This module provides the basics to validate an HTTP
header. User and password information are read from a Unix/Apache
compatible password file.
This library provides, in addition to the HTTP authentication, predicates to read and write password files.
- http_authenticate(+Type, +Request, -Fields)
- True if Request contains the information to continue according
to Type. Type identifies the required authentication technique:
- Use HTTP
Basicauthetication and verify the password from PasswordFile. PasswordFile is a file holding usernames and passwords in a format compatible to Unix and Apache. Each line is record with
:separated fields. The first field is the username and the second the password hash. Password hashes are validated using crypt/2.
Successful authorization is cached for 60 seconds to avoid overhead of decoding and lookup of the user and password data.
http_authenticate/3 just validates the header. If authorization is not provided the browser must be challenged, in response to which it normally opens a user-password dialogue. Example code realising this is below. The exception causes the HTTP wrapper code to generate an HTTP 401 reply.
( http_authenticate(basic(passwd), Request, Fields) -> true ; throw(http_reply(authorise(basic, Realm))) ).
- http_authorization_data(+AuthorizeText, ?Data) is semidet
- Decode the HTTP
Authorizationheader. Data is a term
where Method is the (downcased) authorization method (typically
basic), User is an atom holding the user name and Password is a list of codes holding the password
- cached_authenticated(+Authorization, +File, -User, -RestFields)[private]
- Validate using the cache. If the entry is not in the cache, we also remove all outdated entries from the cache.
- validate(+File, +User, +Passwd, -Fields)[private]
- True if User and Passwd combination appears in File. File uses
the same format as .htaccess files from Apache or Unix password
files. I.e. it consists of one line per entry with fields
:. The first field is the User field, The second contains the Passwd in DES or MD5 encrypted format. See crypt/2 for details.
- http_current_user(+File, ?User, ?Fields) is nondet
- True when User is present in the htpasswd file File and Fields provides the additional fields.
- update_passwd(+File, -Path) is det[private]
- Update passwd/3 to reflect the correct passwords for File. Path is the absolute path for File.
- http_read_passwd_file(+Path, -Data) is det
- Read a password file. Data is a list of terms of the format
below, where User is an atom identifying the user, Hash is a
string containing the salted password hash and Fields contain
additional fields. The string value of each field is converted
using name/2 to either a number or an atom.
passwd(User, Hash, Fields)
- http_write_passwd_file(+File, +Data:list) is det
- Write password data Data to File. Data is a list of entries as
below. See http_read_passwd_file/2 for details.
passwd(User, Hash, Fields)
- http:authenticate(+AuthData, +Request, -Fields)[multifile]
- Plugin for
library(http_dispatch)to perform basic HTTP authentication.
This predicate throws