PAM_YUBICO(8)

Yubico PAM Module Manual

PAM_YUBICO(8)

NAME

pam_yubico - Module for YubiKey authentication

SYNOPSIS

pam_yubico [...]

DESCRIPTION

The module is for authentication of YubiKeys, either with online validation of OTP, or offline validation with HMAC-SHA1 challenge-response.

OPTIONS

debug

Turns on debugging.

debug_file=file

File name to write debug to, the file must exist and be a regular file. Defaults to stdout.

mode=[client|challenge-response]

Mode of operation, client for OTP validation and challenge-response for challenge-response validation. Defaults to client.

authfile=file

Location of the file that holds the mappings of YubiKey token IDs to user names. The format is username:first_public_id:second_public_id:... Default location of the file is $HOME/.yubico/authorized_yubikeys.

id=id

Your API client identity for the validation server.

key=key

Your client key in base64 format. The client key is also known as API key, and provides integrity in the communication between the client (you) and the validation server. If you want to get one for use with the default YubiCloud service, please go to: https://upgrade.yubico.com/getapikey/

alwaysok

Succeed with all authentication attempts (dangerous, presentation mode).

try_first_pass

Before prompting the user for their password, the module first tries the previous stacked module´s password in case that satisfies this module as well.

use_first_pass

Forces the module to use a previous stacked modules password and will never prompt the user - if no password is available or the password is not appropriate, the user will be denied access.

always_prompt

If set, don’t attempt to do a lookup to determine if the user has a YubiKey configured but instead prompt for one no matter what. This is useful in the case where ldap_bind_as_user is enabled but this module is being used to read the user’s password (in a YubiKey+OTP auth scenario).

nullok

Don’t fail when there are no tokens declared for the user in the authorization mapping files or in LDAP. This can be used to make YubiKey authentication optional unless the user has associated tokens.

ldap_starttls

If set, issue a STARTTLS command to the LDAP connection before attempting to bind to it. This is a common setup for servers that only listen on port 389 but still require TLS.

ldap_bind_as_user

Use the user logging in to bind to ldap. This will use the password provided by the user via PAM. If this is set, ldapdn and uid_attr must also be set. Enabling this will cause ldap_bind_user and ldap_bind_password to be ignored.

urllist=list

List of URL templates to be used. This is set by calling ykclient_set_url_bases. The list should be in the format: https://api1.example.com/wsapi/2.0/verify;https://api2.example.com/wsapi/2.0/verify

url=url

This option should not be used, please use the urllist option instead. Set the URL template to use, this is set by calling ykclient_set_url_template. The URL should be set in the format https://api.example.com/wsapi/2.0/verify?id=%d&otp=%s

capath=path

The path where X509 certificates are stored. This is required if https or ldaps are used in url and ldap_uri, respectively.

cainfo=file

Option to allow for usage of a CA bundle instead of path.

proxy=proxy

The proxy to connect to the validation server. Valid schemes are http://, https://, socks4://, socks4a://, socks5:// or socks5h://. Socks5h asks the proxy to do the DNS resolving. If no scheme or port is specified HTTP proxy port 1080 will be used. Example: socks5h://user:pass@10.10.0.1:1080

verbose_otp

Show the One-Time Password when it is entered, i.e. to enable terminal echo of entered characters. You are advised to not use this, if you are using two factor authentication because that will display your password on the screen. This requires the service using the PAM module to display custom fields. This option can not be used with OpenSSH.

ldap_uri=uri

The LDAP server URI (e.g. ldap://localhost).

ldap_server=server

The LDAP server host (default LDAP port is used). Deprecated. Use ldap_uri instead.

ldapdn=dn

The distinguished name (DN) where the users are stored (eg: ou=users,dc=domain,dc=com). If ldap_filter is used this is the base from which the subtree search will be performed.

ldap_clientcertfile=clientcertfile

The path to a client cert file to use when talking to the LDAP server. Note this requires ldap_clientkeyfile to be set as well.

ldap_clientkeyfile=clientkeyfile

The path to a key to be used with the client cert when talking to the LDAP server. Note this requires ldap_clientcertfile to be set as well.

user_attr=attr

The LDAP attribute used to store user names (eg:cn).

yubi_attr=attr

The LDAP attribute used to store the YubiKey ID.

yubi_attr_prefix=prefix

The prefix of the LDAP attribute’s value, in case of a generic attribute, used to store several types of IDs.

token_id_length=length

Length of ID prefixing the OTP (this is 12 if using the YubiCloud).

ldap_bind_user=user

The user to attempt a LDAP bind as.

ldap_bind_password=password

The password to use on LDAP bind.

ldap_filter=filter

A LDAP filter to use for attempting to find the correct object in LDAP. In this string %u will be replaced with the username.

ldap_cacertfile=cacertfile

CA certitificate file for the LDAP connection.

chalresp_path=path

Path of a system-wide directory where challenge-response files can be found for users. Default location is $HOME/.yubico/.

mysql_server=mysqlserver

Hostname/Adress of mysql server. Example 10.0.0.1

mysql_port=mysqlport

Network port of mysql server.

mysql_user=mysqluser

User for accessing to the database. Strongly recommended to use a specific user with read only access.

mysql_password=mysqlpassword

Mysql password associated to the user.

mysql_database=mysqldatabase

the name of the database. Example : otp

EXAMPLES

auth sufficient pam_yubico.so id=16 debug

auth required pam_yubico.so mode=challenge-response

auth required pam_yubico.so id=16 ldap_uri=ldaps://ldap.example.com ldap_filter=(uid=%u) yubi_attr=yubiKeyId

FILES

$HOME/.yubico/authorized_yubikeys

If authfile is not set, this file is used for the mapping between YubiKey public ID and in client mode.

$HOME/.yubico/challenge, $HOME/.yubico/challenge-serial_number

If chalresp_path is not set, these files are used to hold next challenge and expected response for the user in challenge-response mode. If chalresp_path is set the filename will be username instead of challenge.

BUGS

Report yubico-pam bugs in the issue tracker: https://github.com/Yubico/yubico-pam/issues