Add HMAC protection on /approval endpoint

Signed-off-by: Bob Callaway <bcallaway@google.com>

storage/ent/client/authrequest.go

@@ -31,6 +31,7 @@ func (d *Database) CreateAuthRequest(authRequest storage.AuthRequest) error {
 		SetExpiry(authRequest.Expiry.UTC()).
 		SetConnectorID(authRequest.ConnectorID).
 		SetConnectorData(authRequest.ConnectorData).
+		SetHmacKey(authRequest.HMACKey).
 		Save(context.TODO())
 	if err != nil {
 		return convertDBError("create auth request: %w", err)
@@ -94,6 +95,7 @@ func (d *Database) UpdateAuthRequest(id string, updater func(old storage.AuthReq
 		SetExpiry(newAuthRequest.Expiry.UTC()).
 		SetConnectorID(newAuthRequest.ConnectorID).
 		SetConnectorData(newAuthRequest.ConnectorData).
+		SetHmacKey(newAuthRequest.HMACKey).
 		Save(context.TODO())
 	if err != nil {
 		return rollback(tx, "update auth request uploading: %w", err)

storage/ent/client/types.go

@@ -45,6 +45,7 @@ func toStorageAuthRequest(a *db.AuthRequest) storage.AuthRequest {
 			CodeChallenge:       a.CodeChallenge,
 			CodeChallengeMethod: a.CodeChallengeMethod,
 		},
+		HMACKey: a.HmacKey,
 	}
 }