diff options
Diffstat (limited to 'lib/crypto/poly1305-donna64.c')
| -rw-r--r-- | lib/crypto/poly1305-donna64.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/lib/crypto/poly1305-donna64.c b/lib/crypto/poly1305-donna64.c new file mode 100644 index 000000000..d34cf4053 --- /dev/null +++ b/lib/crypto/poly1305-donna64.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. + * + * This is based in part on Andrew Moon's poly1305-donna, which is in the + * public domain. + */ + +#include <linux/kernel.h> +#include <asm/unaligned.h> +#include <crypto/internal/poly1305.h> + +typedef __uint128_t u128; + +void poly1305_core_setkey(struct poly1305_core_key *key, + const u8 raw_key[POLY1305_BLOCK_SIZE]) +{ + u64 t0, t1; + + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + t0 = get_unaligned_le64(&raw_key[0]); + t1 = get_unaligned_le64(&raw_key[8]); + + key->key.r64[0] = t0 & 0xffc0fffffffULL; + key->key.r64[1] = ((t0 >> 44) | (t1 << 20)) & 0xfffffc0ffffULL; + key->key.r64[2] = ((t1 >> 24)) & 0x00ffffffc0fULL; + + /* s = 20*r */ + key->precomputed_s.r64[0] = key->key.r64[1] * 20; + key->precomputed_s.r64[1] = key->key.r64[2] * 20; +} +EXPORT_SYMBOL(poly1305_core_setkey); + +void poly1305_core_blocks(struct poly1305_state *state, + const struct poly1305_core_key *key, const void *src, + unsigned int nblocks, u32 hibit) +{ + const u8 *input = src; + u64 hibit64; + u64 r0, r1, r2; + u64 s1, s2; + u64 h0, h1, h2; + u64 c; + u128 d0, d1, d2, d; + + if (!nblocks) + return; + + hibit64 = ((u64)hibit) << 40; + + r0 = key->key.r64[0]; + r1 = key->key.r64[1]; + r2 = key->key.r64[2]; + + h0 = state->h64[0]; + h1 = state->h64[1]; + h2 = state->h64[2]; + + s1 = key->precomputed_s.r64[0]; + s2 = key->precomputed_s.r64[1]; + + do { + u64 t0, t1; + + /* h += m[i] */ + t0 = get_unaligned_le64(&input[0]); + t1 = get_unaligned_le64(&input[8]); + + h0 += t0 & 0xfffffffffffULL; + h1 += ((t0 >> 44) | (t1 << 20)) & 0xfffffffffffULL; + h2 += (((t1 >> 24)) & 0x3ffffffffffULL) | hibit64; + + /* h *= r */ + d0 = (u128)h0 * r0; + d = (u128)h1 * s2; + d0 += d; + d = (u128)h2 * s1; + d0 += d; + d1 = (u128)h0 * r1; + d = (u128)h1 * r0; + d1 += d; + d = (u128)h2 * s2; + d1 += d; + d2 = (u128)h0 * r2; + d = (u128)h1 * r1; + d2 += d; + d = (u128)h2 * r0; + d2 += d; + + /* (partial) h %= p */ + c = (u64)(d0 >> 44); + h0 = (u64)d0 & 0xfffffffffffULL; + d1 += c; + c = (u64)(d1 >> 44); + h1 = (u64)d1 & 0xfffffffffffULL; + d2 += c; + c = (u64)(d2 >> 42); + h2 = (u64)d2 & 0x3ffffffffffULL; + h0 += c * 5; + c = h0 >> 44; + h0 = h0 & 0xfffffffffffULL; + h1 += c; + + input += POLY1305_BLOCK_SIZE; + } while (--nblocks); + + state->h64[0] = h0; + state->h64[1] = h1; + state->h64[2] = h2; +} +EXPORT_SYMBOL(poly1305_core_blocks); + +void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4], + void *dst) +{ + u8 *mac = dst; + u64 h0, h1, h2, c; + u64 g0, g1, g2; + u64 t0, t1; + + /* fully carry h */ + h0 = state->h64[0]; + h1 = state->h64[1]; + h2 = state->h64[2]; + + c = h1 >> 44; + h1 &= 0xfffffffffffULL; + h2 += c; + c = h2 >> 42; + h2 &= 0x3ffffffffffULL; + h0 += c * 5; + c = h0 >> 44; + h0 &= 0xfffffffffffULL; + h1 += c; + c = h1 >> 44; + h1 &= 0xfffffffffffULL; + h2 += c; + c = h2 >> 42; + h2 &= 0x3ffffffffffULL; + h0 += c * 5; + c = h0 >> 44; + h0 &= 0xfffffffffffULL; + h1 += c; + + /* compute h + -p */ + g0 = h0 + 5; + c = g0 >> 44; + g0 &= 0xfffffffffffULL; + g1 = h1 + c; + c = g1 >> 44; + g1 &= 0xfffffffffffULL; + g2 = h2 + c - (1ULL << 42); + + /* select h if h < p, or h + -p if h >= p */ + c = (g2 >> ((sizeof(u64) * 8) - 1)) - 1; + g0 &= c; + g1 &= c; + g2 &= c; + c = ~c; + h0 = (h0 & c) | g0; + h1 = (h1 & c) | g1; + h2 = (h2 & c) | g2; + + if (likely(nonce)) { + /* h = (h + nonce) */ + t0 = ((u64)nonce[1] << 32) | nonce[0]; + t1 = ((u64)nonce[3] << 32) | nonce[2]; + + h0 += t0 & 0xfffffffffffULL; + c = h0 >> 44; + h0 &= 0xfffffffffffULL; + h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffffULL) + c; + c = h1 >> 44; + h1 &= 0xfffffffffffULL; + h2 += (((t1 >> 24)) & 0x3ffffffffffULL) + c; + h2 &= 0x3ffffffffffULL; + } + + /* mac = h % (2^128) */ + h0 = h0 | (h1 << 44); + h1 = (h1 >> 20) | (h2 << 24); + + put_unaligned_le64(h0, &mac[0]); + put_unaligned_le64(h1, &mac[8]); +} +EXPORT_SYMBOL(poly1305_core_emit); |