Cleanup, and add an even faster Poly1305 on systems that support it.

2 files changed, 273 insertions, 42 deletions

diff --git a/node/Poly1305.cpp b/node/Poly1305.cpp
index 77b32a80..0968170e 100644
--- a/node/Poly1305.cpp
+++ b/node/Poly1305.cpp
@@ -132,9 +132,236 @@ typedef struct poly1305_context {
   unsigned char opaque[136];
 } poly1305_context;
 
-/*
-  poly1305 implementation using 32 bit * 32 bit = 64 bit multiplication and 64 bit addition
-*/
+#if defined(_MSC_VER) || defined(__GNUC__)
+
+//////////////////////////////////////////////////////////////////////////////
+// 128-bit implementation for MSC and GCC
+
+#if defined(_MSC_VER)
+  #include <intrin.h>
+
+  typedef struct uint128_t {
+    unsigned long long lo;
+    unsigned long long hi;
+  } uint128_t;
+
+  #define MUL(out, x, y) out.lo = _umul128((x), (y), &out.hi)
+  #define ADD(out, in) { unsigned long long t = out.lo; out.lo += in.lo; out.hi += (out.lo < t) + in.hi; }
+  #define ADDLO(out, in) { unsigned long long t = out.lo; out.lo += in; out.hi += (out.lo < t); }
+  #define SHR(in, shift) (__shiftright128(in.lo, in.hi, (shift)))
+  #define LO(in) (in.lo)
+
+//  #define POLY1305_NOINLINE __declspec(noinline)
+#elif defined(__GNUC__)
+  #if defined(__SIZEOF_INT128__)
+    typedef unsigned __int128 uint128_t;
+  #else
+    typedef unsigned uint128_t __attribute__((mode(TI)));
+  #endif
+
+  #define MUL(out, x, y) out = ((uint128_t)x * y)
+  #define ADD(out, in) out += in
+  #define ADDLO(out, in) out += in
+  #define SHR(in, shift) (unsigned long long)(in >> (shift))
+  #define LO(in) (unsigned long long)(in)
+
+//  #define POLY1305_NOINLINE __attribute__((noinline))
+#endif
+
+#define poly1305_block_size 16
+
+/* 17 + sizeof(size_t) + 8*sizeof(unsigned long long) */
+typedef struct poly1305_state_internal_t {
+  unsigned long long r[3];
+  unsigned long long h[3];
+  unsigned long long pad[2];
+  size_t leftover;
+  unsigned char buffer[poly1305_block_size];
+  unsigned char final;
+} poly1305_state_internal_t;
+
+/* interpret eight 8 bit unsigned integers as a 64 bit unsigned integer in little endian */
+static inline unsigned long long
+U8TO64(const unsigned char *p) {
+  return
+    (((unsigned long long)(p[0] & 0xff)      ) |
+     ((unsigned long long)(p[1] & 0xff) <<  8) |
+     ((unsigned long long)(p[2] & 0xff) << 16) |
+     ((unsigned long long)(p[3] & 0xff) << 24) |
+     ((unsigned long long)(p[4] & 0xff) << 32) |
+     ((unsigned long long)(p[5] & 0xff) << 40) |
+     ((unsigned long long)(p[6] & 0xff) << 48) |
+     ((unsigned long long)(p[7] & 0xff) << 56));
+}
+
+/* store a 64 bit unsigned integer as eight 8 bit unsigned integers in little endian */
+static inline void
+U64TO8(unsigned char *p, unsigned long long v) {
+  p[0] = (v      ) & 0xff;
+  p[1] = (v >>  8) & 0xff;
+  p[2] = (v >> 16) & 0xff;
+  p[3] = (v >> 24) & 0xff;
+  p[4] = (v >> 32) & 0xff;
+  p[5] = (v >> 40) & 0xff;
+  p[6] = (v >> 48) & 0xff;
+  p[7] = (v >> 56) & 0xff;
+}
+
+static inline void
+poly1305_init(poly1305_context *ctx, const unsigned char key[32]) {
+  poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
+  unsigned long long t0,t1;
+
+  /* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
+  t0 = U8TO64(&key[0]);
+  t1 = U8TO64(&key[8]);
+
+  st->r[0] = ( t0                    ) & 0xffc0fffffff;
+  st->r[1] = ((t0 >> 44) | (t1 << 20)) & 0xfffffc0ffff;
+  st->r[2] = ((t1 >> 24)             ) & 0x00ffffffc0f;
+
+  /* h = 0 */
+  st->h[0] = 0;
+  st->h[1] = 0;
+  st->h[2] = 0;
+
+  /* save pad for later */
+  st->pad[0] = U8TO64(&key[16]);
+  st->pad[1] = U8TO64(&key[24]);
+
+  st->leftover = 0;
+  st->final = 0;
+}
+
+static inline void
+poly1305_blocks(poly1305_state_internal_t *st, const unsigned char *m, size_t bytes) {
+  const unsigned long long hibit = (st->final) ? 0 : ((unsigned long long)1 << 40); /* 1 << 128 */
+  unsigned long long r0,r1,r2;
+  unsigned long long s1,s2;
+  unsigned long long h0,h1,h2;
+  unsigned long long c;
+  uint128_t d0,d1,d2,d;
+
+  r0 = st->r[0];
+  r1 = st->r[1];
+  r2 = st->r[2];
+
+  h0 = st->h[0];
+  h1 = st->h[1];
+  h2 = st->h[2];
+
+  s1 = r1 * (5 << 2);
+  s2 = r2 * (5 << 2);
+
+  while (bytes >= poly1305_block_size) {
+    unsigned long long t0,t1;
+
+    /* h += m[i] */
+    t0 = U8TO64(&m[0]);
+    t1 = U8TO64(&m[8]);
+
+    h0 += (( t0                    ) & 0xfffffffffff);
+    h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffff);
+    h2 += (((t1 >> 24)             ) & 0x3ffffffffff) | hibit;
+
+    /* h *= r */
+    MUL(d0, h0, r0); MUL(d, h1, s2); ADD(d0, d); MUL(d, h2, s1); ADD(d0, d);
+    MUL(d1, h0, r1); MUL(d, h1, r0); ADD(d1, d); MUL(d, h2, s2); ADD(d1, d);
+    MUL(d2, h0, r2); MUL(d, h1, r1); ADD(d2, d); MUL(d, h2, r0); ADD(d2, d);
+
+    /* (partial) h %= p */
+                  c = SHR(d0, 44); h0 = LO(d0) & 0xfffffffffff;
+    ADDLO(d1, c); c = SHR(d1, 44); h1 = LO(d1) & 0xfffffffffff;
+    ADDLO(d2, c); c = SHR(d2, 42); h2 = LO(d2) & 0x3ffffffffff;
+    h0  += c * 5; c = (h0 >> 44);  h0 =    h0  & 0xfffffffffff;
+    h1  += c;
+
+    m += poly1305_block_size;
+    bytes -= poly1305_block_size;
+  }
+
+  st->h[0] = h0;
+  st->h[1] = h1;
+  st->h[2] = h2;
+}
+
+static inline void
+poly1305_finish(poly1305_context *ctx, unsigned char mac[16]) {
+  poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
+  unsigned long long h0,h1,h2,c;
+  unsigned long long g0,g1,g2;
+  unsigned long long t0,t1;
+
+  /* process the remaining block */
+  if (st->leftover) {
+    size_t i = st->leftover;
+    st->buffer[i] = 1;
+    for (i = i + 1; 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];
+
+               c = (h1 >> 44); h1 &= 0xfffffffffff;
+  h2 += c;     c = (h2 >> 42); h2 &= 0x3ffffffffff;
+  h0 += c * 5; c = (h0 >> 44); h0 &= 0xfffffffffff;
+  h1 += c;     c = (h1 >> 44); h1 &= 0xfffffffffff;
+  h2 += c;     c = (h2 >> 42); h2 &= 0x3ffffffffff;
+  h0 += c * 5; c = (h0 >> 44); h0 &= 0xfffffffffff;
+  h1 += c;
+
+  /* compute h + -p */
+  g0 = h0 + 5; c = (g0 >> 44); g0 &= 0xfffffffffff;
+  g1 = h1 + c; c = (g1 >> 44); g1 &= 0xfffffffffff;
+  g2 = h2 + c - ((unsigned long long)1 << 42);
+
+  /* select h if h < p, or h + -p if h >= p */
+  c = (g2 >> ((sizeof(unsigned long long) * 8) - 1)) - 1;
+  g0 &= c;
+  g1 &= c;
+  g2 &= c;
+  c = ~c;
+  h0 = (h0 & c) | g0;
+  h1 = (h1 & c) | g1;
+  h2 = (h2 & c) | g2;
+
+  /* h = (h + pad) */
+  t0 = st->pad[0];
+  t1 = st->pad[1];
+
+  h0 += (( t0                    ) & 0xfffffffffff)    ; c = (h0 >> 44); h0 &= 0xfffffffffff;
+  h1 += (((t0 >> 44) | (t1 << 20)) & 0xfffffffffff) + c; c = (h1 >> 44); h1 &= 0xfffffffffff;
+  h2 += (((t1 >> 24)             ) & 0x3ffffffffff) + c;                 h2 &= 0x3ffffffffff;
+
+  /* mac = h % (2^128) */
+  h0 = ((h0      ) | (h1 << 44));
+  h1 = ((h1 >> 20) | (h2 << 24));
+
+  U64TO8(&mac[0], h0);
+  U64TO8(&mac[8], h1);
+
+  /* zero out the state */
+  st->h[0] = 0;
+  st->h[1] = 0;
+  st->h[2] = 0;
+  st->r[0] = 0;
+  st->r[1] = 0;
+  st->r[2] = 0;
+  st->pad[0] = 0;
+  st->pad[1] = 0;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+#else
+
+//////////////////////////////////////////////////////////////////////////////
+// More portable 64-bit implementation
 
 #define poly1305_block_size 16
 
@@ -257,43 +484,6 @@ poly1305_blocks(poly1305_state_internal_t *st, const unsigned char *m, size_t by
 }
 
 static inline void
-poly1305_update(poly1305_context *ctx, const unsigned char *m, size_t bytes) {
-  poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
-  size_t i;
-
-  /* handle leftover */
-  if (st->leftover) {
-    size_t want = (poly1305_block_size - st->leftover);
-    if (want > bytes)
-      want = bytes;
-    for (i = 0; i < want; i++)
-      st->buffer[st->leftover + i] = m[i];
-    bytes -= want;
-    m += want;
-    st->leftover += want;
-    if (st->leftover < poly1305_block_size)
-      return;
-    poly1305_blocks(st, st->buffer, poly1305_block_size);
-    st->leftover = 0;
-  }
-
-  /* process full blocks */
-  if (bytes >= poly1305_block_size) {
-    size_t want = (bytes & ~(poly1305_block_size - 1));
-    poly1305_blocks(st, m, want);
-    m += want;
-    bytes -= want;
-  }
-
-  /* store leftover */
-  if (bytes) {
-    for (i = 0; i < bytes; i++)
-      st->buffer[st->leftover + i] = m[i];
-    st->leftover += bytes;
-  }
-}
-
-static inline 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;
@@ -380,6 +570,47 @@ poly1305_finish(poly1305_context *ctx, unsigned char mac[16]) {
   st->pad[3] = 0;
 }
 
+//////////////////////////////////////////////////////////////////////////////
+
+#endif // MSC/GCC or not
+
+static inline void
+poly1305_update(poly1305_context *ctx, const unsigned char *m, size_t bytes) {
+  poly1305_state_internal_t *st = (poly1305_state_internal_t *)ctx;
+  size_t i;
+
+  /* handle leftover */
+  if (st->leftover) {
+    size_t want = (poly1305_block_size - st->leftover);
+    if (want > bytes)
+      want = bytes;
+    for (i = 0; i < want; i++)
+      st->buffer[st->leftover + i] = m[i];
+    bytes -= want;
+    m += want;
+    st->leftover += want;
+    if (st->leftover < poly1305_block_size)
+      return;
+    poly1305_blocks(st, st->buffer, poly1305_block_size);
+    st->leftover = 0;
+  }
+
+  /* process full blocks */
+  if (bytes >= poly1305_block_size) {
+    size_t want = (bytes & ~(poly1305_block_size - 1));
+    poly1305_blocks(st, m, want);
+    m += want;
+    bytes -= want;
+  }
+
+  /* store leftover */
+  if (bytes) {
+    for (i = 0; i < bytes; i++)
+      st->buffer[st->leftover + i] = m[i];
+    st->leftover += bytes;
+  }
+}
+
 } // anonymous namespace
 
 void Poly1305::compute(void *auth,const void *data,unsigned int len,const void *key)
diff --git a/node/Utils.cpp b/node/Utils.cpp
index 658c397d..3c6dee32 100644
--- a/node/Utils.cpp
+++ b/node/Utils.cpp
@@ -191,7 +191,7 @@ void Utils::getSecureRandom(void *buf,unsigned int bytes)
 	if (devURandomFd <= 0) {
 		devURandomFd = ::open("/dev/urandom",O_RDONLY);
 		if (devURandomFd <= 0) {
-			fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to open /dev/urandom\r\n");
+			fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to open /dev/urandom\n");
 			exit(1);
 			return;
 		}
@@ -200,7 +200,7 @@ void Utils::getSecureRandom(void *buf,unsigned int bytes)
 	for(unsigned int i=0;i<bytes;++i) {
 		if (randomPtr >= sizeof(randomBuf)) {
 			if ((int)::read(devURandomFd,randomBuf,sizeof(randomBuf)) != (int)sizeof(randomBuf)) {
-				fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to read from /dev/urandom\r\n");
+				fprintf(stderr,"FATAL ERROR: Utils::getSecureRandom() unable to read from /dev/urandom\n");
 				exit(1);
 				return;
 			}