DSAEngine (Javadocs [I2P+ 2.13.0+] - API Version 0.9.70+)

java.lang.Object
- net.i2p.crypto.DSAEngine

```
public final class DSAEngine
extends Object
```
Digital signature algorithm engine supporting DSA, ECDSA, RSA, and EdDSA. Provides signing and verification operations for all supported signature types.

Constructor Summary
Constructors
Constructor and Description
DSAEngine(I2PAppContext context)
Create a DSA engine for the given context.

Constructors
Constructor and Description
`DSAEngine(I2PAppContext context)` Create a DSA engine for the given context.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`static SHA1Hash`	`calculateHash(byte[] source, int offset, int len)` Calculate a SHA-1 hash of the source data.
`SHA1Hash`	`calculateHash(InputStream in)` Reads the stream until EOF.
`static DSAEngine`	`getInstance()` Get the DSA engine instance from the global context.
`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(Hash hash, SigningPrivateKey signingKey)` Nonstandard.
`Signature`	`sign(InputStream in, SigningPrivateKey signingKey)` Sign using DSA-SHA1 ONLY.
`Signature`	`sign(SHA1Hash hash, SigningPrivateKey signingKey)` Sign using DSA-SHA1 ONLY.
`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 a signature using any supported signature type.
`boolean`	`verifySignature(Signature signature, Hash hash, SigningPublicKey verifyingKey)` Nonstandard.
`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, 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)
```
  Create a DSA engine for the given context.
  Parameters:
  context - the context

Method Detail

calculateHash
```
public static SHA1Hash calculateHash(byte[] source,
                                     int offset,
                                     int len)
```
Calculate a SHA-1 hash of the source data.
Parameters:
source - the source
offset - the offset in the source data
len - the length of data to hash
Returns:
the SHA-1 hash

calculateHash
```
public SHA1Hash calculateHash(InputStream in)
```
Reads the stream until EOF. Does not close the stream. Prefer calculateHash(byte[], int, int) for byte array inputs.
Returns:
hash SHA-1 hash, NOT a SHA-256 hash

getInstance
```
public static DSAEngine getInstance()
```
Get the DSA engine instance from the global context.
Returns:
the DSA engine

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(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(Hash hash,
                      SigningPrivateKey signingKey)

Nonstandard. Used by Syndie.

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(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

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

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)

Returns:: true if valid, false otherwise

verifySignature
```
public boolean verifySignature(Signature signature,
                               byte[] signedData,
                               SigningPublicKey verifyingKey)
```
Verify a signature using any supported signature type.
Parameters:
signature - the signature to verify
signedData - the data that was signed
verifyingKey - the public key to verify with
Returns:
true if the signature is valid, false otherwise

verifySignature

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

Nonstandard. Used by Syndie.

Returns:: true if valid, false otherwise

verifySignature

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

Verify using DSA-SHA1 ONLY

Returns:: true if valid, false otherwise

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
Returns:: true if valid, false otherwise

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
Returns:
true if valid, false otherwise

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
Returns:: true if valid, false otherwise

Class DSAEngine

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DSAEngine

Method Detail

calculateHash

calculateHash

getInstance

sign

sign

sign

sign

sign

sign

sign

verifySignature

verifySignature

verifySignature

verifySignature

verifySignature

verifySignature

verifySignature