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authorArd Biesheuvel <ardb@kernel.org>2019-11-08 13:22:08 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2019-11-17 09:02:39 +0800
commit5fb8ef25803ef33e2eb60b626435828b937bed75 (patch)
tree156401ad072c1acc18f74cbdf8eb31859191b9ac /include/crypto
parent746b2e024c67aa605ac12d135cd7085a49cf9dc4 (diff)
crypto: chacha - move existing library code into lib/crypto
Currently, our generic ChaCha implementation consists of a permute function in lib/chacha.c that operates on the 64-byte ChaCha state directly [and which is always included into the core kernel since it is used by the /dev/random driver], and the crypto API plumbing to expose it as a skcipher. In order to support in-kernel users that need the ChaCha streamcipher but have no need [or tolerance] for going through the abstractions of the crypto API, let's expose the streamcipher bits via a library API as well, in a way that permits the implementation to be superseded by an architecture specific one if provided. So move the streamcipher code into a separate module in lib/crypto, and expose the init() and crypt() routines to users of the library. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/crypto')
-rw-r--r--include/crypto/chacha.h77
-rw-r--r--include/crypto/internal/chacha.h53
2 files changed, 113 insertions, 17 deletions
diff --git a/include/crypto/chacha.h b/include/crypto/chacha.h
index d1e723c6a37d..5c662f8fecac 100644
--- a/include/crypto/chacha.h
+++ b/include/crypto/chacha.h
@@ -15,9 +15,8 @@
#ifndef _CRYPTO_CHACHA_H
#define _CRYPTO_CHACHA_H
-#include <crypto/skcipher.h>
+#include <asm/unaligned.h>
#include <linux/types.h>
-#include <linux/crypto.h>
/* 32-bit stream position, then 96-bit nonce (RFC7539 convention) */
#define CHACHA_IV_SIZE 16
@@ -29,26 +28,70 @@
/* 192-bit nonce, then 64-bit stream position */
#define XCHACHA_IV_SIZE 32
-struct chacha_ctx {
- u32 key[8];
- int nrounds;
-};
-
-void chacha_block(u32 *state, u8 *stream, int nrounds);
+void chacha_block_generic(u32 *state, u8 *stream, int nrounds);
static inline void chacha20_block(u32 *state, u8 *stream)
{
- chacha_block(state, stream, 20);
+ chacha_block_generic(state, stream, 20);
}
-void hchacha_block(const u32 *in, u32 *out, int nrounds);
-void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
+void hchacha_block_arch(const u32 *state, u32 *out, int nrounds);
+void hchacha_block_generic(const u32 *state, u32 *out, int nrounds);
+
+static inline void hchacha_block(const u32 *state, u32 *out, int nrounds)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
+ hchacha_block_arch(state, out, nrounds);
+ else
+ hchacha_block_generic(state, out, nrounds);
+}
-int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
- unsigned int keysize);
-int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
- unsigned int keysize);
+void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv);
+static inline void chacha_init_generic(u32 *state, const u32 *key, const u8 *iv)
+{
+ state[0] = 0x61707865; /* "expa" */
+ state[1] = 0x3320646e; /* "nd 3" */
+ state[2] = 0x79622d32; /* "2-by" */
+ state[3] = 0x6b206574; /* "te k" */
+ state[4] = key[0];
+ state[5] = key[1];
+ state[6] = key[2];
+ state[7] = key[3];
+ state[8] = key[4];
+ state[9] = key[5];
+ state[10] = key[6];
+ state[11] = key[7];
+ state[12] = get_unaligned_le32(iv + 0);
+ state[13] = get_unaligned_le32(iv + 4);
+ state[14] = get_unaligned_le32(iv + 8);
+ state[15] = get_unaligned_le32(iv + 12);
+}
-int crypto_chacha_crypt(struct skcipher_request *req);
-int crypto_xchacha_crypt(struct skcipher_request *req);
+static inline void chacha_init(u32 *state, const u32 *key, const u8 *iv)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
+ chacha_init_arch(state, key, iv);
+ else
+ chacha_init_generic(state, key, iv);
+}
+
+void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);
+void chacha_crypt_generic(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds);
+
+static inline void chacha_crypt(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes, int nrounds)
+{
+ if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_CHACHA))
+ chacha_crypt_arch(state, dst, src, bytes, nrounds);
+ else
+ chacha_crypt_generic(state, dst, src, bytes, nrounds);
+}
+
+static inline void chacha20_crypt(u32 *state, u8 *dst, const u8 *src,
+ unsigned int bytes)
+{
+ chacha_crypt(state, dst, src, bytes, 20);
+}
#endif /* _CRYPTO_CHACHA_H */
diff --git a/include/crypto/internal/chacha.h b/include/crypto/internal/chacha.h
new file mode 100644
index 000000000000..c0e40b245431
--- /dev/null
+++ b/include/crypto/internal/chacha.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _CRYPTO_INTERNAL_CHACHA_H
+#define _CRYPTO_INTERNAL_CHACHA_H
+
+#include <crypto/chacha.h>
+#include <crypto/internal/skcipher.h>
+#include <linux/crypto.h>
+
+struct chacha_ctx {
+ u32 key[8];
+ int nrounds;
+};
+
+void crypto_chacha_init(u32 *state, const struct chacha_ctx *ctx, const u8 *iv);
+
+static inline int chacha_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize, int nrounds)
+{
+ struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
+ int i;
+
+ if (keysize != CHACHA_KEY_SIZE)
+ return -EINVAL;
+
+ for (i = 0; i < ARRAY_SIZE(ctx->key); i++)
+ ctx->key[i] = get_unaligned_le32(key + i * sizeof(u32));
+
+ ctx->nrounds = nrounds;
+ return 0;
+}
+
+static inline int chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize)
+{
+ return chacha_setkey(tfm, key, keysize, 20);
+}
+
+static int inline chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize)
+{
+ return chacha_setkey(tfm, key, keysize, 12);
+}
+
+int crypto_chacha20_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize);
+int crypto_chacha12_setkey(struct crypto_skcipher *tfm, const u8 *key,
+ unsigned int keysize);
+
+int crypto_chacha_crypt(struct skcipher_request *req);
+int crypto_xchacha_crypt(struct skcipher_request *req);
+
+#endif /* _CRYPTO_CHACHA_H */