RIOT/pkg/micro-ecc/0002-Include-RIOT-Hardware-RNG-interface.patch

From 2ab8fb085a02fec23ca817bd6de8848df160970b Mon Sep 17 00:00:00 2001
From: Frank Holtz <frank-riot2015@holtznet.de>
Date: Sat, 17 Jan 2015 18:41:14 +0100
Subject: [PATCH 2/2] Include RIOT Hardware RNG interface

---
 uECC.c | 93 +++++++-----------------------------------------------------------
 uECC.h | 28 +-------------------
 2 files changed, 11 insertions(+), 110 deletions(-)

diff --git a/uECC.c b/uECC.c
index aded242..8b355a4 100644
--- a/uECC.c
+++ b/uECC.c
@@ -322,85 +322,6 @@ static void vli_square(uECC_word_t *p_result, uECC_word_t *p_left);
 static void vli_modSquare_fast(uECC_word_t *p_result, uECC_word_t *p_left);
 #endif
 
-#if (defined(_WIN32) || defined(_WIN64))
-/* Windows */
-
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#include <wincrypt.h>
-
-static int default_RNG(uint8_t *p_dest, unsigned p_size)
-{
-    HCRYPTPROV l_prov;
-    if(!CryptAcquireContext(&l_prov, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
-    {
-        return 0;
-    }
-
-    CryptGenRandom(l_prov, p_size, (BYTE *)p_dest);
-    CryptReleaseContext(l_prov, 0);
-    
-    return 1;
-}
-
-#elif defined(unix) || defined(__linux__) || defined(__unix__) || defined(__unix) || \
-    (defined(__APPLE__) && defined(__MACH__)) || defined(uECC_POSIX)
-
-/* Some POSIX-like system with /dev/urandom or /dev/random. */
-#include <sys/types.h>
-#include <fcntl.h>
-#include <unistd.h>
-
-#ifndef O_CLOEXEC
-    #define O_CLOEXEC 0
-#endif
-
-static int default_RNG(uint8_t *p_dest, unsigned p_size)
-{
-    int l_fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC);
-    if(l_fd == -1)
-    {
-        l_fd = open("/dev/random", O_RDONLY | O_CLOEXEC);
-        if(l_fd == -1)
-        {
-            return 0;
-        }
-    }
-    
-    char *l_ptr = (char *)p_dest;
-    size_t l_left = p_size;
-    while(l_left > 0)
-    {
-        int l_read = read(l_fd, l_ptr, l_left);
-        if(l_read <= 0)
-        { // read failed
-            close(l_fd);
-            return 0;
-        }
-        l_left -= l_read;
-        l_ptr += l_read;
-    }
-    
-    close(l_fd);
-    return 1;
-}
-
-#else /* Some other platform */
-
-static int default_RNG(uint8_t *p_dest, unsigned p_size)
-{
-    return 0;
-}
-
-#endif
-
-static uECC_RNG_Function g_rng = &default_RNG;
-
-void uECC_set_rng(uECC_RNG_Function p_rng)
-{
-    g_rng = p_rng;
-}
-
 #ifdef __GNUC__ /* Only support GCC inline asm for now */
     #if (uECC_ASM && (uECC_PLATFORM == uECC_avr))
         #include "asm_avr.inc"
@@ -1782,10 +1703,13 @@ int uECC_make_key(uint8_t p_publicKey[uECC_BYTES*2], uint8_t p_privateKey[uECC_B
     do
     {
     repeat:
-        if(!g_rng((uint8_t *)l_private, sizeof(l_private)) || (l_tries++ >= MAX_TRIES))
+        if(l_tries++ >= MAX_TRIES)
         {
             return 0;
         }
+
+        hwrng_read((uint8_t *)l_private, sizeof(l_private));
+
         if(vli_isZero(l_private))
         {
             goto repeat;
@@ -1814,7 +1738,7 @@ int uECC_shared_secret(const uint8_t p_publicKey[uECC_BYTES*2], const uint8_t p_
     uECC_word_t l_private[uECC_WORDS];
     uECC_word_t l_random[uECC_WORDS];
     
-    g_rng((uint8_t *)l_random, sizeof(l_random));
+    hwrng_read((uint8_t *)l_random, sizeof(l_random));
     
     vli_bytesToNative(l_private, p_privateKey);
     vli_bytesToNative(l_public.x, p_publicKey);
@@ -2155,11 +2079,13 @@ int uECC_sign(const uint8_t p_privateKey[uECC_BYTES], const uint8_t p_hash[uECC_
     do
     {
     repeat:
-        if(!g_rng((uint8_t *)k, sizeof(k)) || (l_tries++ >= MAX_TRIES))
+        if(l_tries++ >= MAX_TRIES)
         {
             return 0;
         }
         
+        hwrng_read((uint8_t *)k, sizeof(k));
+
         if(vli_isZero(k))
         {
             goto repeat;
@@ -2203,10 +2129,11 @@ int uECC_sign(const uint8_t p_privateKey[uECC_BYTES], const uint8_t p_hash[uECC_
     l_tries = 0;
     do
     {
-        if(!g_rng((uint8_t *)l_tmp, sizeof(l_tmp)) || (l_tries++ >= MAX_TRIES))
+        if(l_tries++ >= MAX_TRIES)
         {
             return 0;
         }
+        hwrng_read((uint8_t *)l_tmp, sizeof(l_tmp));
     } while(vli_isZero(l_tmp));
     
     /* Prevent side channel analysis of vli_modInv() to determine
diff --git a/uECC.h b/uECC.h
index 2c9927b..02e2f22 100644
--- a/uECC.h
+++ b/uECC.h
@@ -4,6 +4,7 @@
 #define _MICRO_ECC_H_
 
 #include <stdint.h>
+#include "periph/hwrng.h"
 
 /* Platform selection options.
 If uECC_PLATFORM is not defined, the code will try to guess it based on compiler macros.
@@ -57,33 +58,6 @@ extern "C"
 {
 #endif
 
-/* uECC_RNG_Function type
-The RNG function should fill p_size random bytes into p_dest. It should return 1 if
-p_dest was filled with random data, or 0 if the random data could not be generated.
-The filled-in values should be either truly random, or from a cryptographically-secure PRNG.
-
-A correctly functioning RNG function must be set (using uECC_set_rng()) before calling
-uECC_make_key() or uECC_sign().
-
-A correct RNG function is set by default when building for Windows, Linux, or OS X.
-If you are building on another POSIX-compliant system that supports /dev/random or /dev/urandom,
-you can define uECC_POSIX to use the predefined RNG. For embedded platforms there is no predefined
-RNG function; you must provide your own.
-*/
-typedef int (*uECC_RNG_Function)(uint8_t *p_dest, unsigned p_size);
-
-/* uECC_set_rng() function.
-Set the function that will be used to generate random bytes. The RNG function should
-return 1 if the random data was generated, or 0 if the random data could not be generated.
-
-On platforms where there is no predefined RNG function (eg embedded platforms), this must
-be called before uECC_make_key() or uECC_sign() are used.
-    
-Inputs:
-    p_rng  - The function that will be used to generate random bytes.
-*/
-void uECC_set_rng(uECC_RNG_Function p_rng);
-
 /* uECC_make_key() function.
 Create a public/private key pair.
     
-- 
2.7.1