NAME¶

duo — Duo authentication service

SYNOPSIS¶

#include <duo.h> duo_t *
duo_open(const char *ikey, const char *skey, const char *progname, const char *cafile); void
duo_set_conv_funcs(duo_t *d, char *(*conv_prompt)(void *conv_arg, const char *, char *, size_t), void (*conv_status)(void *conv_arg, const char *msg), void *conv_arg); void
duo_set_host(duo_t *d, const char *hostname); void
duo_set_ssl_verify(duo_t *d, int bool); duo_code_t
duo_login(duo_t *d, const char *username, const char *client_ip, int flags, const char *command); const char *
duo_geterr(duo_t *d); void
duo_close(duo_t *d);

DESCRIPTION¶

The duo API provides access to the Duo two-factor authentication service. duo_open() is used to obtain a handle to the Duo service. ikey and skey are the required integration and secret keys, respectively, for a Duo customer account. progname identifies the program to the Duo service. cafile should be NULL or the pathname of a PEM-format CA certificate to override the default. duo_set_conv_funcs() may be used to override the internal user conversation functions. conv_prompt is called to present the user a login menu and prompt, and gather their response, returning buf or NULL on error. It may be set to NULL if automatic login is specified with DUO_FLAG_AUTO. conv_status is called to display status messages to the user, and may be NULL if no status display is needed. conv_arg is passed as the first argument to these conversation functions. duo_set_host() may be used to override the default Duo API host. duo_set_ssl_verify() may be used to override SSL certificate verification (enabled by default). duo_login() performs secondary authentication via the Duo service for the specified username. client_ip is the source IP address of the connection to be authenticated, or NULL to specify the local host. The following bitmask values are defined for flags: If not NULL, the command to be authorized will be displayed during push authentication. duo_geterr() returns a description of the last-seen error on the specified Duo API handle. The returned constant string should not be modified or freed by the caller. duo_close() closes and frees the specified Duo API handle.

RETURN VALUES¶

duo_open() returns a pointer to the configured Duo API handle, or NULL on failure. duo_login() returns status codes of type duo_code_t, which may have the following values: In the event of a DUO_*_ERROR return, duo_geterr may be called to recover a human-readable error message. duo_geterr() returns a constant string which should not be modified or freed by the caller.

SEE ALSO¶

pam_duo(8), login_duo(1)

AUTHORS¶

Duo Security ⟨duo_unix@duosecurity.com⟩