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-rw-r--r--lib/crypto/poly1305.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/lib/crypto/poly1305.c b/lib/crypto/poly1305.c
new file mode 100644
index 000000000000..32ec293c65ae
--- /dev/null
+++ b/lib/crypto/poly1305.c
@@ -0,0 +1,232 @@
+// 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);
+
+void poly1305_init_generic(struct poly1305_desc_ctx *desc, const u8 *key)
+{
+ poly1305_core_setkey(desc->r, key);
+ desc->s[0] = get_unaligned_le32(key + 16);
+ desc->s[1] = get_unaligned_le32(key + 20);
+ desc->s[2] = get_unaligned_le32(key + 24);
+ desc->s[3] = get_unaligned_le32(key + 28);
+ poly1305_core_init(&desc->h);
+ desc->buflen = 0;
+ desc->sset = true;
+ desc->rset = 1;
+}
+EXPORT_SYMBOL_GPL(poly1305_init_generic);
+
+void poly1305_update_generic(struct poly1305_desc_ctx *desc, const u8 *src,
+ unsigned int nbytes)
+{
+ unsigned int bytes;
+
+ if (unlikely(desc->buflen)) {
+ bytes = min(nbytes, POLY1305_BLOCK_SIZE - desc->buflen);
+ memcpy(desc->buf + desc->buflen, src, bytes);
+ src += bytes;
+ nbytes -= bytes;
+ desc->buflen += bytes;
+
+ if (desc->buflen == POLY1305_BLOCK_SIZE) {
+ poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 1);
+ desc->buflen = 0;
+ }
+ }
+
+ if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
+ poly1305_core_blocks(&desc->h, desc->r, src,
+ nbytes / POLY1305_BLOCK_SIZE, 1);
+ src += nbytes - (nbytes % POLY1305_BLOCK_SIZE);
+ nbytes %= POLY1305_BLOCK_SIZE;
+ }
+
+ if (unlikely(nbytes)) {
+ desc->buflen = nbytes;
+ memcpy(desc->buf, src, nbytes);
+ }
+}
+EXPORT_SYMBOL_GPL(poly1305_update_generic);
+
+void poly1305_final_generic(struct poly1305_desc_ctx *desc, u8 *dst)
+{
+ __le32 digest[4];
+ u64 f = 0;
+
+ if (unlikely(desc->buflen)) {
+ desc->buf[desc->buflen++] = 1;
+ memset(desc->buf + desc->buflen, 0,
+ POLY1305_BLOCK_SIZE - desc->buflen);
+ poly1305_core_blocks(&desc->h, desc->r, desc->buf, 1, 0);
+ }
+
+ poly1305_core_emit(&desc->h, digest);
+
+ /* mac = (h + s) % (2^128) */
+ f = (f >> 32) + le32_to_cpu(digest[0]) + desc->s[0];
+ put_unaligned_le32(f, dst + 0);
+ f = (f >> 32) + le32_to_cpu(digest[1]) + desc->s[1];
+ put_unaligned_le32(f, dst + 4);
+ f = (f >> 32) + le32_to_cpu(digest[2]) + desc->s[2];
+ put_unaligned_le32(f, dst + 8);
+ f = (f >> 32) + le32_to_cpu(digest[3]) + desc->s[3];
+ put_unaligned_le32(f, dst + 12);
+
+ *desc = (struct poly1305_desc_ctx){};
+}
+EXPORT_SYMBOL_GPL(poly1305_final_generic);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 06:11:57 +0000