[][src]Module sequoia_openpgp::cert::key_amalgamation

Key amalgamations.

Whereas a KeyBundle groups a Key with its self signatures, its third-party signatures, and its revocation certificates, a KeyAmalgamation groups a KeyBundle with all of the necessary context needed to correctly implement relevant key-related functionality. Specifically, a KeyAmalgamation includes a reference to the KeyBundle, a reference to the containing certificate, and the key's role (primary or subordinate).

There are two notable differences between KeyBundles and KeyAmalgamations. First, whereas a KeyBundle's role is primarily a marker, a KeyAmalgamation's role determines the KeyAmalgamation's semantics. As such, it is not possible to convert a PrimaryKeyAmalgamation to a SubordinateAmalgamation, and vice versa. Second, a KeyBundle, owns its data, but a KeyAmalgamation only references the contained data.

There are three KeyAmalgamation variants: PrimaryKeyAmalgamation, SubordinateKeyAmalgamation, and ErasedKeyAmalgamation. Unlike a Key or a KeyBundle with an UnspecifiedRole, an ErasedKeyAmalgamation remembers its role. This means that an ErasedKeyAmalgamation implements the correct semantics even though the role marker has been erased (hence the name).

ErasedKeyAmalgamations are returned by Cert::keys. Cert::keys can't return a more specific type, because it returns an iterator that can contain both primary and subordinate keys. The reason that we use a concrete type instead of a trait object is so that when the user converts a KeyAmalgamation to a ValidKeyAmalgamation, the ValidKeyAmalgamation retains the type information about the role. Preserving this type information increases type safety for users of this API.



A key amalgamation.


A validated KeyAmalgamation.



Methods specific to key amalgamations.

Type Definitions


An amalgamation whose role is not known at compile time.


A primary key amalgamation.


A subordinate key amalgamation.


A valid amalgamation whose role is not known at compile time.


A valid primary key amalgamation.


A valid subordinate key amalgamation.