Adaptive HTTP Authentication Scheme Selection

A server computer comprising:

• a processing unit;
• and
• system memory, the system memory including instructions that when executed by the processing unit cause the server computer to:
• receive a first request message from a client computer, the first request message requesting information stored on the server computer;
• in response to receiving the first request message from the client computer, send a first response message to the client computer, the first response message including an HTTP header, the HTTP header including a first scheme identifier and a second scheme identifier, the first scheme identifier indicating a first HTTP authentication scheme and the second scheme identifier indicating a second HTTP authentication scheme;
• receive a second request message from the client computer;
• in response to receiving the second request message from the client computer, determine whether the second request message includes the second scheme identifier;
• in response to determining the second request message includes the second scheme identifier, send a second response message to the client computer, the second response message including the second scheme identifier;
• and
• in response to determining that the second request message does not include the second scheme identifier, send a second response message to the client computer, the second response message including the first scheme identifier.

A computer-readable data storage medium comprising instructions that, when executed by a processing unit of a server computer, cause the server computer to:

• receive a first request message from a client computer, the first request message requesting information stored on the server computer;
• in response to the first request message, send a reply message to the client computer, the reply message including an HTTP header, the HTTP header including a first scheme identifier and a second scheme identifier, the first scheme identifier being “Negotiate” and the second scheme identifier being “Nego2”, the reply message also including a first data block following the second scheme identifier, the first data block including one or more identifiers of authentication protocols that the server computer accepts;
• receive a second request message from the client computer, the second request message including a second HTTP header, the second HTTP header including a third scheme identifier;
• determine whether the third scheme identifier matches the first scheme identifier;
• in response to determining that the third scheme identifier matches the first scheme identifier, select an HTTP authentication scheme indicated by the first scheme identifier;
• determine whether the third scheme identifier matches the second scheme identifier;
• in response to determining that the third scheme identifier matches the second scheme identifier, select an HTTP authentication scheme indicated by the second scheme identifier;
• in response to determining that the third scheme identifier matches the second scheme identifier, identify a client-accepted authentication protocol by processing a second data block included in the second request message, the client-accepted authentication protocol being an authentication protocol accepted by the client computer;
• and
• use the client-accepted authentication protocol to authenticate the client computer at the server computer.