sr_keychain

This is a simple wrapper around credential manager utilities on Windows, macOS and Linux. It respectively interacts with:

• the system credential manager on Windows
• the keychain on macOS
• the "Secret service" of your distribution on Linux (such as gnome-keyring or ksecretservice)

Only sr_keychain.h and sr_keychain.c are required. A basic example in C can be found in the example directory.

Dependencies

• On Windows, this should link against Advapi32.
• On macOS, this should link against Security.framework.
• On Linux, this should link against the libsecret-1 library.

Usage

All strings passed as arguments below should be null-terminated, including the passwords.

Storing a password

int sr_keychain_set_password(const char * domain, char * user, const char * password);

Store a password in the keychain, for a given domain and user name. This will return 0 on success.

Querying a password

int sr_keychain_get_password(const char * domain, const char * user, char ** password);

Retrieve the password previously stored for a given domain and username. The string will be internally allocated and its ownership is transferred to the caller. This will return 0 on success.

Helpers

void sr_keychain_set_stdin_printback(int enable)

Disable printback when querying for user input on stdin, if the terminal honors it.

Customization

sr_keychain internally allocate a few strings (including the retrieved password). By default, it uses the standard malloc and free but these can be overriden by defining SR_KEYCHAIN_MALLOC(S) and SR_KEYCHAIN_FREE(S).

On Linux, a URL identifier is associated to all elements stored by sr_keychain. It defaults to "com.sr.sr_keychain", but can be overriden by defining SR_KEYCHAIN_LINUX_SCHEME_NAME to the desired string.

Limitations

This library currently does not allow for the deletion of existing passwords from the system keychain. It exposes no additional options such as the lifespan of a password, the associated protocol or application, etc. Finally, it doesn't protect the password once it is stored in memory in your application.