Provide API for management of host, service, and user principal aliases

New commands (*-{add,remove}-principal [PKEY] [PRINCIPAL ...])
were added to manage principal aliases.

'add' commands will check the following:
* the correct principal type is supplied as an alias
* the principals have correct realm and the realm/alternative suffix (e.g.
  e-mail) do not overlap with those of trusted AD domains

If the entry does not have canonical principal name, the first returned
principal name will be set as one. This is mostly to smoothly operate on
entries created on older servers.

'remove' commands will check that there is at least one principal alias equal
to the canonical name left on the entry.

See also: http://www.freeipa.org/page/V4/Kerberos_principal_aliases

https://fedorahosted.org/freeipa/ticket/1365
https://fedorahosted.org/freeipa/ticket/3961
https://fedorahosted.org/freeipa/ticket/5413

Reviewed-By: David Kupka <dkupka@redhat.com>
Reviewed-By: Jan Cholasta <jcholast@redhat.com>

8 files changed, 299 insertions, 42 deletions

diff --git a/ACI.txt b/ACI.txt
index 09e4ee7fc..fddd5987f 100644
--- a/ACI.txt
+++ b/ACI.txt
@@ -135,6 +135,8 @@ aci: (targetattr = "krblastpwdchange || krbprincipalkey")(targetfilter = "(&(!(m
 dn: cn=computers,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "createtimestamp || entryusn || ipaallowedtoperform;read_keys || ipaallowedtoperform;write_keys || modifytimestamp || objectclass")(targetfilter = "(objectclass=ipahost)")(version 3.0;acl "permission:System: Manage Host Keytab Permissions";allow (compare,read,search,write) groupdn = "ldap:///cn=System: Manage Host Keytab Permissions,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=computers,cn=accounts,dc=ipa,dc=example
+aci: (targetattr = "krbcanonicalname || krbprincipalname")(targetfilter = "(objectclass=ipahost)")(version 3.0;acl "permission:System: Manage Host Principals";allow (write) groupdn = "ldap:///cn=System: Manage Host Principals,cn=permissions,cn=pbac,dc=ipa,dc=example";)
+dn: cn=computers,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "ipasshpubkey")(targetfilter = "(objectclass=ipahost)")(version 3.0;acl "permission:System: Manage Host SSH Public Keys";allow (write) groupdn = "ldap:///cn=System: Manage Host SSH Public Keys,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=computers,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "description || ipaassignedidview || krbprincipalauthind || l || macaddress || nshardwareplatform || nshostlocation || nsosversion || userclass")(targetfilter = "(objectclass=ipahost)")(version 3.0;acl "permission:System: Modify Hosts";allow (write) groupdn = "ldap:///cn=System: Modify Hosts,cn=permissions,cn=pbac,dc=ipa,dc=example";)
@@ -249,6 +251,8 @@ aci: (targetattr = "krblastpwdchange || krbprincipalkey")(targetfilter = "(objec
 dn: cn=services,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "createtimestamp || entryusn || ipaallowedtoperform;read_keys || ipaallowedtoperform;write_keys || modifytimestamp || objectclass")(targetfilter = "(objectclass=ipaservice)")(version 3.0;acl "permission:System: Manage Service Keytab Permissions";allow (compare,read,search,write) groupdn = "ldap:///cn=System: Manage Service Keytab Permissions,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=services,cn=accounts,dc=ipa,dc=example
+aci: (targetattr = "krbcanonicalname || krbprincipalname")(targetfilter = "(objectclass=ipaservice)")(version 3.0;acl "permission:System: Manage Service Principals";allow (write) groupdn = "ldap:///cn=System: Manage Service Principals,cn=permissions,cn=pbac,dc=ipa,dc=example";)
+dn: cn=services,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "krbprincipalauthind || usercertificate")(targetfilter = "(objectclass=ipaservice)")(version 3.0;acl "permission:System: Modify Services";allow (write) groupdn = "ldap:///cn=System: Modify Services,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=services,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "createtimestamp || entryusn || ipakrbauthzdata || ipakrbprincipalalias || ipauniqueid || krbcanonicalname || krblastpwdchange || krbobjectreferences || krbpasswordexpiration || krbprincipalaliases || krbprincipalauthind || krbprincipalexpiration || krbprincipalname || managedby || memberof || modifytimestamp || objectclass || usercertificate")(targetfilter = "(objectclass=ipaservice)")(version 3.0;acl "permission:System: Read Services";allow (compare,read,search) userdn = "ldap:///all";)
@@ -335,6 +339,8 @@ aci: (targetattr = "krbprincipalkey || passwordhistory || sambalmpassword || sam
 dn: cn=users,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "usercertificate")(targetfilter = "(objectclass=posixaccount)")(version 3.0;acl "permission:System: Manage User Certificates";allow (write) groupdn = "ldap:///cn=System: Manage User Certificates,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=users,cn=accounts,dc=ipa,dc=example
+aci: (targetattr = "krbcanonicalname || krbprincipalname")(targetfilter = "(objectclass=posixaccount)")(version 3.0;acl "permission:System: Manage User Principals";allow (write) groupdn = "ldap:///cn=System: Manage User Principals,cn=permissions,cn=pbac,dc=ipa,dc=example";)
+dn: cn=users,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "ipasshpubkey")(targetfilter = "(objectclass=posixaccount)")(version 3.0;acl "permission:System: Manage User SSH Public Keys";allow (write) groupdn = "ldap:///cn=System: Manage User SSH Public Keys,cn=permissions,cn=pbac,dc=ipa,dc=example";)
 dn: cn=users,cn=accounts,dc=ipa,dc=example
 aci: (targetattr = "businesscategory || carlicense || cn || departmentnumber || description || displayname || employeenumber || employeetype || facsimiletelephonenumber || gecos || givenname || homephone || inetuserhttpurl || initials || l || labeleduri || loginshell || mail || manager || mepmanagedentry || mobile || objectclass || ou || pager || postalcode || preferredlanguage || roomnumber || secretary || seealso || sn || st || street || telephonenumber || title || userclass")(targetfilter = "(objectclass=posixaccount)")(version 3.0;acl "permission:System: Modify Users";allow (write) groupdn = "ldap:///cn=System: Modify Users,cn=permissions,cn=pbac,dc=ipa,dc=example";)
diff --git a/API.txt b/API.txt
index 5d99f5a0b..7d82d353a 100644
--- a/API.txt
+++ b/API.txt
@@ -2310,6 +2310,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: host_add_principal/1
+args: 2,4,3
+arg: Str('fqdn', cli_name='hostname')
+arg: Principal('krbprincipalname+', alwaysask=True)
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: host_allow_create_keytab/1
 args: 1,8,3
 arg: Str('fqdn', cli_name='hostname')
@@ -2436,7 +2447,7 @@ option: Bool('ipakrbokasdelegate?', autofill=False, cli_name='ok_as_delegate')
 option: Bool('ipakrbrequirespreauth?', autofill=False, cli_name='requires_pre_auth')
 option: Str('ipasshpubkey*', autofill=False, cli_name='sshpubkey')
 option: Str('krbprincipalauthind*', autofill=False, cli_name='auth_ind')
-option: Principal('krbprincipalname?', cli_name='principalname')
+option: Principal('krbprincipalname*', autofill=False)
 option: Str('l?', autofill=False, cli_name='locality')
 option: Str('macaddress*', autofill=False)
 option: Flag('no_members', autofill=True, default=False)
@@ -2477,6 +2488,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: host_remove_principal/1
+args: 2,4,3
+arg: Str('fqdn', cli_name='hostname')
+arg: Principal('krbprincipalname+', alwaysask=True)
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: host_show/1
 args: 1,6,3
 arg: Str('fqdn', cli_name='hostname')
@@ -4309,6 +4331,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: service_add_principal/1
+args: 2,4,3
+arg: Principal('krbcanonicalname', cli_name='canonical_principal')
+arg: Principal('krbprincipalname+', alwaysask=True, cli_name='principal')
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: service_allow_create_keytab/1
 args: 1,8,3
 arg: Principal('krbcanonicalname', cli_name='canonical_principal')
@@ -4387,7 +4420,7 @@ option: Flag('all', autofill=True, cli_name='all', default=False)
 option: StrEnum('ipakrbauthzdata*', autofill=False, cli_name='pac_type', values=[u'MS-PAC', u'PAD', u'NONE'])
 option: Principal('krbcanonicalname?', autofill=False, cli_name='canonical_principal')
 option: Str('krbprincipalauthind*', autofill=False, cli_name='auth_ind')
-option: Principal('krbprincipalname?', autofill=False, cli_name='principal')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Str('man_by_host*', cli_name='man_by_hosts')
 option: Flag('no_members', autofill=True, default=True)
 option: Str('not_man_by_host*', cli_name='not_man_by_hosts')
@@ -4401,7 +4434,7 @@ output: ListOfEntries('result')
 output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
 output: Output('truncated', type=[<type 'bool'>])
 command: service_mod/1
-args: 1,13,3
+args: 1,14,3
 arg: Principal('krbcanonicalname', cli_name='canonical_principal')
 option: Str('addattr*', cli_name='addattr')
 option: Flag('all', autofill=True, cli_name='all', default=False)
@@ -4410,6 +4443,7 @@ option: StrEnum('ipakrbauthzdata*', autofill=False, cli_name='pac_type', values=
 option: Bool('ipakrbokasdelegate?', autofill=False, cli_name='ok_as_delegate')
 option: Bool('ipakrbrequirespreauth?', autofill=False, cli_name='requires_pre_auth')
 option: Str('krbprincipalauthind*', autofill=False, cli_name='auth_ind')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Flag('no_members', autofill=True, default=False)
 option: Flag('raw', autofill=True, cli_name='raw', default=False)
 option: Flag('rights', autofill=True, default=False)
@@ -4441,6 +4475,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: service_remove_principal/1
+args: 2,4,3
+arg: Principal('krbcanonicalname', cli_name='canonical_principal')
+arg: Principal('krbprincipalname+', alwaysask=True, cli_name='principal')
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: service_show/1
 args: 1,6,3
 arg: Principal('krbcanonicalname', cli_name='canonical_principal')
@@ -4647,7 +4692,7 @@ option: Str('ipatokenradiusconfiglink?', cli_name='radius')
 option: Str('ipatokenradiususername?', cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', cli_name='principal_expiration')
-option: Principal('krbprincipalname?', autofill=True, cli_name='principal')
+option: Principal('krbprincipalname*', autofill=True, cli_name='principal')
 option: Str('l?', cli_name='city')
 option: Str('loginshell?', cli_name='shell')
 option: Str('mail*', cli_name='email')
@@ -4718,7 +4763,7 @@ option: Str('ipatokenradiusconfiglink?', autofill=False, cli_name='radius')
 option: Str('ipatokenradiususername?', autofill=False, cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', autofill=False, cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', autofill=False, cli_name='principal_expiration')
-option: Principal('krbprincipalname?', autofill=False, cli_name='principal')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Str('l?', autofill=False, cli_name='city')
 option: Str('loginshell?', autofill=False, cli_name='shell')
 option: Str('mail*', autofill=False, cli_name='email')
@@ -4754,7 +4799,7 @@ output: ListOfEntries('result')
 output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
 output: Output('truncated', type=[<type 'bool'>])
 command: stageuser_mod/1
-args: 1,45,3
+args: 1,46,3
 arg: Str('uid', cli_name='login')
 option: Str('addattr*', cli_name='addattr')
 option: Flag('all', autofill=True, cli_name='all', default=False)
@@ -4776,6 +4821,7 @@ option: Str('ipatokenradiusconfiglink?', autofill=False, cli_name='radius')
 option: Str('ipatokenradiususername?', autofill=False, cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', autofill=False, cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', autofill=False, cli_name='principal_expiration')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Str('l?', autofill=False, cli_name='city')
 option: Str('loginshell?', autofill=False, cli_name='shell')
 option: Str('mail*', autofill=False, cli_name='email')
@@ -5634,7 +5680,7 @@ option: Str('ipatokenradiusconfiglink?', cli_name='radius')
 option: Str('ipatokenradiususername?', cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', cli_name='principal_expiration')
-option: Principal('krbprincipalname?', autofill=True, cli_name='principal')
+option: Principal('krbprincipalname*', autofill=True, cli_name='principal')
 option: Str('l?', cli_name='city')
 option: Str('loginshell?', cli_name='shell')
 option: Str('mail*', cli_name='email')
@@ -5685,6 +5731,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: user_add_principal/1
+args: 2,4,3
+arg: Str('uid', cli_name='login')
+arg: Principal('krbprincipalname+', alwaysask=True, autofill=True, cli_name='principal')
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: user_del/1
 args: 1,3,3
 arg: Str('uid+', cli_name='login')
@@ -5733,7 +5790,7 @@ option: Str('ipatokenradiusconfiglink?', autofill=False, cli_name='radius')
 option: Str('ipatokenradiususername?', autofill=False, cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', autofill=False, cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', autofill=False, cli_name='principal_expiration')
-option: Principal('krbprincipalname?', autofill=False, cli_name='principal')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Str('l?', autofill=False, cli_name='city')
 option: Str('loginshell?', autofill=False, cli_name='shell')
 option: Str('mail*', autofill=False, cli_name='email')
@@ -5772,7 +5829,7 @@ output: ListOfEntries('result')
 output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
 output: Output('truncated', type=[<type 'bool'>])
 command: user_mod/1
-args: 1,46,3
+args: 1,47,3
 arg: Str('uid', cli_name='login')
 option: Str('addattr*', cli_name='addattr')
 option: Flag('all', autofill=True, cli_name='all', default=False)
@@ -5794,6 +5851,7 @@ option: Str('ipatokenradiusconfiglink?', autofill=False, cli_name='radius')
 option: Str('ipatokenradiususername?', autofill=False, cli_name='radius_username')
 option: StrEnum('ipauserauthtype*', autofill=False, cli_name='user_auth_type', values=[u'password', u'radius', u'otp'])
 option: DateTime('krbprincipalexpiration?', autofill=False, cli_name='principal_expiration')
+option: Principal('krbprincipalname*', autofill=False, cli_name='principal')
 option: Str('l?', autofill=False, cli_name='city')
 option: Str('loginshell?', autofill=False, cli_name='shell')
 option: Str('mail*', autofill=False, cli_name='email')
@@ -5845,6 +5903,17 @@ option: Str('version?')
 output: Output('completed', type=[<type 'int'>])
 output: Output('failed', type=[<type 'dict'>])
 output: Entry('result')
+command: user_remove_principal/1
+args: 2,4,3
+arg: Str('uid', cli_name='login')
+arg: Principal('krbprincipalname+', alwaysask=True, autofill=True, cli_name='principal')
+option: Flag('all', autofill=True, cli_name='all', default=False)
+option: Flag('no_members', autofill=True, default=False)
+option: Flag('raw', autofill=True, cli_name='raw', default=False)
+option: Str('version?')
+output: Entry('result')
+output: Output('summary', type=[<type 'unicode'>, <type 'NoneType'>])
+output: PrimaryKey('value')
 command: user_show/1
 args: 1,6,3
 arg: Str('uid', cli_name='login')
@@ -6322,6 +6391,7 @@ default: host/1
 default: host_add/1
 default: host_add_cert/1
 default: host_add_managedby/1
+default: host_add_principal/1
 default: host_allow_create_keytab/1
 default: host_allow_retrieve_keytab/1
 default: host_del/1
@@ -6332,6 +6402,7 @@ default: host_find/1
 default: host_mod/1
 default: host_remove_cert/1
 default: host_remove_managedby/1
+default: host_remove_principal/1
 default: host_show/1
 default: hostgroup/1
 default: hostgroup_add/1
@@ -6491,6 +6562,7 @@ default: service/1
 default: service_add/1
 default: service_add_cert/1
 default: service_add_host/1
+default: service_add_principal/1
 default: service_allow_create_keytab/1
 default: service_allow_retrieve_keytab/1
 default: service_del/1
@@ -6501,6 +6573,7 @@ default: service_find/1
 default: service_mod/1
 default: service_remove_cert/1
 default: service_remove_host/1
+default: service_remove_principal/1
 default: service_show/1
 default: servicedelegationrule/1
 default: servicedelegationrule_add/1
@@ -6605,6 +6678,7 @@ default: user/1
 default: user_add/1
 default: user_add_cert/1
 default: user_add_manager/1
+default: user_add_principal/1
 default: user_del/1
 default: user_disable/1
 default: user_enable/1
@@ -6612,6 +6686,7 @@ default: user_find/1
 default: user_mod/1
 default: user_remove_cert/1
 default: user_remove_manager/1
+default: user_remove_principal/1
 default: user_show/1
 default: user_stage/1
 default: user_status/1
diff --git a/VERSION b/VERSION
index dd2e1aba1..b9b5485bc 100644
--- a/VERSION
+++ b/VERSION
@@ -90,5 +90,5 @@ IPA_DATA_VERSION=20100614120000
 #                                                      #
 ########################################################
 IPA_API_VERSION_MAJOR=2
-IPA_API_VERSION_MINOR=207
-# Last change: mbabinsk: Make framework consider krbcanonicalname as service primary key
+IPA_API_VERSION_MINOR=208
+# Last change: mbabinsk: Provide API for management of host, service, and user principal aliases
diff --git a/ipalib/util.py b/ipalib/util.py
index 67865eb04..d101514ca 100644
--- a/ipalib/util.py
+++ b/ipalib/util.py
@@ -912,3 +912,74 @@ def set_krbcanonicalname(entry_attrs):
     if ('krbprincipalname' in entry_attrs
             and 'krbcanonicalname' not in entry_attrs):
         entry_attrs['krbcanonicalname'] = entry_attrs['krbprincipalname']
+
+
+def ensure_last_krbprincipalname(ldap, entry_attrs, *keys):
+    """
+    ensure that the LDAP entry has at least one value of krbprincipalname
+    and that this value is equal to krbcanonicalname
+
+    :param ldap: LDAP connection object
+    :param entry_attrs: LDAP entry made prior to update
+    :param options: command options
+    """
+    entry = ldap.get_entry(
+        entry_attrs.dn, ['krbcanonicalname', 'krbprincipalname'])
+
+    krbcanonicalname = entry.single_value.get('krbcanonicalname', None)
+
+    if krbcanonicalname in keys[-1]:
+        raise errors.ValidationError(
+            name='krbprincipalname',
+            error=_('at least one value equal to the canonical '
+                    'principal name must be present')
+        )
+
+
+def ensure_krbcanonicalname_set(ldap, entry_attrs):
+    old_entry = ldap.get_entry(
+        entry_attrs.dn,
+        ['krbcanonicalname', 'krbprincipalname', 'objectclass'])
+
+    if old_entry.single_value.get('krbcanonicalname', None) is not None:
+        return
+
+    set_krbcanonicalname(old_entry)
+
+    old_entry.pop('krbprincipalname', None)
+    old_entry.pop('objectclass', None)
+
+    entry_attrs.update(old_entry)
+
+
+def check_principal_realm_in_trust_namespace(api_instance, *keys):
+    """
+    Check that principal name's suffix does not overlap with UPNs and realm
+    names of trusted forests.
+
+    :param api_instance: API instance
+    :param suffixes: principal suffixes
+
+    :raises: ValidationError if the suffix coincides with realm name, UPN
+    suffix or netbios name of trusted domains
+    """
+    trust_objects = api_instance.Command.trust_find(u'', sizelimit=0)['result']
+
+    trust_suffix_namespace = set()
+
+    for obj in trust_objects:
+        trust_suffix_namespace.update(
+            set(upn.lower() for upn in obj['ipantadditionalsuffixes']))
+
+        trust_suffix_namespace.update(
+            set((obj['cn'][0].lower(), obj['ipantflatname'][0].lower())))
+
+    for principal in keys[-1]:
+        realm = principal.realm
+        upn = principal.upn_suffix if principal.is_enterprise else None
+
+        if realm in trust_suffix_namespace or upn in trust_suffix_namespace:
+            raise errors.ValidationError(
+                name='krbprincipalname',
+                error=_('realm or UPN suffix overlaps with trusted domain '
+                        'namespace'))
diff --git a/ipaserver/plugins/baseuser.py b/ipaserver/plugins/baseuser.py
index cbb04aaad..c80d5ac0d 100644
--- a/ipaserver/plugins/baseuser.py
+++ b/ipaserver/plugins/baseuser.py
@@ -27,7 +27,8 @@ from ipalib.parameters import Principal
 from ipalib.plugable import Registry
 from .baseldap import (
     DN, LDAPObject, LDAPCreate, LDAPUpdate, LDAPSearch, LDAPDelete,
-    LDAPRetrieve, LDAPAddMember, LDAPRemoveMember)
+    LDAPRetrieve, LDAPAddAttribute, LDAPRemoveAttribute, LDAPAddMember,
+    LDAPRemoveMember)
 from ipaserver.plugins.service import (
    validate_certificate, validate_realm, normalize_principal)
 from ipalib.request import context
@@ -42,7 +43,10 @@ from ipalib.util import (
     remove_sshpubkey_from_output_post,
     remove_sshpubkey_from_output_list_post,
     add_sshpubkey_to_attrs_pre,
-    set_krbcanonicalname
+    set_krbcanonicalname,
+    check_principal_realm_in_trust_namespace,
+    ensure_last_krbprincipalname,
+    ensure_krbcanonicalname_set
 )
 
 if six.PY3:
@@ -212,14 +216,20 @@ class baseuser(LDAPObject):
             label=_('Login shell'),
         ),
         Principal(
-            'krbprincipalname?',
+            'krbcanonicalname?',
+            validate_realm,
+            label=_('Principal name'),
+            flags={'no_option', 'no_create', 'no_update', 'no_search'},
+            normalizer=normalize_user_principal
+        ),
+        Principal(
+            'krbprincipalname*',
             validate_realm,
             cli_name='principal',
-            label=_('Kerberos principal'),
-            default_from=lambda uid: kerberos.Principal.from_text(
+            label=_('Principal alias'),
+            default_from=lambda uid: kerberos.Principal(
                 uid.lower(), realm=api.env.realm),
             autofill=True,
-            flags=['no_update'],
             normalizer=normalize_user_principal,
         ),
         DateTime('krbprincipalexpiration?',
@@ -621,3 +631,20 @@ class baseuser_add_manager(LDAPAddMember):
 
 class baseuser_remove_manager(LDAPRemoveMember):
     member_attributes = ['manager']
+
+
+class baseuser_add_principal(LDAPAddAttribute):
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        check_principal_realm_in_trust_namespace(self.api, *keys)
+        ensure_krbcanonicalname_set(ldap, entry_attrs)
+        return dn
+
+
+class baseuser_remove_principal(LDAPRemoveAttribute):
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        ensure_last_krbprincipalname(ldap, entry_attrs, *keys)
+        return dn
diff --git a/ipaserver/plugins/host.py b/ipaserver/plugins/host.py
index 11bddb505..1c1e934b9 100644
--- a/ipaserver/plugins/host.py
+++ b/ipaserver/plugins/host.py
@@ -35,7 +35,7 @@ from .baseldap import (LDAPQuery, LDAPObject, LDAPCreate,
                                      LDAPAddAttribute, LDAPRemoveAttribute,
                                      LDAPAddAttributeViaOption,
                                      LDAPRemoveAttributeViaOption)
-from ipaserver.plugins.service import (
+from .service import (
     validate_realm, normalize_principal, validate_certificate,
     set_certificate_attrs, ticket_flags_params, update_krbticketflags,
     set_kerberos_attrs, rename_ipaallowedtoperform_from_ldap,
@@ -406,6 +406,12 @@ class host(LDAPObject):
             'ipapermdefaultattr': {'usercertificate'},
             'default_privileges': {'Host Administrators', 'Host Enrollment'},
         },
+        'System: Manage Host Principals': {
+            'ipapermbindruletype': 'permission',
+            'ipapermright': {'write'},
+            'ipapermdefaultattr': {'krbprincipalname', 'krbcanonicalname'},
+            'default_privileges': {'Host Administrators', 'Host Enrollment'},
+        },
         'System: Manage Host Enrollment Password': {
             'ipapermbindruletype': 'permission',
             'ipapermright': {'write'},
@@ -515,11 +521,18 @@ class host(LDAPObject):
             flags={'virtual_attribute', 'no_create', 'no_update', 'no_search'},
         ),
         Principal(
-            'krbprincipalname?',
+            'krbcanonicalname?',
             validate_realm,
             label=_('Principal name'),
             normalizer=normalize_principal,
-            flags=['no_create', 'no_update', 'no_search'],
+            flags={'no_create', 'no_update', 'no_search'},
+        ),
+        Principal(
+            'krbprincipalname*',
+            validate_realm,
+            label=_('Principal alias'),
+            normalizer=normalize_principal,
+            flags=['no_create', 'no_search'],
         ),
         Str('macaddress*',
             normalizer=lambda value: value.upper(),
@@ -839,15 +852,6 @@ class host_mod(LDAPUpdate):
     member_attributes = ['managedby']
 
     takes_options = LDAPUpdate.takes_options + (
-        Principal(
-            'krbprincipalname?',
-            validate_realm,
-            cli_name='principalname',
-            label=_('Principal name'),
-            doc=_('Kerberos principal name for this host'),
-            normalizer=normalize_principal,
-            attribute=True,
-        ),
         Flag('updatedns?',
             doc=_('Update DNS entries'),
             default=False,
@@ -1332,3 +1336,26 @@ class host_remove_cert(LDAPRemoveAttributeViaOption):
             revoke_certs(options['usercertificate'], self.log)
 
         return dn
+
+
+@register()
+class host_add_principal(LDAPAddAttribute):
+    __doc__ = _('Add new principal alias to host entry')
+    msg_summary = _('Added new aliases to host "%(value)s"')
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        util.check_principal_realm_in_trust_namespace(self.api, *keys)
+        util.ensure_krbcanonicalname_set(ldap, entry_attrs)
+        return dn
+
+
+@register()
+class host_remove_principal(LDAPRemoveAttribute):
+    __doc__ = _('Remove principal alias from a host entry')
+    msg_summary = _('Removed aliases from host "%(value)s"')
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        util.ensure_last_krbprincipalname(ldap, entry_attrs, *keys)
+        return dn
diff --git a/ipaserver/plugins/service.py b/ipaserver/plugins/service.py
index 7b0832b23..417be0011 100644
--- a/ipaserver/plugins/service.py
+++ b/ipaserver/plugins/service.py
@@ -422,6 +422,13 @@ class service(LDAPObject):
             ],
             'default_privileges': {'Service Administrators'},
         },
+        'System: Manage Service Principals': {
+            'ipapermright': {'write'},
+            'ipapermdefaultattr': {'krbprincipalname', 'krbcanonicalname'},
+            'default_privileges': {
+                'Service Administrators',
+            },
+        },
         'System: Remove Services': {
             'ipapermright': {'delete'},
             'replaces': [
@@ -439,12 +446,22 @@ class service(LDAPObject):
             'krbcanonicalname',
             validate_realm,
             cli_name='canonical_principal',
-            label=_('Principal'),
+            label=_('Principal name'),
             doc=_('Service principal'),
             primary_key=True,
             normalizer=normalize_principal,
             require_service=True
         ),
+        Principal(
+            'krbprincipalname*',
+            validate_realm,
+            cli_name='principal',
+            label=_('Principal alias'),
+            doc=_('Service principal alias'),
+            normalizer=normalize_principal,
+            require_service=True,
+            flags={'no_create'}
+        ),
         Bytes('usercertificate*', validate_certificate,
             cli_name='certificate',
             label=_('Certificate'),
@@ -503,16 +520,6 @@ class service(LDAPObject):
                   " Use 'radius' to allow RADIUS-based 2FA authentications."
                   " Other values may be used for custom configurations."),
         ),
-        Principal(
-            'krbprincipalname',
-            validate_realm,
-            cli_name='principal',
-            label=_('Principal Alias'),
-            doc=_('Service principal alias'),
-            normalizer=normalize_principal,
-            require_service=True,
-            flags={'no_create', 'no_update'}
-        ),
     ) + ticket_flags_params
 
     def validate_ipakrbauthzdata(self, entry):
@@ -819,7 +826,6 @@ class service_show(LDAPRetrieve):
 
         return dn
 
-
 @register()
 class service_add_host(LDAPAddMember):
     __doc__ = _('Add hosts that can manage this service.')
@@ -978,3 +984,26 @@ class service_remove_cert(LDAPRemoveAttributeViaOption):
             revoke_certs(options['usercertificate'], self.log)
 
         return dn
+
+
+@register()
+class service_add_principal(LDAPAddAttribute):
+    __doc__ = _('Add new principal alias to a service')
+    msg_summary = _('Added new aliases to the service principal "%(value)s"')
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        util.check_principal_realm_in_trust_namespace(self.api, *keys)
+        util.ensure_krbcanonicalname_set(ldap, entry_attrs)
+        return dn
+
+
+@register()
+class service_remove_principal(LDAPRemoveAttribute):
+    __doc__ = _('Remove principal alias from a service')
+    msg_summary = _('Removed aliases to the service principal "%(value)s"')
+    attribute = 'krbprincipalname'
+
+    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
+        util.ensure_last_krbprincipalname(ldap, entry_attrs, *keys)
+        return dn
diff --git a/ipaserver/plugins/user.py b/ipaserver/plugins/user.py
index c231847d5..b3ae7646f 100644
--- a/ipaserver/plugins/user.py
+++ b/ipaserver/plugins/user.py
@@ -43,7 +43,9 @@ from .baseuser import (
     convert_nsaccountlock,
     fix_addressbook_permission_bindrule,
     baseuser_add_manager,
-    baseuser_remove_manager)
+    baseuser_remove_manager,
+    baseuser_add_principal,
+    baseuser_remove_principal)
 from .idviews import remove_ipaobject_overrides
 from ipalib.plugable import Registry
 from .baseldap import (
@@ -287,6 +289,14 @@ class user(baseuser):
                 'Modify Users and Reset passwords',
             },
         },
+        'System: Manage User Principals': {
+            'ipapermright': {'write'},
+            'ipapermdefaultattr': {'krbprincipalname', 'krbcanonicalname'},
+            'default_privileges': {
+                'User Administrators',
+                'Modify Users and Reset passwords',
+            },
+        },
         'System: Modify Users': {
             'ipapermright': {'write'},
             'ipapermdefaultattr': {
@@ -1187,3 +1197,15 @@ class user_add_manager(baseuser_add_manager):
 @register()
 class user_remove_manager(baseuser_remove_manager):
     __doc__ = _("Remove a manager to the user entry")
+
+
+@register()
+class user_add_principal(baseuser_add_principal):
+    __doc__ = _('Add new principal alias to the user entry')
+    msg_summary = _('Added new aliases to user "%(value)s"')
+
+
+@register()
+class user_remove_principal(baseuser_remove_principal):
+    __doc__ = _('Remove principal alias from the user entry')
+    msg_summary = _('Removed aliases from user "%(value)s"')