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### Credential Storage in Linux
Linux systems store credentials in three types of caches, namely **Files** (in `/tmp` directory), **Kernel Keyrings** (a special segment in the Linux kernel), and **Process Memory** (for single-process use). The **default\_ccache\_name** variable in `/etc/krb5.conf` reveals the storage type in use, defaulting to `FILE:/tmp/krb5cc_%{uid}` if not specified.

### Extracting Credentials
The 2017 paper, [**Kerberos Credential Thievery (GNU/Linux)**](https://www.delaat.net/rp/2016-2017/p97/report.pdf), outlines methods for extracting credentials from keyrings and processes, emphasizing the Linux kernel's keyring mechanism for managing and storing keys.

#### Keyring Extraction Overview
The **keyctl system call**, introduced in kernel version 2.6.10, allows user space applications to interact with kernel keyrings. Credentials in keyrings are stored as components (default principal and credentials), distinct from file ccaches which also include a header. The **hercules.sh script** from the paper demonstrates extracting and reconstructing these components into a usable file ccache for credential theft.

#### Ticket Extraction Tool: Tickey
Building on the principles of the **hercules.sh script**, the [**tickey**](https://github.com/TarlogicSecurity/tickey) tool is specifically designed for extracting tickets from keyrings, executed via `/tmp/tickey -i`.

## References
* [**https://www.tarlogic.com/en/blog/how-to-attack-kerberos/**](https://www.tarlogic.com/en/blog/how-to-attack-kerberos/)


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