FIDO_ASSERT_ALLOW_CRED(3) | Library Functions Manual | FIDO_ASSERT_ALLOW_CRED(3)

# NAME

`fido_assert_allow_cred` — allow a credential in a FIDO2 assertion

# SYNOPSIS

library “libfido2” libcbor libcrypto libz
`#include <fido.h>`

int
`fido_assert_allow_cred`(fido_assert_t *assert, const unsigned char *ptr, size_t len);

# DESCRIPTION

The `fido_assert_allow_cred`() function adds ptr to the list of credentials allowed in assert, where ptr points to a credential ID of len bytes. A copy of ptr is made, and no references to the passed pointer are kept. If `fido_assert_allow_cred`() fails, the existing list of allowed credentials is preserved.

For the format of a FIDO2 credential ID, please refer to the Web Authentication (webauthn) standard.

# RETURN VALUES

The error codes returned by `fido_assert_allow_cred`() are defined in `<fido/err.h>`. On success, `FIDO_OK` is returned.

# SEE ALSO

fido_assert_new(3), fido_assert_set_authdata(3), fido_dev_get_assert(3)

July 9, 2025 | Debian