DICOM PS3.7 2025b - Message Exchange
D.3.3.7.2 User Identity Sub-Item Structure (A-ASSOCIATE-AC)

The User Identity Sub-Item shall be made of a sequence of mandatory fixed and variable length fields. This Sub-Item is optional and if supported, only one User Identity Sub-Item shall be present in the User Data Item of the A-ASSOCIATE-AC. Table D.3-15 shows the sequence of the mandatory fields.

Table D.3-15. User Identity Negotiation Sub-Item Fields (A-ASSOCIATE-AC)

Item Bytes

Field Name

Description of Field

1

Item-type

59H

2

Reserved

This reserved field shall be sent with a value 00H but not tested to this value when received.

3-4

Item-length

This Item-length shall be the number of bytes from the first byte of the following field to the last byte of the final field. It shall be encoded as an unsigned binary number.

5-6

Server-response-length

This field shall contain the number of bytes in the Server-response. May be zero.

7-n

Server-response

This field shall contain the Kerberos Server ticket, encoded in accordance with [RFC1510], if the User-Identity-Type value in the A-ASSOCIATE-RQ was 3. This field shall contain the SAML response if the User-Identity-Type value in the A-ASSOCIATE-RQ was 4. This field shall be zero length if the value of the User-Identity-Type in the A-ASSOCIATE-RQ was 1 or 2.


If the Association-Requestor has requested a positive acknowledgment, the Server-response shall be returned with the Kerberos Server ticket when User-Identity-Type is Kerberos Service ticket (3).

DICOM PS3.7 2025b - Message Exchange