FIX: Replace RAND_bytes with CryptographicRandom::fillBuffer

https://www.openssl.org/docs/man1.1.1/man3/RAND_bytes.html:
If the entropy source fails or is not available, the CSPRNG will enter an error state and refuse to generate random bytes. For that reason, it is important to always check the error return value of RAND_bytes() and RAND_priv_bytes() and not take randomness for granted.

Also remove unnecessary cast.

3 files changed, 7 insertions, 8 deletions

diff --git a/src/crypto/CryptStateOCB2.cpp b/src/crypto/CryptStateOCB2.cpp
index 51253b0a5..fbd632963 100644
--- a/src/crypto/CryptStateOCB2.cpp
+++ b/src/crypto/CryptStateOCB2.cpp
@@ -25,6 +25,7 @@
 
 #include "ByteSwap.h"
 #include "CryptStateOCB2.h"
+#include "CryptographicRandom.h"
 
 #include <cstring>
 #include <openssl/rand.h>
@@ -42,9 +43,9 @@ bool CryptStateOCB2::isValid() const {
 }
 
 void CryptStateOCB2::genKey() {
-	RAND_bytes(raw_key, AES_KEY_SIZE_BYTES);
-	RAND_bytes(encrypt_iv, AES_BLOCK_SIZE);
-	RAND_bytes(decrypt_iv, AES_BLOCK_SIZE);
+	CryptographicRandom::fillBuffer(raw_key, AES_KEY_SIZE_BYTES);
+	CryptographicRandom::fillBuffer(encrypt_iv, AES_BLOCK_SIZE);
+	CryptographicRandom::fillBuffer(decrypt_iv, AES_BLOCK_SIZE);
 	AES_set_encrypt_key(raw_key, AES_KEY_SIZE_BITS, &encrypt_key);
 	AES_set_decrypt_key(raw_key, AES_KEY_SIZE_BITS, &decrypt_key);
 	bInit = true;
diff --git a/src/crypto/CryptographicRandom.cpp b/src/crypto/CryptographicRandom.cpp
index 0c2405d43..a162c765d 100644
--- a/src/crypto/CryptographicRandom.cpp
+++ b/src/crypto/CryptographicRandom.cpp
@@ -24,7 +24,7 @@ void CryptographicRandom::fillBuffer(void *buf, int numBytes) {
 	// OpenSSL needs at least 32-bytes of high-entropy random data to seed its CSPRNG.
 	// If OpenSSL cannot acquire enough random data to seed its CSPRNG at the time Mumble and Murmur
 	// are running, there is not much we can do about it other than aborting the program.
-	if (RAND_bytes(reinterpret_cast< unsigned char * >(buf), static_cast< int >(numBytes)) != 1) {
+	if (RAND_bytes(reinterpret_cast< unsigned char * >(buf), numBytes) != 1) {
 		qFatal("CryptographicRandom::fillBuffer(): internal error in OpenSSL's RAND_bytes or entropy pool not yet "
 			   "filled.");
 	}
diff --git a/src/murmur/PBKDF2.cpp b/src/murmur/PBKDF2.cpp
index e1038b6b2..af41c0c7f 100644
--- a/src/murmur/PBKDF2.cpp
+++ b/src/murmur/PBKDF2.cpp
@@ -45,6 +45,7 @@
 #endif
 
 #include "PBKDF2.h"
+#include "crypto/CryptographicRandom.h"
 
 #include <QtCore/QElapsedTimer>
 #include <QtCore/QLatin1String>
@@ -109,10 +110,7 @@ QString PBKDF2::getHash(const QString &hexSalt, const QString &password, int ite
 QString PBKDF2::getSalt() {
 	QByteArray salt(SALT_LENGTH, 0);
 
-	if (RAND_bytes(reinterpret_cast< unsigned char * >(salt.data()), salt.size()) != 1) {
-		qFatal("PBKDF2: RAND_bytes for salt failed: %s", ERR_error_string(ERR_get_error(), nullptr));
-		return QString();
-	}
+	CryptographicRandom::fillBuffer(salt.data(), salt.size());
 
 	return QString::fromLatin1(salt.toHex());
 }