diff options
Diffstat (limited to 'libjava/classpath/gnu/java/security/key/dss/FIPS186.java')
| -rw-r--r-- | libjava/classpath/gnu/java/security/key/dss/FIPS186.java | 108 |
1 files changed, 38 insertions, 70 deletions
diff --git a/libjava/classpath/gnu/java/security/key/dss/FIPS186.java b/libjava/classpath/gnu/java/security/key/dss/FIPS186.java index 5984bcc9393..7277599bd54 100644 --- a/libjava/classpath/gnu/java/security/key/dss/FIPS186.java +++ b/libjava/classpath/gnu/java/security/key/dss/FIPS186.java @@ -40,26 +40,21 @@ package gnu.java.security.key.dss; import gnu.java.security.hash.Sha160; import gnu.java.security.util.PRNG; -import gnu.java.security.util.Prime2; import java.math.BigInteger; import java.security.SecureRandom; /** - * <p>An implementation of the DSA parameters generation as described in - * FIPS-186.</p> - * - * References:<br> + * An implementation of the DSA parameters generation as described in FIPS-186. + * <p> + * References: + * <p> * <a href="http://www.itl.nist.gov/fipspubs/fip186.htm">Digital Signature - * Standard (DSS)</a>, Federal Information Processing Standards Publication 186. - * National Institute of Standards and Technology. + * Standard (DSS)</a>, Federal Information Processing Standards Publication + * 186. National Institute of Standards and Technology. */ public class FIPS186 { - - // Constants and variables - // ------------------------------------------------------------------------- - public static final int DSA_PARAMS_SEED = 0; public static final int DSA_PARAMS_COUNTER = 1; @@ -73,7 +68,7 @@ public class FIPS186 public static final int DSA_PARAMS_G = 5; /** The BigInteger constant 2. */ - private static final BigInteger TWO = new BigInteger("2"); + private static final BigInteger TWO = BigInteger.valueOf(2L); private static final BigInteger TWO_POW_160 = TWO.pow(160); @@ -89,9 +84,6 @@ public class FIPS186 /** Our default source of randomness. */ private PRNG prng = null; - // Constructor(s) - // ------------------------------------------------------------------------- - public FIPS186(int L, SecureRandom rnd) { super(); @@ -100,38 +92,31 @@ public class FIPS186 this.rnd = rnd; } - // Class methods - // ------------------------------------------------------------------------- - - // Instance methods - // ------------------------------------------------------------------------- - /** * This method generates the DSS <code>p</code>, <code>q</code>, and * <code>g</code> parameters only when <code>L</code> (the modulus length) * is not one of the following: <code>512</code>, <code>768</code> and - * <code>1024</code>. For those values of <code>L</code>, this implementation - * uses pre-computed values of <code>p</code>, <code>q</code>, and - * <code>g</code> given in the document <i>CryptoSpec</i> included in the - * security guide documentation of the standard JDK distribution.<p> - * + * <code>1024</code>. For those values of <code>L</code>, this + * implementation uses pre-computed values of <code>p</code>, + * <code>q</code>, and <code>g</code> given in the document <i>CryptoSpec</i> + * included in the security guide documentation of the standard JDK + * distribution. + * <p> * The DSS requires two primes , <code>p</code> and <code>q</code>, * satisfying the following three conditions: - * * <ul> - * <li><code>2<sup>159</sup> < q < 2<sup>160</sup></code></li> - * <li><code>2<sup>L-1</sup> < p < 2<sup>L</sup></code> for a - * specified <code>L</code>, where <code>L = 512 + 64j</code> for some - * <code>0 <= j <= 8</code></li> - * <li>q divides p - 1.</li> + * <li><code>2<sup>159</sup> < q < 2<sup>160</sup></code></li> + * <li><code>2<sup>L-1</sup> < p < 2<sup>L</sup></code> for a + * specified <code>L</code>, where <code>L = 512 + 64j</code> for some + * <code>0 <= j <= 8</code></li> + * <li>q divides p - 1.</li> * </ul> - * * The algorithm used to find these primes is as described in FIPS-186, * section 2.2: GENERATION OF PRIMES. This prime generation scheme starts by - * using the {@link Sha160} and a user supplied <i>SEED</i> - * to construct a prime, <code>q</code>, in the range 2<sup>159</sup> < q - * < 2<sup>160</sup>. Once this is accomplished, the same <i>SEED</i> - * value is used to construct an <code>X</code> in the range <code>2<sup>L-1 + * using the {@link Sha160} and a user supplied <i>SEED</i> to construct a + * prime, <code>q</code>, in the range 2<sup>159</sup> < q < 2<sup>160</sup>. + * Once this is accomplished, the same <i>SEED</i> value is used to construct + * an <code>X</code> in the range <code>2<sup>L-1 * </sup> < X < 2<sup>L</sup>. The prime, <code>p</code>, is then * formed by rounding <code>X</code> to a number congruent to <code>1 mod * 2q</code>. In this implementation we use the same <i>SEED</i> value given @@ -169,9 +154,8 @@ public class FIPS186 u = sha.digest(); } for (int i = 0; i < a.length; i++) - { - a[i] ^= u[i]; - } + a[i] ^= u[i]; + U = new BigInteger(1, a); // 3. Form q from U by setting the most significant bit (the // 2**159 bit) and the least significant bit to 1. In terms of @@ -183,12 +167,9 @@ public class FIPS186 // probability of a non-prime number passing the test is at // most 1/2**80. // 5. If q is not prime, go to step 1. - if (Prime2.isProbablePrime(q)) - { - break step1; - } + if (q.isProbablePrime(80)) + break step1; } // step1 - // 6. Let counter = 0 and offset = 2. counter = 0; offset = 2; @@ -201,9 +182,9 @@ public class FIPS186 { for (int k = 0; k <= n; k++) { - a = SEED_PLUS_OFFSET.add( - BigInteger.valueOf(k & 0xFFFFFFFFL)).mod( - TWO_POW_160).toByteArray(); + a = SEED_PLUS_OFFSET + .add(BigInteger.valueOf(k & 0xFFFFFFFFL)) + .mod(TWO_POW_160).toByteArray(); sha.update(a, 0, a.length); V[k] = new BigInteger(1, sha.digest()); } @@ -214,9 +195,8 @@ public class FIPS186 // Note that 0 <= W < 2**(L-1) and hence 2**(L-1) <= X < 2**L. W = V[0]; for (int k = 1; k < n; k++) - { - W = W.add(V[k].multiply(TWO.pow(k * 160))); - } + W = W.add(V[k].multiply(TWO.pow(k * 160))); + W = W.add(V[n].mod(TWO.pow(b)).multiply(TWO.pow(n * 160))); X = W.add(TWO.pow(L - 1)); // 9. Let c = X mod 2q and set p = X - (c - 1). @@ -228,22 +208,17 @@ public class FIPS186 { // 11. Perform a robust primality test on p. // 12. If p passes the test performed in step 11, go to step 15. - if (Prime2.isProbablePrime(p)) - { - break algorithm; - } + if (p.isProbablePrime(80)) + break algorithm; } // 13. Let counter = counter + 1 and offset = offset + n + 1. counter++; offset += n + 1; // 14. If counter >= 4096 go to step 1, otherwise go to step 7. if (counter >= 4096) - { - continue algorithm; - } + continue algorithm; } // step7 } // algorithm - // compute g. from FIPS-186, Appendix 4: // 1. Generate p and q as specified in Appendix 2. // 2. Let e = (p - 1) / q @@ -258,28 +233,21 @@ public class FIPS186 // 4. Set g = h**e mod p g = h.modPow(e, p); // 5. If g = 1, go to step 3 - if (!g.equals(BigInteger.ONE)) - { - break; - } + if (! g.equals(BigInteger.ONE)) + break; } - return new BigInteger[] { SEED, BigInteger.valueOf(counter), q, p, e, g }; } - // helper methods ---------------------------------------------------------- - /** * Fills the designated byte array with random data. - * + * * @param buffer the byte array to fill with random data. */ private void nextRandomBytes(byte[] buffer) { if (rnd != null) - { - rnd.nextBytes(buffer); - } + rnd.nextBytes(buffer); else getDefaultPRNG().nextBytes(buffer); } |
