StrCat() appends a string to an already existing string. In order to know where the existing string ends, it uses StrLen() which in turn uses strlen(), a function considered unsafe because it doesn't stop until it finds the null character.
Since the string was allocated but not initialized, StrCat() was either:
- Working correctly.
- Copying only a part of the string.
- Making the program crash via strlen().
The fix consists in using StrCpy(), which starts writing at the beginning of the string.
found by cppcheck
[src/Cedar/DDNS.c:656]: (style) Condition 'ret==NULL' is always true
[src/Cedar/DDNS.c:515] -> [src/Cedar/DDNS.c:640]: (style) The expression 'use_https == false' is always true because 'use_https' and 'false' represent the same value.
[src/Cedar/DDNS.c:516] -> [src/Cedar/DDNS.c:648]: (style) The expression 'no_cert_verify == false' is always true because 'no_cert_verify' and 'false' represent the same value.
[src/Cedar/DDNS.c:816] -> [src/Cedar/DDNS.c:860]: (style) The expression 'no_cert_verify == false' is always true because 'no_cert_verify' and 'false' represent the same value.
[src/Cedar/DDNS.c:530]: (style) Variable 'use_vgs' is assigned a value that is never used.
[src/Cedar/DDNS.c:497]: (style) The function 'DCUpdateNow' is never used.
found by cppcheck
[src/Cedar/Account.c:523]: (style) The function 'GetUserPolicy' is never used.
[src/Cedar/Account.c:163]: (style) The function 'NormalizePolicyName' is never used.
found by cppcheck
[src/Cedar/Command.c:23220] -> [src/Cedar/Command.c:23232]: (style) Variable 'len' is reassigned a value before the old one has been used.
found by cppcheck
[src/Cedar/CM.c:4509]: (style) Variable 'easy' is assigned a value that is never used.
[src/Cedar/CM.c:4547]: (style) Variable 'hub_name' is assigned a value that is never used.
[src/Cedar/CM.c:4609]: (style) Variable 'is_account' is assigned a value that is never used.
[src/Cedar/CM.c:8545]: (style) The function 'CmLoadK' is never used.
To fix the bug of OpenVPN 2.4.6 and particular version of kernel mode TAP driver on Linux, the TAP device must be up after the OpenVPN client is connected. However there is no direct push instruction to do so to OpenVPN client. Therefore we push the dummy IPv4 address (RFC7600) to the OpenVPN client to enforce the TAP driver UP state.
This allows an OpenVPN client to bypass a firewall which is aware of the protocol and is able to block it.
The XOR mask set on the server has to be the same on the client, otherwise it will not be able to connect with certain obfuscation modes.
A special OpenVPN client built with the "XOR patch" is required in order to use this function, because it has never been merged in the official OpenVPN repository.
Two parameters are added to the server configuration: "OpenVPNObfuscationMethod" and "OpenVPNObfuscationMask".
Their value can be retrieved with "OpenVpnObfuscationGet" and set with "OpenVpnObfuscationEnable" in the VPN Command Line Management Utility.
resolve possible null pointer dereference
found by cppcheck
[src/Cedar/Protocol.c:3138] -> [src/Cedar/Protocol.c:3071]: (warning) Either the condition 's!=NULL' is redundant or there is possible null pointer dereference: s.
[src/Cedar/Protocol.c:916]: (style) Variable 'save' is assigned a value that is never used.
[src/Cedar/Protocol.c:6242]: (style) Variable 'size' is assigned a value that is never used.
[src/Cedar/Protocol.c:778]: (style) Variable 'old_disable' is assigned a value that is never used.
[src/Cedar/Protocol.c:1021]: (style) Variable 'save' is assigned a value that is never used.
[src/Cedar/Protocol.c:3708]: (style) Variable 'is_vgc' is assigned a value that is never used.
[src/Cedar/Protocol.c:5785]: (style) Variable 's' is assigned a value that is never used.
[src/Cedar/Protocol.c:6164]: (style) The function 'SocksConnectEx' is never used.
[src/Cedar/Protocol.c:907]: (style) The function 'CompareNodeInfo' is never used.
[src/Cedar/Protocol.c:6968]: (style) The function 'ProxyConnect' is never used.
[src/Cedar/Protocol.c:3986]: (style) The function 'SecureDelete' is never used.
[src/Cedar/Protocol.c:4042]: (style) The function 'SecureEnum' is never used.
[src/Cedar/Protocol.c:4127]: (style) The function 'SecureWrite' is never used.
[src/Cedar/Protocol.c:6463]: (style) The function 'SocksConnect' is never used.
[src/Cedar/Protocol.c:7185]: (style) The function 'TcpConnectEx2' is never used.
[src/Cedar/Protocol.c:7206]: (style) The function 'TcpIpConnect' is never used.
1.0.0.1 is a real IP address, owned by CloudFlare and used for their DNS service.
This commit changes the IP address we push to 192.0.0.8, which is defined in RFC7600 as dummy IPv4 address.
found by cppcheck
[src/Cedar/Proto_IkePacket.c:958]: (style) The function 'IkeNewCertPayload' is never used.
[src/Cedar/Proto_IkePacket.c:942]: (style) The function 'IkeNewCertRequestPayload' is never used.
[src/Cedar/Proto_IkePacket.c:875]: (style) The function 'IkeNewNoticeErrorInvalidExchangeTypePayload' is never used.
[src/Cedar/Proto_IkePacket.c:2542]: (style) The function 'IkeNewSpi' is never used.
[src/Cedar/Proto_IkePacket.c:142]: (style) The function 'IkePhase1CryptIdToKeySize' is never used.
[src/Cedar/Proto_IkePacket.c:157]: (style) The function 'IkePhase2CryptIdToKeySize' is never used.
[src/Cedar/Proto_IkePacket.c:172]: (style) The function 'IkeStrToPhase1CryptId' is never used.
[src/Cedar/Proto_IkePacket.c:187]: (style) The function 'IkeStrToPhase1HashId' is never used.
[src/Cedar/Proto_IkePacket.c:196]: (style) The function 'IkeStrToPhase2CryptId' is never used.
[src/Cedar/Proto_IkePacket.c:211]: (style) The function 'IkeStrToPhase2HashId' is never used.
[src/Cedar/Proto_IkePacket.c:2168]: (style) Condition 'b==NULL' is always true
1. ifdef DEBUG -> defined(_DEBUG) || defined(DEBUG)
In VC++ compilers, the macro is "_DEBUG", not "DEBUG".
2. If set memcheck = true, the program will be vitally slow since it will log all malloc() / realloc() / free() calls to find the cause of memory leak.
For normal debug we set memcheck = false.
Please set memcheck = true if you want to test the cause of memory leaks.
