Crate windows_native_keyring_store

Crate windows_native_keyring_store 

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§Windows native credential store for the keyring crate

This module implements a credential store for the keyring crate that uses the Windows Credential Manager as its back end.

§Usage

To make this store the default for creation of keyring entries, execute this code:

keyring_core::set_default_store(windows_native_keyring_store::Store::new().unwrap())

§Mapping service and user values to credentials

Each entry in keyring is mapped to a generic credential in the Windows Credential Manager. The identifier for each credential in Windows is a target_name string. If an entry is created with an explicit target modifier, that value is used as the target_name. Otherwise, a target_name string is generated by concatenating a prefix string, the user, a delimiter string, the service, and a suffix string. The prefix, delimiter, and suffix strings are part of the store configuration. Their default values are: empty strings for the prefix and suffix, and a ‘.’ for the delimiter.

Note that service and user strings, by default, can contain the delimiter string, so it is possible for entries with different service and user strings to map to the same description (and thus the same credential in the store). If you are worried about this, you can avoid it by configuring your store to forbid the delimiter string in the service string.

§Persistence Type

Each generic credential can have one of three persistence types, defined precisely in the Windows API here, and represented in this API by the CredPersist enumeration values Session, Local, and Enterprise.

By default, created credentials have Enterprise persistence, but you can specify a desired persistence by using the persistence modifier at entry creation time with a (case-insensitive) value of Session, Local, or Enterprise. Note that this type will only be applied when the credential’s secret is written; it does not control the persistence of an existing credential in the store whose value is read via the entry. The persistence of an existing credential can be read via its persistence attribute.

§Attributes

In addition to the persistence attribute mentioned in the last section, there are four string attributes that are held on each generic credential: target_name, target_alias, username, and comment. The target_name attribute is read-only (because it’s the unique ID for the credential in the store). The username attribute in an entry created from a specifier will start off as the specifier’s user. All the attributes on existing credentials can be read using the get_attributes method, and their writeable attributes can be set using the update_attributes method.

§Search

This credential store module supports searching for existing credentials. You can (optionally) specify a regular-expression pattern to be matched against each credential’s target_name. If you don’t specify a pattern, all existing generic credentials are returned.

The entries returned from search are all wrappers, of course, but if the wrapped credential can be specified by the store being searched, then the return entry will also be a specifier. But recall that each store can have its own conventions for delimiters used when forming the target_name. Thus, a search in one store may return a wrapper/specifier for an existing credential but that same search in another store may return a wrapper that is not a specifier.

§Warnings

Tests show that operating on the same entry from different threads does not reliably sequence the operations in the same order they are initiated. (For example, setting a password on one thread and then immediately spawning another to get the password may return a NoEntry error on the spawned thread.) So be careful not to access the same entry on multiple threads simultaneously.

Tests show that changing a credential’s persistence type immediately before reading it may cause the read to fail, especially if the credential manager is busy on multiple threads.

Re-exports§

pub use cred::CredPersist;
pub use store::Store;

Modules§

cred
store