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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

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package sun.security.pkcs11;

import java.security.*;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.*;

import java.util.Locale;

import javax.crypto.*;

import javax.crypto.spec.*;

import static sun.security.pkcs11.TemplateManager.*;

import sun.security.pkcs11.wrapper.*;

import static sun.security.pkcs11.wrapper.PKCS11Constants.*;

import sun.security.internal.spec.TlsRsaPremasterSecretParameterSpec;

import sun.security.util.KeyUtil;

/**

 * RSA Cipher implementation class. We currently only support

 * PKCS#1 v1.5 padding on top of CKM_RSA_PKCS.

 *

 * @author  Andreas Sterbenz

 * @since   1.5

 */

final class P11RSACipher extends CipherSpi {

    // minimum length of PKCS#1 v1.5 padding

    private final static int PKCS1_MIN_PADDING_LENGTH = 11;

    // constant byte[] of length 0

    private final static byte[] B0 = new byte[0];

    // mode constant for public key encryption

    private final static int MODE_ENCRYPT = 1;

    // mode constant for private key decryption

    private final static int MODE_DECRYPT = 2;

    // mode constant for private key encryption (signing)

    private final static int MODE_SIGN    = 3;

    // mode constant for public key decryption (verifying)

    private final static int MODE_VERIFY  = 4;

    // padding type constant for NoPadding

    private final static int PAD_NONE = 1;

    // padding type constant for PKCS1Padding

    private final static int PAD_PKCS1 = 2;

    // token instance

    private final Token token;

    // algorithm name (always "RSA")

    private final String algorithm;

    // mechanism id

    private final long mechanism;

    // associated session, if any

    private Session session;

    // mode, one of MODE_* above

    private int mode;

    // padding, one of PAD_* above

    private int padType;

    private byte[] buffer;

    private int bufOfs;

    // key, if init() was called

    private P11Key p11Key;

    // flag indicating whether an operation is initialized

    private boolean initialized;

    // maximum input data size allowed

    // for decryption, this is the length of the key

    // for encryption, length of the key minus minimum padding length

    private int maxInputSize;

    // maximum output size. this is the length of the key

    private int outputSize;

    // cipher parameter for TLS RSA premaster secret

    private AlgorithmParameterSpec spec = null;

    // the source of randomness

    private SecureRandom random;

    P11RSACipher(Token token, String algorithm, long mechanism)

            throws PKCS11Exception {

        super();

        this.token = token;

        this.algorithm = "RSA";

        this.mechanism = mechanism;

    }

    // modes do not make sense for RSA, but allow ECB

    // see JCE spec

    protected void engineSetMode(String mode) throws NoSuchAlgorithmException {

        if (mode.equalsIgnoreCase("ECB") == false) {

            throw new NoSuchAlgorithmException("Unsupported mode " + mode);

        }

    }

    protected void engineSetPadding(String padding)

            throws NoSuchPaddingException {

        String lowerPadding = padding.toLowerCase(Locale.ENGLISH);

        if (lowerPadding.equals("pkcs1padding")) {

            padType = PAD_PKCS1;

        } else if (lowerPadding.equals("nopadding")) {

            padType = PAD_NONE;

        } else {

            throw new NoSuchPaddingException("Unsupported padding " + padding);

        }

    }

    // return 0 as block size, we are not a block cipher

    // see JCE spec

    protected int engineGetBlockSize() {

        return 0;

    }

    // return the output size

    // see JCE spec

    protected int engineGetOutputSize(int inputLen) {

        return outputSize;

    }

    // no IV, return null

    // see JCE spec

    protected byte[] engineGetIV() {

        return null;

    }

    // no parameters, return null

    // see JCE spec

    protected AlgorithmParameters engineGetParameters() {

        return null;

    }

    // see JCE spec

    protected void engineInit(int opmode, Key key, SecureRandom random)

            throws InvalidKeyException {

        implInit(opmode, key);

    }

    // see JCE spec

    protected void engineInit(int opmode, Key key,

            AlgorithmParameterSpec params, SecureRandom random)

            throws InvalidKeyException, InvalidAlgorithmParameterException {

        if (params != null) {

            if (!(params instanceof TlsRsaPremasterSecretParameterSpec)) {

                throw new InvalidAlgorithmParameterException(

                        "Parameters not supported");

            }

            spec = params;

            this.random = random;   // for TLS RSA premaster secret

        }

        implInit(opmode, key);

    }

    // see JCE spec

    protected void engineInit(int opmode, Key key, AlgorithmParameters params,

            SecureRandom random)

            throws InvalidKeyException, InvalidAlgorithmParameterException {

        if (params != null) {

            throw new InvalidAlgorithmParameterException(

                        "Parameters not supported");

        }

        implInit(opmode, key);

    }

    private void implInit(int opmode, Key key) throws InvalidKeyException {

        cancelOperation();

        p11Key = P11KeyFactory.convertKey(token, key, algorithm);

        boolean encrypt;

        if (opmode == Cipher.ENCRYPT_MODE) {

            encrypt = true;

        } else if (opmode == Cipher.DECRYPT_MODE) {

            encrypt = false;

        } else if (opmode == Cipher.WRAP_MODE) {

            if (p11Key.isPublic() == false) {

                throw new InvalidKeyException

                                ("Wrap has to be used with public keys");

            }

            // No further setup needed for C_Wrap(). We'll initialize later if

            // we can't use C_Wrap().

            return;

        } else if (opmode == Cipher.UNWRAP_MODE) {

            if (p11Key.isPrivate() == false) {

                throw new InvalidKeyException

                                ("Unwrap has to be used with private keys");

            }

            // No further setup needed for C_Unwrap(). We'll initialize later

            // if we can't use C_Unwrap().

            return;

        } else {

            throw new InvalidKeyException("Unsupported mode: " + opmode);

        }

        if (p11Key.isPublic()) {

            mode = encrypt ? MODE_ENCRYPT : MODE_VERIFY;

        } else if (p11Key.isPrivate()) {

            mode = encrypt ? MODE_SIGN : MODE_DECRYPT;

        } else {

            throw new InvalidKeyException("Unknown key type: " + p11Key);

        }

        int n = (p11Key.length() + 7) >> 3;

        outputSize = n;

        buffer = new byte[n];

        maxInputSize = ((padType == PAD_PKCS1 && encrypt) ?

                            (n - PKCS1_MIN_PADDING_LENGTH) : n);

        try {

            initialize();

        } catch (PKCS11Exception e) {

            throw new InvalidKeyException("init() failed", e);

        }

    }

    private void cancelOperation() {

        token.ensureValid();

        if (initialized == false) {

            return;

        }

        initialized = false;

        if ((session == null) || (token.explicitCancel == false)) {

            return;

        }

        if (session.hasObjects() == false) {

            session = token.killSession(session);

            return;

        }

        try {

            PKCS11 p11 = token.p11;

            int inLen = maxInputSize;

            int outLen = buffer.length;

            switch (mode) {

            case MODE_ENCRYPT:

                p11.C_Encrypt

                        (session.id(), buffer, 0, inLen, buffer, 0, outLen);

                break;

            case MODE_DECRYPT:

                p11.C_Decrypt

                        (session.id(), buffer, 0, inLen, buffer, 0, outLen);

                break;

            case MODE_SIGN:

                byte[] tmpBuffer = new byte[maxInputSize];

                p11.C_Sign

                        (session.id(), tmpBuffer);

                break;

            case MODE_VERIFY:

                p11.C_VerifyRecover

                        (session.id(), buffer, 0, inLen, buffer, 0, outLen);

                break;

            default:

                throw new ProviderException("internal error");

            }

        } catch (PKCS11Exception e) {

            // XXX ensure this always works, ignore error

        }

    }

    private void ensureInitialized() throws PKCS11Exception {

        token.ensureValid();

        if (initialized == false) {

            initialize();

        }

    }

    private void initialize() throws PKCS11Exception {

        if (session == null) {

            session = token.getOpSession();

        }

        PKCS11 p11 = token.p11;

        CK_MECHANISM ckMechanism = new CK_MECHANISM(mechanism);

        switch (mode) {

        case MODE_ENCRYPT:

            p11.C_EncryptInit(session.id(), ckMechanism, p11Key.keyID);

            break;

        case MODE_DECRYPT:

            p11.C_DecryptInit(session.id(), ckMechanism, p11Key.keyID);

            break;

        case MODE_SIGN:

            p11.C_SignInit(session.id(), ckMechanism, p11Key.keyID);

            break;

        case MODE_VERIFY:

            p11.C_VerifyRecoverInit(session.id(), ckMechanism, p11Key.keyID);

            break;

        default:

            throw new AssertionError("internal error");

        }

        bufOfs = 0;

        initialized = true;

    }

    private void implUpdate(byte[] in, int inOfs, int inLen) {

        try {

            ensureInitialized();

        } catch (PKCS11Exception e) {

            throw new ProviderException("update() failed", e);

        }

        if ((inLen == 0) || (in == null)) {

            return;

        }

        if (bufOfs + inLen > maxInputSize) {

            bufOfs = maxInputSize + 1;

            return;

        }

        System.arraycopy(in, inOfs, buffer, bufOfs, inLen);

        bufOfs += inLen;

    }

    private int implDoFinal(byte[] out, int outOfs, int outLen)

            throws BadPaddingException, IllegalBlockSizeException {

        if (bufOfs > maxInputSize) {

            throw new IllegalBlockSizeException("Data must not be longer "

                + "than " + maxInputSize + " bytes");

        }

        try {

            ensureInitialized();

            PKCS11 p11 = token.p11;

            int n;

            switch (mode) {

            case MODE_ENCRYPT:

                n = p11.C_Encrypt

                        (session.id(), buffer, 0, bufOfs, out, outOfs, outLen);

                break;

            case MODE_DECRYPT:

                n = p11.C_Decrypt

                        (session.id(), buffer, 0, bufOfs, out, outOfs, outLen);

                break;

            case MODE_SIGN:

                byte[] tmpBuffer = new byte[bufOfs];

                System.arraycopy(buffer, 0, tmpBuffer, 0, bufOfs);

                tmpBuffer = p11.C_Sign(session.id(), tmpBuffer);

                if (tmpBuffer.length > outLen) {

                    throw new BadPaddingException("Output buffer too small");

                }

                System.arraycopy(tmpBuffer, 0, out, outOfs, tmpBuffer.length);

                n = tmpBuffer.length;

                break;

            case MODE_VERIFY:

                n = p11.C_VerifyRecover

                        (session.id(), buffer, 0, bufOfs, out, outOfs, outLen);

                break;

            default:

                throw new ProviderException("internal error");

            }

            return n;

        } catch (PKCS11Exception e) {

            throw (BadPaddingException)new BadPaddingException

                ("doFinal() failed").initCause(e);

        } finally {

            initialized = false;

            session = token.releaseSession(session);

        }

    }

    // see JCE spec

    protected byte[] engineUpdate(byte[] in, int inOfs, int inLen) {

        implUpdate(in, inOfs, inLen);

        return B0;

    }

    // see JCE spec

    protected int engineUpdate(byte[] in, int inOfs, int inLen,

            byte[] out, int outOfs) throws ShortBufferException {

        implUpdate(in, inOfs, inLen);

        return 0;

    }

    // see JCE spec

    protected byte[] engineDoFinal(byte[] in, int inOfs, int inLen)

            throws IllegalBlockSizeException, BadPaddingException {

        implUpdate(in, inOfs, inLen);

        int n = implDoFinal(buffer, 0, buffer.length);

        byte[] out = new byte[n];

        System.arraycopy(buffer, 0, out, 0, n);

        return out;

    }

    // see JCE spec

    protected int engineDoFinal(byte[] in, int inOfs, int inLen,

            byte[] out, int outOfs) throws ShortBufferException,

            IllegalBlockSizeException, BadPaddingException {

        implUpdate(in, inOfs, inLen);

        return implDoFinal(out, outOfs, out.length - outOfs);

    }

    private byte[] doFinal() throws BadPaddingException,

            IllegalBlockSizeException {

        byte[] t = new byte[2048];

        int n = implDoFinal(t, 0, t.length);

        byte[] out = new byte[n];

        System.arraycopy(t, 0, out, 0, n);

        return out;

    }

    // see JCE spec

    protected byte[] engineWrap(Key key) throws InvalidKeyException,

            IllegalBlockSizeException {

        String keyAlg = key.getAlgorithm();

        P11Key sKey = null;

        try {

            // The conversion may fail, e.g. trying to wrap an AES key on

            // a token that does not support AES, or when the key size is

            // not within the range supported by the token.

            sKey = P11SecretKeyFactory.convertKey(token, key, keyAlg);

        } catch (InvalidKeyException ike) {

            byte[] toBeWrappedKey = key.getEncoded();

            if (toBeWrappedKey == null) {

                throw new InvalidKeyException

                        ("wrap() failed, no encoding available", ike);

            }

            // Directly encrypt the key encoding when key conversion failed

            implInit(Cipher.ENCRYPT_MODE, p11Key);

            implUpdate(toBeWrappedKey, 0, toBeWrappedKey.length);

            try {

                return doFinal();

            } catch (BadPaddingException bpe) {

                // should not occur

                throw new InvalidKeyException("wrap() failed", bpe);

            } finally {

                // Restore original mode

                implInit(Cipher.WRAP_MODE, p11Key);

            }

        }

        Session s = null;

        try {

            s = token.getOpSession();

            return token.p11.C_WrapKey(s.id(), new CK_MECHANISM(mechanism),

                p11Key.keyID, sKey.keyID);

        } catch (PKCS11Exception e) {

            throw new InvalidKeyException("wrap() failed", e);

        } finally {

            token.releaseSession(s);

        }

    }

    // see JCE spec

    protected Key engineUnwrap(byte[] wrappedKey, String algorithm,

            int type) throws InvalidKeyException, NoSuchAlgorithmException {

        boolean isTlsRsaPremasterSecret =

                algorithm.equals("TlsRsaPremasterSecret");

        Exception failover = null;

        SecureRandom secureRandom = random;

        if (secureRandom == null && isTlsRsaPremasterSecret) {

            secureRandom = new SecureRandom();

        }

        // Should C_Unwrap be preferred for non-TLS RSA premaster secret?

        if (token.supportsRawSecretKeyImport()) {

            // XXX implement unwrap using C_Unwrap() for all keys

            implInit(Cipher.DECRYPT_MODE, p11Key);

            if (wrappedKey.length > maxInputSize) {

                throw new InvalidKeyException("Key is too long for unwrapping");

            }

            byte[] encoded = null;

            implUpdate(wrappedKey, 0, wrappedKey.length);

            try {

                encoded = doFinal();

            } catch (BadPaddingException e) {

                if (isTlsRsaPremasterSecret) {

                    failover = e;

                } else {

                    throw new InvalidKeyException("Unwrapping failed", e);

                }

            } catch (IllegalBlockSizeException e) {

                // should not occur, handled with length check above

                throw new InvalidKeyException("Unwrapping failed", e);

            }

            if (isTlsRsaPremasterSecret) {

                if (!(spec instanceof TlsRsaPremasterSecretParameterSpec)) {

                    throw new IllegalStateException(

                            "No TlsRsaPremasterSecretParameterSpec specified");

                }

                // polish the TLS premaster secret

                TlsRsaPremasterSecretParameterSpec psps =

                        (TlsRsaPremasterSecretParameterSpec)spec;

                encoded = KeyUtil.checkTlsPreMasterSecretKey(

                        psps.getClientVersion(), psps.getServerVersion(),

                        secureRandom, encoded, (failover != null));

            }

            return ConstructKeys.constructKey(encoded, algorithm, type);

        } else {

            Session s = null;

            SecretKey secretKey = null;

            try {