# Bouncy Castle Crypto Package

## 1.0 Introduction

The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. The package is organised so that it contains a light-weight API suitable for use in any environment (including the newly released J2ME) with the additional infrastructure to conform the algorithms to the JCE framework.

Except where otherwise stated, this software is distributed under a license based on the MIT X Consortium license. To view the license, see here. The OpenPGP library also includes a modified BZIP2 library which is licensed under the Apache Software License, Version 2.0.

If you have the full package you will have six jar files, bcprov*.jar which contains the BC provider, jce-*.jar which contains the JCE provider, clean room API, and bcmail*.jar which contains the mail API.

Note: if you are using JDK 1.0, you will just find a class hierarchy in the classes directory.

To view examples, look at the test programs in the packages:

- org.bouncycastle.crypto.test
- org.bouncycastle.jce.provider.test

To verify the packages, run the following Java programs with the appropriate classpath:

- java org.bouncycastle.crypto.test.RegressionTest
- java org.bouncycastle.jce.provider.test.RegressionTest

## 2.0 Patents

Some of the algorithms in the Bouncy Castle APIs are patented in some places. It is upon the user of the library to be aware of what the legal situation is in their own situation, however we have been asked to specifically mention the patents below, in the following terms, at the request of the patent holder.

The BC distribution contains implementations of EC MQV as described in RFC 5753, "Use of ECC Algorithms in CMS". In line with the conditions in:

    https://www.ietf.org/ietf-ftp/IPR/certicom-ipr-rfc-5753.pdf

We state, where EC MQV has not otherwise been disabled or removed: "The use of this product or service is subject to the reasonable, non-discriminatory terms in the Intellectual Property Rights (IPR) Disclosures of Certicom Corp. at the IETF for Use of Elliptic Curve Cryptography (ECC) Algorithms in Cryptographic Message Syntax (CMS) implemented in the product or service."

## 3.0 System Properties

The Bouncy Castle provider can make use of the following two system properties:

- org.bouncycastle.ec.disable_mqv - setting this property to true will disable support for EC MQV in the provider.
- org.bouncycastle.pkcs1.not_strict - some other providers of cryptography services fail to produce PKCS1 encoded block that are the correct length. Setting this property to true will relax the conformance check on the block length.

## 4.0 Specifications

- clean room implementation of the JCE API
- light-weight cryptographic API consisting of support for
  - BlockCipher
  - BufferedBlockCipher
  - AsymmetricBlockCipher
  - BufferedAsymmetricBlockCipher
  - StreamCipher
  - BufferedStreamCipher
  - KeyAgreement
  - IESCipher
  - Digest
  - Mac
  - PBE
  - Signers
- JCE compatible framework for a Bouncy Castle provider "BC".
- JCE compatible framework for a Bouncy Castle post-quantum provider "BCPQC".

## 5.0 Light-weight API

This API has been specifically developed for those circumstances where the rich API and integration requirements of the JCE are not required.

However as a result, the light-weight API requires more effort and understanding on the part of a developer to initialise and utilise the algorithms.

### 5.1 Example

To utilise the light-weight API in a program, the fundamentals are as follows;

    	/*
    	 * This will use a supplied key, and encrypt the data
    	 * This is the equivalent of DES/CBC/PKCS5Padding
    	 */
    	BlockCipher engine = new DESEngine();
    	BufferedBlockCipher cipher = new PaddedBlockCipher(new CBCCipher(engine));

    	byte[] key = keyString.getBytes();
    	byte[] input = inputString.getBytes();

    	cipher.init(true, new KeyParameter(key));

    	byte[] cipherText = new byte[cipher.getOutputSize(input.length)];

    	int outputLen = cipher.processBytes(input, 0, input.length, cipherText, 0);
    	try
    	{
    		cipher.doFinal(cipherText, outputLen);
    	}
    	catch (CryptoException ce)
    	{
    		System.err.println(ce);
    		System.exit(1);
    	}

### 5.2 Algorithms

The light-weight API has built in support for the following:

#### Symmetric (Block)

The base interface is BlockCipher and has the following implementations which match the modes the block cipher can be operated in.

Name | Constructor | Notes
--- | --- | ---
BufferedBlockCipher | BlockCipher |
CBCBlockCipher | BlockCipher |
CFBBlockCipher | BlockCipher, block size (in bits) |
GCFBlockCipher | BlockCipher | GOST CFB mode with CryptoPro key meshing.
EAXBlockCipher | BlockCipher |
OCBBlockCipher | BlockCipher |
OFBBlockCipher | BlockCipher, block size (in bits) |
SICBlockCipher | BlockCipher, block size (in bits) | Also known as CTR mode
KCTRBlockCipher | BlockCipher, block size (in bits) | DSTU7624 CTR mode
OpenPGPCFBBlockCipher | BlockCipher |
GOFBBlockCipher | BlockCipher | GOST OFB mode

The base interface for AEAD (Authenticated Encryption Associated Data) modes is AEADBlockCipher and has the following implemenations.

Name | Constructor | Notes
--- | --- | ---
CCMBlockCipher | BlockCipher | Packet mode - requires all data up front.
EAXBlockCipher | BlockCipher |
CCMBlockCipher | BlockCipher | Packet mode - requires all data up front.
GCMBlockCipher | BlockCipher | Packet mode - NIST SP 800-38D.
GCMSIVBlockCipher | BlockCipher | Packet mode - RFC 8452.
KCCMBlockCipher | BlockCipher | DSTU 7624 Packet mode - requires all data up front.
OCBBlockCipher | BlockCipher |
ChaCha20Poly1305 | AEADCipher |

BufferedBlockCipher has a further sub-classes

Name | Constructor | Notes
--- | --- | ---
PaddedBufferedBlockCipher | BlockCipher | a buffered block cipher that can use padding - default PKCS5/7 padding
CTSBlockCipher | BlockCipher | Cipher Text Stealing
NISTCTSBlockCipher | BlockCipher | Cipher Text Stealing - NIST mode set.

The following paddings can be used with the PaddedBufferedBlockCipher.

Name | Description
--- | ---
PKCS7Padding | PKCS7/PKCS5 padding
ISO10126d2Padding | ISO 10126-2 padding
X932Padding | X9.23 padding
ISO7816d4Padding | ISO 7816-4 padding (ISO 9797-1 scheme 2)
ZeroBytePadding | Pad with Zeros (not recommended)

The following cipher engines are implemented that can be used with the above modes.

Name | KeySizes (in bits) | Block Size | Notes
--- | --- | --- | ---
AESEngine | 0 .. 256 | 128 bit |
AESWrapEngine | 0 .. 256 | 128 bit | Implements FIPS AES key wrapping
AsconEngine | 128 | 128 bit | AEAD Cipher
BlowfishEngine | 0 .. 448 | 64 bit |
CamelliaEngine | 128, 192, 256 | 128 bit |
CamelliaWrapEngine | 128, 192, 256 | 128 bit |
CAST5Engine | 0 .. 128 | 64 bit |
CAST6Engine | 0 .. 256 | 128 bit |
DESEngine | 64 | 64 bit |
DESedeEngine | 128, 192 | 64 bit |
DESedeWrapEngine | 128, 192 | 64 bit | Implements Draft IETF DESede key wrapping
DSTU7624Engine | 128, 256, 512 | 128/256/512 bit | DSTU7624 Block Cipher
DSTU7624WrapEngine | 128, 256, 512 | 128/256/512 bit | DSTU7624 key wrapper
ElephantEngine | 128 | 128 bit | AEAD Cipher
GOST28147Engine | 256 | 64 bit | Has a range of S-boxes
GOST3412_2015Engine | 256 | 128 bit |
IDEAEngine | 128 | 64 bit |
ISAPEngine | 128 | 128 bit | AEAD Cipher
LEAEngine | 128 | 128/192/256 bit |
NoekeonEngine | 128 | 128 bit |
PhotonBeetleEngine | 128 | 128 bit | AEAD Cipher
RC2Engine | 0 .. 1024 | 64 bit |
RC532Engine | 0 .. 128 | 64 bit | Uses a 32 bit word
RC564Engine | 0 .. 128 | 128 bit | Uses a 64 bit word
RC6Engine | 0 .. 256 | 128 bit |
RijndaelEngine | 0 .. 256 | 128 bit, 160 bit, 192 bit, 224 bit, 256 bit |
SEEDEngine | 128 | 128 bit |
SEEDWrapEngine | 128 | 128 bit |
Shacal2Engine | 512 | 256 bit |
SerpentEngine | 128, 192, 256 | 128 bit |
SkipjackEngine | 0 .. 128 | 64 bit |
SM4Engine | 128 | 128 bit |
SparkleEngine | 128 | 128 bit | AEAD Cipher
TEAEngine | 128 | 64 bit |
ThreefishEngine | 256/512/1024 | 256 bit/512 bit/1024 bit | Tweakable block cipher
TwofishEngine | 128, 192, 256 | 128 bit |
XoodyakEngine | 128 | 128 bit | AEAD Cipher
XTEAEngine | 128 | 64 bit |

The following additional key wrapping algorithms are also available: RFC3211WrapEngine, RFC3394WrapEngine, and RFC5649WrapEngine.

#### Symmetric (Stream)

The base interface is StreamCipher and has the following implementations which match the modes the stream cipher can be operated in.

Name | Constructor | Notes
--- | --- | ---
BlockStreamCipher | BlockCipher |

The following cipher engines are implemented that can be used with the above modes.

Name | KeySizes (in bits) | Notes
--- | --- | ---
RC4Engine | 40 .. 2048 |
HC128Engine | 128 |
HC256Engine | 256 |
ChaChaEngine | 128/256 | 64 bit IV
Salsa20Engine | 128/256 | 64 bit IV
XSalsa20Engine | 256 | 192 bit IV
ISAACEngine | 32 .. 8192 |
VMPCEngine | 8 .. 6144 |
Grainv1Engine | 80 | 64 bit IV
Grain128Engine | 128 | 96 bit IV
Zuc128Engine | 128 | 128 bit IV
Zuc256Engine | 256 | 200 bit IV

#### Block Asymmetric

The base interface is AsymmetricBlockCipher and has the following implementations which match the modes the cipher can be operated in.

Name | Constructor | Notes
--- | --- | ---
BufferedAsymmetricBlockCipher | AsymmetricBlockCipher |
OAEPEncoding | AsymmetricBlockCipher |
PKCS1Encoding | AsymmetricBlockCipher |
ISO9796d1Encoding | AsymmetricBlockCipher | ISO9796-1

The following cipher engines are implemented that can be used with the above modes.

Name | KeySizes (in bits) | Notes
--- | --- | ---
RSAEngine | any multiple of 8 large enough for the encoding. |
ElGamalEngine | any multiple of 8 large enough for the encoding. |
NTRUEngine | any multiple of 8 large enough for the encoding. |

The following asymmetric ciphers are also supported and allow variable block sizes:

- IESEngine
- SM2Engine

#### Digest

The base interface is Digest and has the following implementations

Name | Output (in bits) | Notes
--- | --- | ---
AsconDigest | 256 |
AsconXof | XOF |
Blake2bDigest | 224, 256, 384, 512 |
Blake3Digest | 224, 256, 384, 512 |
CSHAKEDigest | XOF | SP 800-185, based on SHAKE128/SHAKE256
DSTU7564Digest | 256, 384, 512 |
ISAPDigest | 256 |
Kangaroo | XOF | Built on Keccak-p
KeccakDigest | 224, 256, 288, 384, 512 |
MD2Digest | 128 |
MD4Digest | 128 |
MD5Digest | 128 |
ParallelHash | XOF | XOF based on cSHAKE (SP 800-185).
PhotonBeetleDigest | 256 |
RipeMD128Digest | 128 | basic RipeMD
RipeMD160Digest | 160 | enhanced version of RipeMD
RipeMD256Digest | 256 | expanded version of RipeMD128
RipeMD320Digest | 320 | expanded version of RipeMD160
SHA1Digest | 160 |
SHA224Digest | 224 | FIPS 180-2
SHA256Digest | 256 | FIPS 180-2
SHA384Digest | 384 | FIPS 180-2
SHA512Digest | 512 | FIPS 180-2
SHA3Digest | 224, 256, 384, 512 |
SHAKEDigest | 128, 256 | cSHAKE primitive also supported.
SkeinDigest | any byte length | 256 bit, 512 bit and 1024 state sizes. Additional parameterisation using SkeinParameters.
SM3Digest | 256 | The SM3 Digest.
SparkleDigest | 256 |
TigerDigest | 192 | The Tiger Digest.
TupleHash | XOF | XOF based on cSHAKE (SP 800-185).
GOST3411Digest | 256 | The GOST-3411 Digest.
GOST3411_2012_256Digest | 256 | The GOST-3411-2012-256 Digest.
GOST3411_2012_512Digest | 512 | The GOST-3411-2012-512 Digest.
WhirlpoolDigest | 512 | The Whirlpool Digest.
Haraka256Digest | 256 | Haraka V2 - 256 bit input version.
Haraka512Digest | 256 | Haraka V2 - 512 bit input version.
XoodyakDigest | 256 |

#### MAC

The base interface is Mac and has the following implementations

Name | Output (in bits) | Notes
--- | --- | ---
CBCBlockCipherMac | blocksize/2 unless specified |
CFBBlockCipherMac | blocksize/2, in CFB 8 mode, unless specified |
CMac | 24 to cipher block size bits | Usable with block ciphers, NIST SP 800-38B.
GMac | 32 to 128 bits | Usable with GCM mode ciphers, defined for AES, NIST SP 800-38D.
GOST28147Mac | 32 bits |
ISO9797Alg3Mac | multiple of 8 bits up to underlying cipher size. |
HMac | digest length |
DSTU7564 | 256, 384, 512 bits |
DSTU7624 | 128, 256, 512 bits |
Poly1305 | 128 bits | Usable with 128 bit block ciphers. Use Poly1305KeyGenerator to generate keys.
SkeinMac | any byte length | 256 bit, 512 bit and 1024 state size variants. Additional parameterisation using SkeinParameters.
SipHash | 64 bits |
SipHash128 | 128 bits |
VMPCMac | 160 bits |
Zuc128Mac | 32 bits |
Zuc256Mac | 32, 64, 128 bits |

#### PBE and Password Hashing

The base class is PBEParametersGenerator and has the following sub-classes

Name | Constructor | Notes
--- | --- | ---
PKCS5S1ParametersGenerator | Digest |
PKCS5S2ParametersGenerator |  | Uses SHA1/Hmac as defined
PKCS12ParametersGenerator | Digest |
OpenSSLPBEParametersGenerator |  | Uses MD5 as defined

The following password hashing schemes are supported:

Name | Constructor | Notes
--- | --- | ---
Argon2 |  |
BCrypt |  |
OpenBSDBcyrpt |  |
SCrypt |  |

#### IESCipher

The IES cipher is based on the one described in IEEE P1363a (draft 10), for use with either traditional Diffie-Hellman or Elliptic Curve Diffie-Hellman.

Note: At the moment this is still a draft, don't use it for anything that may be subject to long term storage, the key values produced may well change as the draft is finalised.

#### Commitments

The base class is Committer and has the following sub-classes

Name | Notes
--- | ---
HashCommitter | Hash commitment algorithm described in Usenix RPC MixNet Paper (2002)

#### Key Agreement

Two versions of Diffie-Hellman key agreement are supported, the basic version, and one for use with long term public keys. Two versions of key agreement using Elliptic Curve cryptography are also supported, standard Diffie-Hellman key agreement and standard key agreement with co-factors.

The agreement APIs are in the org.bouncycastle.crypto.agreement package. Classes for generating Diffie-Hellman parameters can be found in the org.bouncycastle.crypto.params and org.bouncycastle.crypto.generators packages.

#### Key Encapsulation Mechanisms

The first non-post-quantum set use the EncapsulatedSecretGenerator and EncapsulatedSecretGenerator interfaces.

Name | Notes
--- | ---
RSA | RSA-KEM from ISO 18033-2, implemented in RSAKEMExtractor and RSAKEMGenerator
ECIES | ECIES-KEM from ISO 18033-2, implemented in ECIESKEMExtractor and ECIESKEMGenerator

The second, post-quantum set use EncapsulatedSecretGenerator and EncapsulatedSecretGenerator.

Name | Security Strength (in bits) | Implementations | Notes
--- | --- | --- | ---
BIKE | 128-256. | BIKEKEMGenerator, BIKEKEMExtractor | Round 4
Classic McEliece | 128-256. | CMCEKEMGenerator, CMCEKEMExtractor | Round 4
FrodoKEM | 128-256. | FrodoKEMGenerator, FrodoKEMExtractor |
HQC | 128-256. | HQCKEMGenerator, HQCKEMExtractor | Round 4
Kyber | 128-256. | KyberKEMGenerator, KyberKEMExtractor | Finalist
NTRU | 128-256. | NTRUKEMGenerator, NTRUKEMExtractor |
NTRU Prime | 128-256. | NTRULPRimeKEMGenerator, NTRULPRimeKEMExtractor SNTRUPrimeKEMGenerator, SNTRUPrimeKEMExtractor |
SABER | 128-256. | SABERKEMGenerator, SABERKEMExtractor |

#### Signers

DSA, ECDSA, ISO-9796-2, GOST-3410-94, GOST-3410-2001, GOST-3410-2012, DSTU-4145-2002, and RSA-PSS are supported by the org.bouncycastle.crypto.signers package. Note: as these are light weight classes, if you need to use SHA1 or GOST-3411 (as defined in the relevant standards) you'll also need to make use of the appropriate digest class in conjunction with these. Classes for generating DSA and ECDSA parameters can be found in the org.bouncycastle.crypto.params and org.bouncycastle.crypto.generators packages.

### 5.4 Elliptic Curve Transforms.

The org.bouncycastle.crypto.ec package contains implementations for a variety of EC cryptographic transforms such as EC ElGamal.

### 5.5 TLS/DTLS

The org.bouncycastle.crypto.tls package contains implementations for TLS 1.1, 1.2 and DTLS 1.0, 1.2.

### 5.6 Deterministic Random Bit Generators (DRBG) and SecureRandom wrappers

The org.bouncycastle.crypto.prng package contains implementations for a variety of bit generators including those from SP 800-90A and X9.31, as well as builders for SecureRandom objects based around them.

### 5.7 ASN.1 package

The light-weight API has direct interfaces into a package capable of reading and writing DER-encoded ASN.1 objects and for the generation of X.509 V3 certificate objects and PKCS12 files. BER InputStream and OutputStream classes are provided as well.

## 6.0 Bouncy Castle Provider

The Bouncy Castle provider is a JCE compliant provider that is a wrapper built on top of the light-weight API. The main provider is referred to with the name "BC", the post quantum provider is indicated by "BCPQC".

The advantage for writing application code that uses the provider interface to cryptographic algorithms is that the actual provider used can be selected at run time. This is extremely valuable for applications that may wish to make use of a provider that has underlying hardware for cryptographic computation, or where an application may have been developed in an environment with cryptographic export controls.

### 6.1 Example

To utilise the JCE provider in a program, the fundamentals are as follows;

    	/*
    	 * This will generate a random key, and encrypt the data
    	 */
    	Key		key;
    	KeyGenerator	keyGen;
    	Cipher		encrypt;

    	Security.addProvider(new BouncyCastleProvider());

    	try
    	{
    		// "BC" is the name of the BouncyCastle provider
    		keyGen = KeyGenerator.getInstance("DES", "BC");
    		keyGen.init(new SecureRandom());

    		key = keyGen.generateKey();

    		encrypt = Cipher.getInstance("DES/CBC/PKCS5Padding", "BC");
    	}
    	catch (Exception e)
    	{
    		System.err.println(e);
    		System.exit(1);
    	}

    	encrypt.init(Cipher.ENCRYPT_MODE, key);

    	bOut = new ByteArrayOutputStream();
    	cOut = new CipherOutputStream(bOut, encrypt);

    	cOut.write("plaintext".getBytes());
    	cOut.close();

    	// bOut now contains the cipher text

The provider can also be configured as part of your environment via static registration by adding an entry to the java.security properties file (found in $JAVA_HOME/jre/lib/security/java.security, where $JAVA_HOME is the location of your JDK/JRE distribution). You'll find detailed instructions in the file but basically it comes down to adding a line:

        security.provider.<n>=org.bouncycastle.jce.provider.BouncyCastleProvider

Where <n> is the preference you want the provider at (1 being the most prefered).

Where you put the jar is up to mostly up to you, although with jdk1.3 and jdk1.4 the best (and in some cases only) place to have it is in $JAVA_HOME/jre/lib/ext. Note: under Windows there will normally be a JRE and a JDK install of Java if you think you have installed it correctly and it still doesn't work chances are you have added the provider to the installation not being used.

Note: with JDK 1.4 and later you will need to have installed the unrestricted policy files to take full advantage of the provider. If you do not install the policy files you are likely to get something like the following:

            java.lang.SecurityException: Unsupported keysize or algorithm parameters
                    at javax.crypto.Cipher.init(DashoA6275)

The policy files can be found at the same place you downloaded the JDK.

### 6.2 Algorithms

#### Symmetric (Block)

Modes:

- ECB
- CBC
- OFB(n)
- CFB(n)
- SIC (also known as CTR)
- OpenPGPCFB
- CTS (equivalent to CBC/WithCTS)
- FF1
- FF3-1
- GOFB
- GCFB
- CCM (AEAD)
- EAX (AEAD)
- GCM (AEAD)
- GCM-SIV (AEAD)
- OCB (AEAD)

Where (n) is a multiple of 8 that gives the blocksize in bits, eg, OFB8. Note that OFB and CFB mode can be used with plain text that is not an exact multiple of the block size if NoPadding has been specified.

All AEAD (Authenticated Encryption Associated Data) modes support Additional Authentication Data (AAD) using the `Cipher.updateAAD()` methods added in Java SE 7.
On Java 7 and later, AEAD modes will throw `javax.crypto.AEADBadTagException` on an authentication failure. On earlier version of Java, `javax.crypto.BadPaddingException` is thrown.

Padding Schemes:

- No padding
- PKCS5/7
- ISO10126/ISO10126-2
- ISO7816-4/ISO9797-1
- X9.23/X923
- TBC
- ZeroByte
- withCTS (if used with ECB mode)

When placed together this gives a specification for an algorithm as;

- DES/CBC/X9.23Padding
- DES/OFB8/NoPadding
- IDEA/CBC/ISO10126Padding
- IDEA/CBC/ISO7816-4Padding
- SKIPJACK/ECB/PKCS7Padding
- DES/ECB/WithCTS

Note: default key sizes are in bold.

Name | KeySizes (in bits) | Block Size | Notes
--- | --- | --- | ---
AES | 0 .. 256 (192) | 128 bit |
AESWrap | 0 .. 256 (192) | 128 bit | A FIPS AES key wrapper
ARIA | 0 .. 256 (192) | 128 bit |
ARIAWrap | 0 .. 256 (192) | 128 bit | An ARIA key wrapper (based on RFC 5649)
Blowfish | 0 .. 448 (448) | 64 bit |
Camellia | 128, 192, 256 | 128 bit |
CamelliaWrap | 128, 192, 256 | 128 bit |
CAST5 | 0 .. 128(128) | 64 bit |
CAST6 | 0 .. 256(256) | 128 bit |
DES | 64 | 64 bit |
DESede | 128, 192 | 64 bit |
DESedeWrap | 128, 192 | 128 bit | A Draft IETF DESede key wrapper
DSTU7624 | 128, 256, 512 | 128/256/512 bit | DSTU7624 Block Cipher
DSTU7624Wrap | 128, 256, 512 | 128/256/512 bit | DSTU7624 key wrapper
GCM | 128, 192, 256(192) | AEAD Mode Cipher | Galois/Counter Mode, as defined in NIST Special Publication SP 800-38D.
GOST28147 | 256 | 64 bit |
IDEA | 128 (128) | 64 bit |
Noekeon | 128(128) | 128 bit |
RC2 | 0 .. 1024 (128) | 64 bit |
RC5 | 0 .. 128 (128) | 64 bit | Uses a 32 bit word
RC5-64 | 0 .. 256 (256) | 128 bit | Uses a 64 bit word
RC6 | 0 .. 256 (128) | 128 bit |
Rijndael | 0 .. 256 (192) | 128 bit |
SEED | 128(128) | 128 bit |
SEEDWrap | 128(128) | 128 bit |
Serpent | 128, 192, 256 (256) | 128 bit |
Skipjack | 0 .. 128 (128) | 64 bit |
SM4 | 128(128) | 128 bit |
TEA | 128 (128) | 64 bit |
Threefish-256 | 256 | 256 bit |
Threefish-512 | 512 | 512 bit |
Threefish-1024 | 1024 | 1024 bit |
Twofish | 128, 192, 256 (256) | 128 bit |
XTEA | 128 (128) | 64 bit |

#### Symmetric (Stream)

Note: default key sizes are in bold.

Name | KeySizes (in bits) | Notes
--- | --- | ---
RC4 | 40 .. 2048 bits (128) |
HC128 | (128) |
HC256 | (256) |
ChaCha | 128/256 | 64 bit IV
Salsa20 | 128/256 | 64 bit IV
XSalsa20 | 256 | 182 bit IV
VMPC | 128/6144(128) |
Grainv1 | 80 | 64 bit IV
Grain128 | 128 | 96 bit IV
Grain128AEAD | 128 | 96 bit IV
Zuc128 | 128 | 128 bit IV
Zuc256 | 256 | 200 bit IV

#### Block Asymmetric

Encoding:

- OAEP - Optimal Asymmetric Encryption Padding
- PCKS1 - PKCS v1.5 Padding
- ISO9796-1 - ISO9796-1 edition 1 Padding

Note: except as indicated in PKCS 1v2 we recommend you use OAEP, as mandated in X9.44.

When placed together with RSA this gives a specification for an algorithm as;

- RSA/NONE/NoPadding
- RSA/NONE/PKCS1Padding
- RSA/NONE/OAEPWithMD5AndMGF1Padding
- RSA/NONE/OAEPWithSHA1AndMGF1Padding
- RSA/NONE/OAEPWithSHA224AndMGF1Padding
- RSA/NONE/OAEPWithSHA256AndMGF1Padding
- RSA/NONE/OAEPWithSHA384AndMGF1Padding
- RSA/NONE/OAEPWithSHA512AndMGF1Padding
- RSA/NONE/OAEPWithSHA3-224AndMGF1Padding
- RSA/NONE/OAEPWithSHA3-256AndMGF1Padding
- RSA/NONE/OAEPWithSHA3-384AndMGF1Padding
- RSA/NONE/OAEPWithSHA3-512AndMGF1Padding
- RSA/NONE/ISO9796-1Padding

Name | KeySizes (in bits) | Notes
--- | --- | ---
RSA | any multiple of 8 bits large enough for the encryption(2048) |
ElGamal | any multiple of 8 bits large enough for the encryption(1024) |

#### Key Agreement

Diffie-Hellman key agreement is supported using the "DH", "DHU" (Diffie-Hellman Unified", "ECDH", "ECCDH" (EC Cofactor DH), "ECKAEG" (BSI EC KAEG key agreement"), "ECMQV" and "ECCDHU" (EC Cofactor DH Unified) key agreement instances and their variations. Key exchange, which also uses the KeyAgreement API is supported by "NH" (the NewHope algorithm (BCPQC)). SM2 key exchange is currently supported in the lightweight API.

Support is provided for the standard SEC algorithm set for EC. Names appear in the form of [Agreement]with[KDF PRF Digest][KDF type]. For example:

- "ECCDHwithSHA256KDF" which represents EC cofactor DH using the X9.63 KDF with SHA256 as the PRF
- "ECMQVwithSHA1CKDF" which represents EC MQV using the concetantion KDF with SHA1 as the PRF

Note: with basic "DH" only the basic algorithm fits in with the JCE API, if you're using long-term public keys you may want to look at the light-weight API, there are also additional JCE support classes for UserKeyingMaterial and MQVParameters in the org.bouncycastle.jcajce.spec package.

#### Key Encapsulation Mechanisms

Name | ParameterSpec Class | Notes
--- | --- | ---
CMCE | CMCEParameterSpec | Class McEliece (NIST Alternate Candidate)
Frodo | FrodoParameterSpec | FrodoKEM (NIST Alternate Candidate)
SABER | SABERParameterSpec | SABER (NIST Finalist)

If used for key wrapping via the Cipher class, you will also need to make use of the KEMParameterSpec class to specify a symmetric wrapping algorithm.

If access to the shared secret is required, KeyGenerator implementations can also be used in conjuction with the KEMGenerateSpec and the KEMExtractSpec which return the shared secret directly.

#### ECIES

An implementation of ECIES (stream mode) as described in IEEE P 1363a. This now based more formally on Victor Shoup's paper and should be compatible with the implementation in Crypto++ (version 6 onwards).

#### Digest

Name | Output (in bits) | Notes
--- | --- | ---
Blake2b-160 | 160 |
Blake2b-256 | 256 |
Blake2b-384 | 384 |
Blake2b-512 | 512 |
Blake2s-128 | 128 |
Blake2s-160 | 160 |
Blake2s-224 | 224 |
Blake2s-256 | 256 |
Blake3-256 | 256 |
DSTU7564-256 | 256 |
DSTU7564-384 | 384 |
DSTU7564-512 | 512 |
GOST3411 | 256 |
GOST3411-2012-256 | 256 |
GOST3411-2012-512 | 512 |
Haraka-256 | 256 |
Haraka-512 | 256 |
Keccak-224 | 224 |
Keccak-288 | 288 |
Keccak-256 | 256 |
Keccak-384 | 384 |
Keccak-512 | 512 |
MD2 | 128 |
MD4 | 128 |
MD5 | 128 |
RipeMD128 | 128 | basic RipeMD
RipeMD160 | 160 | enhanced version of RipeMD
RipeMD256 | 256 | expanded version of RipeMD128
RipeMD320 | 320 | expanded version of RipeMD160
SHA1 | 160 |
SHA-224 | 224 | FIPS 180-2
SHA-256 | 256 | FIPS 180-2
SHA-384 | 384 | FIPS 180-2
SHA-512 | 512 | FIPS 180-2
SHA3-224 | 224 | FIPS 202
SHA3-256 | 256 | FIPS 202
SHA3-384 | 384 | FIPS 202
SHA3-512 | 512 | FIPS 202
Skein-256-* | 128, 160, 224, 256 | e.g. Skein-256-160
Skein-512-* | 128, 160, 224, 256, 384, 512 | e.g. Skein-512-256
Skein-1024-* | 384, 512, 1024 | e.g. Skein-1024-1024
SM3 | 256 |
Tiger | 192 |
Whirlpool | 512 |

#### MAC

Name | Output (in bits) | Notes
--- | --- | ---
Any MAC based on a block cipher, CBC (the default) and CFB modes. | half the cipher's block size (usually 32 bits) |
*-GMAC | 32 to 128 bits | Usable with GCM mode ciphers, defined for AES, NIST SP 800-38D. e.g. AES-GMAC.
VMPC-MAC | 128 |
HMac-GOST3411 | 256 |
HMac-GOST3411-2012-256 | 256 |
HMac-GOST3411-2012-512 | 512 |
HMac-KECCAK224 | 224 |
HMac-KECCAK256 | 256 |
HMac-KECCAK288 | 288 |
HMac-KECCAK384 | 384 |
HMac-KECCAK512 | 512 |
HMac-MD2 | 128 |
HMac-MD4 | 128 |
HMac-MD5 | 128 |
HMac-RipeMD128 | 128 |
HMac-RipeMD160 | 160 |
HMac-SHA1 | 160 |
HMac-SHA224 | 224 |
HMac-SHA256 | 256 |
HMac-SHA384 | 384 |
HMac-SHA512 | 512 |
HMac-SHA3-224 | 224 |
HMac-SHA3-256 | 256 |
HMac-SHA3-384 | 384 |
HMac-SHA3-512 | 512 |
HMAC-Skein-256-* | 128, 160, 224, 256 | e.g. HMAC-Skein-256-160
HMAC-Skein-512-* | 128, 160, 224, 256, 384, 512 | e.g. HMAC-Skein-512-256
HMAC-Skein-1024-* | 384, 512, 1024 | e.g. HMAC-Skein-1024-1024
Siphash-2-4 (SipHash) | 64 |
Siphash-4-8 | 64 |
Siphash128-2-4 (SipHash128) | 128 |
Skein-MAC-256-* | 128, 160, 224, 256 | e.g. Skein-MAC-256-160
Skein-MAC-512-* | 128, 160, 224, 256, 384, 512 | e.g. Skein-MAC-512-256
Skein-MAC-1024-* | 384, 512, 1024 | e.g. Skein-MAC-1024-1024
HMac-Tiger | 192 |
Poly1305-* | 128 | Defined for recent 128 bit block ciphers, e.g. Poly1305-AES, Poly1305-Serpent
ZUC-128 | 32 |
ZUC-256-32 | 32 |
ZUC-256-64 | 64 |
ZUC-256-128 | 128 |

Examples:

- DESMac
- DESMac/CFB8
- DESedeMac
- DESedeMac/CFB8
- DESedeMac64
- SKIPJACKMac
- SKIPJACKMac/CFB8
- IDEAMac
- IDEAMac/CFB8
- RC2Mac
- RC2Mac/CFB8
- RC5Mac
- RC5Mac/CFB8
- ISO9797ALG3Mac

#### Signature Algorithms

Schemes:

- DSTU4145
- Ed25519
- Ed448
- GOST3411withGOST3410 (GOST3411withGOST3410-94)
- GOST3411withECGOST3410 (GOST3411withGOST3410-2001)
- MD2withRSA
- MD5withRSA
- SHA1withRSA
- RIPEMD128withRSA
- RIPEMD160withRSA
- RIPEMD160withDSA
- RIPEMD160withECDSA
- RIPEMD256withRSA
- SHA1withDSA
- SHA224withDSA
- SHA256withDSA
- SHA384withDSA
- SHA512withDSA
- SHA3-224withDSA
- SHA3-256withDSA
- SHA3-384withDSA
- SHA3-512withDSA
- SHA1withDDSA
- SHA224withDDSA
- SHA256withDDSA
- SHA384withDDSA
- SHA512withDDSA
- SHA3-224withDDSA
- SHA3-256withDDSA
- SHA3-384withDDSA
- SHA3-512withDDSA
- NONEwithDSA
- SHA1withDetECDSA
- SHA224withECDDSA
- SHA256withECDDSA
- SHA384withECDDSA
- SHA512withECDDSA
- SHA1withECDSA
- NONEwithECDSA
- SHA224withECDSA
- SHA256withECDSA
- SHA384withECDSA
- SHA512withECDSA
- SHA3-224withECDSA
- SHA3-256withECDSA
- SHA3-384withECDSA
- SHA3-512withECDSA
- SHAKE128withECDSA
- SHAKE256withECDSA
- SHA1withPLAIN-ECDSA
- SHA224withPLAIN-ECDSA
- SHA256withPLAIN-ECDSA
- SHA384withPLAIN-ECDSA
- SHA512withPLAIN-ECDSA
- SHA3-224withPLAIN-ECDSA
- SHA3-256withPLAIN-ECDSA
- SHA3-384withPLAIN-ECDSA
- SHA3-512withPLAIN-ECDSA
- SHA1withECNR
- SHA224withECNR
- SHA256withECNR
- SHA384withECNR
- SHA512withECNR
- SHA224withRSA
- SHA256withRSA
- SHA384withRSA
- SHA512withRSA
- SHA512(224)withRSA
- SHA512(256)withRSA
- SHA3-224withRSA
- SHA3-256withRSA
- SHA3-384withRSA
- SHA3-512withRSA
- SHA1withRSAandMGF1
- SHA256withRSAandMGF1
- SHA384withRSAandMGF1
- SHA512withRSAandMGF1
- SHA512(224)withRSAandMGF1
- SHA512(256)withRSAandMGF1
- SHA1withRSA/ISO9796-2
- RIPEMD160withRSA/ISO9796-2
- SHA1withRSA/X9.31
- SHA224withRSA/X9.31
- SHA256withRSA/X9.31
- SHA384withRSA/X9.31
- SHA512withRSA/X9.31
- SHA512(224)withRSA/X9.31
- SHA512(256)withRSA/X9.31
- RIPEMD128withRSA/X9.31
- RIPEMD160withRSA/X9.31
- WHIRLPOOLwithRSA/X9.31
- SHA512withSPHINCS256 (BCPQC)
- SHA3-512withSPHINCS256 (BCPQC)
- SHA256withSM2
- SM3withSM2
- LMS
- Dilithium
- Falcon
- Picnic
- SPHINCS+
- XMSS-SHA256
- XMSS-SHA512
- XMSS-SHAKE128
- XMSS-SHAKE256
- XMSSMT-SHA256
- XMSSMT-SHA512
- XMSSMT-SHAKE128
- XMSSMT-SHAKE256
- SHA256withXMSS-SHA256
- SHA512withXMSS-SHA512
- SHAKE128withXMSS-SHAKE128
- SHAKE256withXMSS-SHAKE256
- SHA256withXMSSMT-SHA256
- SHA512withXMSSMT-SHA512
- SHAKE128withXMSSMT-SHAKE128
- SHAKE256withXMSSMT-SHAKE256

#### Password Hashing and PBE

Schemes:

- BCrypt
- OpenBSDBcyrpt
- SCrypt
- PKCS5S1, any Digest, any symmetric Cipher, ASCII
- PKCS5S2, any HMac, any symmetric Cipher, ASCII, UTF8
- PKCS12, any Digest, any symmetric Cipher, Unicode

Defined in Bouncy Castle JCE Provider

Name | Key Generation Scheme | Key Length (in bits) | Char to Byte conversion
--- | --- | --- | ---
PBEWithMD2AndDES | PKCS5 Scheme 1 | 64 | 8 bit chars
PBEWithMD2AndRC2 | PKCS5 Scheme 1 | 128 | 8 bit chars
PBEWithMD5AndDES | PKCS5 Scheme 1 | 64 | 8 bit chars
PBEWithMD5AndRC2 | PKCS5 Scheme 1 | 128 | 8 bit chars
PBEWithSHA1AndDES | PKCS5 Scheme 1 | 64 | 8 bit chars
PBEWithSHA1AndRC2 | PKCS5 Scheme 1 | 128 | 8 bit chars
PBKDF2WithHmacSHA1 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA1AndUTF8 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA1And8bit | PKCS5 Scheme 2 | variable | 8 bit chars
PBKDF2WithHmacSHA224 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA256 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA384 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA512 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA3-224 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA3-256 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA3-384 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSHA3-512 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacGOST3411 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBKDF2WithHmacSM3 | PKCS5 Scheme 2 | variable | UTF-8 chars
PBEWithSHAAnd2-KeyTripleDES-CBC | PKCS12 | 128 | 16 bit chars
PBEWithSHAAnd3-KeyTripleDES-CBC | PKCS12 | 192 | 16 bit chars
PBEWithSHAAnd128BitRC2-CBC | PKCS12 | 128 | 16 bit chars
PBEWithSHAAnd40BitRC2-CBC | PKCS12 | 40 | 16 bit chars
PBEWithSHAAnd128BitRC4 | PKCS12 | 128 | 16 bit chars
PBEWithSHAAnd40BitRC4 | PKCS12 | 40 | 16 bit chars
PBEWithSHAAndTwofish-CBC | PKCS12 | 256 | 16 bit chars
PBEWithSHAAndIDEA-CBC | PKCS12 | 128 | 16 bit chars

### 6.3 Certificates

The Bouncy Castle provider will read X.509 certficates (v2 or v3) as per the examples in the java.security.cert.CertificateFactory class. They can be provided either in the normal PEM encoded format, or as DER binaries.

The CertificateFactory will also read X.509 CRLs (v2) from either PEM or DER encodings.

In addition to the classes in the org.bouncycastle.asn1.x509 package for certificate, CRLs, and OCSP, CRMF, and CMP message generation a more JCE "friendly" class is provided in the package org.bouncycastle.cert. The JCE "friendly" classes found in the jcajce subpackages support RSA, DSA, GOST, DTSU, and EC-DSA.

### 6.4 Keystore

The Bouncy Castle package has four implementation of a keystore.

The first "BKS" is a keystore that will work with the keytool in the same fashion as the Sun "JKS" keystore. The keystore is resistent to tampering but not inspection.

The second, Keystore.BouncyCastle, or Keystore.UBER will only work with the keytool if the password is provided on the command line, as the entire keystore is encrypted with a PBE based on SHA1 and Twofish. PBEWithSHAAndTwofish-CBC. This makes the entire keystore resistant to tampering and inspection, and forces verification. The Sun JDK provided keytool will attempt to load a keystore even if no password is given, this is impossible for this version. (One might wonder about going to all this trouble and then having the password on the command line! New keytool anyone?).

In the first case, the keys are encrypted with 3-Key-TripleDES.

The third is a PKCS12 compatible keystore. PKCS12 provides a slightly different situation from the regular key store, the keystore password is currently the only password used for storing keys. Otherwise it supports all the functionality required for it to be used with the keytool. In some situations other libraries always expect to be dealing with Sun certificates, if this is the case use PKCS12-DEF, and the certificates produced by the key store will be made using the default provider. In the default case PKCS12 uses 3DES for key protection and 40 bit RC2 for protecting the certificates. It is also possible to use 3DES for both by using PKCS12-3DES-3DES or PKCS12-DEF-3DES-3DES as the KeyStore type.

There is an example program that produces PKCS12 files suitable for loading into browsers. It is in the package org.bouncycastle.jce.examples.

The fourth is the BCFKS key store which is a FIPS compliant key store which is also designed for general key storage and based on ASN.1. This key store type is encrypted and supports the use of SCRYPT and the storage of some symmetric key types.

### 6.5 Additional support classes for Elliptic Curve.

There are no classes for supporting EC in the JDK prior to JDK 1.5. If you are using an earlier JDK you can find classes for using EC in the following packages:

- org.bouncycastle.jce.spec
- org.bouncycastle.jce.interfaces
- org.bouncycastle.jce

### 7.0 BouncyCastle S/MIME

To be able to fully compile and utilise the BouncyCastle S/MIME package (including the test classes) you need the jar files for the following APIs.

- Junit - https://www.junit.org
- JavaMail - https://java.sun.com/products/javamail/index.html
- The Java Activation Framework - https://java.sun.com/products/javabeans/glasgow/jaf.html

### 7.1 Setting up BouncyCastle S/MIME in JavaMail

The BouncyCastle S/MIME handlers may be set in JavaMail two ways.

- STATICALLY
  Add the following entries to the mailcap file:

          application/pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_signature
          application/pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_mime
          application/x-pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_signature
          application/x-pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_mime
          multipart/signed;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.multipart_signed

- DYNAMICALLY
  The following code will add the BouncyCastle S/MIME handlers dynamically:

          import javax.activation.MailcapCommandMap;
          import javax.activation.CommandMap;

          public static void setDefaultMailcap()
          {
              MailcapCommandMap _mailcap =
                  (MailcapCommandMap)CommandMap.getDefaultCommandMap();

              _mailcap.addMailcap("application/pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_signature");
              _mailcap.addMailcap("application/pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.pkcs7_mime");
              _mailcap.addMailcap("application/x-pkcs7-signature;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_signature");
              _mailcap.addMailcap("application/x-pkcs7-mime;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.x_pkcs7_mime");
              _mailcap.addMailcap("multipart/signed;; x-java-content-handler=org.bouncycastle.mail.smime.handlers.multipart_signed");

              CommandMap.setDefaultCommandMap(_mailcap);
          }