New file poly1305-internal.c

1 files changed, 189 insertions, 0 deletions

diff --git a/poly1305-internal.c b/poly1305-internal.c
new file mode 100644
index 00000000..72806625
--- /dev/null
+++ b/poly1305-internal.c
@@ -0,0 +1,189 @@
+/* nettle, low-level cryptographics library
+ *
+ * Placed by the author under public domain or the MIT license.
+ * (see https://github.com/floodyberry/poly1305-donna )
+ * Modified for nettle by Nikos Mavrogiannopoulos.
+ *
+ * Copyright: 2012-2013 Andrew M. (floodyberry)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <string.h>
+
+#include "poly1305.h"
+
+#include "macros.h"
+
+#define mul32x32_64(a,b) ((uint64_t)(a) * (b))
+
+void
+poly1305_set_key(struct poly1305_ctx *ctx, const uint8_t key[16])
+{
+  uint32_t t0,t1,t2,t3;
+
+  t0 = LE_READ_UINT32(key);
+  t1 = LE_READ_UINT32(key+4);
+  t2 = LE_READ_UINT32(key+8);
+  t3 = LE_READ_UINT32(key+12);
+
+  ctx->r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6;
+  ctx->r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12;
+  ctx->r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18;
+  ctx->r3 = t2 & 0x3f03fff; t3 >>= 8;
+  ctx->r4 = t3 & 0x00fffff;
+
+  ctx->s1 = ctx->r1 * 5;
+  ctx->s2 = ctx->r2 * 5;
+  ctx->s3 = ctx->r3 * 5;
+  ctx->s4 = ctx->r4 * 5;
+
+  ctx->h0 = 0;
+  ctx->h1 = 0;
+  ctx->h2 = 0;
+  ctx->h3 = 0;
+  ctx->h4 = 0;
+}
+
+
+void
+poly1305_block (struct poly1305_ctx *ctx, const uint8_t m[16])
+{
+  uint32_t t0,t1,t2,t3;
+  uint32_t b;
+  uint64_t t[5];
+  uint64_t c;
+
+  /* full blocks */
+  t0 = LE_READ_UINT32(m);
+  t1 = LE_READ_UINT32(m+4);
+  t2 = LE_READ_UINT32(m+8);
+  t3 = LE_READ_UINT32(m+12);
+
+  ctx->h0 += t0 & 0x3ffffff;
+  ctx->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
+  ctx->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
+  ctx->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
+  ctx->h4 += (t3 >> 8) | (1 << 24);
+
+  /* poly1305_donna_mul: */
+  t[0]  = mul32x32_64(ctx->h0,ctx->r0) + mul32x32_64(ctx->h1,ctx->s4) + mul32x32_64(ctx->h2,ctx->s3) + mul32x32_64(ctx->h3,ctx->s2) + mul32x32_64(ctx->h4,ctx->s1);
+  t[1]  = mul32x32_64(ctx->h0,ctx->r1) + mul32x32_64(ctx->h1,ctx->r0) + mul32x32_64(ctx->h2,ctx->s4) + mul32x32_64(ctx->h3,ctx->s3) + mul32x32_64(ctx->h4,ctx->s2);
+  t[2]  = mul32x32_64(ctx->h0,ctx->r2) + mul32x32_64(ctx->h1,ctx->r1) + mul32x32_64(ctx->h2,ctx->r0) + mul32x32_64(ctx->h3,ctx->s4) + mul32x32_64(ctx->h4,ctx->s3);
+  t[3]  = mul32x32_64(ctx->h0,ctx->r3) + mul32x32_64(ctx->h1,ctx->r2) + mul32x32_64(ctx->h2,ctx->r1) + mul32x32_64(ctx->h3,ctx->r0) + mul32x32_64(ctx->h4,ctx->s4);
+  t[4]  = mul32x32_64(ctx->h0,ctx->r4) + mul32x32_64(ctx->h1,ctx->r3) + mul32x32_64(ctx->h2,ctx->r2) + mul32x32_64(ctx->h3,ctx->r1) + mul32x32_64(ctx->h4,ctx->r0);
+
+  ctx->h0 = (uint32_t)t[0] & 0x3ffffff; c =           (t[0] >> 26);
+  t[1] += c;      ctx->h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26);
+  t[2] += b;      ctx->h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26);
+  t[3] += b;      ctx->h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26);
+  t[4] += b;      ctx->h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26);
+  ctx->h0 += b * 5;
+}
+
+void
+poly1305_digest (struct poly1305_ctx *ctx,
+ 		 size_t length, uint8_t *digest)
+{
+  uint32_t t0,t1,t2,t3;
+  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;
+  uint8_t mp[16];
+  uint8_t td[16];
+
+  /* final bytes */
+  /* poly1305_donna_atmost15bytes: */
+  if (!ctx->index) goto poly1305_donna_finish;
+
+  for (j = 0; j < ctx->index; j++) mp[j] = ctx->block[j];
+  mp[j++] = 1;
+  for (; j < 16; j++)	mp[j] = 0;
+
+  t0 = LE_READ_UINT32(mp);
+  t1 = LE_READ_UINT32(mp+4);
+  t2 = LE_READ_UINT32(mp+8);
+  t3 = LE_READ_UINT32(mp+12);
+
+  ctx->h0 += t0 & 0x3ffffff;
+  ctx->h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
+  ctx->h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
+  ctx->h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
+  ctx->h4 += (t3 >> 8);
+
+  /* poly1305_donna_mul: */
+  t[0]  = mul32x32_64(ctx->h0,ctx->r0) + mul32x32_64(ctx->h1,ctx->s4) + mul32x32_64(ctx->h2,ctx->s3) + mul32x32_64(ctx->h3,ctx->s2) + mul32x32_64(ctx->h4,ctx->s1);
+  t[1]  = mul32x32_64(ctx->h0,ctx->r1) + mul32x32_64(ctx->h1,ctx->r0) + mul32x32_64(ctx->h2,ctx->s4) + mul32x32_64(ctx->h3,ctx->s3) + mul32x32_64(ctx->h4,ctx->s2);
+  t[2]  = mul32x32_64(ctx->h0,ctx->r2) + mul32x32_64(ctx->h1,ctx->r1) + mul32x32_64(ctx->h2,ctx->r0) + mul32x32_64(ctx->h3,ctx->s4) + mul32x32_64(ctx->h4,ctx->s3);
+  t[3]  = mul32x32_64(ctx->h0,ctx->r3) + mul32x32_64(ctx->h1,ctx->r2) + mul32x32_64(ctx->h2,ctx->r1) + mul32x32_64(ctx->h3,ctx->r0) + mul32x32_64(ctx->h4,ctx->s4);
+  t[4]  = mul32x32_64(ctx->h0,ctx->r4) + mul32x32_64(ctx->h1,ctx->r3) + mul32x32_64(ctx->h2,ctx->r2) + mul32x32_64(ctx->h3,ctx->r1) + mul32x32_64(ctx->h4,ctx->r0);
+
+  ctx->h0 = (uint32_t)t[0] & 0x3ffffff; c =           (t[0] >> 26);
+  t[1] += c;      ctx->h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26);
+  t[2] += b;      ctx->h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26);
+  t[3] += b;      ctx->h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26);
+  t[4] += b;      ctx->h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26);
+  ctx->h0 += b * 5;
+
+ poly1305_donna_finish:
+  b = ctx->h0 >> 26; ctx->h0 = ctx->h0 & 0x3ffffff;
+  ctx->h1 +=     b; b = ctx->h1 >> 26; ctx->h1 = ctx->h1 & 0x3ffffff;
+  ctx->h2 +=     b; b = ctx->h2 >> 26; ctx->h2 = ctx->h2 & 0x3ffffff;
+  ctx->h3 +=     b; b = ctx->h3 >> 26; ctx->h3 = ctx->h3 & 0x3ffffff;
+  ctx->h4 +=     b; b = ctx->h4 >> 26; ctx->h4 = ctx->h4 & 0x3ffffff;
+  ctx->h0 += b * 5; b = ctx->h0 >> 26; ctx->h0 = ctx->h0 & 0x3ffffff;
+  ctx->h1 +=     b;
+
+  g0 = ctx->h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff;
+  g1 = ctx->h1 + b; b = g1 >> 26; g1 &= 0x3ffffff;
+  g2 = ctx->h2 + b; b = g2 >> 26; g2 &= 0x3ffffff;
+  g3 = ctx->h3 + b; b = g3 >> 26; g3 &= 0x3ffffff;
+  g4 = ctx->h4 + b - (1 << 26);
+
+  b = (g4 >> 31) - 1;
+  nb = ~b;
+  ctx->h0 = (ctx->h0 & nb) | (g0 & b);
+  ctx->h1 = (ctx->h1 & nb) | (g1 & b);
+  ctx->h2 = (ctx->h2 & nb) | (g2 & b);
+  ctx->h3 = (ctx->h3 & nb) | (g3 & b);
+  ctx->h4 = (ctx->h4 & nb) | (g4 & b);
+
+  f0 = ((ctx->h0      ) | (ctx->h1 << 26)) + (uint64_t)LE_READ_UINT32(ctx->s);
+  f1 = ((ctx->h1 >>  6) | (ctx->h2 << 20)) + (uint64_t)LE_READ_UINT32(ctx->s+4);
+  f2 = ((ctx->h2 >> 12) | (ctx->h3 << 14)) + (uint64_t)LE_READ_UINT32(ctx->s+8);
+  f3 = ((ctx->h3 >> 18) | (ctx->h4 <<  8)) + (uint64_t)LE_READ_UINT32(ctx->s+12);
+
+  LE_WRITE_UINT32(td, f0);
+  f1 += (f0 >> 32);
+  LE_WRITE_UINT32(&td[4], f1);
+  f2 += (f1 >> 32);
+  LE_WRITE_UINT32(&td[8], f2);
+  f3 += (f2 >> 32);
+  LE_WRITE_UINT32(&td[12], f3);
+
+  memcpy(digest, td, length);
+}