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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* 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 javax.crypto.*;
import static sun.security.pkcs11.TemplateManager.*;
import sun.security.pkcs11.wrapper.*;
import static sun.security.pkcs11.wrapper.PKCS11Constants.*;
/**
* KeyGenerator implementation class. This class currently supports
* DES, DESede, AES, ARCFOUR, and Blowfish.
*
* @author Andreas Sterbenz
* @since 1.5
*/
final class P11KeyGenerator extends KeyGeneratorSpi {
// token instance
private final Token token;
// algorithm name
private final String algorithm;
// mechanism id
private long mechanism;
// raw key size in bits, e.g. 64 for DES. Always valid.
private int keySize;
// bits of entropy in the key, e.g. 56 for DES. Always valid.
private int significantKeySize;
// keyType (CKK_*), needed for TemplateManager call only.
private long keyType;
// for determining if both 112 and 168 bits of DESede key lengths
// are supported.
private boolean supportBothKeySizes;
/**
* Utility method for checking if the specified key size is valid
* and within the supported range. Return the significant key size
* upon successful validation.
* @param keyGenMech the PKCS#11 key generation mechanism.
* @param keySize the to-be-checked key size for this mechanism.
* @param token token which provides this mechanism.
* @return the significant key size (in bits) corresponding to the
* specified key size.
* @throws InvalidParameterException if the specified key size is invalid.
* @throws ProviderException if this mechanism isn't supported by SunPKCS11
* or underlying native impl.
*/
static int checkKeySize(long keyGenMech, int keySize, Token token)
throws InvalidAlgorithmParameterException, ProviderException {
int sigKeySize;
switch ((int)keyGenMech) {
case (int)CKM_DES_KEY_GEN:
if ((keySize != 64) && (keySize != 56)) {
throw new InvalidAlgorithmParameterException
("DES key length must be 56 bits");
}
sigKeySize = 56;
break;
case (int)CKM_DES2_KEY_GEN:
case (int)CKM_DES3_KEY_GEN:
if ((keySize == 112) || (keySize == 128)) {
sigKeySize = 112;
} else if ((keySize == 168) || (keySize == 192)) {
sigKeySize = 168;
} else {
throw new InvalidAlgorithmParameterException
("DESede key length must be 112, or 168 bits");
}
break;
default:
// Handle all variable-key-length algorithms here
CK_MECHANISM_INFO info = null;
try {
info = token.getMechanismInfo(keyGenMech);
} catch (PKCS11Exception p11e) {
// Should never happen
throw new ProviderException
("Cannot retrieve mechanism info", p11e);
}
if (info == null) {
// XXX Unable to retrieve the supported key length from
// the underlying native impl. Skip the checking for now.
return keySize;
}
// PKCS#11 defines these to be in number of bytes except for
// RC4 which is in bits. However, some PKCS#11 impls still use
// bytes for all mechs, e.g. NSS. We try to detect this
// inconsistency if the minKeySize seems unreasonably small.
int minKeySize = (int)info.ulMinKeySize;
int maxKeySize = (int)info.ulMaxKeySize;
if (keyGenMech != CKM_RC4_KEY_GEN || minKeySize < 8) {
minKeySize = (int)info.ulMinKeySize << 3;
maxKeySize = (int)info.ulMaxKeySize << 3;
}
// Explicitly disallow keys shorter than 40-bits for security
if (minKeySize < 40) minKeySize = 40;
if (keySize < minKeySize || keySize > maxKeySize) {
throw new InvalidAlgorithmParameterException
("Key length must be between " + minKeySize +
" and " + maxKeySize + " bits");
}
if (keyGenMech == CKM_AES_KEY_GEN) {
if ((keySize != 128) && (keySize != 192) &&
(keySize != 256)) {
throw new InvalidAlgorithmParameterException
("AES key length must be " + minKeySize +
(maxKeySize >= 192? ", 192":"") +
(maxKeySize >= 256? ", or 256":"") + " bits");
}
}
sigKeySize = keySize;
}
return sigKeySize;
}
P11KeyGenerator(Token token, String algorithm, long mechanism)
throws PKCS11Exception {
super();
this.token = token;
this.algorithm = algorithm;
this.mechanism = mechanism;
if (this.mechanism == CKM_DES3_KEY_GEN) {
/* Given the current lookup order specified in SunPKCS11.java,
if CKM_DES2_KEY_GEN is used to construct this object, it
means that CKM_DES3_KEY_GEN is disabled or unsupported.
*/
supportBothKeySizes =
(token.provider.config.isEnabled(CKM_DES2_KEY_GEN) &&
(token.getMechanismInfo(CKM_DES2_KEY_GEN) != null));
}
setDefaultKeySize();
}
// set default keysize and also initialize keyType
private void setDefaultKeySize() {
switch ((int)mechanism) {
case (int)CKM_DES_KEY_GEN:
keySize = 64;
keyType = CKK_DES;
break;
case (int)CKM_DES2_KEY_GEN:
keySize = 128;
keyType = CKK_DES2;
break;
case (int)CKM_DES3_KEY_GEN:
keySize = 192;
keyType = CKK_DES3;
break;
case (int)CKM_AES_KEY_GEN:
keySize = 128;
keyType = CKK_AES;
break;
case (int)CKM_RC4_KEY_GEN:
keySize = 128;
keyType = CKK_RC4;
break;
case (int)CKM_BLOWFISH_KEY_GEN:
keySize = 128;
keyType = CKK_BLOWFISH;
break;
default:
throw new ProviderException("Unknown mechanism " + mechanism);
}
try {
significantKeySize = checkKeySize(mechanism, keySize, token);
} catch (InvalidAlgorithmParameterException iape) {
throw new ProviderException("Unsupported default key size", iape);
}
}
// see JCE spec
protected void engineInit(SecureRandom random) {
token.ensureValid();
setDefaultKeySize();
}
// see JCE spec
protected void engineInit(AlgorithmParameterSpec params,
SecureRandom random) throws InvalidAlgorithmParameterException {
throw new InvalidAlgorithmParameterException
("AlgorithmParameterSpec not supported");
}
// see JCE spec
protected void engineInit(int keySize, SecureRandom random) {
token.ensureValid();
int newSignificantKeySize;
try {
newSignificantKeySize = checkKeySize(mechanism, keySize, token);
} catch (InvalidAlgorithmParameterException iape) {
throw (InvalidParameterException)
(new InvalidParameterException().initCause(iape));
}
if ((mechanism == CKM_DES2_KEY_GEN) ||
(mechanism == CKM_DES3_KEY_GEN)) {
long newMechanism = (newSignificantKeySize == 112 ?
CKM_DES2_KEY_GEN : CKM_DES3_KEY_GEN);
if (mechanism != newMechanism) {
if (supportBothKeySizes) {
mechanism = newMechanism;
// Adjust keyType to reflect the mechanism change
keyType = (mechanism == CKM_DES2_KEY_GEN ?
CKK_DES2 : CKK_DES3);
} else {
throw new InvalidParameterException
("Only " + significantKeySize +
"-bit DESede is supported");
}
}
}
this.keySize = keySize;
this.significantKeySize = newSignificantKeySize;
}
// see JCE spec
protected SecretKey engineGenerateKey() {
Session session = null;
try {
session = token.getObjSession();
CK_ATTRIBUTE[] attributes;
switch ((int)keyType) {
case (int)CKK_DES:
case (int)CKK_DES2:
case (int)CKK_DES3:
// fixed length, do not specify CKA_VALUE_LEN
attributes = new CK_ATTRIBUTE[] {
new CK_ATTRIBUTE(CKA_CLASS, CKO_SECRET_KEY),
};
break;
default:
attributes = new CK_ATTRIBUTE[] {
new CK_ATTRIBUTE(CKA_CLASS, CKO_SECRET_KEY),
new CK_ATTRIBUTE(CKA_VALUE_LEN, keySize >> 3),
};
break;
}
attributes = token.getAttributes
(O_GENERATE, CKO_SECRET_KEY, keyType, attributes);
long keyID = token.p11.C_GenerateKey
(session.id(), new CK_MECHANISM(mechanism), attributes);
return P11Key.secretKey
(session, keyID, algorithm, significantKeySize, attributes);
} catch (PKCS11Exception e) {
throw new ProviderException("Could not generate key", e);
} finally {
token.releaseSession(session);
}
}
}