M tinycrypt/ed25519.c → tinycrypt/ed25519.c

@@ -142,7 +142,7 @@
   return !(buf[32] & (1 << 7));
 }
 
-void
+static void
 add512 (uint8_t *h, const uint8_t *c)
 {
   uint16_t acc = 0;
@@ -178,20 +178,7 @@ acc >>= 8;
     }
 }
 
-bool
-greater512 (const uint8_t *a, const uint8_t *b)
-{
-  uint8_t buf[64];
-  for (unsigned int i = 0; i < 64; ++i)
-    {
-      buf[i] = a[i];
-    }
-  sub512 (buf, b);
-
-  return !(buf[63] & (1 << 7));
-}
-
-bool
+static bool
 greater512_unsigned (const uint8_t *a, const uint8_t *b)
 {
   uint8_t a_int[65], b_int[65];
@@ -207,7 +194,7 @@
   return !(a_int[64] & (1 << 7));
 }
 
-void
+static void
 modp512 (const uint8_t *in, uint8_t *out)
 {
   const uint8_t P[64] = {
@@ -246,7 +233,7 @@ out[i] = accumulator[i];
     }
 }
 
-void
+static void
 mult256_modp (const uint8_t *a, const uint8_t *b, uint8_t *out)
 {
   uint8_t intermediate[64];
@@ -290,7 +277,7 @@ add512 (intermediates[0], intermediates[1]);
   modp512 (intermediates[0], out);
 }
 
-void
+static void
 inv256_modp (const uint8_t *x, uint8_t *out)
 {
   uint8_t buf[64];
@@ -471,7 +458,7 @@ mult256_modp (intermediates[4], intermediates[5], z3);
   mult256_modp (intermediates[3], intermediates[6], t3);
 }
 
-bool
+static bool
 points_eq (const uint8_t *x1, const uint8_t *y1, const uint8_t *z1,
            const uint8_t *t1, const uint8_t *x2, const uint8_t *y2,
            const uint8_t *z2, const uint8_t *t2)
@@ -612,7 +599,7 @@ out[i] = i0[i];
     }
 }
 
-void
+static void
 xB_lowmem (const uint8_t *k, uint8_t *x, uint8_t *y, uint8_t *z, uint8_t *t)
 {
   const uint8_t BX[32] = {
@@ -669,7 +656,7 @@ #ifndef TCT_LOWMEM
 
 #include "tinycrypt/ed25519_precompute.h"
 
-void
+static void
 xB (const uint8_t *k, uint8_t *x, uint8_t *y, uint8_t *z, uint8_t *t)
 {
   const uint8_t ONE[32] = {
@@ -720,7 +707,7 @@ }
 
 #else
 
-void
+static void
 xB (const uint8_t *k, uint8_t *x, uint8_t *y, uint8_t *z, uint8_t *t)
 {
   xB_lowmem (k, x, y, z, t);

M tinycrypt/ed25519.h → tinycrypt/ed25519.h

@@ -20,19 +20,9 @@ bool tct_ed25519_verify (const uint8_t *pubkey, const uint8_t *msg,
                          const uint64_t msg_len, uint8_t *working_buf,
                          const uint8_t *signature);
 
+/// Constructs a memory-speed-tradeoff lookup table for use in Ed25519
+/// verifications, similar (but larger by ~2x) to the method described in
+/// https://ed25519.cr.yp.to/ed25519-20110926.pdf.
 void tct_ed25519_pctable_gen (uint8_t *out);
-
-void xB (const uint8_t *k, uint8_t *x, uint8_t *y, uint8_t *z, uint8_t *t);
-
-void inv256_modp (const uint8_t *x, uint8_t *out);
-
-void mult256_modp (const uint8_t *a, const uint8_t *b, uint8_t *out);
-
-bool points_eq (const uint8_t *x1, const uint8_t *y1, const uint8_t *z1,
-                const uint8_t *t1, const uint8_t *x2, const uint8_t *y2,
-                const uint8_t *z2, const uint8_t *t2);
-
-void xB_lowmem (const uint8_t *k, uint8_t *x, uint8_t *y, uint8_t *z,
-                uint8_t *t);
 
 #endif