Example usage for org.bouncycastle.bcpg ArmoredInputStream available

Introduction

In this page you can find the example usage for org.bouncycastle.bcpg ArmoredInputStream available.

Prototype

public int available() throws IOException 

Source Link

Usage

From source file:cc.arduino.packages.security.ClearSignedVerifier.java

License:Open Source License

/**
 * Verify a PGP clearText-signature./*from  ww w .  j a v  a2  s  . c o  m*/
 *
 * @param signedTextFile A File containing the clearText signature
 * @param pubKeyRing     A public key-ring containing the public key needed for the
 *                       signature verification
 * @return A VerifyResult class with the clearText and the signature
 * verification status
 * @throws FileNotFoundException
 */
public static VerifyResult verify(File signedTextFile, PGPPublicKeyRingCollection pubKeyRing) {
    // Create the result object
    VerifyResult result = new VerifyResult();
    result.clearText = null;
    result.verified = false;
    result.error = null;

    ArmoredInputStream in = null;
    try {
        // Extract clear text.
        // Dash-encoding is removed by ArmoredInputStream.
        in = new ArmoredInputStream(new FileInputStream(signedTextFile));
        ByteArrayOutputStream temp = new ByteArrayOutputStream(in.available());
        while (true) {
            int c = in.read();
            if (c == -1)
                throw new IOException("Unexpected end of file");
            if (!in.isClearText())
                break;
            temp.write(c);
        }
        byte clearText[] = temp.toByteArray();
        result.clearText = clearText;

        // Extract signature from clear-signed text
        PGPObjectFactory pgpFact = new PGPObjectFactory(in);
        PGPSignatureList p3 = (PGPSignatureList) pgpFact.nextObject();
        PGPSignature sig = p3.get(0);

        // Decode public key
        PGPPublicKey publicKey = pubKeyRing.getPublicKey(sig.getKeyID());

        // Verify signature
        Security.addProvider(new BouncyCastleProvider());
        sig.init(new JcaPGPContentVerifierBuilderProvider().setProvider("BC"), publicKey);
        // RFC 4880, section 7: http://tools.ietf.org/html/rfc4880#section-7
        // The signature must be validated using clear text:
        // - without trailing white spaces on every line
        // - using CR LF line endings, no matter what the original line ending is
        // - without the latest line ending
        BufferedReader textIn = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(clearText)));
        while (true) {
            // remove trailing whitespace and line endings
            String line = StringUtils.rtrim(textIn.readLine());
            sig.update(line.getBytes());
            if (!textIn.ready()) // skip latest line ending
                break;
            // always use CR LF
            sig.update((byte) '\r');
            sig.update((byte) '\n');
        }

        // Prepare the result
        result.verified = sig.verify();
    } catch (Exception e) {
        result.error = e;
    } finally {
        if (in != null)
            try {
                in.close();
            } catch (IOException e) {
                // ignored
            }
    }
    return result;
}

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