diff options
Diffstat (limited to 'libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/jcajce/JceCMSContentEncryptorBuilder.java')
-rw-r--r-- | libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/jcajce/JceCMSContentEncryptorBuilder.java | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/jcajce/JceCMSContentEncryptorBuilder.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/jcajce/JceCMSContentEncryptorBuilder.java new file mode 100644 index 000000000..5711df3d9 --- /dev/null +++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/jcajce/JceCMSContentEncryptorBuilder.java @@ -0,0 +1,160 @@ +package org.spongycastle.cms.jcajce; + +import java.io.OutputStream; +import java.security.AlgorithmParameters; +import java.security.GeneralSecurityException; +import java.security.Provider; +import java.security.SecureRandom; + +import javax.crypto.Cipher; +import javax.crypto.CipherOutputStream; +import javax.crypto.KeyGenerator; +import javax.crypto.SecretKey; + +import org.spongycastle.asn1.ASN1ObjectIdentifier; +import org.spongycastle.asn1.pkcs.PKCSObjectIdentifiers; +import org.spongycastle.asn1.x509.AlgorithmIdentifier; +import org.spongycastle.cms.CMSException; +import org.spongycastle.operator.DefaultSecretKeySizeProvider; +import org.spongycastle.operator.GenericKey; +import org.spongycastle.operator.OutputEncryptor; +import org.spongycastle.operator.SecretKeySizeProvider; +import org.spongycastle.operator.jcajce.JceGenericKey; + +public class JceCMSContentEncryptorBuilder +{ + private static final SecretKeySizeProvider KEY_SIZE_PROVIDER = DefaultSecretKeySizeProvider.INSTANCE; + + + private final ASN1ObjectIdentifier encryptionOID; + private final int keySize; + + private EnvelopedDataHelper helper = new EnvelopedDataHelper(new DefaultJcaJceExtHelper()); + private SecureRandom random; + + public JceCMSContentEncryptorBuilder(ASN1ObjectIdentifier encryptionOID) + { + this(encryptionOID, KEY_SIZE_PROVIDER.getKeySize(encryptionOID)); + } + + public JceCMSContentEncryptorBuilder(ASN1ObjectIdentifier encryptionOID, int keySize) + { + this.encryptionOID = encryptionOID; + this.keySize = keySize; + + int fixedSize = KEY_SIZE_PROVIDER.getKeySize(encryptionOID); + + if (encryptionOID.equals(PKCSObjectIdentifiers.des_EDE3_CBC)) + { + if (keySize != 168 && keySize != fixedSize) + { + throw new IllegalArgumentException("incorrect keySize for encryptionOID passed to builder."); + } + } + else + { + if (fixedSize > 0 && fixedSize != keySize) + { + throw new IllegalArgumentException("incorrect keySize for encryptionOID passed to builder."); + } + } + } + + public JceCMSContentEncryptorBuilder setProvider(Provider provider) + { + this.helper = new EnvelopedDataHelper(new ProviderJcaJceExtHelper(provider)); + + return this; + } + + public JceCMSContentEncryptorBuilder setProvider(String providerName) + { + this.helper = new EnvelopedDataHelper(new NamedJcaJceExtHelper(providerName)); + + return this; + } + + public JceCMSContentEncryptorBuilder setSecureRandom(SecureRandom random) + { + this.random = random; + + return this; + } + + public OutputEncryptor build() + throws CMSException + { + return new CMSOutputEncryptor(encryptionOID, keySize, random); + } + + private class CMSOutputEncryptor + implements OutputEncryptor + { + private SecretKey encKey; + private AlgorithmIdentifier algorithmIdentifier; + private Cipher cipher; + + CMSOutputEncryptor(ASN1ObjectIdentifier encryptionOID, int keySize, SecureRandom random) + throws CMSException + { + KeyGenerator keyGen = helper.createKeyGenerator(encryptionOID); + + if (random == null) + { + random = new SecureRandom(); + } + + if (keySize < 0) + { + keyGen.init(random); + } + else + { + if (encryptionOID.equals(PKCSObjectIdentifiers.des_EDE3_CBC) && keySize == 192) + { + keySize = 168; + } + keyGen.init(keySize, random); + } + + cipher = helper.createCipher(encryptionOID); + encKey = keyGen.generateKey(); + AlgorithmParameters params = helper.generateParameters(encryptionOID, encKey, random); + + try + { + cipher.init(Cipher.ENCRYPT_MODE, encKey, params, random); + } + catch (GeneralSecurityException e) + { + throw new CMSException("unable to initialize cipher: " + e.getMessage(), e); + } + + // + // If params are null we try and second guess on them as some providers don't provide + // algorithm parameter generation explicity but instead generate them under the hood. + // + if (params == null) + { + params = cipher.getParameters(); + } + + algorithmIdentifier = helper.getAlgorithmIdentifier(encryptionOID, params); + } + + public AlgorithmIdentifier getAlgorithmIdentifier() + { + return algorithmIdentifier; + } + + public OutputStream getOutputStream(OutputStream dOut) + { + return new CipherOutputStream(dOut, cipher); + } + + public GenericKey getKey() + { + return new JceGenericKey(algorithmIdentifier, encKey); + } + } +} |