PAM_AUTHENTICATE(3)

🌸 NAME 🌸

okay so this page is PAM_AUTHENTICATE(3) from the Linux-PAM Manual, and it’s giving pam_authenticate — account authentication. periodt. 💅

✨ SYNOPSIS ✨

#include <security/pam_appl.h>

int pam_authenticate(pam_handle_t *pamh, int flags);

💖 DESCRIPTION 💖

The pam_authenticate function is used to authenticate the user. bestie, that means the user has to provide an authentication token depending upon the authentication service — usually this is a password, but could also be a finger print. 🔥

The PAM service module may request that the user enter their username via the conversation mechanism (see pam_start(3) and pam_conv(3)). The name of the authenticated user will be present in the PAM item PAM_USER. This item may be recovered with a call to pam_get_item(3). iykyk. 🌈

The pamh argument is an authentication handle obtained by a prior call to pam_start(). The flags argument is the binary or of zero or more of the following values:

🎀 the flags values, bestie 🎀

• PAM_SILENT — Do not emit any messages. 🤫
• PAM_DISALLOW_NULL_AUTHTOK — The PAM module service should return PAM_AUTH_ERR if the user does not have a registered authentication token. 🚫

😭 RETURN VALUES 😭

• PAM_ABORT — The application should exit immediately after calling pam_end(3) first. 🚨 like, actually exit immediately.
• PAM_AUTH_ERR — The user was not authenticated. nope. 😭
• PAM_CRED_INSUFFICIENT — For some reason the application does not have sufficient credentials to authenticate the user. 🙈
• PAM_AUTHINFO_UNAVAIL — The modules were not able to access the authentication information. This might be due to a network or hardware failure etc. 💀
• PAM_MAXTRIES — One or more of the authentication modules has reached its limit of tries authenticating the user. Do not try again. periodt. 🛑
• PAM_SUCCESS — The user was successfully authenticated. slay! ✨
• PAM_USER_UNKNOWN — User unknown to authentication service. 👻

🦋 SEE ALSO 🦋

go check out pam_start(3), pam_setcred(3), pam_chauthtok(3), pam_strerror(3), and pam(8). iykyk, bestie. 💜

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with love from Linux-PAM, dated 07/08/2026 🫶💖