacks and for the XTS tweak encryption.

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

include/crypto/speck.h

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common values for the Speck algorithm
+ */
+
+#ifndef _CRYPTO_SPECK_H
+#define _CRYPTO_SPECK_H
+
+#include <linux/types.h>
+
+/* Speck128 */
+
+#define SPECK128_BLOCK_SIZE	16
+
+#define SPECK128_128_KEY_SIZE	16
+#define SPECK128_128_NROUNDS	32
+
+#define SPECK128_192_KEY_SIZE	24
+#define SPECK128_192_NROUNDS	33
+
+#define SPECK128_256_KEY_SIZE	32
+#define SPECK128_256_NROUNDS	34
+
+struct speck128_tfm_ctx {
+	u64 round_keys[SPECK128_256_NROUNDS];
+	int nrounds;
+};
+
+void crypto_speck128_encrypt(const struct speck128_tfm_ctx *ctx,
+			     u8 *out, const u8 *in);
+
+void crypto_speck128_decrypt(const struct speck128_tfm_ctx *ctx,
+			     u8 *out, const u8 *in);
+
+int crypto_speck128_setkey(struct speck128_tfm_ctx *ctx, const u8 *key,
+			   unsigned int keysize);
+
+/* Speck64 */
+
+#define SPECK64_BLOCK_SIZE	8
+
+#define SPECK64_96_KEY_SIZE	12
+#define SPECK64_96_NROUNDS	26
+
+#define SPECK64_128_KEY_SIZE	16
+#define SPECK64_128_NROUNDS	27
+
+struct speck64_tfm_ctx {
+	u32 round_keys[SPECK64_128_NROUNDS];
+	int nrounds;
+};
+
+void crypto_speck64_encrypt(const struct speck64_tfm_ctx *ctx,
+			    u8 *out, const u8 *in);
+
+void crypto_speck64_decrypt(const struct speck64_tfm_ctx *ctx,
+			    u8 *out, const u8 *in);
+
+int crypto_speck64_setkey(struct speck64_tfm_ctx *ctx, const u8 *key,
+			  unsigned int keysize);
+
+#endif /* _CRYPTO_SPECK_H */