Restore Scout/Arduino test code with better RNG.

2026-08-21 09:20:08 +00:00 · 2014-10-08 22:54:44 -07:00
parent a12c8aac11
commit 1fce01e69c
1 changed files with 115 additions and 0 deletions
@@ -0,0 +1,115 @@
+#include <uECC.h>
+
+#include <j0g.h>
+#include <js0n.h>
+
+#include <lwm.h>
+
+#include <bitlash.h>
+
+#include <GS.h>
+
+#include <SPI.h>
+#include <Wire.h>
+#include <Scout.h>
+#include <Shell.h>
+
+
+#include <uECC.h>
+
+extern "C" {
+
+static int RNG(uint8_t *p_dest, unsigned p_size)
+{
+  // Use the least-significant bits from the ADC for an unconnected pin (or connected to a source of random noise)
+  // This can take a long time to generate random data if the result of analogRead(0) doesn't change very frequently.
+  while(p_size) {
+    uint8_t l_val = 0;
+    for(unsigned i=0; i<8; ++i)
+    {
+      int l_init = analogRead(0);
+      int l_count = 0;
+      while(analogRead(0) == l_init)
+      {
+        ++l_count;
+      }
+      
+      if(l_count == 0)
+      {
+         l_val = (l_val << 1) | (l_init & 0x01);
+      }
+      else
+      {
+         l_val = (l_val << 1) | (l_count & 0x01);
+      }
+    }
+    *p_dest = l_val;
+    ++p_dest;
+    --p_size;
+  }
+  
+  // NOTE: it would be a good idea to hash the resulting random data using SHA-256 or similar.
+  return 1;
+}
+
+}
+
+void setup()
+{
+  Scout.setup();
+  
+  Serial.print("Testing ecc\n");
+  
+  uECC_set_rng(&RNG);
+}
+
+void loop() {
+  uint8_t l_private1[uECC_BYTES];
+  uint8_t l_private2[uECC_BYTES];
+  
+  uint8_t l_public1[uECC_BYTES * 2];
+  uint8_t l_public2[uECC_BYTES * 2];
+  
+  uint8_t l_secret1[uECC_BYTES];
+  uint8_t l_secret2[uECC_BYTES];
+  
+  unsigned long a = millis();
+  uECC_make_key(l_public1, l_private1);
+  unsigned long b = millis();
+  
+  Serial.print("Made key 1 in "); Serial.println(b-a);
+  a = millis();
+  uECC_make_key(l_public2, l_private2);
+  b = millis();
+  Serial.print("Made key 2 in "); Serial.println(b-a);
+
+  a = millis();
+  int r = uECC_shared_secret(l_public2, l_private1, l_secret1);
+  b = millis();
+  Serial.print("Shared secret 1 in "); Serial.println(b-a);
+  if(!r)
+  {
+    Serial.print("shared_secret() failed (1)\n");
+    return;
+  }
+
+  a = millis();
+  r = uECC_shared_secret(l_public1, l_private2, l_secret2);
+  b = millis();
+  Serial.print("Shared secret 2 in "); Serial.println(b-a);
+  if(!r)
+  {
+    Serial.print("shared_secret() failed (2)\n");
+    return;
+  }
+    
+  if(memcmp(l_secret1, l_secret2, sizeof(l_secret1)) != 0)
+  {
+    Serial.print("Shared secrets are not identical!\n");
+  }
+  else
+  {
+    Serial.print("Shared secrets are identical\n");
+  }
+}
+