Webauthn'u çalıştırmaya çalışıyorum

Aug 17 2020

Bir süre önce bir Fido2 / WebAuthn projesine başladım ve microsofts webauthn uygulamasını başlatmaya çalıştım. Bunun için bu projede webauthn.h dosyasının bir çevirisi var (bugün bu dosyaya yalnızca Mozilla ve Chromium tarayıcılarının kodunda referans bulduğum için ...).

Şimdi ... Sadece kimlik bilgilerini oluşturmak için bir komut veren bir düğmeyle form oluşturmaya çalıştım, ancak bu çağrı @ $ 0000EA60 bir erişim ihlali ile sefil bir şekilde başarısız oluyor ve bunun neye neden olabileceği konusunda hiçbir fikrim yok. Neyi yanlış yapabilirim ???

Burada bir düğme onClick işleyicisinin kodu.

uses Webauthn;

// just a test JSON object that I obtained from a browser request
const cClientData : UTF8String = '{' +
 '"hashAlgorithm": "SHA-256",' +
 '"challenge": "fzjg31IEKi6ZxKqsQ9S_XHG9WvdmcXPah5EXd11p1bU",' +
 '"origin": "https:\/\/fidotest.com",' +
 '"clientExtensions": {},' +
 '"type": "webauthn.create"' +
 '}';

procedure TfrmWebAuthnTest.btnCredentialClick(Sender: TObject);
var RpInformation : TWebAuthnRPEntityInformation; // _In_
    UserInformation : TWebAuthUserEntityInformation; // _In_
    PubKeyCredParams : TWebauthnCoseCredentialParameters; // _In_
    WebAuthNClientData : TWebAuthnClientData; // _In_
    WebAuthNMakeCredentialOptions : TWebAuthnAuthenticatorMakeCredentialOptions; // _In_opt_
    pWebAuthNCredentialAttestation : PWEBAUTHN_CREDENTIAL_ATTESTATION; // _Outptr_result_maybenull_
    hr : HRESULT;
    coseParams : Array[0..1] of WEBAUTHN_COSE_CREDENTIAL_PARAMETER;
    i : integer;
    challenge : Array[0..31] of byte;
    cancellationID : TGuid;
    bufClientData : UTF8String;
begin
     // ################################################
     // #### relying party
     FillChar(RpInformation, sizeof(RpInformation), 0);
     RpInformation.dwVersion := WEBAUTHN_RP_ENTITY_INFORMATION_CURRENT_VERSION;
     RpInformation.pwszId := 'fidotest.com';
     RpInformation.pwszName := 'Sweet home localhost';
     RpInformation.pwszIcon := nil;

     // ################################################
     // #### user information
     FillChar(UserInformation, sizeof(UserInformation), 0);
     UserInformation.dwVersion := WEBAUTHN_USER_ENTITY_INFORMATION_CURRENT_VERSION;
     UserInformation.cbId := sizeof( challenge );

     Randomize;

     // create credentials
     for i := 0 to Length(challenge) - 1 do
     begin
          challenge[i] := Byte( Random(High(byte) + 1) );
     end;

     UserInformation.pbId := @challenge[0];
     UserInformation.pwszName := 'Mike';
     UserInformation.pwszIcon := niL;
     UserInformation.pwszDisplayName := 'Mike Rabat';

     // ################################################
     // #### Client data
     bufClientData := Copy( cClientData, 1, Length(cClientData));
     FillChar(WebAuthNClientData, sizeof(WebAuthNClientData), 0);
     WebAuthNClientData.dwVersion := WEBAUTHN_CLIENT_DATA_CURRENT_VERSION;
     WebAuthNClientData.cbClientDataJSON := Length(cClientData);
     WebAuthNClientData.pbClientDataJSON := PAnsiChar(bufClientData);
     WebAuthNClientData.pwszHashAlgId := WEBAUTHN_HASH_ALGORITHM_SHA_256;

     // ################################################
     // #### pub ked credential params
     PubKeyCredParams.cCredentialParameters := sizeof(coseParams);
     PubKeyCredParams.pCredentialParameters := @coseParams[0];

     coseParams[0].dwVersion := WEBAUTHN_COSE_CREDENTIAL_PARAMETER_CURRENT_VERSION;
     coseParams[0].pwszCredentialType := WEBAUTHN_CREDENTIAL_TYPE_PUBLIC_KEY;
     coseParams[0].lAlg := WEBAUTHN_COSE_ALGORITHM_ECDSA_P256_WITH_SHA256;

     coseParams[1].dwVersion := WEBAUTHN_COSE_CREDENTIAL_PARAMETER_CURRENT_VERSION;
     coseParams[1].pwszCredentialType := WEBAUTHN_CREDENTIAL_TYPE_PUBLIC_KEY;
     coseParams[1].lAlg := WEBAUTHN_COSE_ALGORITHM_RSASSA_PKCS1_V1_5_WITH_SHA256;

     // ###########################################
     // #### Fill in params
     FillChar(WebAuthNMakeCredentialOptions, sizeof(WebAuthNMakeCredentialOptions), 0);
     WebAuthNMakeCredentialOptions.dwVersion := WEBAUTHN_AUTHENTICATOR_MAKE_CREDENTIAL_OPTIONS_CURRENT_VERSION;
     WebAuthNMakeCredentialOptions.dwTimeoutMilliseconds := 60000;
     WebAuthNMakeCredentialOptions.bRequireResidentKey := False;
     WebAuthNMakeCredentialOptions.dwAuthenticatorAttachment := WEBAUTHN_AUTHENTICATOR_ATTACHMENT_CROSS_PLATFORM;
     WebAuthNMakeCredentialOptions.dwUserVerificationRequirement := WEBAUTHN_USER_VERIFICATION_REQUIREMENT_REQUIRED;
     WebAuthNMakeCredentialOptions.dwAttestationConveyancePreference := WEBAUTHN_ATTESTATION_CONVEYANCE_PREFERENCE_DIRECT;

     // ###########################################
     // #### Cancellation
     assert( WebAuthNGetCancellationId(cancellationID) = S_OK, 'Cancellation ID failed');
     WebAuthNMakeCredentialOptions.pCancellationId := @cancellationID;

     // ###########################################
     // #### do the magic
     pWebAuthNCredentialAttestation := nil;
     hr := WebAuthNAuthenticatorMakeCredential( Handle,
                                                @RpInformation,
                                                @UserInformation,
                                                @PubKeyCredParams,
                                                @WebAuthNClientData,
                                                @WebAuthNMakeCredentialOptions,
                                                pWebAuthNCredentialAttestation );

     if hr = S_OK then
     begin
          // WriteCredAttest( pWebAuthNCredentialAttestation );

          WebAuthNFreeCredentialAttestation( pWebAuthNCredentialAttestation );
          memLog.Lines.Add('Finished');
     end
     else
     begin
          memLog.Lines.Add('Make Cred failed with: ' + WebAuthNGetErrorName( hr ));
     end;
end;

Delphi2010 kullanıyorum, bu nedenle JSON istemci veri dizesi dışındaki tüm dizeler unicode olmalıdır.

Yanıtlar

mrabat Aug 26 2020 at 13:18

Mozilla Tarayıcısının C ++ kodunu uzun süre çalıştıktan sonra, sanırım sorunu buldum. COSE_PARAMS yapısının boyut alanındaydı.

 // #### pub ked credential params
 PubKeyCredParams.cCredentialParameters := Length(coseParams);// sizeof(coseParams);
 PubKeyCredParams.pCredentialParameters := @coseParams[0];

Bayt cinsinden boyut yerine, ekli coseParams dizisinin uzunluğunu bekliyor gibi görünüyorlar. Bu yanlış anlama AV'ye yol açtı.