BACKPORT, FROMGIT: crypto: nhpoly1305 - add NHPoly1305 support
Add a generic implementation of NHPoly1305, an ε-almost-∆-universal hash
function used in the Adiantum encryption mode.
CONFIG_NHPOLY1305 is not selectable by itself since there won't be any
real reason to enable it without also enabling Adiantum support.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit 26609a21a9460145e37d90947ad957b358a05288
https://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git master)
Conflicts:
crypto/testmgr.c
crypto/testmgr.h
Bug: 112008522
Test: As series, see Ic61c13b53facfd2173065be715a7ee5f3af8760b
Change-Id: If6f00c01fab530fc2458c44ca111f84604cb85c1
Signed-off-by: Eric Biggers <ebiggers@google.com>
diff --git a/include/crypto/nhpoly1305.h b/include/crypto/nhpoly1305.h
new file mode 100644
index 0000000..53c0442
--- /dev/null
+++ b/include/crypto/nhpoly1305.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common values and helper functions for the NHPoly1305 hash function.
+ */
+
+#ifndef _NHPOLY1305_H
+#define _NHPOLY1305_H
+
+#include <crypto/hash.h>
+#include <crypto/poly1305.h>
+
+/* NH parameterization: */
+
+/* Endianness: little */
+/* Word size: 32 bits (works well on NEON, SSE2, AVX2) */
+
+/* Stride: 2 words (optimal on ARM32 NEON; works okay on other CPUs too) */
+#define NH_PAIR_STRIDE 2
+#define NH_MESSAGE_UNIT (NH_PAIR_STRIDE * 2 * sizeof(u32))
+
+/* Num passes (Toeplitz iteration count): 4, to give ε = 2^{-128} */
+#define NH_NUM_PASSES 4
+#define NH_HASH_BYTES (NH_NUM_PASSES * sizeof(u64))
+
+/* Max message size: 1024 bytes (32x compression factor) */
+#define NH_NUM_STRIDES 64
+#define NH_MESSAGE_WORDS (NH_PAIR_STRIDE * 2 * NH_NUM_STRIDES)
+#define NH_MESSAGE_BYTES (NH_MESSAGE_WORDS * sizeof(u32))
+#define NH_KEY_WORDS (NH_MESSAGE_WORDS + \
+ NH_PAIR_STRIDE * 2 * (NH_NUM_PASSES - 1))
+#define NH_KEY_BYTES (NH_KEY_WORDS * sizeof(u32))
+
+#define NHPOLY1305_KEY_SIZE (POLY1305_BLOCK_SIZE + NH_KEY_BYTES)
+
+struct nhpoly1305_key {
+ struct poly1305_key poly_key;
+ u32 nh_key[NH_KEY_WORDS];
+};
+
+struct nhpoly1305_state {
+
+ /* Running total of polynomial evaluation */
+ struct poly1305_state poly_state;
+
+ /* Partial block buffer */
+ u8 buffer[NH_MESSAGE_UNIT];
+ unsigned int buflen;
+
+ /*
+ * Number of bytes remaining until the current NH message reaches
+ * NH_MESSAGE_BYTES. When nonzero, 'nh_hash' holds the partial NH hash.
+ */
+ unsigned int nh_remaining;
+
+ __le64 nh_hash[NH_NUM_PASSES];
+};
+
+typedef void (*nh_t)(const u32 *key, const u8 *message, size_t message_len,
+ __le64 hash[NH_NUM_PASSES]);
+
+int crypto_nhpoly1305_setkey(struct crypto_shash *tfm,
+ const u8 *key, unsigned int keylen);
+
+int crypto_nhpoly1305_init(struct shash_desc *desc);
+int crypto_nhpoly1305_update(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen);
+int crypto_nhpoly1305_update_helper(struct shash_desc *desc,
+ const u8 *src, unsigned int srclen,
+ nh_t nh_fn);
+int crypto_nhpoly1305_final(struct shash_desc *desc, u8 *dst);
+int crypto_nhpoly1305_final_helper(struct shash_desc *desc, u8 *dst,
+ nh_t nh_fn);
+
+#endif /* _NHPOLY1305_H */