FEAT: added new system function Random_Bytes, which fills destination…

… buffer with given number of random bytes in OS independent way.
Oldes · Sep 25, 2018 · 7d9a21d · 7d9a21d
1 parent 73496e9
commit 7d9a21d
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Showing 4 changed files with 35 additions and 51 deletions.
diff --git a/src/core/f-random.c b/src/core/f-random.c
@@ -179,3 +179,34 @@ static REBI64 ran_arr_cycle()
 	if (s < 0.0) s += 1.8446744073709552e19;
 	return (s * t) * r;
 }
+
+/***********************************************************************
+**
+*/	void Random_Bytes(REBYTE* dest, REBCNT length, REBOOL	no_zeros)
+/*
+**		Fills destination buffer with random bytes.
+**
+***********************************************************************/
+{
+	REBI64 rnd;
+	REBCNT k = length / 8;
+	REBCNT r = length % 8;
+	REBYTE *cp = dest;
+
+	for (REBCNT i = 0; i < k; i++) {
+		rnd = Random_Int(TRUE);
+		memcpy(cp, (REBYTE*)&rnd, 8);
+		cp += 8;
+	}
+	if (r > 0) {
+		rnd = Random_Int(TRUE);
+		memcpy(cp, (REBYTE*)&rnd, r);
+	}
+	if(no_zeros) {
+		// make result without null bytes
+		for (REBCNT i = 0; i < length; i++) {
+			while (dest[i] == 0) 
+				dest[i] = (u8)(rand());
+		}
+	}
+}
diff --git a/src/core/u-dh.c b/src/core/u-dh.c
@@ -3,6 +3,7 @@ Simple implementation of Diffie-Hellman algorithm (c) 2013 Richard Smolak
 The code uses Bigint implementation Copyright (c) 2007, Cameron Rich
 */
 
+#include "sys-core.h"
 #include "sys-dh.h"
 
 void DH_generate_key(DH_CTX *dh_ctx)
@@ -16,7 +17,7 @@ void DH_generate_key(DH_CTX *dh_ctx)
 	bi_permanent(g);
 
     //generate private key  X
-	get_random_NZ(len, dh_ctx->x);
+	Random_Bytes(dh_ctx->x, len, 1);
 	x = bi_import(bi_ctx, dh_ctx->x, len);
 	bi_permanent(x);
 

diff --git a/src/core/u-rsa.c b/src/core/u-rsa.c
@@ -34,6 +34,7 @@
  */
 
 #include "reb-config.h"
+#include "sys-core.h"
 
 //#include <stdio.h>
 #include <string.h>
@@ -47,48 +48,6 @@
 #endif
 
 #include "sys-rsa.h"
-#ifdef TO_WINDOWS
-    #include <windows.h>
-    #include <wincrypt.h>
-#else
-    #include <fcntl.h>
-#endif
-
-
-#ifdef TO_WINDOWS
-static HCRYPTPROV gCryptProv;
-#else
-static int rng_fd = -1;
-#endif
-
-/**
- * Set a series of bytes with a random number. Individual bytes can be 0
- */
-void get_random(int num_rand_bytes, uint8_t *rand_data)
-{
-#ifdef TO_WINDOWS
-    /* use Microsoft Crypto Libraries */
-    CryptGenRandom(gCryptProv, num_rand_bytes, rand_data);
-#else
-    if (rng_fd == -1) rng_fd = open("/dev/urandom", O_RDONLY);
-    read(rng_fd, rand_data, num_rand_bytes);
-#endif
-}
-
-/**
- * Set a series of bytes with a random number. Individual bytes are not zero.
- */
-void get_random_NZ(int num_rand_bytes, uint8_t *rand_data)
-{
-    int i;
-    get_random(num_rand_bytes, rand_data);
-
-    for (i = 0; i < num_rand_bytes; i++)
-    {
-        while (rand_data[i] == 0)  /* can't be 0 */
-            rand_data[i] = (uint8_t)(rand());
-    }
-}
 
 void RSA_priv_key_new(RSA_CTX **ctx,
         const uint8_t *modulus, int mod_len,
@@ -327,7 +286,7 @@ int RSA_encrypt(const RSA_CTX *ctx, const uint8_t *in_data, uint16_t in_len,
 		else /* randomize the encryption padding with non-zero bytes */
 		{
 			out_data[1] = 2;
-			get_random_NZ(num_pads_needed, &out_data[2]);
+			Random_Bytes(&out_data[2], num_pads_needed, 1);
 		}
 
 		out_data[2+num_pads_needed] = 0;

diff --git a/src/include/sys-rsa.h b/src/include/sys-rsa.h
@@ -104,13 +104,6 @@ int RSA_encrypt(const RSA_CTX *ctx, const uint8_t *in_data, uint16_t in_len,
 void RSA_print(const RSA_CTX *ctx);
 #endif
 
-/**************************************************************************
- * RNG declarations
- **************************************************************************/
-void get_random(int num_rand_bytes, uint8_t *rand_data);
-void get_random_NZ(int num_rand_bytes, uint8_t *rand_data);
-
-
 #ifdef __cplusplus
 }
 #endif