crypto: poly1305 - use structures for key and accumulator

In preparation for exposing a low-level Poly1305 API which implements
the ε-almost-∆-universal (εA∆U) hash function underlying the Poly1305
MAC and supports block-aligned inputs only, create structures
poly1305_key and poly1305_state which hold the limbs of the Poly1305
"r" key and accumulator, respectively.

These structures could actually have the same type (e.g. poly1305_val),
but different types are preferable, to prevent misuse.

Acked-by: Martin Willi <martin@strongswan.org>
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>

diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
index f012b7e..88cc015 100644 (file)
--- a/arch/x86/crypto/poly1305_glue.c
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -83,35 +83,37 @@ static unsigned int poly1305_simd_blocks(struct poly1305_desc_ctx *dctx,
        if (poly1305_use_avx2 && srclen >= POLY1305_BLOCK_SIZE * 4) {
                if (unlikely(!sctx->wset)) {
                        if (!sctx->uset) {
-                               memcpy(sctx->u, dctx->r, sizeof(sctx->u));
-                               poly1305_simd_mult(sctx->u, dctx->r);
+                               memcpy(sctx->u, dctx->r.r, sizeof(sctx->u));
+                               poly1305_simd_mult(sctx->u, dctx->r.r);
                                sctx->uset = true;
                        }
                        memcpy(sctx->u + 5, sctx->u, sizeof(sctx->u));
-                       poly1305_simd_mult(sctx->u + 5, dctx->r);
+                       poly1305_simd_mult(sctx->u + 5, dctx->r.r);
                        memcpy(sctx->u + 10, sctx->u + 5, sizeof(sctx->u));
-                       poly1305_simd_mult(sctx->u + 10, dctx->r);
+                       poly1305_simd_mult(sctx->u + 10, dctx->r.r);
                        sctx->wset = true;
                }
                blocks = srclen / (POLY1305_BLOCK_SIZE * 4);
-               poly1305_4block_avx2(dctx->h, src, dctx->r, blocks, sctx->u);
+               poly1305_4block_avx2(dctx->h.h, src, dctx->r.r, blocks,
+                                    sctx->u);
                src += POLY1305_BLOCK_SIZE * 4 * blocks;
                srclen -= POLY1305_BLOCK_SIZE * 4 * blocks;
        }
 #endif
        if (likely(srclen >= POLY1305_BLOCK_SIZE * 2)) {
                if (unlikely(!sctx->uset)) {
-                       memcpy(sctx->u, dctx->r, sizeof(sctx->u));
-                       poly1305_simd_mult(sctx->u, dctx->r);
+                       memcpy(sctx->u, dctx->r.r, sizeof(sctx->u));
+                       poly1305_simd_mult(sctx->u, dctx->r.r);
                        sctx->uset = true;
                }
                blocks = srclen / (POLY1305_BLOCK_SIZE * 2);
-               poly1305_2block_sse2(dctx->h, src, dctx->r, blocks, sctx->u);
+               poly1305_2block_sse2(dctx->h.h, src, dctx->r.r, blocks,
+                                    sctx->u);
                src += POLY1305_BLOCK_SIZE * 2 * blocks;
                srclen -= POLY1305_BLOCK_SIZE * 2 * blocks;
        }
        if (srclen >= POLY1305_BLOCK_SIZE) {
-               poly1305_block_sse2(dctx->h, src, dctx->r, 1);
+               poly1305_block_sse2(dctx->h.h, src, dctx->r.r, 1);
                srclen -= POLY1305_BLOCK_SIZE;
        }
        return srclen;

diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c
index 47d3a6b..a23173f 100644 (file)
--- a/crypto/poly1305_generic.c
+++ b/crypto/poly1305_generic.c
@@ -38,7 +38,7 @@ int crypto_poly1305_init(struct shash_desc *desc)
 {
        struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 
-       memset(dctx->h, 0, sizeof(dctx->h));
+       memset(dctx->h.h, 0, sizeof(dctx->h.h));
        dctx->buflen = 0;
        dctx->rset = false;
        dctx->sset = false;
@@ -50,11 +50,11 @@ EXPORT_SYMBOL_GPL(crypto_poly1305_init);
 static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key)
 {
        /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
-       dctx->r[0] = (get_unaligned_le32(key +  0) >> 0) & 0x3ffffff;
-       dctx->r[1] = (get_unaligned_le32(key +  3) >> 2) & 0x3ffff03;
-       dctx->r[2] = (get_unaligned_le32(key +  6) >> 4) & 0x3ffc0ff;
-       dctx->r[3] = (get_unaligned_le32(key +  9) >> 6) & 0x3f03fff;
-       dctx->r[4] = (get_unaligned_le32(key + 12) >> 8) & 0x00fffff;
+       dctx->r.r[0] = (get_unaligned_le32(key +  0) >> 0) & 0x3ffffff;
+       dctx->r.r[1] = (get_unaligned_le32(key +  3) >> 2) & 0x3ffff03;
+       dctx->r.r[2] = (get_unaligned_le32(key +  6) >> 4) & 0x3ffc0ff;
+       dctx->r.r[3] = (get_unaligned_le32(key +  9) >> 6) & 0x3f03fff;
+       dctx->r.r[4] = (get_unaligned_le32(key + 12) >> 8) & 0x00fffff;
 }
 
 static void poly1305_setskey(struct poly1305_desc_ctx *dctx, const u8 *key)
@@ -107,22 +107,22 @@ static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx,
                srclen = datalen;
        }
 
-       r0 = dctx->r[0];
-       r1 = dctx->r[1];
-       r2 = dctx->r[2];
-       r3 = dctx->r[3];
-       r4 = dctx->r[4];
+       r0 = dctx->r.r[0];
+       r1 = dctx->r.r[1];
+       r2 = dctx->r.r[2];
+       r3 = dctx->r.r[3];
+       r4 = dctx->r.r[4];
 
        s1 = r1 * 5;
        s2 = r2 * 5;
        s3 = r3 * 5;
        s4 = r4 * 5;
 
-       h0 = dctx->h[0];
-       h1 = dctx->h[1];
-       h2 = dctx->h[2];
-       h3 = dctx->h[3];
-       h4 = dctx->h[4];
+       h0 = dctx->h.h[0];
+       h1 = dctx->h.h[1];
+       h2 = dctx->h.h[2];
+       h3 = dctx->h.h[3];
+       h4 = dctx->h.h[4];
 
        while (likely(srclen >= POLY1305_BLOCK_SIZE)) {
 
@@ -157,11 +157,11 @@ static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx,
                srclen -= POLY1305_BLOCK_SIZE;
        }
 
-       dctx->h[0] = h0;
-       dctx->h[1] = h1;
-       dctx->h[2] = h2;
-       dctx->h[3] = h3;
-       dctx->h[4] = h4;
+       dctx->h.h[0] = h0;
+       dctx->h.h[1] = h1;
+       dctx->h.h[2] = h2;
+       dctx->h.h[3] = h3;
+       dctx->h.h[4] = h4;
 
        return srclen;
 }
@@ -220,11 +220,11 @@ int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
        }
 
        /* fully carry h */
-       h0 = dctx->h[0];
-       h1 = dctx->h[1];
-       h2 = dctx->h[2];
-       h3 = dctx->h[3];
-       h4 = dctx->h[4];
+       h0 = dctx->h.h[0];
+       h1 = dctx->h.h[1];
+       h2 = dctx->h.h[2];
+       h3 = dctx->h.h[3];
+       h4 = dctx->h.h[4];
 
        h2 += (h1 >> 26);     h1 = h1 & 0x3ffffff;
        h3 += (h2 >> 26);     h2 = h2 & 0x3ffffff;

diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h
index f718a19..493244c 100644 (file)
--- a/include/crypto/poly1305.h
+++ b/include/crypto/poly1305.h
@@ -13,13 +13,21 @@
 #define POLY1305_KEY_SIZE      32
 #define POLY1305_DIGEST_SIZE   16
 
+struct poly1305_key {
+       u32 r[5];       /* key, base 2^26 */
+};
+
+struct poly1305_state {
+       u32 h[5];       /* accumulator, base 2^26 */
+};
+
 struct poly1305_desc_ctx {
        /* key */
-       u32 r[5];
+       struct poly1305_key r;
        /* finalize key */
        u32 s[4];
        /* accumulator */
-       u32 h[5];
+       struct poly1305_state h;
        /* partial buffer */
        u8 buf[POLY1305_BLOCK_SIZE];
        /* bytes used in partial buffer */