/// <summary>Verifies certificates against a list of CRLs and OCSP responses.</summary> /// <param name="signCert">the signing certificate</param> /// <param name="issuerCert">the issuer's certificate</param> /// <returns> /// a list of <code>VerificationOK</code> objects. /// The list will be empty if the certificate couldn't be verified. /// </returns> /// <exception cref="Org.BouncyCastle.Security.GeneralSecurityException"/> /// <exception cref="System.IO.IOException"/> /// <seealso cref="RootStoreVerifier.Verify(Org.BouncyCastle.X509.X509Certificate, Org.BouncyCastle.X509.X509Certificate, System.DateTime) /// "/> public override IList <VerificationOK> Verify(X509Certificate signCert, X509Certificate issuerCert, DateTime signDate) { // we'll verify agains the rootstore (if present) RootStoreVerifier rootStoreVerifier = new RootStoreVerifier(verifier); rootStoreVerifier.SetRootStore(rootStore); // We'll verify against a list of CRLs CRLVerifier crlVerifier = new CRLVerifier(rootStoreVerifier, GetCRLsFromDSS()); crlVerifier.SetRootStore(rootStore); crlVerifier.SetOnlineCheckingAllowed(latestRevision || onlineCheckingAllowed); // We'll verify against a list of OCSPs OCSPVerifier ocspVerifier = new OCSPVerifier(crlVerifier, GetOCSPResponsesFromDSS()); ocspVerifier.SetRootStore(rootStore); ocspVerifier.SetOnlineCheckingAllowed(latestRevision || onlineCheckingAllowed); // We verify the chain return(ocspVerifier.Verify(signCert, issuerCert, signDate)); }
/// <summary> /// Verifies if an OCSP response is genuine /// If it doesn't verify against the issuer certificate and response's certificates, it may verify /// using a trusted anchor or cert. /// </summary> /// <param name="ocspResp">the OCSP response</param> /// <param name="issuerCert">the issuer certificate. This certificate is considered trusted and valid by this method. /// </param> /// <param name="signDate">sign date</param> public virtual void IsValidResponse(BasicOcspResp ocspResp, X509Certificate issuerCert, DateTime signDate) { // OCSP response might be signed by the issuer certificate or // the Authorized OCSP responder certificate containing the id-kp-OCSPSigning extended key usage extension X509Certificate responderCert = null; // first check if the issuer certificate signed the response // since it is expected to be the most common case if (IsSignatureValid(ocspResp, issuerCert)) { responderCert = issuerCert; } // if the issuer certificate didn't sign the ocsp response, look for authorized ocsp responses // from properties or from certificate chain received with response if (responderCert == null) { if (ocspResp.GetCerts() != null) { //look for existence of Authorized OCSP responder inside the cert chain in ocsp response IEnumerable <X509Certificate> certs = SignUtils.GetCertsFromOcspResponse(ocspResp); foreach (X509Certificate cert in certs) { IList keyPurposes = null; try { keyPurposes = cert.GetExtendedKeyUsage(); if ((keyPurposes != null) && keyPurposes.Contains(id_kp_OCSPSigning) && IsSignatureValid(ocspResp, cert)) { responderCert = cert; break; } } catch (CertificateParsingException) { } } // Certificate signing the ocsp response is not found in ocsp response's certificate chain received // and is not signed by the issuer certificate. if (responderCert == null) { throw new VerificationException(issuerCert, "OCSP response could not be verified"); } // RFC 6960 4.2.2.2. Authorized Responders: // "Systems relying on OCSP responses MUST recognize a delegation certificate as being issued // by the CA that issued the certificate in question only if the delegation certificate and the // certificate being checked for revocation were signed by the same key." // and // "This certificate MUST be issued directly by the CA that is identified in the request" responderCert.Verify(issuerCert.GetPublicKey()); // check if lifetime of certificate is ok responderCert.CheckValidity(signDate); // validating ocsp signers certificate // Check if responders certificate has id-pkix-ocsp-nocheck extension, // in which case we do not validate (perform revocation check on) ocsp certs for lifetime of certificate if (responderCert.GetExtensionValue(OcspObjectIdentifiers.PkixOcspNocheck.Id) == null) { X509Crl crl; try { // TODO should also check for Authority Information Access according to RFC6960 4.2.2.2.1. "Revocation Checking of an Authorized Responder" // TODO should also respect onlineCheckingAllowed property? crl = CertificateUtil.GetCRL(responderCert); } catch (Exception) { crl = (X509Crl)null; } if (crl != null && crl is X509Crl) { CRLVerifier crlVerifier = new CRLVerifier(null, null); crlVerifier.SetRootStore(rootStore); crlVerifier.SetOnlineCheckingAllowed(onlineCheckingAllowed); if (!crlVerifier.Verify((X509Crl)crl, responderCert, issuerCert, signDate)) { throw new VerificationException(issuerCert, "Authorized OCSP responder certificate was revoked."); } } else { ILog logger = LogManager.GetLogger(typeof(iText.Signatures.OCSPVerifier)); logger.Error("Authorized OCSP responder certificate revocation status cannot be checked"); } } } else { // TODO throw exception starting from iText version 7.2, but only after OCSPVerifier would allow explicit setting revocation check end points/provide revocation data // throw new VerificationException(issuerCert, "Authorized OCSP responder certificate revocation status cannot be checked."); // certificate chain is not present in response received // try to verify using rootStore according to RFC 6960 2.2. Response: // "The key used to sign the response MUST belong to one of the following: // - ... // - a Trusted Responder whose public key is trusted by the requestor; // - ..." if (rootStore != null) { try { foreach (X509Certificate anchor in SignUtils.GetCertificates(rootStore)) { if (IsSignatureValid(ocspResp, anchor)) { // certificate from the root store is considered trusted and valid by this method responderCert = anchor; break; } } } catch (Exception) { responderCert = (X509Certificate)null; } } if (responderCert == null) { throw new VerificationException(issuerCert, "OCSP response could not be verified: it does not contain certificate chain and response is not signed by issuer certificate or any from the root store." ); } } } }
/// <summary> /// Verifies if an OCSP response is genuine /// If it doesn't verify against the issuer certificate and response's certificates, it may verify /// using a trusted anchor or cert. /// </summary> /// <param name="ocspResp">the OCSP response</param> /// <param name="issuerCert">the issuer certificate</param> /// <exception cref="Org.BouncyCastle.Security.GeneralSecurityException"/> /// <exception cref="System.IO.IOException"/> public virtual void IsValidResponse(BasicOcspResp ocspResp, X509Certificate issuerCert) { //OCSP response might be signed by the issuer certificate or //the Authorized OCSP responder certificate containing the id-kp-OCSPSigning extended key usage extension X509Certificate responderCert = null; //first check if the issuer certificate signed the response //since it is expected to be the most common case if (IsSignatureValid(ocspResp, issuerCert)) { responderCert = issuerCert; } //if the issuer certificate didn't sign the ocsp response, look for authorized ocsp responses // from properties or from certificate chain received with response if (responderCert == null) { if (ocspResp.GetCerts() != null) { //look for existence of Authorized OCSP responder inside the cert chain in ocsp response IEnumerable <X509Certificate> certs = SignUtils.GetCertsFromOcspResponse(ocspResp); foreach (X509Certificate cert in certs) { IList keyPurposes = null; try { keyPurposes = cert.GetExtendedKeyUsage(); if ((keyPurposes != null) && keyPurposes.Contains(id_kp_OCSPSigning) && IsSignatureValid(ocspResp, cert)) { responderCert = cert; break; } } catch (CertificateParsingException) { } } // Certificate signing the ocsp response is not found in ocsp response's certificate chain received // and is not signed by the issuer certificate. if (responderCert == null) { throw new VerificationException(issuerCert, "OCSP response could not be verified"); } } else { //certificate chain is not present in response received //try to verify using rootStore if (rootStore != null) { try { foreach (X509Certificate anchor in SignUtils.GetCertificates(rootStore)) { if (IsSignatureValid(ocspResp, anchor)) { responderCert = anchor; break; } } } catch (Exception) { responderCert = (X509Certificate)null; } } // OCSP Response does not contain certificate chain, and response is not signed by any // of the rootStore or the issuer certificate. if (responderCert == null) { throw new VerificationException(issuerCert, "OCSP response could not be verified"); } } } //check "This certificate MUST be issued directly by the CA that issued the certificate in question". responderCert.Verify(issuerCert.GetPublicKey()); // validating ocsp signers certificate // Check if responders certificate has id-pkix-ocsp-nocheck extension, // in which case we do not validate (perform revocation check on) ocsp certs for lifetime of certificate if (responderCert.GetExtensionValue(OcspObjectIdentifiers.PkixOcspNocheck.Id) == null) { X509Crl crl; try { crl = CertificateUtil.GetCRL(responderCert); } catch (Exception) { crl = (X509Crl)null; } if (crl != null && crl is X509Crl) { CRLVerifier crlVerifier = new CRLVerifier(null, null); crlVerifier.SetRootStore(rootStore); crlVerifier.SetOnlineCheckingAllowed(onlineCheckingAllowed); crlVerifier.Verify((X509Crl)crl, responderCert, issuerCert, DateTimeUtil.GetCurrentUtcTime()); return; } } //check if lifetime of certificate is ok responderCert.CheckValidity(); }