Package net.i2p.crypto

Class DSAEngine

java.lang.Object

net.i2p.crypto.DSAEngine

public final class DSAEngine
extends Object

Sign and verify using DSA-SHA1 and other signature algorithms. Also contains methods to sign and verify using a SHA-256 Hash. The primary implementation is code from TheCryto. As of 0.8.7, also included is an alternate implementation using java.security libraries, which is slightly slower. This implementation could in the future be easily modified to use a new signing algorithm from java.security when we change the signing algorithm. Params and rv's changed from Hash to SHA1Hash for version 0.8.1 Hash variants of sign() and verifySignature() restored in 0.8.3, required by Syndie. As of 0.9.9, certain methods support RSA and ECDSA keys and signatures, i.e. all types specified in SigType. The type is specified by the getType() method in Signature, SigningPublicKey, and SigningPrivateKey. See Javadocs for individual methods for the supported types. Methods encountering an unsupported type will throw an IllegalArgumentException. EdDSA support added in 0.9.15

Constructor Summary

Constructors

Constructor	Description
DSAEngine(I2PAppContext context)

Method Summary

Modifier and Type	Method	Description
static SHA1Hash	calculateHash(byte[] source, int offset, int len)
SHA1Hash	calculateHash(InputStream in)	Deprecated. unused
static DSAEngine	getInstance()
Signature	sign(byte[] data, int offset, int length, SigningPrivateKey signingKey)	Sign using any key type as of 0.9.12 (DSA-SHA1 only prior to that)
Signature	sign(byte[] data, SigningPrivateKey signingKey)	Sign using any key type.
Signature	sign(InputStream in, SigningPrivateKey signingKey)	Sign using DSA-SHA1 ONLY.
Signature	sign(SHA1Hash hash, SigningPrivateKey signingKey)	Sign using DSA-SHA1 ONLY.
Signature	sign(Hash hash, SigningPrivateKey signingKey)	Nonstandard.
Signature	sign(SimpleDataStructure hash, PrivateKey privKey, SigType type)	Generic signature type.
Signature	sign(SimpleDataStructure hash, SigningPrivateKey signingKey)	Generic signature type.
boolean	verifySignature(Signature signature, byte[] signedData, int offset, int size, SigningPublicKey verifyingKey)	Verify using any sig type as of 0.9.12 (DSA only prior to that)
boolean	verifySignature(Signature signature, byte[] signedData, SigningPublicKey verifyingKey)	Verify using any sig type.
boolean	verifySignature(Signature signature, InputStream in, SigningPublicKey verifyingKey)	Verify using DSA-SHA1 ONLY
boolean	verifySignature(Signature signature, SHA1Hash hash, SigningPublicKey verifyingKey)	Verify using DSA-SHA1 ONLY
boolean	verifySignature(Signature signature, Hash hash, SigningPublicKey verifyingKey)	Nonstandard.
boolean	verifySignature(Signature signature, SimpleDataStructure hash, PublicKey pubKey)	Generic signature type.
boolean	verifySignature(Signature signature, SimpleDataStructure hash, SigningPublicKey verifyingKey)	Generic signature type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DSAEngine

public DSAEngine(I2PAppContext context)

Method Detail

getInstance

public static DSAEngine getInstance()

verifySignature

public boolean verifySignature(Signature signature,
                               byte[] signedData,
                               SigningPublicKey verifyingKey)

Verify using any sig type. Uses TheCrypto code for DSA-SHA1 unless configured to use the java.security libraries.

verifySignature

public boolean verifySignature(Signature signature,
                               byte[] signedData,
                               int offset,
                               int size,
                               SigningPublicKey verifyingKey)

Verify using any sig type as of 0.9.12 (DSA only prior to that)

verifySignature

public boolean verifySignature(Signature signature,
                               InputStream in,
                               SigningPublicKey verifyingKey)

Verify using DSA-SHA1 ONLY

verifySignature

public boolean verifySignature(Signature signature,
                               SHA1Hash hash,
                               SigningPublicKey verifyingKey)

Verify using DSA-SHA1 ONLY

Parameters:

hash - SHA-1 hash, NOT a SHA-256 hash

verifySignature

public boolean verifySignature(Signature signature,
                               Hash hash,
                               SigningPublicKey verifyingKey)

Nonstandard. Used by Syndie.

Since:

0.8.3 (restored, was removed in 0.8.1 and 0.8.2)

verifySignature

public boolean verifySignature(Signature signature,
                               SimpleDataStructure hash,
                               SigningPublicKey verifyingKey)

Generic signature type. Warning, nonstandard for EdDSA, double-hashes, not recommended.

Parameters:

hash - SHA1Hash, Hash, Hash384, or Hash512

Since:

0.9.9

verifySignature

public boolean verifySignature(Signature signature,
                               SimpleDataStructure hash,
                               PublicKey pubKey)

Generic signature type. If you have a Java pubkey, use this, so you don't lose the key parameters, which may be different than the ones defined in SigType. Warning, nonstandard for EdDSA, double-hashes, not recommended.

Parameters:

hash - SHA1Hash, Hash, Hash384, or Hash512

pubKey - Java key

Since:

0.9.9

sign

public Signature sign(byte[] data,
                      SigningPrivateKey signingKey)

Sign using any key type. Uses TheCrypto code unless configured to use the java.security libraries.

Returns:

null on error

sign

public Signature sign(byte[] data,
                      int offset,
                      int length,
                      SigningPrivateKey signingKey)

Sign using any key type as of 0.9.12 (DSA-SHA1 only prior to that)

Returns:

null on error

sign

public Signature sign(InputStream in,
                      SigningPrivateKey signingKey)

Sign using DSA-SHA1 ONLY. Reads the stream until EOF. Does not close the stream.

Returns:

null on error

sign

public Signature sign(SHA1Hash hash,
                      SigningPrivateKey signingKey)

Sign using DSA-SHA1 ONLY.

Parameters:

hash - SHA-1 hash, NOT a SHA-256 hash

Returns:

null on error

sign

public Signature sign(Hash hash,
                      SigningPrivateKey signingKey)

Nonstandard. Used by Syndie.

Returns:

null on error

Since:

0.8.3 (restored, was removed in 0.8.1 and 0.8.2)

sign

public Signature sign(SimpleDataStructure hash,
                      SigningPrivateKey signingKey)

Generic signature type. Warning, nonstandard for EdDSA, double-hashes, not recommended.

Parameters:

hash - SHA1Hash, Hash, Hash384, or Hash512

Returns:

null on error

Since:

0.9.9

sign

public Signature sign(SimpleDataStructure hash,
                      PrivateKey privKey,
                      SigType type)

Generic signature type. If you have a Java privkey, use this, so you don't lose the key parameters, which may be different than the ones defined in SigType. Warning, nonstandard for EdDSA, double-hashes, not recommended.

Parameters:

hash - SHA1Hash, Hash, Hash384, or Hash512

privKey - Java key

type - returns a Signature of this type

Returns:

null on error

Since:

0.9.9

calculateHash

public SHA1Hash calculateHash(InputStream in)

Deprecated.

unused

Reads the stream until EOF. Does not close the stream.

Returns:

hash SHA-1 hash, NOT a SHA-256 hash

calculateHash

public static SHA1Hash calculateHash(byte[] source,
                                     int offset,
                                     int len)

Returns:

hash SHA-1 hash, NOT a SHA-256 hash