Package dirhash defines hashes over directory trees.

Package note defines the notes signed by the Go module database server.

Package storage defines storage interfaces for and a basic implementation of a checksum database.

Package tlog implements a tamper-evident log used in the Go module go.sum database server.

NewClient returns a new [Client] using the given [ClientOps].

NewServer returns a new Server using the given operations.

NewTestServer constructs a new [TestServer] that will sign its tree with the given signer key (see [golang.org/x/mod/sumdb/note]) and fetch new records as needed by calling gosum.

ErrGONOSUMDB is returned by [Client.Lookup] for paths that match a pattern listed in the GONOSUMDB list (set by [Client.SetGONOSUMDB], usually from the environment variable).

ErrSecurity is returned by [Client] operations that invoke Client.SecurityError.

ErrWriteConflict signals a write conflict during Client.WriteConfig.

ServerPaths are the URL paths the Server can (and should) serve.

A Client is a client connection to a checksum database.

A Server is the checksum database HTTP server, which implements http.Handler and should be invoked to serve the paths listed in [ServerPaths].

A TestServer is an in-memory implementation of [ServerOps] for testing.

A ClientOps provides the external operations (file caching, HTTP fetches, and so on) needed by the [Client].

A ServerOps provides the external operations (underlying database access and so on) needed by the [Server].