diff options
Diffstat (limited to 'pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java')
| -rwxr-xr-x | pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java | 281 |
1 files changed, 140 insertions, 141 deletions
diff --git a/pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java b/pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java index cec2b97b..cd7b8de3 100755 --- a/pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java +++ b/pki/base/util/src/netscape/security/provider/DSAParameterGenerator.java @@ -46,7 +46,7 @@ import java.security.spec.InvalidParameterSpecException; */ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { - + // the modulus length private int modLen = 1024; // default @@ -62,83 +62,82 @@ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { private SHA sha; public DSAParameterGenerator() { - this.sha = new SHA(); + this.sha = new SHA(); } /** * Initializes this parameter generator for a certain strength * and source of randomness. - * + * * @param strength the strength (size of prime) in bits * @param random the source of randomness */ protected void engineInit(int strength, SecureRandom random) { - /* - * Bruce Schneier, "Applied Cryptography", 2nd Edition, - * Description of DSA: - * [...] The algorithm uses the following parameter: - * p=a prime number L bits long, when L ranges from 512 to 1024 and is - * a multiple of 64. [...] - */ - if ((strength < 512) || (strength > 1024) || (strength % 64 != 0)) { - throw new InvalidParameterException - ("Prime size must range from 512 to 1024 " - + "and be a multiple of 64"); - } - this.modLen = strength; - this.random = random; + /* + * Bruce Schneier, "Applied Cryptography", 2nd Edition, + * Description of DSA: + * [...] The algorithm uses the following parameter: + * p=a prime number L bits long, when L ranges from 512 to 1024 and is + * a multiple of 64. [...] + */ + if ((strength < 512) || (strength > 1024) || (strength % 64 != 0)) { + throw new InvalidParameterException("Prime size must range from 512 to 1024 " + + "and be a multiple of 64"); + } + this.modLen = strength; + this.random = random; } /** * Initializes this parameter generator with a set of * algorithm-specific parameter generation values. - * + * * @param params the set of algorithm-specific parameter generation values * @param random the source of randomness - * + * * @exception InvalidAlgorithmParameterException if the given parameter - * generation values are inappropriate for this parameter generator + * generation values are inappropriate for this parameter generator */ protected void engineInit(AlgorithmParameterSpec genParamSpec, - SecureRandom random) - throws InvalidAlgorithmParameterException { - throw new InvalidAlgorithmParameterException("Invalid parameter"); + SecureRandom random) + throws InvalidAlgorithmParameterException { + throw new InvalidAlgorithmParameterException("Invalid parameter"); } /** * Generates the parameters. - * + * * @return the new AlgorithmParameters object */ protected AlgorithmParameters engineGenerateParameters() { - AlgorithmParameters algParams = null; - try { - if (this.random == null) { - this.random = new SecureRandom(); - } - - BigInteger[] pAndQ = generatePandQ(this.random, this.modLen); - BigInteger paramP = pAndQ[0]; - BigInteger paramQ = pAndQ[1]; - BigInteger paramG = generateG(paramP, paramQ); - - DSAParameterSpec dsaParamSpec = new DSAParameterSpec(paramP, - paramQ, - paramG); - algParams = AlgorithmParameters.getInstance("DSA", "SUN"); - algParams.init(dsaParamSpec); - } catch (InvalidParameterSpecException e) { - // this should never happen - throw new RuntimeException(e.getMessage()); - } catch (NoSuchAlgorithmException e) { - // this should never happen, because we provide it - throw new RuntimeException(e.getMessage()); - } catch (NoSuchProviderException e) { - // this should never happen, because we provide it - throw new RuntimeException(e.getMessage()); - } - - return algParams; + AlgorithmParameters algParams = null; + try { + if (this.random == null) { + this.random = new SecureRandom(); + } + + BigInteger[] pAndQ = generatePandQ(this.random, this.modLen); + BigInteger paramP = pAndQ[0]; + BigInteger paramQ = pAndQ[1]; + BigInteger paramG = generateG(paramP, paramQ); + + DSAParameterSpec dsaParamSpec = new DSAParameterSpec(paramP, + paramQ, + paramG); + algParams = AlgorithmParameters.getInstance("DSA", "SUN"); + algParams.init(dsaParamSpec); + } catch (InvalidParameterSpecException e) { + // this should never happen + throw new RuntimeException(e.getMessage()); + } catch (NoSuchAlgorithmException e) { + // this should never happen, because we provide it + throw new RuntimeException(e.getMessage()); + } catch (NoSuchProviderException e) { + // this should never happen, because we provide it + throw new RuntimeException(e.getMessage()); + } + + return algParams; } /* @@ -155,16 +154,16 @@ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { * <code>q</code> at index 1. */ BigInteger[] generatePandQ(SecureRandom random, int L) { - BigInteger[] result = null; - byte[] seed = new byte[20]; - - while(result == null) { - for (int i = 0; i < 20; i++) { - seed[i] = (byte)random.nextInt(); - } - result = generatePandQ(seed, L); - } - return result; + BigInteger[] result = null; + byte[] seed = new byte[20]; + + while (result == null) { + for (int i = 0; i < 20; i++) { + seed[i] = (byte) random.nextInt(); + } + result = generatePandQ(seed, L); + } + return result; } /* @@ -183,68 +182,68 @@ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { */ BigInteger[] generatePandQ(byte[] seed, int L) { - /* Useful variables */ - int g = seed.length * 8; - int n = (L - 1) / 160; - int b = (L - 1) % 160; + /* Useful variables */ + int g = seed.length * 8; + int n = (L - 1) / 160; + int b = (L - 1) % 160; - BigInteger SEED = new BigInteger(1, seed); - BigInteger TWOG = TWO.pow(2 * g); + BigInteger SEED = new BigInteger(1, seed); + BigInteger TWOG = TWO.pow(2 * g); - /* Step 2 (Step 1 is getting seed). */ - byte[] U1 = SHA(seed); + /* Step 2 (Step 1 is getting seed). */ + byte[] U1 = SHA(seed); byte[] U2 = SHA(toByteArray((SEED.add(ONE)).mod(TWOG))); - xor(U1, U2); - byte[] U = U1; - - /* Step 3: For q by setting the msb and lsb to 1 */ - U[0] |= 0x80; - U[19] |= 1; - BigInteger q = new BigInteger(1, U); - - /* Step 5 */ - if (!q.isProbablePrime(40)) { - return null; - - } else { - BigInteger V[] = new BigInteger[n + 1]; - BigInteger offset = TWO; - - /* Step 6 */ - for (int counter = 0; counter < 4096; counter++) { - - /* Step 7 */ - for (int k = 0; k <= n; k++) { - BigInteger K = BigInteger.valueOf(k); - BigInteger tmp = (SEED.add(offset).add(K)).mod(TWOG); - V[k] = new BigInteger(1, SHA(toByteArray(tmp))); - } - - /* Step 8 */ - BigInteger W = V[0]; - for (int i = 1; i < n; i++) { - W = W.add(V[i].multiply(TWO.pow(i * 160))); - } - W = W.add((V[n].mod(TWO.pow(b))).multiply(TWO.pow(n * 160))); - - BigInteger TWOLm1 = TWO.pow(L - 1); - BigInteger X = W.add(TWOLm1); - - /* Step 9 */ - BigInteger c = X.mod(q.multiply(TWO)); - BigInteger p = X.subtract(c.subtract(ONE)); - - /* Step 10 - 13 */ - if (p.compareTo(TWOLm1) > -1 && p.isProbablePrime(15)) { - BigInteger[] result = {p, q, SEED, - BigInteger.valueOf(counter)}; - return result; - } - offset = offset.add(BigInteger.valueOf(n)).add(ONE); - } - return null; - } + xor(U1, U2); + byte[] U = U1; + + /* Step 3: For q by setting the msb and lsb to 1 */ + U[0] |= 0x80; + U[19] |= 1; + BigInteger q = new BigInteger(1, U); + + /* Step 5 */ + if (!q.isProbablePrime(40)) { + return null; + + } else { + BigInteger V[] = new BigInteger[n + 1]; + BigInteger offset = TWO; + + /* Step 6 */ + for (int counter = 0; counter < 4096; counter++) { + + /* Step 7 */ + for (int k = 0; k <= n; k++) { + BigInteger K = BigInteger.valueOf(k); + BigInteger tmp = (SEED.add(offset).add(K)).mod(TWOG); + V[k] = new BigInteger(1, SHA(toByteArray(tmp))); + } + + /* Step 8 */ + BigInteger W = V[0]; + for (int i = 1; i < n; i++) { + W = W.add(V[i].multiply(TWO.pow(i * 160))); + } + W = W.add((V[n].mod(TWO.pow(b))).multiply(TWO.pow(n * 160))); + + BigInteger TWOLm1 = TWO.pow(L - 1); + BigInteger X = W.add(TWOLm1); + + /* Step 9 */ + BigInteger c = X.mod(q.multiply(TWO)); + BigInteger p = X.subtract(c.subtract(ONE)); + + /* Step 10 - 13 */ + if (p.compareTo(TWOLm1) > -1 && p.isProbablePrime(15)) { + BigInteger[] result = { p, q, SEED, + BigInteger.valueOf(counter) }; + return result; + } + offset = offset.add(BigInteger.valueOf(n)).add(ONE); + } + return null; + } } /* @@ -256,23 +255,23 @@ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { * @param the <code>g</code> */ BigInteger generateG(BigInteger p, BigInteger q) { - BigInteger h = ONE; - BigInteger pMinusOneOverQ = (p.subtract(ONE)).divide(q); - BigInteger g = ONE; - while (g.compareTo(TWO) < 0) { - g = h.modPow(pMinusOneOverQ, p); - h = h.add(ONE); - } - return g; + BigInteger h = ONE; + BigInteger pMinusOneOverQ = (p.subtract(ONE)).divide(q); + BigInteger g = ONE; + while (g.compareTo(TWO) < 0) { + g = h.modPow(pMinusOneOverQ, p); + h = h.add(ONE); + } + return g; } /* * Returns the SHA-1 digest of some data */ private byte[] SHA(byte[] array) { - sha.engineReset(); - sha.engineUpdate(array, 0, array.length); - return sha.engineDigest(); + sha.engineReset(); + sha.engineUpdate(array, 0, array.length); + return sha.engineDigest(); } /* @@ -280,21 +279,21 @@ public class DSAParameterGenerator extends AlgorithmParameterGeneratorSpi { * signed magnitude representation for any positive number. */ private byte[] toByteArray(BigInteger bigInt) { - byte[] result = bigInt.toByteArray(); - if (result[0] == 0) { - byte[] tmp = new byte[result.length - 1]; - System.arraycopy(result, 1, tmp, 0, tmp.length); - result = tmp; - } - return result; + byte[] result = bigInt.toByteArray(); + if (result[0] == 0) { + byte[] tmp = new byte[result.length - 1]; + System.arraycopy(result, 1, tmp, 0, tmp.length); + result = tmp; + } + return result; } /* * XORs U2 into U1 */ private void xor(byte[] U1, byte[] U2) { - for (int i = 0; i < U1.length; i++) { - U1[i] ^= U2[i]; - } + for (int i = 0; i < U1.length; i++) { + U1[i] ^= U2[i]; + } } } |