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-rw-r--r--poly1305.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/poly1305.c b/poly1305.c
new file mode 100644
index 0000000..6fd1fc8
--- /dev/null
+++ b/poly1305.c
@@ -0,0 +1,160 @@
+/*
+ * Public Domain poly1305 from Andrew Moon
+ * poly1305-donna-unrolled.c from https://github.com/floodyberry/poly1305-donna
+ */
+
+/* $OpenBSD: poly1305.c,v 1.3 2013/12/19 22:57:13 djm Exp $ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#ifdef HAVE_STDINT_H
+# include <stdint.h>
+#endif
+
+#include "poly1305.h"
+
+#define mul32x32_64(a,b) ((uint64_t)(a) * (b))
+
+#define U8TO32_LE(p) \
+ (((uint32_t)((p)[0])) | \
+ ((uint32_t)((p)[1]) << 8) | \
+ ((uint32_t)((p)[2]) << 16) | \
+ ((uint32_t)((p)[3]) << 24))
+
+#define U32TO8_LE(p, v) \
+ do { \
+ (p)[0] = (uint8_t)((v)); \
+ (p)[1] = (uint8_t)((v) >> 8); \
+ (p)[2] = (uint8_t)((v) >> 16); \
+ (p)[3] = (uint8_t)((v) >> 24); \
+ } while (0)
+
+void
+poly1305_auth(unsigned char out[POLY1305_TAGLEN], const unsigned char *m, size_t inlen, const unsigned char key[POLY1305_KEYLEN]) {
+ uint32_t t0,t1,t2,t3;
+ uint32_t h0,h1,h2,h3,h4;
+ uint32_t r0,r1,r2,r3,r4;
+ uint32_t s1,s2,s3,s4;
+ uint32_t b, nb;
+ size_t j;
+ uint64_t t[5];
+ uint64_t f0,f1,f2,f3;
+ uint32_t g0,g1,g2,g3,g4;
+ uint64_t c;
+ unsigned char mp[16];
+
+ /* clamp key */
+ t0 = U8TO32_LE(key+0);
+ t1 = U8TO32_LE(key+4);
+ t2 = U8TO32_LE(key+8);
+ t3 = U8TO32_LE(key+12);
+
+ /* precompute multipliers */
+ r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6;
+ r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12;
+ r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18;
+ r3 = t2 & 0x3f03fff; t3 >>= 8;
+ r4 = t3 & 0x00fffff;
+
+ s1 = r1 * 5;
+ s2 = r2 * 5;
+ s3 = r3 * 5;
+ s4 = r4 * 5;
+
+ /* init state */
+ h0 = 0;
+ h1 = 0;
+ h2 = 0;
+ h3 = 0;
+ h4 = 0;
+
+ /* full blocks */
+ if (inlen < 16) goto poly1305_donna_atmost15bytes;
+poly1305_donna_16bytes:
+ m += 16;
+ inlen -= 16;
+
+ t0 = U8TO32_LE(m-16);
+ t1 = U8TO32_LE(m-12);
+ t2 = U8TO32_LE(m-8);
+ t3 = U8TO32_LE(m-4);
+
+ h0 += t0 & 0x3ffffff;
+ h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
+ h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
+ h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
+ h4 += (t3 >> 8) | (1 << 24);
+
+
+poly1305_donna_mul:
+ t[0] = mul32x32_64(h0,r0) + mul32x32_64(h1,s4) + mul32x32_64(h2,s3) + mul32x32_64(h3,s2) + mul32x32_64(h4,s1);
+ t[1] = mul32x32_64(h0,r1) + mul32x32_64(h1,r0) + mul32x32_64(h2,s4) + mul32x32_64(h3,s3) + mul32x32_64(h4,s2);
+ t[2] = mul32x32_64(h0,r2) + mul32x32_64(h1,r1) + mul32x32_64(h2,r0) + mul32x32_64(h3,s4) + mul32x32_64(h4,s3);
+ t[3] = mul32x32_64(h0,r3) + mul32x32_64(h1,r2) + mul32x32_64(h2,r1) + mul32x32_64(h3,r0) + mul32x32_64(h4,s4);
+ t[4] = mul32x32_64(h0,r4) + mul32x32_64(h1,r3) + mul32x32_64(h2,r2) + mul32x32_64(h3,r1) + mul32x32_64(h4,r0);
+
+ h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26);
+ t[1] += c; h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26);
+ t[2] += b; h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26);
+ t[3] += b; h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26);
+ t[4] += b; h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26);
+ h0 += b * 5;
+
+ if (inlen >= 16) goto poly1305_donna_16bytes;
+
+ /* final bytes */
+poly1305_donna_atmost15bytes:
+ if (!inlen) goto poly1305_donna_finish;
+
+ for (j = 0; j < inlen; j++) mp[j] = m[j];
+ mp[j++] = 1;
+ for (; j < 16; j++) mp[j] = 0;
+ inlen = 0;
+
+ t0 = U8TO32_LE(mp+0);
+ t1 = U8TO32_LE(mp+4);
+ t2 = U8TO32_LE(mp+8);
+ t3 = U8TO32_LE(mp+12);
+
+ h0 += t0 & 0x3ffffff;
+ h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
+ h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
+ h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
+ h4 += (t3 >> 8);
+
+ goto poly1305_donna_mul;
+
+poly1305_donna_finish:
+ b = h0 >> 26; h0 = h0 & 0x3ffffff;
+ h1 += b; b = h1 >> 26; h1 = h1 & 0x3ffffff;
+ h2 += b; b = h2 >> 26; h2 = h2 & 0x3ffffff;
+ h3 += b; b = h3 >> 26; h3 = h3 & 0x3ffffff;
+ h4 += b; b = h4 >> 26; h4 = h4 & 0x3ffffff;
+ h0 += b * 5; b = h0 >> 26; h0 = h0 & 0x3ffffff;
+ h1 += b;
+
+ g0 = h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff;
+ g1 = h1 + b; b = g1 >> 26; g1 &= 0x3ffffff;
+ g2 = h2 + b; b = g2 >> 26; g2 &= 0x3ffffff;
+ g3 = h3 + b; b = g3 >> 26; g3 &= 0x3ffffff;
+ g4 = h4 + b - (1 << 26);
+
+ b = (g4 >> 31) - 1;
+ nb = ~b;
+ h0 = (h0 & nb) | (g0 & b);
+ h1 = (h1 & nb) | (g1 & b);
+ h2 = (h2 & nb) | (g2 & b);
+ h3 = (h3 & nb) | (g3 & b);
+ h4 = (h4 & nb) | (g4 & b);
+
+ f0 = ((h0 ) | (h1 << 26)) + (uint64_t)U8TO32_LE(&key[16]);
+ f1 = ((h1 >> 6) | (h2 << 20)) + (uint64_t)U8TO32_LE(&key[20]);
+ f2 = ((h2 >> 12) | (h3 << 14)) + (uint64_t)U8TO32_LE(&key[24]);
+ f3 = ((h3 >> 18) | (h4 << 8)) + (uint64_t)U8TO32_LE(&key[28]);
+
+ U32TO8_LE(&out[ 0], f0); f1 += (f0 >> 32);
+ U32TO8_LE(&out[ 4], f1); f2 += (f1 >> 32);
+ U32TO8_LE(&out[ 8], f2); f3 += (f2 >> 32);
+ U32TO8_LE(&out[12], f3);
+}