there is four parts that we have to do,
- bioauthtty(8)
it look like getty(8) so we just do something that can replace the traditional of linux ,getty.
- pam_bioauth
PAM module used for authentication (this stuff we have to work much with this. just study how PAM API works and for PAM there are three part , the first one is PAM module (with this thing we need to make a file that have extend (.so) ) and the second one is PAM Application (with this thing we need to write a codeby use PAMlibraries) and the last one is PAM adminstrator ( with this thing we just config PAM config file)
- libbioauth
performs fingerprint verification (this stuff we don't need to do because we already have had Verifinger4.2 SDK Linux so we just study how it works? and how to use it? )
- uareu module
it's a device driver for AES4000 scanner (also this stuff we don't need to deo because we already have had Verifinger4.2 SDK Linux so we just study how it works? and how to use it? )
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ok let's start at bioauthtty(8) in side there must have open(2) /dev/tty3 (for this project we are going to use this termial na) and must have pam_start() for just initialize the pam_handle_t for bioauthtty(8) and must have do_prompt for display the contents of /etc/issue (this stuff i just had worked with this for a short time i think it's so hard because there is a special charecter for display something like "/v" is, display version of this platform and it have to include some library to use this thing and there are many case(in switch function) and must have pam_authenticate() for attemp to authenticate the use (no comment i still have no idea with this )
thencall a pam_bioauth in this function for open(2) /dev/usb/AES4000 and select(2) until a scanned fingerprint is received then call libbioauth with the image data after that return SUCCESS or FAILURE if it's success then set the username for bioauthtty(8) and if it's failure then return(PAM_AUTH_ERR) , authentication has failed.
then back to bioauthtty(8) in case SUCCESS do such a things pam_get_item() to retrieve the username and getpwnam(3) to retrieve group , shell, etc. and pam_end() to free pam handle then fork(2) and last thing is execvp(3) to launch shell (bash(1), tcsh(1) , etc.) in case FAILURE just syslog(3) and printf(3) to stard error and exit(3) to go back to respawn by init(8)
that's all that we should do but this time we are so busy so just clear our part time job and then after 15 of September we are going to continue again
