6.32. pam_timestamp - authenticate using cached successful authentication attempts
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## 6.32. pam_timestamp - authenticate using cached successful authentication attempts

`pam_timestamp.so` [ timestampdir=`directory` ] [ timestamp_timeout=`number` ] [ verbose ] [ debug ]

### 6.32.1. DESCRIPTION

In a nutshell, pam_timestamp caches successful authentication attempts, and allows you to use a recent successful attempt as the basis for authentication. This is similar mechanism which is used in sudo.

When an application opens a session using pam_timestamp, a timestamp file is created in the timestampdir directory for the user. When an application attempts to authenticate the user, a pam_timestamp will treat a sufficiently recent timestamp file as grounds for succeeding.

The default encryption hash is taken from the HMAC_CRYPTO_ALGO variable from /etc/login.defs.

### 6.32.2. OPTIONS

`timestampdir=`directory``

  Specify an alternate directory where pam_timestamp creates timestamp files.

`timestamp_timeout=`number``

  How long should pam_timestamp treat timestamp as valid after their last modification date (in seconds). Default is 300 seconds.

`verbose`

  Attempt to inform the user when access is granted.

`debug`

  Turns on debugging messages sent to syslog(3).

### 6.32.3. MODULE TYPES PROVIDED

The `auth` and `session` module types are provided.

### 6.32.4. RETURN VALUES

PAM_AUTH_ERR

  The module was not able to retrieve the user name or no valid timestamp file was found.

PAM_SUCCESS

  Everything was successful.

PAM_SESSION_ERR

  Timestamp file could not be created or updated.

### 6.32.5. NOTES

Users can get confused when they are not always asked for passwords when running a given program. Some users reflexively begin typing information before noticing that it is not being asked for.

### 6.32.6. EXAMPLES

    auth sufficient pam_timestamp.so verbose
    auth required   pam_unix.so

    session required pam_unix.so
    session optional pam_timestamp.so

### 6.32.7. FILES

`/var/run/pam_timestamp/...`

  timestamp files and directories

### 6.32.8. AUTHOR

pam_timestamp was written by Nalin Dahyabhai.

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