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authorArd Biesheuvel <ardb@kernel.org>2019-11-08 15:22:19 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2019-11-17 04:02:41 +0300
commit48ea8c6ebc96bc0990e12ee1c43d0832c23576bb (patch)
tree2344893a15adb14df257f4375a306353cf0dfdab /include/crypto
parent22cf705360707ced15f9fe5423938f313c7df536 (diff)
downloadlinux-48ea8c6ebc96bc0990e12ee1c43d0832c23576bb.tar.xz
crypto: poly1305 - move core routines into a separate library
Move the core Poly1305 routines shared between the generic Poly1305 shash driver and the Adiantum and NHPoly1305 drivers into a separate library so that using just this pieces does not pull in the crypto API pieces of the generic Poly1305 routine. In a subsequent patch, we will augment this generic library with init/update/final routines so that Poyl1305 algorithm can be used directly without the need for using the crypto API's shash abstraction. 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/internal/poly1305.h67
-rw-r--r--include/crypto/poly1305.h23
2 files changed, 67 insertions, 23 deletions
diff --git a/include/crypto/internal/poly1305.h b/include/crypto/internal/poly1305.h
new file mode 100644
index 000000000000..cb58e61f73a7
--- /dev/null
+++ b/include/crypto/internal/poly1305.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values for the Poly1305 algorithm
+ */
+
+#ifndef _CRYPTO_INTERNAL_POLY1305_H
+#define _CRYPTO_INTERNAL_POLY1305_H
+
+#include <asm/unaligned.h>
+#include <linux/types.h>
+#include <crypto/poly1305.h>
+
+struct shash_desc;
+
+/*
+ * Poly1305 core functions. These implement the ε-almost-∆-universal hash
+ * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce
+ * ("s key") at the end. They also only support block-aligned inputs.
+ */
+void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key);
+static inline void poly1305_core_init(struct poly1305_state *state)
+{
+ *state = (struct poly1305_state){};
+}
+
+void poly1305_core_blocks(struct poly1305_state *state,
+ const struct poly1305_key *key, const void *src,
+ unsigned int nblocks, u32 hibit);
+void poly1305_core_emit(const struct poly1305_state *state, void *dst);
+
+/* Crypto API helper functions for the Poly1305 MAC */
+int crypto_poly1305_init(struct shash_desc *desc);
+
+int crypto_poly1305_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen);
+int crypto_poly1305_final(struct shash_desc *desc, u8 *dst);
+
+/*
+ * Poly1305 requires a unique key for each tag, which implies that we can't set
+ * it on the tfm that gets accessed by multiple users simultaneously. Instead we
+ * expect the key as the first 32 bytes in the update() call.
+ */
+static inline
+unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
+ const u8 *src, unsigned int srclen)
+{
+ if (!dctx->sset) {
+ if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) {
+ poly1305_core_setkey(&dctx->r, src);
+ src += POLY1305_BLOCK_SIZE;
+ srclen -= POLY1305_BLOCK_SIZE;
+ dctx->rset = true;
+ }
+ if (srclen >= POLY1305_BLOCK_SIZE) {
+ dctx->s[0] = get_unaligned_le32(src + 0);
+ dctx->s[1] = get_unaligned_le32(src + 4);
+ dctx->s[2] = get_unaligned_le32(src + 8);
+ dctx->s[3] = get_unaligned_le32(src + 12);
+ src += POLY1305_BLOCK_SIZE;
+ srclen -= POLY1305_BLOCK_SIZE;
+ dctx->sset = true;
+ }
+ }
+ return srclen;
+}
+
+#endif
diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h
index 34317ed2071e..f5a4319c2a1f 100644
--- a/include/crypto/poly1305.h
+++ b/include/crypto/poly1305.h
@@ -38,27 +38,4 @@ struct poly1305_desc_ctx {
bool sset;
};
-/*
- * Poly1305 core functions. These implement the ε-almost-∆-universal hash
- * function underlying the Poly1305 MAC, i.e. they don't add an encrypted nonce
- * ("s key") at the end. They also only support block-aligned inputs.
- */
-void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key);
-static inline void poly1305_core_init(struct poly1305_state *state)
-{
- memset(state->h, 0, sizeof(state->h));
-}
-void poly1305_core_blocks(struct poly1305_state *state,
- const struct poly1305_key *key,
- const void *src, unsigned int nblocks);
-void poly1305_core_emit(const struct poly1305_state *state, void *dst);
-
-/* Crypto API helper functions for the Poly1305 MAC */
-int crypto_poly1305_init(struct shash_desc *desc);
-unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx,
- const u8 *src, unsigned int srclen);
-int crypto_poly1305_update(struct shash_desc *desc,
- const u8 *src, unsigned int srclen);
-int crypto_poly1305_final(struct shash_desc *desc, u8 *dst);
-
#endif