Implement OpenID module (#599) (#1812)

* Implement OpenID module (#599)

- Unrelated: change Riot references to Element in client API routing

Signed-off-by: Bruce MacDonald <contact@bruce-macdonald.com>

* OpenID module tweaks (#599)

- specify expiry is ms rather than vague ts
- add OpenID token lifetime to configuration
- use Go naming conventions for the path params
- store plaintext token rather than hash
- remove openid table sqllite mutex

* Add default OpenID token lifetime (#599)

* Update dendrite-config.yaml

Co-authored-by: Kegsay <kegsay@gmail.com>
Co-authored-by: Kegsay <kegan@matrix.org>

userapi/storage/accounts/sqlite3/openid_table.go

@@ -0,0 +1,86 @@
+package sqlite3
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/gomatrixserverlib"
+	log "github.com/sirupsen/logrus"
+)
+
+const openIDTokenSchema = `
+-- Stores data about accounts.
+CREATE TABLE IF NOT EXISTS open_id_tokens (
+	-- The value of the token issued to a user
+	token TEXT NOT NULL PRIMARY KEY,
+    -- The Matrix user ID for this account
+	localpart TEXT NOT NULL,
+	-- When the token expires, as a unix timestamp (ms resolution).
+	token_expires_at_ms BIGINT NOT NULL
+);
+`
+
+const insertTokenSQL = "" +
+	"INSERT INTO open_id_tokens(token, localpart, token_expires_at_ms) VALUES ($1, $2, $3)"
+
+const selectTokenSQL = "" +
+	"SELECT localpart, token_expires_at_ms FROM open_id_tokens WHERE token = $1"
+
+type tokenStatements struct {
+	db              *sql.DB
+	insertTokenStmt *sql.Stmt
+	selectTokenStmt *sql.Stmt
+	serverName      gomatrixserverlib.ServerName
+}
+
+func (s *tokenStatements) prepare(db *sql.DB, server gomatrixserverlib.ServerName) (err error) {
+	s.db = db
+	_, err = db.Exec(openIDTokenSchema)
+	if err != nil {
+		return err
+	}
+	if s.insertTokenStmt, err = db.Prepare(insertTokenSQL); err != nil {
+		return
+	}
+	if s.selectTokenStmt, err = db.Prepare(selectTokenSQL); err != nil {
+		return
+	}
+	s.serverName = server
+	return
+}
+
+// insertToken inserts a new OpenID Connect token to the DB.
+// Returns new token, otherwise returns error if the token already exists.
+func (s *tokenStatements) insertToken(
+	ctx context.Context,
+	txn *sql.Tx,
+	token, localpart string,
+	expiresAtMS int64,
+) (err error) {
+	stmt := sqlutil.TxStmt(txn, s.insertTokenStmt)
+	_, err = stmt.ExecContext(ctx, token, localpart, expiresAtMS)
+	return
+}
+
+// selectOpenIDTokenAtrributes gets the attributes associated with an OpenID token from the DB
+// Returns the existing token's attributes, or err if no token is found
+func (s *tokenStatements) selectOpenIDTokenAtrributes(
+	ctx context.Context,
+	token string,
+) (*api.OpenIDTokenAttributes, error) {
+	var openIDTokenAttrs api.OpenIDTokenAttributes
+	err := s.selectTokenStmt.QueryRowContext(ctx, token).Scan(
+		&openIDTokenAttrs.UserID,
+		&openIDTokenAttrs.ExpiresAtMS,
+	)
+	if err != nil {
+		if err != sql.ErrNoRows {
+			log.WithError(err).Error("Unable to retrieve token from the db")
+		}
+		return nil, err
+	}
+
+	return &openIDTokenAttrs, nil
+}