3540484 - SAML2.0: User source <> is longer than maximum length of an user alias: 40 characters

When performing a SAML 2.0 authentication, the process fails, leading to a redirection to a logon screen.

The SAML Security Diagnostic Tool trace displays an error such as "User source <NameID sent by the IDP> is longer than maximum length of a user alias: 40 characters".

Additionally, the SAML Security Diagnostic Tool trace shows the following exception:

SAML20 SP (client):  Exception raised:
SAML20  SAML20 CX_SAML20_FEDERATION: User with alias <NameID sent by the IDP truncated to a maximum of 40 characters> does not exist in client <Client Number>. Long text: User with alias <NameID sent by the IDP truncated to a maximum of 40 characters> does not exist in client <Client Number>.

logon, login, username, password, SAML, SSO, Single Sign-On, 40 characters, exception, user alias, logon alias, User ID Mapping Mode, NameID, NameID Format, Unspecified  , KBA , BC-SEC-LGN-SML , SAML 2.0 for ABAP , BC-SEC-LGN , Authentication , Problem