HardCode

There are some hooks in mod_authnz_external designed to make it easy to replace the call to an external authenticator with a call to an internal function. This is a bit weird, as such internal functions have none of the advantages of an external authenticator, but this can be a short-cut way to create a custom authentication module.

The procedure is as follows:

Step 1:

Edit "mod_authnz_external.c"

Step 2:

Uncomment the _HARDCODE_ #define.

Step 3:

Uncomment the line:

/* #include "your_function_here.c" */

Actually, I think it might be better to embed the function itself directly in this file instead of including it. Modules work better if they are implemented in a single source file.

Your function should start something like:

int example(char *user_name,char *user_passwd,char *config_path)

Obviously you should call it something other than example, but the rest of the function declaration should be just as above.

It should return 0 if the password is correct for the given user, and other values if it is not, pretty much just like external authentication programs do.

You'll want to code this very carefully. A crash will crash not just your program but the entire httpd.

DO NOT use exit() or other such calls that will cause your function to exit abnormally or dump core. It will take the entire httpd with it and display a message to your browser saying "no data". Use "return" instead of exit().

Step 4:

Choose an all-caps function name for your function. ie: 'RADIUS' or 'SYBASE' This will be used for telling mod_authnz_external which hard coded function you want to call. In this documentation we will call it EXAMPLE.

Step 5:

Find the exec_hardcode() function inside mod_authnz_external.c. Find the big commented section there. Replace the example call to example() with a call to your function. Also change the name "EXAMPLE" to the name you chose for your function.

The function call in exec_hardcode() should look something like:

if (strcmp(check_type,"EXAMPLE")==0) {
    code = example(c->user,sent_pw,config_file);
}

Here, we replace "EXAMPLE" with the name you chose in step 4 and "example" with whatever you called your function in step 3.

Step 6:

Save your work. Also save some whales.

Step 7:

Compile and configure mod_authnz_external as described on the Installation and Configuration pages.

The AddExternalAuth command in your httpd.conf file might look something like

AddExternalAuth whatever EXAMPLE:/usr/local/data/configfile

Here 'whatever' is the name you will use to invoke this authenticator in the AuthExternal commands in your .htaccess files. 'EXAMPLE' is the name you choose in step 4 and inserted into the "if" statement in step 5. Any data after the colon will be passed into your function as the argument called "'config_path`" in the sample function declaration in step 3. It might be a config file path or something else.