This is the "encrypted argument" format used by a lot of FFXIV programs and is used in place of regular plaintext command line arguments. However, this is barely a security measure and just prevents easily snooping stuff like your login token. Despite this, the SqexArg format is well known, reversible and easily breakable.
The resulting bytes when you decode the base64 string is going to Blowfish ECB encrypted.
* However, please note that Square Enix does some weird bitflip endian-encoding nonsense which means your out-of-box Blowfish library might not work. I would highly recommend reading up on some existing implementations to get an idea of what to do:
* Before encrypting or decrypting, ensure the buffer is padded.
**Note:** In the new Steam launcher update, Square Enix has actually switched to a more sane version of Blowfish ECB without their weird changes. Please look at [XIVQuickLauncher for the changes](https://github.com/goatcorp/FFXIVQuickLauncher/blob/master/src/XIVLauncher.Common/Encryption/BlockCipher/Blowfish.cs) required, as I have not tested this yet.
The key used for encrypting/decrypting the encrypted arguments is just your **system's uptime clock**. All FFXIV executables just call `GetTickCount()`, and theres about ~50 or so ticks of freedom before the game or launcher considers it invalid. There is a specific transformation you need to do in order to fetch a valid key though:
```
unsigned int rawTicks = TickCount();
unsigned int ticks = rawTicks & 0xFFFFFFFFu;
unsigned int key = ticks & 0xFFFF0000u;
char buffer[9] = {};
sprintf(buffer, "%08x", key);
```
To make this easier, here is a couple of platform-specific implementations of `TickCount()`. Thank you Wine for being easily searchable, as this is what Wine is actually doing under the hood to emulate `GetTickCount()`, so these are exact and have been tested on Astra for all platforms.
Every instance where SqexArg is used, the first argument is always `T`, where `T` is set to the value of `ticks` (as shown above). I'm not sure what the purpose of this really is, maybe for verifying the checksum?
The arguments (before encoding of course) must be formatted as `" /%1 =%2"`. The extra space is required, even at the beginning of the arguments. Make sure that any spaces in your string is double padded as well.
