Use the ChaCha-Poly1305 cipher for the SPTPS protocol.

[meshlink] / src / chacha-poly1305 / poly1305.c

diff --git a/src/chacha-poly1305/poly1305.c b/src/chacha-poly1305/poly1305.c
new file mode 100644 (file)
index 0000000..f1ddf2d
--- /dev/null
+++ b/src/chacha-poly1305/poly1305.c
@@ -0,0 +1,197 @@
+/* 
+ * Public Domain poly1305 from Andrew Moon
+ * poly1305-donna-unrolled.c from https://github.com/floodyberry/poly1305-donna
+ */
+
+#include "../system.h"
+
+#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);
+}