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-rw-r--r--lib/crypto/poly1305-donna64.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/lib/crypto/poly1305-donna64.c b/lib/crypto/poly1305-donna64.c
new file mode 100644
index 000000000000..6ae181bb4345
--- /dev/null
+++ b/lib/crypto/poly1305-donna64.c
@@ -0,0 +1,185 @@
+// 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[16])
+{
+ 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);