Package org.mozilla.jss.crypto
Class PQGParams
java.lang.Object
java.security.spec.DSAParameterSpec
org.mozilla.jss.crypto.PQGParams
- All Implemented Interfaces:
DSAParams
,AlgorithmParameterSpec
PQG parameters for DSA key generation, along with the seed, counter,
and H values for verification.
This class has two main purposes:
generating PQG parameters and verifying PQG parameters. To generate
PQG parameters, call one of the static generate
methods.
They will return a new set of PQG parameters. To verify existing PQG
parameters, create a new PQGParams
object with the
constructor and call paramsAreValid
on the object.
It is necessary to call CryptoManager.initialize
before
using this class.
-
Field Summary
Fields -
Constructor Summary
ConstructorsConstructorDescriptionPQGParams
(BigInteger P, BigInteger Q, BigInteger G, BigInteger seed, int counter, BigInteger H) Creates a PQGParams object from a set of pre-computed DSA parameters. -
Method Summary
Modifier and TypeMethodDescriptionstatic byte[]
Produces an unsigned byte-array representation of a BigInteger.static PQGParams
generate
(int keySize) Generates P, Q, and G parameters for DSA key generation.static PQGParams
generate
(int keySize, int seedBytes) Generates P, Q, and G parameters for DSA key generation.private static PQGParams
generateNative
(int keySize) Does the actual work of generation, but does not verify.private static PQGParams
generateNative
(int keySize, int seedBytes) Does the actual work of generation, but does not verify.int
getH()
getSeed()
boolean
Verifies the PQG parameters using the seed, counter, and H values.private boolean
paramsAreValidNative
(byte[] P, byte[] Q, byte[] G, byte[] seed, int counter, byte[] H) Methods inherited from class java.security.spec.DSAParameterSpec
getG, getP, getQ
-
Field Details
-
seed
-
counter
private int counter -
H
-
-
Constructor Details
-
PQGParams
public PQGParams(BigInteger P, BigInteger Q, BigInteger G, BigInteger seed, int counter, BigInteger H) Creates a PQGParams object from a set of pre-computed DSA parameters.- Parameters:
P
- The DSA prime parameter.Q
- The DSA sub-prime parameter.G
- The DSA base parameter.seed
- The Seed used to calculate P, Q, and G.counter
- The Counter (C) used to calculate P, Q, and G.H
- The H value used to generate P, Q, and G.
-
-
Method Details
-
generate
public static PQGParams generate(int keySize) throws InvalidParameterException, PQGParamGenException Generates P, Q, and G parameters for DSA key generation. Also provides the seed, counter, and H values for verification of the P, Q, and G. The parameters are generated and then verified before being returned. The length of the Seed will equal the length of P. It is necessary to call one of theCryptoManager.initialize
functions before calling this method.- Parameters:
keySize
- The size of P in bits. Keys generated by these P, Q, and G values will have this length. Valid key sizes are multiples of 64 in the closed interval [512,1024]. This also dictates the length of H and Seed.- Returns:
- A new set of P, Q, and G parameters, along with the Seed, Counter, and H values used to generate them.
- Throws:
InvalidParameterException
- If the keySize is outside the bounds described by the DSA key pair generation algorithm.PQGParamGenException
- If an error occurs during the generation process.- See Also:
-
generateNative
private static PQGParams generateNative(int keySize) throws InvalidParameterException, PQGParamGenException Does the actual work of generation, but does not verify. -
generate
public static PQGParams generate(int keySize, int seedBytes) throws InvalidParameterException, PQGParamGenException Generates P, Q, and G parameters for DSA key generation. Also provides the seed, counter, and H values for verification of the P, Q, and G. The parameters are generated and then verified before being returned. It is necessary to call one of theCryptoManager.initialize
functions before calling this method.- Parameters:
keySize
- The size of P in bits. Keys generated by these P, Q, and G values will have this length. Valid key sizes are multiples of 64 in the closed interval [512,1024]. This also dictates the length of H.seedBytes
- The number of bytes in the Seed value used to generate P, Q, and G.seedBytes
must be from the closed interval [20,255].- Returns:
- A new set of P, Q, and G parameters, along with the Seed, Counter, and H values used to generate them.
- Throws:
InvalidParameterException
- If the keySize or number of seed bytes is outside the bounds described by the DSA key pair generation algorithm.PQGParamGenException
- If an error occurs during the generation process.- See Also:
-
generateNative
private static PQGParams generateNative(int keySize, int seedBytes) throws InvalidParameterException, PQGParamGenException Does the actual work of generation, but does not verify. -
BigIntegerToUnsignedByteArray
Produces an unsigned byte-array representation of a BigInteger.BigInteger adds an extra sign bit to the beginning of its byte array representation. In some cases this will cause the size of the byte array to increase, which may be unacceptable for some applications. This function returns a minimal byte array representing the BigInteger without extra sign bits.
- Returns:
- An unsigned, big-endian byte array representation of a BigInteger.
-
paramsAreValid
public boolean paramsAreValid()Verifies the PQG parameters using the seed, counter, and H values.- Returns:
- true if the parameters verified correctly, false if they did not verify.
-
paramsAreValidNative
private boolean paramsAreValidNative(byte[] P, byte[] Q, byte[] G, byte[] seed, int counter, byte[] H) -
getSeed
- Returns:
- The Seed used to generate P, Q, and G.
-
getCounter
public int getCounter()- Returns:
- The Counter (C) used to generate P, Q, and G.
-
getH
- Returns:
- The H value used to generate P, Q, and G.
-