fido2-cred

FIDO2-CRED(1) General Commands Manual FIDO2-CRED(1)

fido2-cred
make/verify a FIDO 2 credential

fido2-cred -M [
-dhqruv
] [
-c cred_protect
] [
-i input_file
] [
-o output_file
] device [
type
]

fido2-cred -V [
-dhv
] [
-c cred_protect
] [
-i input_file
] [
-o output_file
] [
type
]

fido2-cred makes or verifies a FIDO 2 credential.
A credential type may be es256 (denoting ECDSA over NIST P-256 with SHA-256), rs256 (denoting 2048-bit RSA with PKCS#1.5 padding and SHA-256), or eddsa (denoting EDDSA over Curve25519 with SHA-512). If type is not specified, es256 is assumed.
When making a credential, the authenticator may require the user to authenticate with a PIN. If the -q option is not specified, fido2-cred will prompt the user for the PIN. If a tty is available, fido2-cred will use it to obtain the PIN. Otherwise, stdin is used.
The input of fido2-cred is defined by the parameters of the credential to be made/verified. See the INPUT FORMAT section for details.
The output of fido2-cred is defined by the result of the selected operation. See the OUTPUT FORMAT section for details.
If a credential is successfully created or verified, fido2-cred exits 0. Otherwise, fido2-cred exits 1.
The options are as follows:
Tells fido2-cred to make a new credential on device.
Tells fido2-cred to verify a credential.
cred_protect
If making a credential, set the credential's protection level to cred_protect. If verifying a credential, check whether the credential's protection level was signed by the authenticator as cred_protect.
Causes fido2-cred to emit debugging output on stderr.
If making a credential, enable the FIDO2 hmac-secret extension. If verifying a credential, check whether the extension data bit was signed by the authenticator.
input_file
Tells fido2-cred to read the parameters of the credential from input_file instead of stdin.
output_file
Tells fido2-cred to write output on output_file instead of stdout.
Tells fido2-cred to be quiet. If a PIN is required and -q is specified, fido2-cred will fail.
Create a resident credential.
Create a U2F credential. By default, fido2-cred will use FIDO2 if supported by the authenticator, and fallback to U2F otherwise.
If making a credential, request user verification. If verifying a credential, check whether the user verification bit was signed by the authenticator.

The input of fido2-cred consists of base64 blobs and UTF-8 strings separated by newline characters ('\n').
When making a credential, fido2-cred expects its input to consist of:
  1. client data hash (base64 blob);
  2. relying party id (UTF-8 string);
  3. user name (UTF-8 string);
  4. user id (base64 blob).
When verifying a credential, fido2-cred expects its input to consist of:
  1. client data hash (base64 blob);
  2. relying party id (UTF-8 string);
  3. credential format (UTF-8 string);
  4. authenticator data (base64 blob);
  5. credential id (base64 blob);
  6. attestation signature (base64 blob);
  7. attestation certificate (optional, base64 blob).
UTF-8 strings passed to fido2-cred must not contain embedded newline or NUL characters.

The output of fido2-cred consists of base64 blobs, UTF-8 strings, and PEM-encoded public keys separated by newline characters ('\n').
Upon the successful generation of a credential, fido2-cred outputs:
  1. client data hash (base64 blob);
  2. relying party id (UTF-8 string);
  3. credential format (UTF-8 string);
  4. authenticator data (base64 blob);
  5. credential id (base64 blob);
  6. attestation signature (base64 blob);
  7. attestation certificate, if present (base64 blob).
Upon the successful verification of a credential, fido2-cred outputs:
  1. credential id (base64 blob);
  2. PEM-encoded credential key.

Create a new es256 credential on /dev/hidraw5, verify it, and save the id and the public key of the credential in cred:
$ echo credential challenge | openssl sha256 -binary | base64 > cred_param
$ echo relying party >> cred_param
$ echo user name >> cred_param
$ dd if=/dev/urandom bs=1 count=32 | base64 >> cred_param
$ fido2-cred -M -i cred_param /dev/hidraw5 | fido2-cred -V -o cred

fido2-assert(1), fido2-token(1)

Please note that fido2-cred handles Basic Attestation and Self Attestation transparently.
November 5, 2019 Linux 5.3.12-arch1-1