Example usage for org.bouncycastle.crypto.signers GenericSigner verifySignature

Introduction

In this page you can find the example usage for org.bouncycastle.crypto.signers GenericSigner verifySignature.

Prototype

public boolean verifySignature(byte[] signature) 

Source Link

Document

return true if the internal state represents the signature described in the passed in array.

Usage

From source file:net.wstech2.me.httpsclient.CertificateValidatorUtils.java

License:Apache License

/**
 * //from  w ww  . jav a2 s  . c  o m
 * Inspected and display various informations from the Certificate passed as
 * parameter. Keys are presented in HEX values and ASN1 structures dumped
 * using ASN1Dump.dumpAsString.
 * 
 * This method is intended for debug purposes only.
 * 
 * 
 * @param cert
 *            The X509CertificateStructure to be inspected.
 * 
 */
public static void dumpCertificateInfo(org.bouncycastle.asn1.x509.Certificate cert) {
    boolean valid = false;
    TBSCertificate tbs = cert.getTBSCertificate();
    RSAEngine engine = new RSAEngine();
    SHA1Digest digest = new SHA1Digest();

    GenericSigner signer = new GenericSigner((engine), digest);
    RSAPublicKey signingKey;
    try {
        signingKey = RSAPublicKey.getInstance(cert.getSubjectPublicKeyInfo().parsePublicKey());

        HttpsConnectionUtils.logDebug("Public Key:[[" + cert.getSubjectPublicKeyInfo().parsePublicKey() + "]]");

        RSAKeyParameters keySpec = new RSAKeyParameters(false, signingKey.getModulus(),
                signingKey.getPublicExponent());
        signer.init(false, keySpec);
        HttpsConnectionUtils.logDebug("TBS DER object:[[" + tbs.getEncoded("DER") + "]]");

        signer.update(tbs.getEncoded(), 0, tbs.getEncoded().length);

        valid = signer.verifySignature(cert.getSignature().getBytes());

        HttpsConnectionUtils.logDebug("signer.verifySignature:[[" + valid + "]]");

        SHA1Digest d2 = new SHA1Digest();
        d2.update(tbs.getEncoded("DER"), 0, tbs.getEncoded("DER").length);
        byte[] hash = new byte[d2.getDigestSize()];
        d2.doFinal(hash, 0);
        HttpsConnectionUtils.logDebug("tbs.getDEREncoded() HASH:[[" + new String(Hex.encode(hash)) + "]]");
        DEROctetString asn1Hash = new DEROctetString(hash);
        HttpsConnectionUtils.logDebug(
                "ASN1 DEROctetString hash:[[" + new String(Hex.encode(asn1Hash.getEncoded("DER"))) + "]]");

        d2 = new SHA1Digest();
        d2.update(cert.getEncoded(), 0, cert.getEncoded().length);
        hash = new byte[d2.getDigestSize()];
        d2.doFinal(hash, 0);
        HttpsConnectionUtils.logDebug("cert.getEncoded() HASH:[[" + new String(Hex.encode(hash)) + "]]");

        byte[] signature = cert.getSignature().getBytes();
        HttpsConnectionUtils
                .logDebug("cert.getSignature().getBytes():[[" + new String(Hex.encode(signature)) + "]]");

        PKCS1Encoding engine2 = new PKCS1Encoding(new RSAEngine());
        engine2.init(false, keySpec);
        byte[] decryptedHash = engine2.processBlock(signature, 0, signature.length);
        HttpsConnectionUtils.logDebug("decryptedHash:[[" + new String(Hex.encode(decryptedHash)) + "]]");

        ASN1Object o = ASN1Primitive.fromByteArray(decryptedHash);
        HttpsConnectionUtils.logDebug(
                "decryptedHash.getDEREncoded():[[" + new String(Hex.encode(o.getEncoded("DER"))) + "]]");

        HttpsConnectionUtils.logDebug(
                "ASN1Dump.dumpAsString(decryptedHash,true):[[" + ASN1Dump.dumpAsString(o, true) + "]]");

        HttpsConnectionUtils.logDebug("engine.getInputBlockSize():[[" + engine2.getInputBlockSize() + "]]");

        HttpsConnectionUtils.logDebug("engine.getOutputBlockSize():[[" + engine2.getOutputBlockSize() + "]]");

        ASN1Sequence asn1SignSeq = (ASN1Sequence) ASN1Sequence.fromByteArray(decryptedHash);
        HttpsConnectionUtils
                .logDebug("Signature ASN1 Sequence:[[" + ASN1Dump.dumpAsString(asn1SignSeq, true) + "]]");

        AlgorithmIdentifier algorithm = AlgorithmIdentifier.getInstance(asn1SignSeq.getObjectAt(0));
        HttpsConnectionUtils.logDebug("AlgorithmIdentifier:[[" + ASN1Dump.dumpAsString(algorithm, true) + "]]");

        DEROctetString signedHash = (DEROctetString) DEROctetString.getInstance(asn1SignSeq.getObjectAt(1));
        HttpsConnectionUtils.logDebug("signedHash:[[" + ASN1Dump.dumpAsString(signedHash, true) + "]]");

    } catch (Exception e) {
        e.printStackTrace();
    }

}

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