Kerberos Error Codes

Code	Code Name	Description	Possible causes
0x0	KDC_ERR_NONE	No error	No errors were found
0x1	KDC_ERR_NAME_EXP	Client’s entry in KDC database has expired	No information
0x2	KDC_ERR_SERVICE_EXP	Server’s entry in KDC database has expired	No information
0x3	KDC_ERR_BAD_PVNO	Requested Kerberos version number not supported	No information
0x4	KDC_ERR_C_OLD_MAST_KVNO	Client’s key encrypted in old master key	No information
0x5	KDC_ERR_S_OLD_MAST_KVNO	Server’s key encrypted in old master key	No information
0x6	KDC_ERR_C_PRINCIPAL_UNKNOWN	Client not found in Kerberos database	The username doesn’t exist.
0x7	KDC_ERR_S_PRINCIPAL_UNKNOWN	Server not found in Kerberos database	This error can occur if the domain controller can’t find the server’s name in Active Directory. This error is similar to KDC_ERR_C_PRINCIPAL_UNKNOWN except that it occurs when the server name can’t be found.
0x8	KDC_ERR_PRINCIPAL_NOT_UNIQUE	Multiple principal entries in KDC database	This error occurs if duplicate principal names exist. Unique principal names are crucial for ensuring mutual authentication. Thus, duplicate principal names are strictly forbidden, even across multiple realms. Without unique principal names, the client has no way of ensuring that the server it is communicating with is the correct one.
0x9	KDC_ERR_NULL_KEY	The client or server has a null key (master key)	No master key was found for client or server. Usually it means that administrator should reset the password on the account.
0xA	KDC_ERR_CANNOT_POSTDATE	Ticket (TGT) not eligible for postdating	This error can occur if a client requests postdating of a Kerberos ticket. Postdating is the act of requesting that a ticket’s start time be set into the future. It also can occur if there is a time difference between the client and the KDC.
0xB	KDC_ERR_NEVER_VALID	Requested start time is later than end time	There’s a time difference between the KDC and the client.
0xC	KDC_ERR_POLICY	Requested start time is later than end time	This error is usually the result of logon restrictions in place on a user’s account. For example workstation restriction, smart card authentication requirement or logon time restriction.
0xD	KDC_ERR_BADOPTION	KDC cannot accommodate requested option	Impending expiration of a TGT. The SPN to which the client is attempting to delegate credentials isn’t in its Allowed-to-delegate-to list
0xE	KDC_ERR_ETYPE_NOTSUPP	KDC has no support for encryption type	In general, this error occurs when the KDC or a client receives a packet that it can’t decrypt.
0xF	KDC_ERR_SUMTYPE_NOSUPP	KDC has no support for checksum type	The KDC, server, or client receives a packet for which it doesn’t have a key of the appropriate encryption type. The result is that the computer is unable to decrypt the ticket.
0x10	KDC_ERR_PADATA_TYPE_NOSUPP	KDC has no support for PADATA type (pre-authentication data)	Smart card logon is being attempted and the proper certificate can’t be located. This can happen because the wrong certification authority (CA) is being queried or the proper CA can’t be contacted. It can also happen when a domain controller doesn’t have a certificate installed for smart cards (Domain Controller or Domain Controller Authentication templates). This error code can’t occur in event 4768. A Kerberos authentication ticket (TGT) was requested”. It occurs in 4771. Kerberos pre-authentication failed” event.
0x11	KDC_ERR_TRTYPE_NO_SUPP	KDC has no support for transited type	No information.
0x12	KDC_ERR_CLIENT_REVOKED	Client’s credentials have been revoked	This might be because of an explicit disabling or because of other restrictions in place on the account. For example: account disabled, expired, or locked out.
0x13	KDC_ERR_SERVICE_REVOKED	Credentials for server have been revoked	No information.
0x14	KDC_ERR_TGT_REVOKED	TGT has been revoked	Since the remote KDC may change its PKCROSS key while there are PKCROSS tickets still active, it SHOULD cache the old PKCROSS keys until the last issued PKCROSS ticket expires. Otherwise, the remote KDC will respond to a client with a KRB-ERROR message of type KDC_ERR_TGT_REVOKED. See RFC1510 for more details.
0x15	KDC_ERR_CLIENT_NOTYET	Client not yet valid—try again later	No information.
0x16	KDC_ERR_SERVICE_NOTYET	Server not yet valid—try again later	No information.
0x17	KDC_ERR_KEY_EXPIRED	Password has expired—change password to reset	The user’s password has expired. This error code can’t occur in event “4768. A Kerberos authentication ticket (TGT) was requested”. It occurs in “4771. Kerberos pre-authentication failed” event.
0x18	KDC_ERR_PREAUTH_FAILED	Pre-authentication information was invalid	The wrong password was provided. This error code can’t occur in event “4768. A Kerberos authentication ticket (TGT) was requested”. It occurs in “4771. Kerberos pre-authentication failed” event.
0x19	KDC_ERR_PREAUTH_REQUIRED	Additional pre-authentication required	This error often occurs in UNIX interoperability scenarios. MIT-Kerberos clients don’t request pre-authentication when they send a KRB_AS_REQ message. If pre-authentication is required (the default), Windows systems will send this error. Most MIT-Kerberos clients will respond to this error by giving the pre-authentication, in which case the error can be ignored, but some clients might not respond in this way.
0x1A	KDC_ERR_SERVER_NOMATCH	KDC does not know about the requested server	No information.
0x1B	KDC_ERR_MUST_USE_USER2USER	Server principal valid for user2user only	This error occurs because the service is missing an SPN.
0x1F	KRB_AP_ERR_BAD_INTEGRITY	Integrity check on decrypted field failed	The authenticator was encrypted with something other than the session key. The result is that the client can’t decrypt the resulting message. The modification of the message could be the result of an attack or it could be because of network noise.
0x20	KRB_AP_ERR_TKT_EXPIRED	The ticket has expired	The smaller the value for the “Maximum lifetime for user ticket” Kerberos policy setting, the more likely it is that this error will occur. Because ticket renewal is automatic, you should not have to do anything if you get this message.
0x21	KRB_AP_ERR_TKT_NYV	The ticket is not yet valid	The ticket presented to the server isn’t yet valid (in relationship to the server time). The most probable cause is that the clocks on the KDC and the client aren’t synchronized. If cross-realm Kerberos authentication is being attempted, then you should verify time synchronization between the KDC in the target realm and the KDC in the client realm, as well.
0x22	KRB_AP_ERR_REPEAT	The request is a replay	This error indicates that a specific authenticator showed up twice — the KDC has detected that this session ticket duplicates one that it has already received.
0x23	KRB_AP_ERR_NOT_US	The ticket is not for us	The server has received a ticket that was meant for a different realm.
0x24	KRB_AP_ERR_BADMATCH	The ticket and authenticator do not match	The KRB_TGS_REQ is being sent to the wrong KDC. There’s an account mismatch during protocol transition.
0x25	KRB_AP_ERR_SKEW	The clock skew is too great	This error is logged if a client computer sends a timestamp whose value differs from that of the server’s timestamp by more than the number of minutes found in the “Maximum tolerance for computer clock synchronization” setting in Kerberos policy.
0x26	KRB_AP_ERR_BADADDR	Network address in network layer header doesn’t match address inside ticket	Session tickets MAY include the addresses from which they are valid. This error can occur if the address of the computer sending the ticket is different from the valid address in the ticket. A possible cause of this could be an Internet Protocol (IP) address change. Another possible cause is when a ticket is passed through a proxy server or NAT. The client is unaware of the address scheme used by the proxy server, so unless the program caused the client to request a proxy server ticket with the proxy server’s source address, the ticket could be invalid
0x27	KRB_AP_ERR_BADVERSION	Protocol version numbers don’t match (PVNO)	When an application receives a KRB_SAFE message, it verifies it. If any error occurs, an error code is reported for use by the application. The message is first checked by verifying that the protocol version and type fields match the current version and KRB_SAFE, respectively. A mismatch generates a KRB_AP_ERR_BADVERSION. See RFC4120 for more details.
0x28	KRB_AP_ERR_MSG_TYPE	Message type is unsupported	This message is generated when target server finds that message format is wrong. This applies to KRB_AP_REQ, KRB_SAFE, KRB_PRIV and KRB_CRED messages. This error also generated if use of UDP protocol is being attempted with User-to-User authentication.
0x29	KRB_AP_ERR_MODIFIED	Message stream modified and checksum didn’t match	The authentication data was encrypted with the wrong key for the intended server. The authentication data was modified in transit by a hardware or software error, or by an attacker. The client sent the authentication data to the wrong server because incorrect DNS data caused the client to send the request to the wrong server. The client sent the authentication data to the wrong server because DNS data was out-of-date on the client.
0x2A	KRB_AP_ERR_BADORDER	Message out of order (possible tampering)	This event generates for KRB_SAFE and KRB_PRIV messages if an incorrect sequence number is included, or if a sequence number is expected but not present. See RFC4120 for more details.
0x2C	KRB_AP_ERR_BADKEYVER	Specified version of key is not available	This error might be generated on server side during receipt of invalid KRB_AP_REQ message. If the key version indicated by the Ticket in the KRB_AP_REQ isn’t one the server can use (e.g., it indicates an old key, and the server no longer possesses a copy of the old key), the KRB_AP_ERR_BADKEYVER error is returned.
0x2D	KRB_AP_ERR_NOKEY	Service key not available	This error might be generated on server side during receipt of invalid KRB_AP_REQ message. Because it is possible for the server to be registered in multiple realms, with different keys in each, the realm field in the unencrypted portion of the ticket in the KRB_AP_REQ is used to specify which secret key the server should use to decrypt that ticket. The KRB_AP_ERR_NOKEY error code is returned if the server doesn’t have the proper key to decipher the ticket.
0x2E	KRB_AP_ERR_MUT_FAIL	Mutual authentication failed	No information.
0x2F	KRB_AP_ERR_BADDIRECTION	Incorrect message direction	No information.
0x31	KRB_AP_ERR_BADSEQ	Incorrect sequence number in message	No information.
0x32	KRB_AP_ERR_INAPP_CKSUM	Inappropriate type of checksum in message (checksum may be unsupported)	When KDC receives KRB_TGS_REQ message it decrypts it, and after the user-supplied checksum in the Authenticator MUST be verified against the contents of the request, and the message MUST be rejected if the checksums don’t match (with an error code of KRB_AP_ERR_MODIFIED) or if the checksum isn’t collision-proof (with an error code of KRB_AP_ERR_INAPP_CKSUM).
0x33	KRB_AP_PATH_NOT_ACCEPTED	Desired path is unreachable	No information.
0x34	KRB_ERR_RESPONSE_TOO_BIG	Too much data	The size of a ticket is too large to be transmitted reliably via UDP. In a Windows environment, this message is purely informational. A computer running a Windows operating system will automatically try TCP if UDP fails.
0x3C	KRB_ERR_GENERIC	Generic error	Group membership has overloaded the PAC. Multiple recent password changes haven’t propagated. Crypto subsystem error caused by running out of memory. SPN too long. SPN has too many parts.
0x3D	KRB_ERR_FIELD_TOOLONG	Field is too long for this implementation	Each request (KRB_KDC_REQ) and response (KRB_KDC_REP or KRB_ERROR) sent over the TCP stream is preceded by the length of the request as 4 octets in network byte order. The high bit of the length is reserved for future expansion and MUST currently be set to zero. If a KDC that doesn’t understand how to interpret a set high bit of the length encoding receives a request with the high order bit of the length set, it MUST return a KRB-ERROR message with the error KRB_ERR_FIELD_TOOLONG and MUST close the TCP stream.
0x3E	KDC_ERR_CLIENT_NOT_TRUSTED	The client trust failed or is not implemented	This typically happens when user’s smart-card certificate is revoked or the root Certification Authority that issued the smart card certificate (in a chain) isn’t trusted by the domain controller.
0x3F	KDC_ERR_KDC_NOT_TRUSTED	The KDC server trust failed or could not be verified	The trustedCertifiers field contains a list of certification authorities trusted by the client, in the case that the client doesn’t possess the KDC’s public key certificate. If the KDC has no certificate signed by any of the trustedCertifiers, then it returns an error of type KDC_ERR_KDC_NOT_TRUSTED. See RFC1510 for more details.
0x40	KDC_ERR_INVALID_SIG	The signature is invalid	This error is related to PKINIT. If a PKI trust relationship exists, the KDC then verifies the client’s signature on AuthPack (TGT request signature). If that fails, the KDC returns an error message of type KDC_ERR_INVALID_SIG.
0x41	KDC_ERR_KEY_TOO_WEAK	A higher encryption level is needed	If the clientPublicValue field is filled in, indicating that the client wishes to use Diffie-Hellman key agreement, then the KDC checks to see that the parameters satisfy its policy. If they don’t (e.g., the prime size is insufficient for the expected encryption type), then the KDC sends back an error message of type KDC_ERR_KEY_TOO_WEAK.
0x42	KRB_AP_ERR_USER_TO_USER_REQUIRED	User-to-user authorization is required	In the case that the client application doesn’t know that a service requires user-to-user authentication, and requests and receives a conventional KRB_AP_REP, the client will send the KRB_AP_REP request, and the server will respond with a KRB_ERROR token as described in RFC1964, with a msg-type of KRB_AP_ERR_USER_TO_USER_REQUIRED.
0x43	KRB_AP_ERR_NO_TGT	No TGT was presented or available	In user-to-user authentication if the service doesn’t possess a ticket granting ticket, it should return the error KRB_AP_ERR_NO_TGT.
0x44	KDC_ERR_WRONG_REALM	Incorrect domain or principal	Although this error rarely occurs, it occurs when a client presents a cross-realm TGT to a realm other than the one specified in the TGT. Typically, this results from incorrectly configured DNS.