diff options
Diffstat (limited to 'src/libcryptobox/poly1305/poly1305-donna-32.h')
| -rw-r--r-- | src/libcryptobox/poly1305/poly1305-donna-32.h | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/src/libcryptobox/poly1305/poly1305-donna-32.h b/src/libcryptobox/poly1305/poly1305-donna-32.h new file mode 100644 index 000000000..c45aab33a --- /dev/null +++ b/src/libcryptobox/poly1305/poly1305-donna-32.h @@ -0,0 +1,219 @@ +/* + poly1305 implementation using 32 bit * 32 bit = 64 bit multiplication and 64 bit addition +*/ + +#if defined(_MSC_VER) + #define POLY1305_NOINLINE __declspec(noinline) +#elif defined(__GNUC__) + #define POLY1305_NOINLINE __attribute__((noinline)) +#else + #define POLY1305_NOINLINE +#endif + +#define poly1305_block_size 16 + +/* 17 + sizeof(size_t) + 14*sizeof(unsigned long) */ +typedef struct poly1305_state_internal_t { + unsigned long r[5]; + unsigned long h[5]; + unsigned long pad[4]; + size_t leftover; + unsigned char buffer[poly1305_block_size]; + unsigned char final; +} poly1305_state_internal_t; + +/* interpret four 8 bit unsigned integers as a 32 bit unsigned integer in little endian */ +static unsigned long +U8TO32(const unsigned char *p) { + return + (((unsigned long)(p[0] & 0xff) ) | + ((unsigned long)(p[1] & 0xff) << 8) | + ((unsigned long)(p[2] & 0xff) << 16) | + ((unsigned long)(p[3] & 0xff) << 24)); +} + +/* store a 32 bit unsigned integer as four 8 bit unsigned integers in little endian */ +static void +U32TO8(unsigned char *p, unsigned long v) { + p[0] = (v ) & 0xff; + p[1] = (v >> 8) & 0xff; + p[2] = (v >> 16) & 0xff; + p[3] = (v >> 24) & 0xff; +} + +void +poly1305_init(poly1305_context *ctx, const unsigned char key[32]) { + poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx; + + /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */ + st->r[0] = (U8TO32(&key[ 0]) ) & 0x3ffffff; + st->r[1] = (U8TO32(&key[ 3]) >> 2) & 0x3ffff03; + st->r[2] = (U8TO32(&key[ 6]) >> 4) & 0x3ffc0ff; + st->r[3] = (U8TO32(&key[ 9]) >> 6) & 0x3f03fff; + st->r[4] = (U8TO32(&key[12]) >> 8) & 0x00fffff; + + /* h = 0 */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + + /* save pad for later */ + st->pad[0] = U8TO32(&key[16]); + st->pad[1] = U8TO32(&key[20]); + st->pad[2] = U8TO32(&key[24]); + st->pad[3] = U8TO32(&key[28]); + + st->leftover = 0; + st->final = 0; +} + +static void +poly1305_blocks(poly1305_state_internal_t *st, const unsigned char *m, size_t bytes) { + const unsigned long hibit = (st->final) ? 0 : (1 << 24); /* 1 << 128 */ + unsigned long r0,r1,r2,r3,r4; + unsigned long s1,s2,s3,s4; + unsigned long h0,h1,h2,h3,h4; + unsigned long long d0,d1,d2,d3,d4; + unsigned long c; + + r0 = st->r[0]; + r1 = st->r[1]; + r2 = st->r[2]; + r3 = st->r[3]; + r4 = st->r[4]; + + s1 = r1 * 5; + s2 = r2 * 5; + s3 = r3 * 5; + s4 = r4 * 5; + + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; + + while (bytes >= poly1305_block_size) { + /* h += m[i] */ + h0 += (U8TO32(m+ 0) ) & 0x3ffffff; + h1 += (U8TO32(m+ 3) >> 2) & 0x3ffffff; + h2 += (U8TO32(m+ 6) >> 4) & 0x3ffffff; + h3 += (U8TO32(m+ 9) >> 6) & 0x3ffffff; + h4 += (U8TO32(m+12) >> 8) | hibit; + + /* h *= r */ + d0 = ((unsigned long long)h0 * r0) + ((unsigned long long)h1 * s4) + ((unsigned long long)h2 * s3) + ((unsigned long long)h3 * s2) + ((unsigned long long)h4 * s1); + d1 = ((unsigned long long)h0 * r1) + ((unsigned long long)h1 * r0) + ((unsigned long long)h2 * s4) + ((unsigned long long)h3 * s3) + ((unsigned long long)h4 * s2); + d2 = ((unsigned long long)h0 * r2) + ((unsigned long long)h1 * r1) + ((unsigned long long)h2 * r0) + ((unsigned long long)h3 * s4) + ((unsigned long long)h4 * s3); + d3 = ((unsigned long long)h0 * r3) + ((unsigned long long)h1 * r2) + ((unsigned long long)h2 * r1) + ((unsigned long long)h3 * r0) + ((unsigned long long)h4 * s4); + d4 = ((unsigned long long)h0 * r4) + ((unsigned long long)h1 * r3) + ((unsigned long long)h2 * r2) + ((unsigned long long)h3 * r1) + ((unsigned long long)h4 * r0); + + /* (partial) h %= p */ + c = (unsigned long)(d0 >> 26); h0 = (unsigned long)d0 & 0x3ffffff; + d1 += c; c = (unsigned long)(d1 >> 26); h1 = (unsigned long)d1 & 0x3ffffff; + d2 += c; c = (unsigned long)(d2 >> 26); h2 = (unsigned long)d2 & 0x3ffffff; + d3 += c; c = (unsigned long)(d3 >> 26); h3 = (unsigned long)d3 & 0x3ffffff; + d4 += c; c = (unsigned long)(d4 >> 26); h4 = (unsigned long)d4 & 0x3ffffff; + h0 += c * 5; c = (h0 >> 26); h0 = h0 & 0x3ffffff; + h1 += c; + + m += poly1305_block_size; + bytes -= poly1305_block_size; + } + + st->h[0] = h0; + st->h[1] = h1; + st->h[2] = h2; + st->h[3] = h3; + st->h[4] = h4; +} + +POLY1305_NOINLINE void +poly1305_finish(poly1305_context *ctx, unsigned char mac[16]) { + poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx; + unsigned long h0,h1,h2,h3,h4,c; + unsigned long g0,g1,g2,g3,g4; + unsigned long long f; + unsigned long mask; + + /* process the remaining block */ + if (st->leftover) { + size_t i = st->leftover; + st->buffer[i++] = 1; + for (; i < poly1305_block_size; i++) + st->buffer[i] = 0; + st->final = 1; + poly1305_blocks(st, st->buffer, poly1305_block_size); + } + + /* fully carry h */ + h0 = st->h[0]; + h1 = st->h[1]; + h2 = st->h[2]; + h3 = st->h[3]; + h4 = st->h[4]; + + c = h1 >> 26; h1 = h1 & 0x3ffffff; + h2 += c; c = h2 >> 26; h2 = h2 & 0x3ffffff; + h3 += c; c = h3 >> 26; h3 = h3 & 0x3ffffff; + h4 += c; c = h4 >> 26; h4 = h4 & 0x3ffffff; + h0 += c * 5; c = h0 >> 26; h0 = h0 & 0x3ffffff; + h1 += c; + + /* compute h + -p */ + g0 = h0 + 5; c = g0 >> 26; g0 &= 0x3ffffff; + g1 = h1 + c; c = g1 >> 26; g1 &= 0x3ffffff; + g2 = h2 + c; c = g2 >> 26; g2 &= 0x3ffffff; + g3 = h3 + c; c = g3 >> 26; g3 &= 0x3ffffff; + g4 = h4 + c - (1 << 26); + + /* select h if h < p, or h + -p if h >= p */ + mask = (g4 >> ((sizeof(unsigned long) * 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) */ + h0 = ((h0 ) | (h1 << 26)) & 0xffffffff; + h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff; + h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff; + h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff; + + /* mac = (h + pad) % (2^128) */ + f = (unsigned long long)h0 + st->pad[0] ; h0 = (unsigned long)f; + f = (unsigned long long)h1 + st->pad[1] + (f >> 32); h1 = (unsigned long)f; + f = (unsigned long long)h2 + st->pad[2] + (f >> 32); h2 = (unsigned long)f; + f = (unsigned long long)h3 + st->pad[3] + (f >> 32); h3 = (unsigned long)f; + + U32TO8(mac + 0, h0); + U32TO8(mac + 4, h1); + U32TO8(mac + 8, h2); + U32TO8(mac + 12, h3); + + /* zero out the state */ + st->h[0] = 0; + st->h[1] = 0; + st->h[2] = 0; + st->h[3] = 0; + st->h[4] = 0; + st->r[0] = 0; + st->r[1] = 0; + st->r[2] = 0; + st->r[3] = 0; + st->r[4] = 0; + st->pad[0] = 0; + st->pad[1] = 0; + st->pad[2] = 0; + st->pad[3] = 0; +} + |