| Message ID | 20181117012631.23528-12-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | crypto: Adiantum support | expand |
On Fri, 16 Nov 2018 at 17:29, Eric Biggers <ebiggers@kernel.org> wrote: > > From: Eric Biggers <ebiggers@google.com> > > Expose 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. > > This is needed for Adiantum hashing, which builds an εA∆U hash function > from NH and a polynomial evaluation in GF(2^{130}-5); this polynomial > evaluation is identical to the one the Poly1305 MAC does. However, the > crypto_shash Poly1305 API isn't very appropriate for this because its > calling convention assumes it is used as a MAC, with a 32-byte "one-time > key" provided for every digest. > > But by design, in Adiantum hashing the performance of the polynomial > evaluation isn't nearly as critical as NH. So it suffices to just have > some C helper functions. Thus, this patch adds such functions. > > Acked-by: Martin Willi <martin@strongswan.org> > Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > crypto/poly1305_generic.c | 174 ++++++++++++++++++++++---------------- > include/crypto/poly1305.h | 16 ++++ > 2 files changed, 115 insertions(+), 75 deletions(-) > > diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c > index a23173f351b7..2a06874204e8 100644 > --- 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.h, 0, sizeof(dctx->h.h)); > + poly1305_core_init(&dctx->h); > dctx->buflen = 0; > dctx->rset = false; > dctx->sset = false; > @@ -47,23 +47,16 @@ int crypto_poly1305_init(struct shash_desc *desc) > } > EXPORT_SYMBOL_GPL(crypto_poly1305_init); > > -static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key) > +void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key) > { > /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ > - 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) > -{ > - dctx->s[0] = get_unaligned_le32(key + 0); > - dctx->s[1] = get_unaligned_le32(key + 4); > - dctx->s[2] = get_unaligned_le32(key + 8); > - dctx->s[3] = get_unaligned_le32(key + 12); > + 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 > @@ -75,13 +68,16 @@ unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, > { > if (!dctx->sset) { > if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) { > - poly1305_setrkey(dctx, src); > + poly1305_core_setkey(&dctx->r, src); > src += POLY1305_BLOCK_SIZE; > srclen -= POLY1305_BLOCK_SIZE; > dctx->rset = true; > } > if (srclen >= POLY1305_BLOCK_SIZE) { > - poly1305_setskey(dctx, src); > + 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; > @@ -91,41 +87,37 @@ unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, > } > EXPORT_SYMBOL_GPL(crypto_poly1305_setdesckey); > > -static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx, > - const u8 *src, unsigned int srclen, > - u32 hibit) > +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; > - unsigned int datalen; > > - if (unlikely(!dctx->sset)) { > - datalen = crypto_poly1305_setdesckey(dctx, src, srclen); > - src += srclen - datalen; > - srclen = datalen; > - } > + if (!nblocks) > + return; > > - 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]; > + 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 = 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)) { > + 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; > @@ -154,16 +146,36 @@ static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx, > h1 += h0 >> 26; h0 = h0 & 0x3ffffff; > > src += POLY1305_BLOCK_SIZE; > - srclen -= POLY1305_BLOCK_SIZE; > - } > + } while (--nblocks); > > - 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; > + state->h[0] = h0; > + state->h[1] = h1; > + state->h[2] = h2; > + state->h[3] = h3; > + state->h[4] = h4; > +} > > - return srclen; > +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) > +{ > + unsigned int datalen; > + > + if (unlikely(!dctx->sset)) { > + datalen = crypto_poly1305_setdesckey(dctx, src, srclen); > + src += srclen - datalen; > + srclen = datalen; > + } > + > + poly1305_blocks_internal(&dctx->h, &dctx->r, > + src, srclen / POLY1305_BLOCK_SIZE, hibit); > } > > int crypto_poly1305_update(struct shash_desc *desc, > @@ -187,9 +199,9 @@ int crypto_poly1305_update(struct shash_desc *desc, > } > > if (likely(srclen >= POLY1305_BLOCK_SIZE)) { > - bytes = poly1305_blocks(dctx, src, srclen, 1 << 24); > - src += srclen - bytes; > - srclen = bytes; > + poly1305_blocks(dctx, src, srclen, 1 << 24); > + src += srclen - (srclen % POLY1305_BLOCK_SIZE); > + srclen %= POLY1305_BLOCK_SIZE; > } > > if (unlikely(srclen)) { > @@ -201,30 +213,18 @@ int crypto_poly1305_update(struct shash_desc *desc, > } > EXPORT_SYMBOL_GPL(crypto_poly1305_update); > > -int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) > +void poly1305_core_emit(const struct poly1305_state *state, void *dst) > { > - struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); > u32 h0, h1, h2, h3, h4; > u32 g0, g1, g2, g3, g4; > u32 mask; > - u64 f = 0; > - > - if (unlikely(!dctx->sset)) > - return -ENOKEY; > - > - if (unlikely(dctx->buflen)) { > - 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); > - } > > /* fully carry h */ > - 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]; > + 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; > @@ -254,16 +254,40 @@ int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) > h4 = (h4 & mask) | g4; > > /* h = h % (2^128) */ > - h0 = (h0 >> 0) | (h1 << 26); > - h1 = (h1 >> 6) | (h2 << 20); > - h2 = (h2 >> 12) | (h3 << 14); > - h3 = (h3 >> 18) | (h4 << 8); > + 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); > + __le32 digest[4]; > + u64 f = 0; > + > + if (unlikely(!dctx->sset)) > + return -ENOKEY; > + > + if (unlikely(dctx->buflen)) { > + 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_emit(&dctx->h, digest); > > /* mac = (h + s) % (2^128) */ > - f = (f >> 32) + h0 + dctx->s[0]; put_unaligned_le32(f, dst + 0); > - f = (f >> 32) + h1 + dctx->s[1]; put_unaligned_le32(f, dst + 4); > - f = (f >> 32) + h2 + dctx->s[2]; put_unaligned_le32(f, dst + 8); > - f = (f >> 32) + h3 + dctx->s[3]; put_unaligned_le32(f, dst + 12); > + f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0]; > + put_unaligned_le32(f, dst + 0); > + f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1]; > + put_unaligned_le32(f, dst + 4); > + f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2]; > + put_unaligned_le32(f, dst + 8); > + f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3]; > + put_unaligned_le32(f, dst + 12); > > return 0; > } > diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h > index 493244c46664..34317ed2071e 100644 > --- a/include/crypto/poly1305.h > +++ b/include/crypto/poly1305.h > @@ -38,6 +38,22 @@ 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); > -- > 2.19.1.1215.g8438c0b245-goog >
diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c index a23173f351b7..2a06874204e8 100644 --- 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.h, 0, sizeof(dctx->h.h)); + poly1305_core_init(&dctx->h); dctx->buflen = 0; dctx->rset = false; dctx->sset = false; @@ -47,23 +47,16 @@ int crypto_poly1305_init(struct shash_desc *desc) } EXPORT_SYMBOL_GPL(crypto_poly1305_init); -static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key) +void poly1305_core_setkey(struct poly1305_key *key, const u8 *raw_key) { /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ - 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) -{ - dctx->s[0] = get_unaligned_le32(key + 0); - dctx->s[1] = get_unaligned_le32(key + 4); - dctx->s[2] = get_unaligned_le32(key + 8); - dctx->s[3] = get_unaligned_le32(key + 12); + 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 @@ -75,13 +68,16 @@ unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, { if (!dctx->sset) { if (!dctx->rset && srclen >= POLY1305_BLOCK_SIZE) { - poly1305_setrkey(dctx, src); + poly1305_core_setkey(&dctx->r, src); src += POLY1305_BLOCK_SIZE; srclen -= POLY1305_BLOCK_SIZE; dctx->rset = true; } if (srclen >= POLY1305_BLOCK_SIZE) { - poly1305_setskey(dctx, src); + 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; @@ -91,41 +87,37 @@ unsigned int crypto_poly1305_setdesckey(struct poly1305_desc_ctx *dctx, } EXPORT_SYMBOL_GPL(crypto_poly1305_setdesckey); -static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx, - const u8 *src, unsigned int srclen, - u32 hibit) +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; - unsigned int datalen; - if (unlikely(!dctx->sset)) { - datalen = crypto_poly1305_setdesckey(dctx, src, srclen); - src += srclen - datalen; - srclen = datalen; - } + if (!nblocks) + return; - 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]; + 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 = 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)) { + 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; @@ -154,16 +146,36 @@ static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx, h1 += h0 >> 26; h0 = h0 & 0x3ffffff; src += POLY1305_BLOCK_SIZE; - srclen -= POLY1305_BLOCK_SIZE; - } + } while (--nblocks); - 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; + state->h[0] = h0; + state->h[1] = h1; + state->h[2] = h2; + state->h[3] = h3; + state->h[4] = h4; +} - return srclen; +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) +{ + unsigned int datalen; + + if (unlikely(!dctx->sset)) { + datalen = crypto_poly1305_setdesckey(dctx, src, srclen); + src += srclen - datalen; + srclen = datalen; + } + + poly1305_blocks_internal(&dctx->h, &dctx->r, + src, srclen / POLY1305_BLOCK_SIZE, hibit); } int crypto_poly1305_update(struct shash_desc *desc, @@ -187,9 +199,9 @@ int crypto_poly1305_update(struct shash_desc *desc, } if (likely(srclen >= POLY1305_BLOCK_SIZE)) { - bytes = poly1305_blocks(dctx, src, srclen, 1 << 24); - src += srclen - bytes; - srclen = bytes; + poly1305_blocks(dctx, src, srclen, 1 << 24); + src += srclen - (srclen % POLY1305_BLOCK_SIZE); + srclen %= POLY1305_BLOCK_SIZE; } if (unlikely(srclen)) { @@ -201,30 +213,18 @@ int crypto_poly1305_update(struct shash_desc *desc, } EXPORT_SYMBOL_GPL(crypto_poly1305_update); -int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) +void poly1305_core_emit(const struct poly1305_state *state, void *dst) { - struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc); u32 h0, h1, h2, h3, h4; u32 g0, g1, g2, g3, g4; u32 mask; - u64 f = 0; - - if (unlikely(!dctx->sset)) - return -ENOKEY; - - if (unlikely(dctx->buflen)) { - 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); - } /* fully carry h */ - 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]; + 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; @@ -254,16 +254,40 @@ int crypto_poly1305_final(struct shash_desc *desc, u8 *dst) h4 = (h4 & mask) | g4; /* h = h % (2^128) */ - h0 = (h0 >> 0) | (h1 << 26); - h1 = (h1 >> 6) | (h2 << 20); - h2 = (h2 >> 12) | (h3 << 14); - h3 = (h3 >> 18) | (h4 << 8); + 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); + __le32 digest[4]; + u64 f = 0; + + if (unlikely(!dctx->sset)) + return -ENOKEY; + + if (unlikely(dctx->buflen)) { + 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_emit(&dctx->h, digest); /* mac = (h + s) % (2^128) */ - f = (f >> 32) + h0 + dctx->s[0]; put_unaligned_le32(f, dst + 0); - f = (f >> 32) + h1 + dctx->s[1]; put_unaligned_le32(f, dst + 4); - f = (f >> 32) + h2 + dctx->s[2]; put_unaligned_le32(f, dst + 8); - f = (f >> 32) + h3 + dctx->s[3]; put_unaligned_le32(f, dst + 12); + f = (f >> 32) + le32_to_cpu(digest[0]) + dctx->s[0]; + put_unaligned_le32(f, dst + 0); + f = (f >> 32) + le32_to_cpu(digest[1]) + dctx->s[1]; + put_unaligned_le32(f, dst + 4); + f = (f >> 32) + le32_to_cpu(digest[2]) + dctx->s[2]; + put_unaligned_le32(f, dst + 8); + f = (f >> 32) + le32_to_cpu(digest[3]) + dctx->s[3]; + put_unaligned_le32(f, dst + 12); return 0; } diff --git a/include/crypto/poly1305.h b/include/crypto/poly1305.h index 493244c46664..34317ed2071e 100644 --- a/include/crypto/poly1305.h +++ b/include/crypto/poly1305.h @@ -38,6 +38,22 @@ 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);