Information processing system, client device, authentication and authorization server, control method, and storage medium

A method for controlling an information processing system comprising a client terminal configured to add a signature using an encryption key to a request, and an authentication and authorization server which issues an authorization token for accessing a resource server and which is configured to verify the signature added to the request from the client terminal using a decryption key, the method comprising:

• causing the client terminal to perform transmitting, to the authentication and authorization server, an authorization token request including a time at which the signature is issued in order to obtain an authorization token, and receiving and verifying, from the authentication and authorization server, a response to the authorization token request;
• causing the authentication and authorization server to perform determining whether at least a predetermined difference is present between an issue time of the signature included in the transmitted authorization token request and a time of the authentication and authorization server, and responding based on a determination result by the determining;
• responding to the client terminal with an error including the time of the authentication and authorization server in a case where it is determined by the determining that at least a predetermined difference is present between an issue time of the signature included in a first authorization token request transmitted by the transmitting and the time of the authentication and authorization server;
• transmitting a second authorization token request including the time of the authentication and authorization server to the authentication and authorization server in a case where it is determined by the determining that the error includes the time of the authentication and authorization server;
• managing, by the client terminal, a time difference between the time of the authentication and authorization server included in the error and a time of the client terminal;
• and
• transmitting a third authorization token request including the issue time corrected based on the time difference to the authentication and authorization server.

A client terminal which adds a signature using an encryption key to a request to an authentication and authorization server which issues an authorization token for accessing a resource server, the client terminal comprising:

• one or more processors;
• and
• at least one memory coupled to the one or more processors and having stored thereon instructions, which when executed by the one or more processors, cause the client terminal to:
• transmit, to the authentication and authorization server, a first authorization token request including an issue time at which the signature is issued in order to obtain an authorization token;
• receive a response to the first authorization token request from the authentication and authorization server;
• transmit, in a case where the response is an error, a second authorization token request including a time of the authentication and authorization server together with the received error;
• manage a time difference between the time of the authentication and authorization server and a time of the client terminal;
• and
• transmit a third authorization token request including the issue time corrected based on the time difference to the authentication and authorization server.

A method for controlling a client terminal which adds a signature using an encryption key to a request to an authentication and authorization server which issues an authorization token for accessing a resource server, the method comprising:

• causing the client terminal to transmit, to the authentication and authorization server, a first authorization token request including an issue time at which the signature is issued in order to obtain an authorization token;
• receiving a response to the transmitted first authorization token request from the authentication and authorization server;
• transmitting, in a case where the received response is an error, a second authorization token request including a time of the authentication and authorization server together with the received error;
• managing a time difference between the time of the authentication and authorization server and a time of the client terminal;
• and
• transmitting a third authorization token request including the issue time corrected based on the time difference to the authentication and authorization server.

A non-transitory computer-readable storage medium storing instructions, which when executed by one or more processors of a client terminal configured to add a signature using an encryption key to a request to an authentication and authorization server which issues an authorization token for accessing a resource server, cause the client terminal to:

• transmit, to the authentication and authorization server, a first authorization token request including an issue time at which the signature is issued in order to obtain an authorization token;
• receive a response to the first authorization token request from the authentication and authorization server;
• transmit, in a case where the response is an error, a second authorization token request including a time of the authentication and authorization server together with the received error;
• manage a time difference between the time of the authentication and authorization server and a time of the client terminal;
• and
• transmit a third authorization token request including the issue time corrected based on the time difference to the authentication and authorization server.