add BN pseudo random function

src/ssl.c

@@ -17035,8 +17035,8 @@ WOLFSSL_EVP_PKEY* wolfSSL_PKEY_new()
             DYNAMIC_TYPE_PUBLIC_KEY);
     if (pkey != NULL) {
         XMEMSET(pkey, 0, sizeof(WOLFSSL_EVP_PKEY));
+        pkey->type = WOLFSSL_EVP_PKEY_DEFAULT;
     }
-    pkey->type = WOLFSSL_EVP_PKEY_DEFAULT;
 
     return pkey;
 }
@@ -19190,6 +19190,91 @@ int wolfSSL_BN_rand(WOLFSSL_BIGNUM* bn, int bits, int top, int bottom)
     return ret;
 }
 
+
+/* SSL_SUCCESS on ok
+ * code is same as wolfSSL_BN_rand except for how top and bottom is handled.
+ * top -1 then leave most sig bit alone
+ * top 0 then most sig is set to 1
+ * top is 1 then first two most sig bits are 1
+ *
+ * bottom is hot then odd number */
+int wolfSSL_BN_pseudo_rand(WOLFSSL_BIGNUM* bn, int bits, int top, int bottom)
+{
+    int           ret    = 0;
+    int           len    = bits / 8;
+    int           initTmpRng = 0;
+    WC_RNG*       rng    = NULL;
+#ifdef WOLFSSL_SMALL_STACK
+    WC_RNG*       tmpRNG = NULL;
+    byte*         buff   = NULL;
+#else
+    WC_RNG        tmpRNG[1];
+    byte          buff[1024];
+#endif
+
+    WOLFSSL_MSG("wolfSSL_BN_rand");
+
+    if (bits % 8)
+        len++;
+
+#ifdef WOLFSSL_SMALL_STACK
+    buff   = (byte*)XMALLOC(1024,        NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    tmpRNG = (WC_RNG*) XMALLOC(sizeof(WC_RNG), NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    if (buff == NULL || tmpRNG == NULL) {
+        XFREE(buff,   NULL, DYNAMIC_TYPE_TMP_BUFFER);
+        XFREE(tmpRNG, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+        return ret;
+    }
+#endif
+
+    if (bn == NULL || bn->internal == NULL)
+        WOLFSSL_MSG("Bad function arguments");
+    else if (wc_InitRng(tmpRNG) == 0) {
+        rng = tmpRNG;
+        initTmpRng = 1;
+    }
+    else if (initGlobalRNG)
+        rng = &globalRNG;
+
+    if (rng) {
+        if (wc_RNG_GenerateBlock(rng, buff, len) != 0)
+            WOLFSSL_MSG("Bad wc_RNG_GenerateBlock");
+        else {
+            switch (top) {
+                case -1:
+                    break;
+
+                case 0:
+                    buff[0] |= 0x80;
+                    break;
+
+                case 1:
+                    buff[0] |= 0x80 | 0x40;
+                    break;
+            }
+
+            if (bottom == 1) {
+                buff[len-1] |= 0x01;
+            }
+
+            if (mp_read_unsigned_bin((mp_int*)bn->internal,buff,len) != MP_OKAY)
+                WOLFSSL_MSG("mp read bin failed");
+            else
+                ret = SSL_SUCCESS;
+        }
+    }
+
+    if (initTmpRng)
+        wc_FreeRng(tmpRNG);
+
+#ifdef WOLFSSL_SMALL_STACK
+    XFREE(buff,   NULL, DYNAMIC_TYPE_TMP_BUFFER);
+    XFREE(tmpRNG, NULL, DYNAMIC_TYPE_TMP_BUFFER);
+#endif
+
+    return ret;
+}
+
 /* return code compliant with OpenSSL :
  *   1 if bit set, 0 else
  */

tests/api.c

@@ -14759,6 +14759,40 @@ static void test_wolfSSL_BUF(void)
 }
 
 
+static void test_wolfSSL_pseudo_rand(void)
+{
+    #if defined(OPENSSL_EXTRA)
+    BIGNUM* bn;
+    unsigned char bin[8];
+    int i;
+
+    printf(testingFmt, "wolfSSL_pseudo_rand()");
+
+    /* BN_pseudo_rand returns 1 on success 0 on failure
+     * int BN_pseudo_rand(BIGNUM* bn, int bits, int top, int bottom) */
+    for (i = 0; i < 10; i++) {
+        AssertNotNull(bn = BN_new());
+        XMEMSET(bn, 0, sizeof(bn));
+        AssertIntEQ(BN_pseudo_rand(bn, 8, 0, 0), SSL_SUCCESS);
+        AssertIntGT(BN_bn2bin(bn, bin),0);
+        AssertIntEQ((bin[0] & 0x80), 0x80); /* top bit should be set */
+        BN_free(bn);
+    }
+
+    for (i = 0; i < 10; i++) {
+        AssertNotNull(bn = BN_new());
+        XMEMSET(bn, 0, sizeof(bn));
+        AssertIntEQ(BN_pseudo_rand(bn, 8, 1, 1), SSL_SUCCESS);
+        AssertIntGT(BN_bn2bin(bn, bin),0);
+        AssertIntEQ((bin[0] & 0xc1), 0xc1); /* top bit should be set */
+        BN_free(bn);
+    }
+
+    printf(resultFmt, passed);
+    #endif
+}
+
+
 static void test_no_op_functions(void)
 {
     #if defined(OPENSSL_EXTRA)
@@ -15556,6 +15590,7 @@ void ApiTest(void)
     test_wolfSSL_CTX_add_client_CA();
     test_wolfSSL_CTX_set_srp_username();
     test_wolfSSL_CTX_set_srp_password();
+    test_wolfSSL_pseudo_rand();
     AssertIntEQ(test_wolfSSL_Cleanup(), WOLFSSL_SUCCESS);
 
     /* test the no op functions for compatibility */

wolfssl/openssl/bn.h

@@ -78,6 +78,8 @@ WOLFSSL_API WOLFSSL_BIGNUM* wolfSSL_BN_bin2bn(const unsigned char*, int len,
 
 WOLFSSL_API int wolfSSL_mask_bits(WOLFSSL_BIGNUM*, int n);
 
+WOLFSSL_API int wolfSSL_BN_pseudo_rand(WOLFSSL_BIGNUM*, int bits, int top,
+        int bottom);
 WOLFSSL_API int wolfSSL_BN_rand(WOLFSSL_BIGNUM*, int bits, int top, int bottom);
 WOLFSSL_API int wolfSSL_BN_is_bit_set(const WOLFSSL_BIGNUM*, int n);
 WOLFSSL_API int wolfSSL_BN_hex2bn(WOLFSSL_BIGNUM**, const char* str);
@@ -141,9 +143,10 @@ typedef WOLFSSL_BN_GENCB BN_GENCB;
 
 #define BN_mask_bits wolfSSL_mask_bits
 
-#define BN_rand       wolfSSL_BN_rand
-#define BN_is_bit_set wolfSSL_BN_is_bit_set
-#define BN_hex2bn     wolfSSL_BN_hex2bn
+#define BN_pseudo_rand wolfSSL_BN_pseudo_rand
+#define BN_rand        wolfSSL_BN_rand
+#define BN_is_bit_set  wolfSSL_BN_is_bit_set
+#define BN_hex2bn      wolfSSL_BN_hex2bn
 
 #define BN_dup  wolfSSL_BN_dup
 #define BN_copy wolfSSL_BN_copy