modules/crypto/pbkdf2v2: use arc4random_buf() to generate salt

This is slightly more efficient and less ugly than calling arc4random()
multiple times.

diff --git a/modules/crypto/pbkdf2v2.c b/modules/crypto/pbkdf2v2.c
index 3e7a2f76e6574c22c6fb252ba540aee815b1b32e..ce6818e02f8c9e293b1f27b855b403c77c7155c2 100644 (file)
--- a/modules/crypto/pbkdf2v2.c
+++ b/modules/crypto/pbkdf2v2.c
@@ -52,11 +52,16 @@ static unsigned int pbkdf2v2_rounds = PBKDF2_C_DEF;
 
 static const char *pbkdf2v2_make_salt(void)
 {
-       char            salt[PBKDF2_SALTLEN + 1];
+       unsigned char   rawsalt[PBKDF2_SALTLEN];
+       char            salt[sizeof rawsalt + 1];
        static char     result[PASSLEN];
 
-       for (int i = 0; i < PBKDF2_SALTLEN; i++)
-               salt[i] = salt_chars[arc4random() % sizeof salt_chars];
+       /* Fill salt array with random bytes */
+       (void) arc4random_buf(rawsalt, sizeof rawsalt);
+
+       /* Use random byte as index into printable character array, turning it into a printable string */
+       for (size_t i = 0; i < sizeof rawsalt; i++)
+               salt[i] = salt_chars[rawsalt[i] % sizeof salt_chars];
 
        /* NULL-terminate the string */
        salt[PBKDF2_SALTLEN] = 0x00;