com.nimbusds.jose.crypto.RSADecrypter Maven / Gradle / Ivy
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package com.nimbusds.jose.crypto;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.util.HashSet;
import java.util.Set;
import javax.crypto.SecretKey;
import net.jcip.annotations.ThreadSafe;
import com.nimbusds.jose.EncryptionMethod;
import com.nimbusds.jose.JOSEException;
import com.nimbusds.jose.JWEAlgorithm;
import com.nimbusds.jose.JWEDecrypter;
import com.nimbusds.jose.JWEHeader;
import com.nimbusds.jose.util.Base64URL;
import com.nimbusds.jose.util.StringUtils;
/**
* RSA decrypter of {@link com.nimbusds.jose.JWEObject JWE objects}. This class
* is thread-safe.
*
* Supports the following JWE algorithms:
*
*
* - {@link com.nimbusds.jose.JWEAlgorithm#RSA1_5}
*
- {@link com.nimbusds.jose.JWEAlgorithm#RSA_OAEP}
*
- {@link com.nimbusds.jose.JWEAlgorithm#RSA_OAEP_256}
*
*
* Supports the following encryption methods:
*
*
* - {@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256}
*
- {@link com.nimbusds.jose.EncryptionMethod#A192CBC_HS384}
*
- {@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512}
*
- {@link com.nimbusds.jose.EncryptionMethod#A128GCM}
*
- {@link com.nimbusds.jose.EncryptionMethod#A192GCM}
*
- {@link com.nimbusds.jose.EncryptionMethod#A256GCM}
*
- {@link com.nimbusds.jose.EncryptionMethod#A128CBC_HS256_DEPRECATED}
*
- {@link com.nimbusds.jose.EncryptionMethod#A256CBC_HS512_DEPRECATED}
*
*
* Accepts all {@link com.nimbusds.jose.JWEHeader#getRegisteredParameterNames
* registered JWE header parameters}. Use {@link #setAcceptedAlgorithms} and
* {@link #setAcceptedEncryptionMethods} to restrict the acceptable JWE
* algorithms and encryption methods.
*
* @author David Ortiz
* @author Vladimir Dzhuvinov
* @version $version$ (2014-08-20)
*
*/
@ThreadSafe
public class RSADecrypter extends RSACryptoProvider implements JWEDecrypter {
/**
* The accepted JWE algorithms.
*/
private Set acceptedAlgs =
new HashSet<>(supportedAlgorithms());
/**
* The accepted encryption methods.
*/
private Set acceptedEncs =
new HashSet<>(supportedEncryptionMethods());
/**
* The critical header parameter checker.
*/
private final CriticalHeaderParameterChecker critParamChecker =
new CriticalHeaderParameterChecker();
/**
* The private RSA key.
*/
private final RSAPrivateKey privateKey;
/**
* Creates a new RSA decrypter.
*
* @param privateKey The private RSA key. Must not be {@code null}.
*/
public RSADecrypter(final RSAPrivateKey privateKey) {
if (privateKey == null) {
throw new IllegalArgumentException("The private RSA key must not be null");
}
this.privateKey = privateKey;
}
/**
* Gets the private RSA key.
*
* @return The private RSA key.
*/
public RSAPrivateKey getPrivateKey() {
return privateKey;
}
@Override
public Set getAcceptedAlgorithms() {
return acceptedAlgs;
}
@Override
public void setAcceptedAlgorithms(final Set acceptedAlgs) {
if (acceptedAlgs == null) {
throw new IllegalArgumentException("The accepted JWE algorithms must not be null");
}
if (! supportedAlgorithms().containsAll(acceptedAlgs)) {
throw new IllegalArgumentException("Unsupported JWE algorithm(s)");
}
this.acceptedAlgs = acceptedAlgs;
}
@Override
public Set getAcceptedEncryptionMethods() {
return acceptedEncs;
}
@Override
public void setAcceptedEncryptionMethods(final Set acceptedEncs) {
if (acceptedEncs == null)
throw new IllegalArgumentException("The accepted encryption methods must not be null");
if (!supportedEncryptionMethods().containsAll(acceptedEncs)) {
throw new IllegalArgumentException("Unsupported encryption method(s)");
}
this.acceptedEncs = acceptedEncs;
}
@Override
public Set getIgnoredCriticalHeaderParameters() {
return critParamChecker.getIgnoredCriticalHeaders();
}
@Override
public void setIgnoredCriticalHeaderParameters(final Set headers) {
critParamChecker.setIgnoredCriticalHeaders(headers);
}
@Override
public byte[] decrypt(final JWEHeader header,
final Base64URL encryptedKey,
final Base64URL iv,
final Base64URL cipherText,
final Base64URL authTag)
throws JOSEException {
// Validate required JWE parts
if (encryptedKey == null) {
throw new JOSEException("The encrypted key must not be null");
}
if (iv == null) {
throw new JOSEException("The initialization vector (IV) must not be null");
}
if (authTag == null) {
throw new JOSEException("The authentication tag must not be null");
}
if (! critParamChecker.headerPasses(header)) {
throw new JOSEException("Unsupported critical header parameter");
}
// Derive the content encryption key
JWEAlgorithm alg = header.getAlgorithm();
SecretKey cek;
if (alg.equals(JWEAlgorithm.RSA1_5)) {
int keyLength = header.getEncryptionMethod().cekBitLength();
// Protect against MMA attack by generating random CEK on failure,
// see http://www.ietf.org/mail-archive/web/jose/current/msg01832.html
SecureRandom randomGen = getSecureRandom();
SecretKey randomCEK = AES.generateKey(keyLength, randomGen);
try {
cek = RSA1_5.decryptCEK(privateKey, encryptedKey.decode(), keyLength, keyEncryptionProvider);
if (cek == null) {
// CEK length mismatch, signalled by null instead of
// exception to prevent MMA attack
cek = randomCEK;
}
} catch (Exception e) {
// continue
cek = randomCEK;
}
} else if (alg.equals(JWEAlgorithm.RSA_OAEP)) {
cek = RSA_OAEP.decryptCEK(privateKey, encryptedKey.decode(), keyEncryptionProvider);
} else if (alg.equals(JWEAlgorithm.RSA_OAEP_256)) {
cek = RSA_OAEP_256.decryptCEK(privateKey, encryptedKey.decode(), keyEncryptionProvider);
} else {
throw new JOSEException("Unsupported JWE algorithm, must be RSA1_5 or RSA_OAEP");
}
// Compose the AAD
byte[] aad = StringUtils.toByteArray(header.toBase64URL().toString());
// Decrypt the cipher text according to the JWE enc
EncryptionMethod enc = header.getEncryptionMethod();
byte[] plainText;
if (enc.equals(EncryptionMethod.A128CBC_HS256) ||
enc.equals(EncryptionMethod.A192CBC_HS384) ||
enc.equals(EncryptionMethod.A256CBC_HS512) ) {
plainText = AESCBC.decryptAuthenticated(
cek,
iv.decode(),
cipherText.decode(),
aad,
authTag.decode(),
contentEncryptionProvider,
macProvider);
} else if (enc.equals(EncryptionMethod.A128GCM) ||
enc.equals(EncryptionMethod.A192GCM) ||
enc.equals(EncryptionMethod.A256GCM) ) {
plainText = AESGCM.decrypt(
cek,
iv.decode(),
cipherText.decode(),
aad,
authTag.decode(),
contentEncryptionProvider);
} else if (enc.equals(EncryptionMethod.A128CBC_HS256_DEPRECATED) ||
enc.equals(EncryptionMethod.A256CBC_HS512_DEPRECATED) ) {
plainText = AESCBC.decryptWithConcatKDF(
header,
cek,
encryptedKey,
iv,
cipherText,
authTag,
contentEncryptionProvider,
macProvider);
} else {
throw new JOSEException("Unsupported encryption method, must be A128CBC_HS256, A192CBC_HS384, A256CBC_HS512, A128GCM, A192GCM or A256GCM");
}
// Apply decompression if requested
return DeflateHelper.applyDecompression(header, plainText);
}
}