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diff --git a/man/fido2-assert.1 b/man/fido2-assert.1 new file mode 100644 index 0000000..882b7ab --- /dev/null +++ b/man/fido2-assert.1 @@ -0,0 +1,286 @@ +.\" Copyright (c) 2018-2023 Yubico AB. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions are +.\" met: +.\" +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in +.\" the documentation and/or other materials provided with the +.\" distribution. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +.\" "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +.\" A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +.\" HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +.\" OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +.\" +.\" SPDX-License-Identifier: BSD-2-Clause +.\" +.Dd $Mdocdate: July 3 2023 $ +.Dt FIDO2-ASSERT 1 +.Os +.Sh NAME +.Nm fido2-assert +.Nd get/verify a FIDO2 assertion +.Sh SYNOPSIS +.Nm +.Fl G +.Op Fl bdhpruvw +.Op Fl t Ar option +.Op Fl i Ar input_file +.Op Fl o Ar output_file +.Ar device +.Nm +.Fl V +.Op Fl dhpv +.Op Fl i Ar input_file +.Ar key_file +.Op Ar type +.Sh DESCRIPTION +.Nm +gets or verifies a FIDO2 assertion. +.Pp +The input of +.Nm +is defined by the parameters of the assertion to be obtained/verified. +See the +.Sx INPUT FORMAT +section for details. +.Pp +The output of +.Nm +is defined by the result of the selected operation. +See the +.Sx OUTPUT FORMAT +section for details. +.Pp +If an assertion is successfully obtained or verified, +.Nm +exits 0. +Otherwise, +.Nm +exits 1. +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl G +Tells +.Nm +to obtain a new assertion from +.Ar device . +.It Fl V +Tells +.Nm +to verify an assertion using the PEM-encoded public key in +.Ar key_file +of type +.Ar type , +where +.Ar type +may be +.Em es256 +(denoting ECDSA over NIST P-256 with SHA-256), +.Em rs256 +(denoting 2048-bit RSA with PKCS#1.5 padding and SHA-256), or +.Em eddsa +(denoting EDDSA over Curve25519 with SHA-512). +If +.Ar type +is not specified, +.Em es256 +is assumed. +.It Fl b +Request the credential's +.Dq largeBlobKey , +a 32-byte symmetric key associated with the asserted credential. +.It Fl h +If obtaining an assertion, enable the FIDO2 hmac-secret +extension. +If verifying an assertion, check whether the extension data bit was +signed by the authenticator. +.It Fl d +Causes +.Nm +to emit debugging output on +.Em stderr . +.It Fl i Ar input_file +Tells +.Nm +to read the parameters of the assertion from +.Ar input_file +instead of +.Em stdin . +.It Fl o Ar output_file +Tells +.Nm +to write output on +.Ar output_file +instead of +.Em stdout . +.It Fl p +If obtaining an assertion, request user presence. +If verifying an assertion, check whether the user presence bit was +signed by the authenticator. +.It Fl r +Obtain an assertion using a resident credential. +If +.Fl r +is specified, +.Nm +will not expect a credential id in its input, and may output +multiple assertions. +Resident credentials are called +.Dq discoverable credentials +in CTAP 2.1. +.It Fl t Ar option +Toggles a key/value +.Ar option , +where +.Ar option +is a string of the form +.Dq key=value . +The options supported at present are: +.Bl -tag -width Ds +.It Cm up Ns = Ns Ar true|false +Asks the authenticator for user presence to be enabled or disabled. +.It Cm uv Ns = Ns Ar true|false +Asks the authenticator for user verification to be enabled or +disabled. +.It Cm pin Ns = Ns Ar true|false +Tells +.Nm +whether to prompt for a PIN and request user verification. +.El +.Pp +The +.Fl t +option may be specified multiple times. +.It Fl u +Obtain an assertion using U2F. +By default, +.Nm +will use FIDO2 if supported by the authenticator, and fallback to +U2F otherwise. +.It Fl v +If obtaining an assertion, prompt the user for a PIN and request +user verification from the authenticator. +If verifying an assertion, check whether the user verification bit +was signed by the authenticator. +.It Fl w +Tells +.Nm +that the first line of input when obtaining an assertion shall be +interpreted as unhashed client data. +This is required by Windows Hello, which calculates the client data hash +internally. +.El +.Pp +If a +.Em tty +is available, +.Nm +will use it to obtain the PIN. +Otherwise, +.Em stdin +is used. +.Sh INPUT FORMAT +The input of +.Nm +consists of base64 blobs and UTF-8 strings separated +by newline characters ('\\n'). +.Pp +When obtaining an assertion, +.Nm +expects its input to consist of: +.Pp +.Bl -enum -offset indent -compact +.It +client data hash (base64 blob); +.It +relying party id (UTF-8 string); +.It +credential id, if credential not resident (base64 blob); +.It +hmac salt, if the FIDO2 hmac-secret extension is enabled +(base64 blob); +.El +.Pp +When verifying an assertion, +.Nm +expects its input to consist of: +.Pp +.Bl -enum -offset indent -compact +.It +client data hash (base64 blob); +.It +relying party id (UTF-8 string); +.It +authenticator data (base64 blob); +.It +assertion signature (base64 blob); +.El +.Pp +UTF-8 strings passed to +.Nm +must not contain embedded newline or NUL characters. +.Sh OUTPUT FORMAT +The output of +.Nm +consists of base64 blobs and UTF-8 strings separated +by newline characters ('\\n'). +.Pp +For each generated assertion, +.Nm +outputs: +.Pp +.Bl -enum -offset indent -compact +.It +client data hash (base64 blob); +.It +relying party id (UTF-8 string); +.It +authenticator data (base64 blob); +.It +assertion signature (base64 blob); +.It +user id, if credential resident (base64 blob); +.It +hmac secret, if the FIDO2 hmac-secret extension is enabled +(base64 blob); +.It +the credential's associated 32-byte symmetric key +.Pq Dq largeBlobKey , +if requested (base64 blob). +.El +.Pp +When verifying an assertion, +.Nm +produces no output. +.Sh EXAMPLES +Assuming +.Pa cred +contains a +.Em es256 +credential created according to the steps outlined in +.Xr fido2-cred 1 , +obtain an assertion from an authenticator at +.Pa /dev/hidraw5 +and verify it: +.Pp +.Dl $ echo assertion challenge | openssl sha256 -binary | base64 > assert_param +.Dl $ echo relying party >> assert_param +.Dl $ head -1 cred >> assert_param +.Dl $ tail -n +2 cred > pubkey +.Dl $ fido2-assert -G -i assert_param /dev/hidraw5 | fido2-assert -V pubkey es256 +.Sh SEE ALSO +.Xr fido2-cred 1 , +.Xr fido2-token 1 |