nuts-foundation/nuts-node

/*
 * Copyright (C) 2023 Nuts community
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

package openid4vci

// ErrorCode specifies error codes as defined by the OpenID4VCI spec.
type ErrorCode string

const (
    // InvalidRequest is returned when:
    // - the Authorization Server does not expect a PIN in the pre-authorized flow but the client provides a PIN
    // - the Authorization Server expects a PIN in the pre-authorized flow but the client does not provide a PIN
    // - Credential Request was malformed. One or more of the parameters (i.e. format, proof) are missing or malformed.
    InvalidRequest ErrorCode = "invalid_request"
    // InvalidClient is returned when:
    // - the client tried to send a Token Request with a Pre-Authorized Code without Client ID but the Authorization Server does not support anonymous access
    InvalidClient ErrorCode = "invalid_client"
    // InvalidGrant is returned when (in addition to cases defined by OAuth2):
    // - the Authorization Server expects a PIN in the pre-authorized flow but the client provides the wrong PIN
    // - the End-User provides the wrong Pre-Authorized Code or the Pre-Authorized Code has expired
    InvalidGrant ErrorCode = "invalid_grant"
    // InvalidToken is returned when (in addition to cases defined by OAuth2):
    // - Credential Request contains the wrong Access Token or the Access Token is missing
    InvalidToken ErrorCode = "invalid_token"
    // UnsupportedGrantType is returned when the Authorization Server does not support the requested grant type.
    UnsupportedGrantType ErrorCode = "unsupported_grant_type"
    // ServerError is returned when the Authorization Server encounters an unexpected condition that prevents it from fulfilling the request.
    ServerError ErrorCode = "server_error"
    // UnsupportedCredentialType is returned when the credential issuer does not support the requested credential type.
    UnsupportedCredentialType ErrorCode = "unsupported_credential_type"
    // UnsupportedCredentialFormat is returned when the credential issuer does not support the requested credential format.
    UnsupportedCredentialFormat ErrorCode = "unsupported_credential_format"
    // InvalidProof is returned when the Credential Request did not contain a proof,
    // or proof was invalid, i.e. it was not bound to a Credential Issuer provided nonce
    InvalidProof ErrorCode = "invalid_proof"
)

// Error is an error that signals the error was (probably) caused by the client (e.g. bad request),
// or that the client can recover from the error (e.g. retry). Errors are specified by the OpenID4VCI specification.
// Invalid proof errors may also add a new c_nonce that the client must use in the next credential request.
type Error struct {
    // CNonce is a random string that the client must send in the next credential request.
    CNonce *string `json:"c_nonce,omitempty"`
    // CNonceExpiresIn is the number of seconds until the c_nonce expires.
    CNonceExpiresIn *int `json:"c_nonce_expires_in,omitempty"`
    // Code is the error code as defined by the OpenID4VCI spec.
    Code ErrorCode `json:"error"`
    // Err is the underlying error, may be omitted. It is not intended to be returned to the client.
    Err error `json:"-"`
    // StatusCode is the HTTP status code that should be returned to the client.
    StatusCode int `json:"-"`
}

// Error returns the error message, which is either the underlying error or the code if there is no underlying error
func (e Error) Error() string {
    if e.Err == nil {
        return string(e.Code)
    }
    return string(e.Code) + " - " + e.Err.Error()
}