User Authentication Modules Leland Wallace Sr. Engineer AppleShare Leland Wallace Sr. Engineer AppleShare

Introduction Overview What UAMs Do UAM Packaging How it Works Client API Server API Example NIS UAM Developer Opportunities Overview What UAMs Do UAM Packaging How it Works Client API Server API Example NIS UAM Developer Opportunities

Overview AppleShare Client has supported User Authentication Module plug-ins (UAMs) since System 7. Client UAM API updated and made transport independent. ASIP 6.0 adds plug-in UAM API to the Server. AppleShare Client has supported User Authentication Module plug-ins (UAMs) since System 7. Client UAM API updated and made transport independent. ASIP 6.0 adds plug-in UAM API to the Server.

What UAMs Do Allow ASIP to fit into an existing authentication infrastructure –Kerberos, NIS (yellow pages), Windows NT Domains, NDS Permit client to connect to different AFP servers using the server’s native authentication Allow ASIP to fit into an existing authentication infrastructure –Kerberos, NIS (yellow pages), Windows NT Domains, NDS Permit client to connect to different AFP servers using the server’s native authentication

UAM Packaging Server UAM –CFM library –Loaded by the ASIP Registry at startup –Called at deferred task time Client UAM –Code resource –Loaded on demand –Called at main event time Server UAM –CFM library –Loaded by the ASIP Registry at startup –Called at deferred task time Client UAM –Code resource –Loaded on demand –Called at main event time

How it Works Client gets the list of supported UAMs from the server. User chooses from the list of supported UAMs Example: AFP login AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works Client loads the selected UAM & calls UAMOpen() AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works Client calls UAMLogin(), UAM opens the session with the OpenSession() callback AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works Server passes the UAM request to the registry AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works The Registry calls the Server UAM with the message from the client AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works AppleShare Client AppleShare Server ASIP Registry Server UAM The Server UAM contacts an external Authentication server External Auth server Client UAM

How it Works Replies from the Server UAM are sent back to the client along the reverse path. The Client UAM can send other messages via the SendMessage callback AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works The Client UAM returns from the UAMLogin() call AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

How it Works The Client calls UAMClose() and unloads the UAM AppleShare Client AppleShare Server ASIP Registry Server UAM External Auth server Client UAM

Client UAM API Single entry point Three required commands: –UAMOpen, UAMLogin, UAMClose Optional commands: –UAMPWDlog, UAMVSDlog, UAMChgPassDlg, –UAMChgPass, UAMGetInfoSize, UAMGetInfo Callback functions: –GetClientInfo, OpenSession, SendMessage –CloseSession, SetMIC Single entry point Three required commands: –UAMOpen, UAMLogin, UAMClose Optional commands: –UAMPWDlog, UAMVSDlog, UAMChgPassDlg, –UAMChgPass, UAMGetInfoSize, UAMGetInfo Callback functions: –GetClientInfo, OpenSession, SendMessage –CloseSession, SetMIC

Server UAM API Single entry point One required command: –UAMAuthLogin Optional commands: –UAMAuthLoginContinue, UAMAuthChangeKey –UAMAuthChangeKeyContinue, UAMGetMICKey Server UAM API functionality –Get & Set user attributes –Change User ID –Create a new User –Put the UAM thread to sleep –Wakeup the UAM thread Single entry point One required command: –UAMAuthLogin Optional commands: –UAMAuthLoginContinue, UAMAuthChangeKey –UAMAuthChangeKeyContinue, UAMGetMICKey Server UAM API functionality –Get & Set user attributes –Change User ID –Create a new User –Put the UAM thread to sleep –Wakeup the UAM thread

Authenticates a user with an NIS server If the user is not in the server’s registry, the UAM will create the user and assign them the proper group memberships Requires that the server admin set up a proxy user for the UAM and set up groups Authenticates a user with an NIS server If the user is not in the server’s registry, the UAM will create the user and assign them the proper group memberships Requires that the server admin set up a proxy user for the UAM and set up groups NIS (Yellow Pages) Example

INIT(){ Get the NIS domain name from the prefs Call yp_bind Initalize prng } UAMOpen(UAMArgs* nArgs){ Initalize prng Figure out the AFP version using the ClientInfo callback Return the config flags that specify the default UI } UAMLogin(UAMArgs* nArgs){ Generate first message in DH exchange (Ma) Using the user name passed in, build the AFP command Use the open session callback to connect to the server INIT(){ Get the NIS domain name from the prefs Call yp_bind Initalize prng } UAMOpen(UAMArgs* nArgs){ Initalize prng Figure out the AFP version using the ClientInfo callback Return the config flags that specify the default UI } UAMLogin(UAMArgs* nArgs){ Generate first message in DH exchange (Ma) Using the user name passed in, build the AFP command Use the open session callback to connect to the server NIS UAM Server UAMClient UAM

OAMAuthenticate() { // state = kLoginState Get the User Name from the AuthInfo buffer Get Ma from the buffer Generate (Mb) the second message in the DH exchange from Rb Create the Key from Ma and Rb Save the username & the key in AuthStateOut Put Mb into the reply buffer Return kAuthContinue; } UAMLogin Get Mb out of the reply buffer Create the Key from Mb and Ra Take the password and encrypt it with the key Use the Send Message callback to send the encrypted password to the server OAMAuthenticate() { // state = kLoginState Get the User Name from the AuthInfo buffer Get Ma from the buffer Generate (Mb) the second message in the DH exchange from Rb Create the Key from Ma and Rb Save the username & the key in AuthStateOut Put Mb into the reply buffer Return kAuthContinue; } UAMLogin Get Mb out of the reply buffer Create the Key from Mb and Ra Take the password and encrypt it with the key Use the Send Message callback to send the encrypted password to the server Login,AFPVers,NISProxy,NISUser,UserName,Ma Server UAM Client UAM AuthContinue, Mb

OAMAuthenticate() { // state = kLoginContinueState Get the encrypted password from the AuthDataIn buffer Get the key from the authState Decrypt the encrypted passwrd with the key Get the username from the authState Call yp_match on the “passwd.byname” table to get the /etc/passwd style entry If the match succeeds Use the salt from the passwd entry and crypt() to verify the password from the user. If the user is authenticated, look the user up in the Registry If the user is not found Create the user using UAMCreateObject() Use yp_match again to get the group memberships Add the user to the proper groups Call UAMChangeUID() to change to the proper user Return noErr } OAMAuthenticate() { // state = kLoginContinueState Get the encrypted password from the AuthDataIn buffer Get the key from the authState Decrypt the encrypted passwrd with the key Get the username from the authState Call yp_match on the “passwd.byname” table to get the /etc/passwd style entry If the match succeeds Use the salt from the passwd entry and crypt() to verify the password from the user. If the user is authenticated, look the user up in the Registry If the user is not found Create the user using UAMCreateObject() Use yp_match again to get the group memberships Add the user to the proper groups Call UAMChangeUID() to change to the proper user Return noErr } Server UAM Client UAM LoginContinue,(Password)K noError

Server UAM Client UAM UAMLogin return the session reference number } UAMClose(){ clean up any data structures }

Developer Opportunities Kerberos-based UAM LDAP-based UAM License UAM Java UAM Smartcard-based UAM Looking for a Windows PDC UAM Kerberos-based UAM LDAP-based UAM License UAM Java UAM Smartcard-based UAM Looking for a Windows PDC UAM

Where to go from here Check the AppleShare IP website for documentation and SDK info me to get the latest UAM SDK Check the AppleShare IP website for documentation and SDK info me to get the latest UAM SDK