duo(3) Duo authentication service


Fd #include <duo.h> Ft duo_t * Fn duo_open const char *ikey const char *skey const char *progname const char *cafile Ft void Fn 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 Ft void Fn duo_set_host duo_t *d const char *hostname Ft void Fn duo_set_ssl_verify duo_t *d int bool Ft duo_code_t Fn duo_login duo_t *d const char *username const char *client_ip int flags const char *command Ft const char * Fn duo_geterr duo_t *d Ft void Fn duo_close duo_t *d


The API provides access to the Duo two-factor authentication service.

Fn duo_open is used to obtain a handle to the Duo service. Fa ikey and Fa skey are the required integration and secret keys, respectively, for a Duo customer account. Fa progname identifies the program to the Duo service. Fa cafile should be NULL or the pathname of a PEM-format CA certificate to override the default.

Fn duo_set_conv_funcs may be used to override the internal user conversation functions. Fa conv_prompt is called to present the user a login menu and Fa prompt , and gather their response, returning Fa buf or NULL on error. It may be set to NULL if automatic login is specified with DUO_FLAG_AUTO. Fa conv_status is called to display status messages to the user, and may be NULL if no status display is needed. Fa conv_arg is passed as the first argument to these conversation functions.

Fn duo_set_host may be used to override the default Duo API host.

Fn duo_set_ssl_verify may be used to override SSL certificate verification (enabled by default).

Fn duo_login performs secondary authentication via the Duo service for the specified Fa username Ns . Fa 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 Fa flags :

Attempt authentication without prompting the user, using their default out-of-band authentication factor.
Do not report incremental status during authentication (e.g. voice callback progress) - only issue one status message per authentication attempt.

If not NULL the Fa command to be authorized will be displayed during push authentication.

Fn 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.

Fn duo_close closes and frees the specified Duo API handle.


Fn duo_open returns a pointer to the configured Duo API handle, or NULL on failure.

Fn duo_login returns status codes of type Ft duo_code_t , which may have the following values:

User authenticated
User failed to authenticate
User denied by policy
Unexpected library error
Duo service unreachable
Invalid client parameters to API call
Duo service error

In the event of a DUO_*_ERROR return, duo_geterr may be called to recover a human-readable error message.

Fn duo_geterr returns a constant string which should not be modified or freed by the caller.


Duo Security Aq [email protected]