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 these pieces does not pull in the crypto
API parts of the generic Poly1305 routine.
In a subsequent patch, we will augment this generic library with
init/update/final routines so that the Poly1305 algorithm can be used
directly without the need for using the crypto API's shash abstraction.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/x86/crypto/poly1305_glue.c | 2 +-
crypto/Kconfig | 8 +-
crypto/adiantum.c | 5 +-
crypto/nhpoly1305.c | 3 +-
crypto/poly1305_generic.c | 195 +-------------------
include/crypto/internal/poly1305.h | 67 +++++++
include/crypto/poly1305.h | 23 ---
lib/crypto/Makefile | 3 +
lib/crypto/poly1305.c | 158 ++++++++++++++++
9 files changed, 248 insertions(+), 216 deletions(-)
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
index 4a1c05dce950..6ccf8eb26324 100644
--- a/arch/x86/crypto/poly1305_glue.c
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -7,8 +7,8 @@
#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
+#include <crypto/internal/poly1305.h>
#include <crypto/internal/simd.h>
-#include <crypto/poly1305.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
#include <linux/module.h>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 33ee76c82740..e510caf587df 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -445,7 +445,7 @@ config CRYPTO_KEYWRAP
config CRYPTO_NHPOLY1305
tristate
select CRYPTO_HASH
- select CRYPTO_POLY1305
+ select CRYPTO_LIB_POLY1305_GENERIC
config CRYPTO_NHPOLY1305_SSE2
tristate "NHPoly1305 hash function (x86_64 SSE2 implementation)"
@@ -466,7 +466,7 @@ config CRYPTO_NHPOLY1305_AVX2
config CRYPTO_ADIANTUM
tristate "Adiantum support"
select CRYPTO_CHACHA20
- select CRYPTO_POLY1305
+ select CRYPTO_LIB_POLY1305_GENERIC
select CRYPTO_NHPOLY1305
select CRYPTO_MANAGER
help
@@ -682,9 +682,13 @@ config CRYPTO_GHASH
GHASH is the hash function used in GCM (Galois/Counter Mode).
It is not a general-purpose cryptographic hash function.
+config CRYPTO_LIB_POLY1305_GENERIC
+ tristate
+
config CRYPTO_POLY1305
tristate "Poly1305 authenticator algorithm"
select CRYPTO_HASH
+ select CRYPTO_LIB_POLY1305_GENERIC
help
Poly1305 authenticator algorithm, RFC7539.
diff --git a/crypto/adiantum.c b/crypto/adiantum.c
index 395a3ddd3707..aded26092268 100644
--- a/crypto/adiantum.c
+++ b/crypto/adiantum.c
@@ -33,6 +33,7 @@
#include <crypto/b128ops.h>
#include <crypto/chacha.h>
#include <crypto/internal/hash.h>
+#include <crypto/internal/poly1305.h>
#include <crypto/internal/skcipher.h>
#include <crypto/nhpoly1305.h>
#include <crypto/scatterwalk.h>
@@ -242,11 +243,11 @@ static void adiantum_hash_header(struct skcipher_request *req)
BUILD_BUG_ON(sizeof(header) % POLY1305_BLOCK_SIZE != 0);
poly1305_core_blocks(&state, &tctx->header_hash_key,
- &header, sizeof(header) / POLY1305_BLOCK_SIZE);
+ &header, sizeof(header) / POLY1305_BLOCK_SIZE, 1);
BUILD_BUG_ON(TWEAK_SIZE % POLY1305_BLOCK_SIZE != 0);
poly1305_core_blocks(&state, &tctx->header_hash_key, req->iv,
- TWEAK_SIZE / POLY1305_BLOCK_SIZE);
+ TWEAK_SIZE / POLY1305_BLOCK_SIZE, 1);
poly1305_core_emit(&state, &rctx->header_hash);
}
diff --git a/crypto/nhpoly1305.c b/crypto/nhpoly1305.c
index 9ab4e07cde4d..f6b6a52092b4 100644
--- a/crypto/nhpoly1305.c
+++ b/crypto/nhpoly1305.c
@@ -33,6 +33,7 @@
#include <asm/unaligned.h>
#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
+#include <crypto/internal/poly1305.h>
#include <crypto/nhpoly1305.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
@@ -78,7 +79,7 @@ static void process_nh_hash_value(struct nhpoly1305_state *state,
BUILD_BUG_ON(NH_HASH_BYTES % POLY1305_BLOCK_SIZE != 0);
poly1305_core_blocks(&state->poly_state, &key->poly_key, state->nh_hash,
- NH_HASH_BYTES / POLY1305_BLOCK_SIZE);
+ NH_HASH_BYTES / POLY1305_BLOCK_SIZE, 1);
}
/*
diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c
index adc40298c749..067f493c2504 100644
--- a/crypto/poly1305_generic.c
+++ b/crypto/poly1305_generic.c
@@ -13,27 +13,12 @@
#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
-#include <crypto/poly1305.h>
+#include <crypto/internal/poly1305.h>
#include <linux/crypto.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/unaligned.h>
-static inline u64 mlt(u64 a, u64 b)
-{
- return a * b;
-}
-
-static inline u32 sr(u64 v, u_char n)
-{
- return v >> n;
-}
-
-static inline u32 and(u32 v, u32 mask)
-{
- return v & mask;
-}
-
int crypto_poly1305_init(struct shash_desc *desc)
{
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
@@ -47,124 +32,8 @@ int crypto_poly1305_init(struct shash_desc *desc)
}
EXPORT_SYMBOL_GPL(crypto_poly1305_init);
-void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key)
-{
- /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
- key->r[0] = (get_unaligned_le32(raw_key + 0) >> 0) & 0x3ffffff;
- key->r[1] = (get_unaligned_le32(raw_key + 3) >> 2) & 0x3ffff03;
- key->r[2] = (get_unaligned_le32(raw_key + 6) >> 4) & 0x3ffc0ff;
- key->r[3] = (get_unaligned_le32(raw_key + 9) >> 6) & 0x3f03fff;
- key->r[4] = (get_unaligned_le32(raw_key + 12) >> 8) & 0x00fffff;
-}
-EXPORT_SYMBOL_GPL(poly1305_core_setkey);
-
-/*
- * 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.
- */
-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;
-}
-EXPORT_SYMBOL_GPL(crypto_poly1305_setdesckey);
-
-static void poly1305_blocks_internal(struct poly1305_state *state,
- const struct poly1305_key *key,
- const void *src, unsigned int nblocks,
- u32 hibit)
-{
- u32 r0, r1, r2, r3, r4;
- u32 s1, s2, s3, s4;
- u32 h0, h1, h2, h3, h4;
- u64 d0, d1, d2, d3, d4;
-
- if (!nblocks)
- return;
-
- r0 = key->r[0];
- r1 = key->r[1];
- r2 = key->r[2];
- r3 = key->r[3];
- r4 = key->r[4];
-
- s1 = r1 * 5;
- s2 = r2 * 5;
- s3 = r3 * 5;
- s4 = r4 * 5;
-
- h0 = state->h[0];
- h1 = state->h[1];
- h2 = state->h[2];
- h3 = state->h[3];
- h4 = state->h[4];
-
- do {
- /* h += m[i] */
- h0 += (get_unaligned_le32(src + 0) >> 0) & 0x3ffffff;
- h1 += (get_unaligned_le32(src + 3) >> 2) & 0x3ffffff;
- h2 += (get_unaligned_le32(src + 6) >> 4) & 0x3ffffff;
- h3 += (get_unaligned_le32(src + 9) >> 6) & 0x3ffffff;
- h4 += (get_unaligned_le32(src + 12) >> 8) | hibit;
-
- /* h *= r */
- d0 = mlt(h0, r0) + mlt(h1, s4) + mlt(h2, s3) +
- mlt(h3, s2) + mlt(h4, s1);
- d1 = mlt(h0, r1) + mlt(h1, r0) + mlt(h2, s4) +
- mlt(h3, s3) + mlt(h4, s2);
- d2 = mlt(h0, r2) + mlt(h1, r1) + mlt(h2, r0) +
- mlt(h3, s4) + mlt(h4, s3);
- d3 = mlt(h0, r3) + mlt(h1, r2) + mlt(h2, r1) +
- mlt(h3, r0) + mlt(h4, s4);
- d4 = mlt(h0, r4) + mlt(h1, r3) + mlt(h2, r2) +
- mlt(h3, r1) + mlt(h4, r0);
-
- /* (partial) h %= p */
- d1 += sr(d0, 26); h0 = and(d0, 0x3ffffff);
- d2 += sr(d1, 26); h1 = and(d1, 0x3ffffff);
- d3 += sr(d2, 26); h2 = and(d2, 0x3ffffff);
- d4 += sr(d3, 26); h3 = and(d3, 0x3ffffff);
- h0 += sr(d4, 26) * 5; h4 = and(d4, 0x3ffffff);
- h1 += h0 >> 26; h0 = h0 & 0x3ffffff;
-
- src += POLY1305_BLOCK_SIZE;
- } while (--nblocks);
-
- state->h[0] = h0;
- state->h[1] = h1;
- state->h[2] = h2;
- state->h[3] = h3;
- state->h[4] = h4;
-}
-
-void poly1305_core_blocks(struct poly1305_state *state,
- const struct poly1305_key *key,
- const void *src, unsigned int nblocks)
-{
- poly1305_blocks_internal(state, key, src, nblocks, 1 << 24);
-}
-EXPORT_SYMBOL_GPL(poly1305_core_blocks);
-
-static void poly1305_blocks(struct poly1305_desc_ctx *dctx,
- const u8 *src, unsigned int srclen, u32 hibit)
+static void poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
+ unsigned int srclen)
{
unsigned int datalen;
@@ -174,8 +43,8 @@ static void poly1305_blocks(struct poly1305_desc_ctx *dctx,
srclen = datalen;
}
- poly1305_blocks_internal(&dctx->h, &dctx->r,
- src, srclen / POLY1305_BLOCK_SIZE, hibit);
+ poly1305_core_blocks(&dctx->h, &dctx->r, src,
+ srclen / POLY1305_BLOCK_SIZE, 1);
}
int crypto_poly1305_update(struct shash_desc *desc,
@@ -193,13 +62,13 @@ int crypto_poly1305_update(struct shash_desc *desc,
if (dctx->buflen == POLY1305_BLOCK_SIZE) {
poly1305_blocks(dctx, dctx->buf,
- POLY1305_BLOCK_SIZE, 1 << 24);
+ POLY1305_BLOCK_SIZE);
dctx->buflen = 0;
}
}
if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
- poly1305_blocks(dctx, src, srclen, 1 << 24);
+ poly1305_blocks(dctx, src, srclen);
src += srclen - (srclen % POLY1305_BLOCK_SIZE);
srclen %= POLY1305_BLOCK_SIZE;
}
@@ -213,54 +82,6 @@ int crypto_poly1305_update(struct shash_desc *desc,
}
EXPORT_SYMBOL_GPL(crypto_poly1305_update);
-void poly1305_core_emit(const struct poly1305_state *state, void *dst)
-{
- u32 h0, h1, h2, h3, h4;
- u32 g0, g1, g2, g3, g4;
- u32 mask;
-
- /* fully carry h */
- h0 = state->h[0];
- h1 = state->h[1];
- h2 = state->h[2];
- h3 = state->h[3];
- h4 = state->h[4];
-
- h2 += (h1 >> 26); h1 = h1 & 0x3ffffff;
- h3 += (h2 >> 26); h2 = h2 & 0x3ffffff;
- h4 += (h3 >> 26); h3 = h3 & 0x3ffffff;
- h0 += (h4 >> 26) * 5; h4 = h4 & 0x3ffffff;
- h1 += (h0 >> 26); h0 = h0 & 0x3ffffff;
-
- /* compute h + -p */
- g0 = h0 + 5;
- g1 = h1 + (g0 >> 26); g0 &= 0x3ffffff;
- g2 = h2 + (g1 >> 26); g1 &= 0x3ffffff;
- g3 = h3 + (g2 >> 26); g2 &= 0x3ffffff;
- g4 = h4 + (g3 >> 26) - (1 << 26); g3 &= 0x3ffffff;
-
- /* select h if h < p, or h + -p if h >= p */
- mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1;
- g0 &= mask;
- g1 &= mask;
- g2 &= mask;
- g3 &= mask;
- g4 &= mask;
- mask = ~mask;
- h0 = (h0 & mask) | g0;
- h1 = (h1 & mask) | g1;
- h2 = (h2 & mask) | g2;
- h3 = (h3 & mask) | g3;
- h4 = (h4 & mask) | g4;
-
- /* h = h % (2^128) */
- put_unaligned_le32((h0 >> 0) | (h1 << 26), dst + 0);
- put_unaligned_le32((h1 >> 6) | (h2 << 20), dst + 4);
- put_unaligned_le32((h2 >> 12) | (h3 << 14), dst + 8);
- put_unaligned_le32((h3 >> 18) | (h4 << 8), dst + 12);
-}
-EXPORT_SYMBOL_GPL(poly1305_core_emit);
-
int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
{
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
@@ -274,7 +95,7 @@ int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
dctx->buf[dctx->buflen++] = 1;
memset(dctx->buf + dctx->buflen, 0,
POLY1305_BLOCK_SIZE - dctx->buflen);
- poly1305_blocks(dctx, dctx->buf, POLY1305_BLOCK_SIZE, 0);
+ poly1305_core_blocks(&dctx->h, &dctx->r, dctx->buf, 1, 0);
}
poly1305_core_emit(&dctx->h, digest);
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
diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile
index 0ce40604e104..b58ab6843a9d 100644
--- a/lib/crypto/Makefile
+++ b/lib/crypto/Makefile
@@ -13,5 +13,8 @@ libarc4-y := arc4.o
obj-$(CONFIG_CRYPTO_LIB_DES) += libdes.o
libdes-y := des.o
+obj-$(CONFIG_CRYPTO_LIB_POLY1305_GENERIC) += libpoly1305.o
+libpoly1305-y := poly1305.o
+
obj-$(CONFIG_CRYPTO_LIB_SHA256) += libsha256.o
libsha256-y := sha256.o
diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c
new file mode 100644
index 000000000000..f019a57dbc1b
--- /dev/null
+++ b/lib/crypto/poly1305.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Poly1305 authenticator algorithm, RFC7539
+ *
+ * Copyright (C) 2015 Martin Willi
+ *
+ * Based on public domain code by Andrew Moon and Daniel J. Bernstein.
+ */
+
+#include <crypto/internal/poly1305.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <asm/unaligned.h>
+
+static inline u64 mlt(u64 a, u64 b)
+{
+ return a * b;
+}
+
+static inline u32 sr(u64 v, u_char n)
+{
+ return v >> n;
+}
+
+static inline u32 and(u32 v, u32 mask)
+{
+ return v & mask;
+}
+
+void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key)
+{
+ /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
+ key->r[0] = (get_unaligned_le32(raw_key + 0) >> 0) & 0x3ffffff;
+ key->r[1] = (get_unaligned_le32(raw_key + 3) >> 2) & 0x3ffff03;
+ key->r[2] = (get_unaligned_le32(raw_key + 6) >> 4) & 0x3ffc0ff;
+ key->r[3] = (get_unaligned_le32(raw_key + 9) >> 6) & 0x3f03fff;
+ key->r[4] = (get_unaligned_le32(raw_key + 12) >> 8) & 0x00fffff;
+}
+EXPORT_SYMBOL_GPL(poly1305_core_setkey);
+
+void poly1305_core_blocks(struct poly1305_state *state,
+ const struct poly1305_key *key, const void *src,
+ unsigned int nblocks, u32 hibit)
+{
+ u32 r0, r1, r2, r3, r4;
+ u32 s1, s2, s3, s4;
+ u32 h0, h1, h2, h3, h4;
+ u64 d0, d1, d2, d3, d4;
+
+ if (!nblocks)
+ return;
+
+ r0 = key->r[0];
+ r1 = key->r[1];
+ r2 = key->r[2];
+ r3 = key->r[3];
+ r4 = key->r[4];
+
+ s1 = r1 * 5;
+ s2 = r2 * 5;
+ s3 = r3 * 5;
+ s4 = r4 * 5;
+
+ h0 = state->h[0];
+ h1 = state->h[1];
+ h2 = state->h[2];
+ h3 = state->h[3];
+ h4 = state->h[4];
+
+ do {
+ /* h += m[i] */
+ h0 += (get_unaligned_le32(src + 0) >> 0) & 0x3ffffff;
+ h1 += (get_unaligned_le32(src + 3) >> 2) & 0x3ffffff;
+ h2 += (get_unaligned_le32(src + 6) >> 4) & 0x3ffffff;
+ h3 += (get_unaligned_le32(src + 9) >> 6) & 0x3ffffff;
+ h4 += (get_unaligned_le32(src + 12) >> 8) | (hibit << 24);
+
+ /* h *= r */
+ d0 = mlt(h0, r0) + mlt(h1, s4) + mlt(h2, s3) +
+ mlt(h3, s2) + mlt(h4, s1);
+ d1 = mlt(h0, r1) + mlt(h1, r0) + mlt(h2, s4) +
+ mlt(h3, s3) + mlt(h4, s2);
+ d2 = mlt(h0, r2) + mlt(h1, r1) + mlt(h2, r0) +
+ mlt(h3, s4) + mlt(h4, s3);
+ d3 = mlt(h0, r3) + mlt(h1, r2) + mlt(h2, r1) +
+ mlt(h3, r0) + mlt(h4, s4);
+ d4 = mlt(h0, r4) + mlt(h1, r3) + mlt(h2, r2) +
+ mlt(h3, r1) + mlt(h4, r0);
+
+ /* (partial) h %= p */
+ d1 += sr(d0, 26); h0 = and(d0, 0x3ffffff);
+ d2 += sr(d1, 26); h1 = and(d1, 0x3ffffff);
+ d3 += sr(d2, 26); h2 = and(d2, 0x3ffffff);
+ d4 += sr(d3, 26); h3 = and(d3, 0x3ffffff);
+ h0 += sr(d4, 26) * 5; h4 = and(d4, 0x3ffffff);
+ h1 += h0 >> 26; h0 = h0 & 0x3ffffff;
+
+ src += POLY1305_BLOCK_SIZE;
+ } while (--nblocks);
+
+ state->h[0] = h0;
+ state->h[1] = h1;
+ state->h[2] = h2;
+ state->h[3] = h3;
+ state->h[4] = h4;
+}
+EXPORT_SYMBOL_GPL(poly1305_core_blocks);
+
+void poly1305_core_emit(const struct poly1305_state *state, void *dst)
+{
+ u32 h0, h1, h2, h3, h4;
+ u32 g0, g1, g2, g3, g4;
+ u32 mask;
+
+ /* fully carry h */
+ h0 = state->h[0];
+ h1 = state->h[1];
+ h2 = state->h[2];
+ h3 = state->h[3];
+ h4 = state->h[4];
+
+ h2 += (h1 >> 26); h1 = h1 & 0x3ffffff;
+ h3 += (h2 >> 26); h2 = h2 & 0x3ffffff;
+ h4 += (h3 >> 26); h3 = h3 & 0x3ffffff;
+ h0 += (h4 >> 26) * 5; h4 = h4 & 0x3ffffff;
+ h1 += (h0 >> 26); h0 = h0 & 0x3ffffff;
+
+ /* compute h + -p */
+ g0 = h0 + 5;
+ g1 = h1 + (g0 >> 26); g0 &= 0x3ffffff;
+ g2 = h2 + (g1 >> 26); g1 &= 0x3ffffff;
+ g3 = h3 + (g2 >> 26); g2 &= 0x3ffffff;
+ g4 = h4 + (g3 >> 26) - (1 << 26); g3 &= 0x3ffffff;
+
+ /* select h if h < p, or h + -p if h >= p */
+ mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1;
+ g0 &= mask;
+ g1 &= mask;
+ g2 &= mask;
+ g3 &= mask;
+ g4 &= mask;
+ mask = ~mask;
+ h0 = (h0 & mask) | g0;
+ h1 = (h1 & mask) | g1;
+ h2 = (h2 & mask) | g2;
+ h3 = (h3 & mask) | g3;
+ h4 = (h4 & mask) | g4;
+
+ /* h = h % (2^128) */
+ put_unaligned_le32((h0 >> 0) | (h1 << 26), dst + 0);
+ put_unaligned_le32((h1 >> 6) | (h2 << 20), dst + 4);
+ put_unaligned_le32((h2 >> 12) | (h3 << 14), dst + 8);
+ put_unaligned_le32((h3 >> 18) | (h4 << 8), dst + 12);
+}
+EXPORT_SYMBOL_GPL(poly1305_core_emit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@xxxxxxxxxxxxxx>");
--
2.20.1
