auth_generic_meta

## Name

auth_generic_meta, auth_generic — Generic authentication request

## Synopsis

#include <courierauth.h>

`int rc=auth_generic_meta(` | struct auth_meta *meta,
| const char *service,
| const char *authtype,
| const char *authdata,
| int (*callback_func) `(`struct authinfo *, void *`)`,
| void *callback_arg`)`;

`int rc=auth_generic(` | const char *service,
| const char *authtype,
| const char *authdata,
| int (*callback_func) `(`struct authinfo *, void *`)`,
| void *callback_arg`)`;

## DESCRIPTION

`auth_generic_meta` processes a generic authentication request. You do not want to use this function by itself. You really want to use auth_login_meta(3). `service` specifies which so-called "service" is being authenticated; like “imap” or “pop3”. `service` may or may not be used by the Courier authentication library's configured back-end module.

`authtype` specifies the format of the authentication request. Three authentication formats are defined in `courierauth.h`:

`AUTHTYPE_LOGIN`

  `authdata` contains the following string: “`userid`\n`password`\n”. That is, the userid being authenticated, an ASCII newline character, the password, and a second newline character.

`AUTHTYPE_CRAMMD5` or `AUTHTYPE_CRAMSHA1`

  This format is used with CRAM-MD5 or CRAM-SHA1. `authdata` contains the following string: “`challenge`\n`response`\n”. `challenge` is the base64-encoded challenge, which is followed by an ASCII newline character. `response` is a base64-encoded string that's followed by a second newline character. The base64-encoded string consists of the responding userid, a space character, then the response to the challenge expressed as hexadecimal digits.

A NULL `meta` is equivalent to using the default auth_meta returned by auth_meta_init_default(3).

`auth_generic_meta`() should not be used by itself, but only together with auth_sasl_ex(3).

`auth_generic`() is deprecated and should not be used in new code.

## RETURNS

`callback_func` will be invoked if `auth_generic_meta` succeeds, and `callback_func`'s return value becomes the return value from `auth_generic_meta` (which should be 0, by convention). `callback_func` will not be invoked if an error occurs, which is reported by a non-zero return value from `auth_generic_meta`. By convention, a positive return value indicates an internal, temporary failure, such as the authentication daemon process not running; a negative return value indicates that this request was processed, but it failed.

The second argument to `callback_func` will be `callback_arg`, which is not interpreted by this function in any way. The first argument will be a pointer to the following structure:

>     struct authinfo {
>     	const char *sysusername;
>     	const uid_t *sysuserid;
>     	gid_t sysgroupid;
>     	const char *homedir;

>     	const char *address;
>     	const char *fullname;
>     	const char *maildir;
>     	const char *quota;
>     	const char *passwd;
>     	const char *clearpasswd;

>     	const char *options;

>     	} ;

Description of the above fields:

address

  The authenticated login ID.

sysusername

  The authenticated account's userid and groupid can be looked up in the password file using `address`. If this field is `NULL`, obtain the userid and the groupid from `sysuserid` and `sysgroupid`.

sysuserid

  `sysuserid` may be `NULL` if `sysusername` is initialized, otherwise it's a pointer to the account's numeric userid.

sysgroupid

  Account's numeric groupid. `sysgroupid` is only used when `sysusername` is `NULL`.

fullname

  This is the account's full name. This field is optional, it may be `NULL`.

homedir

  The account's home directory. This field cannot be `NULL`.

maildir

  The pathname to the account's mailbox. This field is optional, it can be `NULL` in which case the default location is assumed.

quota

  Optional maildir quota on the account's mailbox (and `NULL` if no quota is set).

passwd

  The account's encrypted password, if available. If the account has a cleartext password defined, this field can be set to `NULL`. The encrypted password can take several formats:

  - A traditional triple-DES crypted password, or a MD5+salt-hashed password, as used in Linux.

  - “{MD5}” followed by a base64-encoded MD5 hash of the password.

  - “{SHA}” followed by a base64-encoded SHA1 hash of the password.

clearpasswd

  The account's cleartext password, if available. If the account has an encrypted password defined, this field can be set to `NULL`.

options

  A comma-separated list of miscellaneous account options. See below for more information.

### Account options

Depending on the configuration of the Courier authentication library, accounts may have individual options associated with them. If the authentication library configuration does not implement account options, the option string will be a `NULL` value. Otherwise it will be a comma-separated list of “`option`=`value`” settings.

### Note

The application is responsible for actually implementing the options. For example, sn authentication request for service “imap”, for example, will succeed provided that the userid and the password are valid, even if “disableimap=1” is set. The application's `callback_func` should check for this condition, and return a negative return code.

### Note

The following list of account options is a combined list of implemented options supported by Courier, Courier-IMAP, and SqWebMail packages. Some of the following information is obviously not applicable for a particular package. The inapplicable bits should be obvious.

The following options are recognized by the various Courier packages:

`disableimap=``n`

  If "n" is 1, IMAP access to this account should be disabled.

`disablepop3=``n`

  If "n" is 1, POP3 access to this account should be disabled.

`disableinsecureimap=``n`

  If "n" is 1, unencrypted IMAP access to this account should be disabled.

`disableinsecurepop3=``n`

  If "n" is 1, unencrypted POP3 access to this account should be disabled.

`disablewebmail=``n`

  If "n" is 1, webmail access to this account should be disabled.

`disableshared=``n`

  If "n" is 1, this account should not have access to shared folders or be able to share its own folders with other people.

`group=``name`

  This option is used by Courier-IMAP in calculating access control lists. This option places the account as a member of access group `name`. Instead of granting access rights on individual mail folders to individual accounts, the access rights can be granted to an access group “name”, and all members of this group get the specified access rights.

  The access group name “administrators” is a reserved group. All accounts in the `administrators` group automatically receive all rights to all accessible folders.

  ### Note

  This option may be specified multiple times to specify that the account belongs to multiple account groups.

`sharedgroup=``name`

  Another option used by Courier-IMAP. Append "name" to the name of the top level virtual shared folder index file. This setting restricts which virtual shared folders this account could possibly access (and that's on top of whatever else the access control lists say). See the virtual shared folder documentation for more information.

  For technical reasons, group names may not include comma, tab, "/" or "|" characters.

## SEE ALSO

authlib(3), auth_meta(3), auth_login_meta(3), auth_getuserinfo_meta(3), auth_enumerate(3), auth_passwd(3), auth_getoption(3).