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Diffstat (limited to 'core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2Vector.java')
| -rw-r--r-- | core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2Vector.java | 539 |
1 files changed, 0 insertions, 539 deletions
diff --git a/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2Vector.java b/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2Vector.java deleted file mode 100644 index ec35b682..00000000 --- a/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2Vector.java +++ /dev/null @@ -1,539 +0,0 @@ -package org.bouncycastle.pqc.math.linearalgebra; - -import java.security.SecureRandom; - -/** - * This class implements the abstract class <tt>Vector</tt> for the case of - * vectors over the finite field GF(2). <br> - * For the vector representation the array of type int[] is used, thus one - * element of the array holds 32 elements of the vector. - * - * @see Vector - */ -public class GF2Vector - extends Vector -{ - - /** - * holds the elements of this vector - */ - private int[] v; - - /** - * Construct the zero vector of the given length. - * - * @param length the length of the vector - */ - public GF2Vector(int length) - { - if (length < 0) - { - throw new ArithmeticException("Negative length."); - } - this.length = length; - v = new int[(length + 31) >> 5]; - } - - /** - * Construct a random GF2Vector of the given length. - * - * @param length the length of the vector - * @param sr the source of randomness - */ - public GF2Vector(int length, SecureRandom sr) - { - this.length = length; - - int size = (length + 31) >> 5; - v = new int[size]; - - // generate random elements - for (int i = size - 1; i >= 0; i--) - { - v[i] = sr.nextInt(); - } - - // erase unused bits - int r = length & 0x1f; - if (r != 0) - { - // erase unused bits - v[size - 1] &= (1 << r) - 1; - } - } - - /** - * Construct a random GF2Vector of the given length with the specified - * number of non-zero coefficients. - * - * @param length the length of the vector - * @param t the number of non-zero coefficients - * @param sr the source of randomness - */ - public GF2Vector(int length, int t, SecureRandom sr) - { - if (t > length) - { - throw new ArithmeticException( - "The hamming weight is greater than the length of vector."); - } - this.length = length; - - int size = (length + 31) >> 5; - v = new int[size]; - - int[] help = new int[length]; - for (int i = 0; i < length; i++) - { - help[i] = i; - } - - int m = length; - for (int i = 0; i < t; i++) - { - int j = RandUtils.nextInt(sr, m); - setBit(help[j]); - m--; - help[j] = help[m]; - } - } - - /** - * Construct a GF2Vector of the given length and with elements from the - * given array. The array is copied and unused bits are masked out. - * - * @param length the length of the vector - * @param v the element array - */ - public GF2Vector(int length, int[] v) - { - if (length < 0) - { - throw new ArithmeticException("negative length"); - } - this.length = length; - - int size = (length + 31) >> 5; - - if (v.length != size) - { - throw new ArithmeticException("length mismatch"); - } - - this.v = IntUtils.clone(v); - - int r = length & 0x1f; - if (r != 0) - { - // erase unused bits - this.v[size - 1] &= (1 << r) - 1; - } - } - - /** - * Copy constructor. - * - * @param other another {@link GF2Vector} - */ - public GF2Vector(GF2Vector other) - { - this.length = other.length; - this.v = IntUtils.clone(other.v); - } - - /** - * Construct a new {@link GF2Vector} of the given length and with the given - * element array. The array is not changed and only a reference to the array - * is stored. No length checking is performed either. - * - * @param v the element array - * @param length the length of the vector - */ - protected GF2Vector(int[] v, int length) - { - this.v = v; - this.length = length; - } - - /** - * Construct a new GF2Vector with the given length out of the encoded - * vector. - * - * @param length the length of the vector - * @param encVec the encoded vector - * @return the decoded vector - */ - public static GF2Vector OS2VP(int length, byte[] encVec) - { - if (length < 0) - { - throw new ArithmeticException("negative length"); - } - - int byteLen = (length + 7) >> 3; - - if (encVec.length > byteLen) - { - throw new ArithmeticException("length mismatch"); - } - - return new GF2Vector(length, LittleEndianConversions.toIntArray(encVec)); - } - - /** - * Encode this vector as byte array. - * - * @return the encoded vector - */ - public byte[] getEncoded() - { - int byteLen = (length + 7) >> 3; - return LittleEndianConversions.toByteArray(v, byteLen); - } - - /** - * @return the int array representation of this vector - */ - public int[] getVecArray() - { - return v; - } - - /** - * Return the Hamming weight of this vector, i.e., compute the number of - * units of this vector. - * - * @return the Hamming weight of this vector - */ - public int getHammingWeight() - { - int weight = 0; - for (int i = 0; i < v.length; i++) - { - int e = v[i]; - for (int j = 0; j < 32; j++) - { - int b = e & 1; - if (b != 0) - { - weight++; - } - e >>>= 1; - } - } - return weight; - } - - /** - * @return whether this is the zero vector (i.e., all elements are zero) - */ - public boolean isZero() - { - for (int i = v.length - 1; i >= 0; i--) - { - if (v[i] != 0) - { - return false; - } - } - return true; - } - - /** - * Return the value of the bit of this vector at the specified index. - * - * @param index the index - * @return the value of the bit (0 or 1) - */ - public int getBit(int index) - { - if (index >= length) - { - throw new IndexOutOfBoundsException(); - } - int q = index >> 5; - int r = index & 0x1f; - return (v[q] & (1 << r)) >>> r; - } - - /** - * Set the coefficient at the given index to 1. If the index is out of - * bounds, do nothing. - * - * @param index the index of the coefficient to set - */ - public void setBit(int index) - { - if (index >= length) - { - throw new IndexOutOfBoundsException(); - } - v[index >> 5] |= 1 << (index & 0x1f); - } - - /** - * Adds another GF2Vector to this vector. - * - * @param other another GF2Vector - * @return <tt>this + other</tt> - * @throws ArithmeticException if the other vector is not a GF2Vector or has another - * length. - */ - public Vector add(Vector other) - { - if (!(other instanceof GF2Vector)) - { - throw new ArithmeticException("vector is not defined over GF(2)"); - } - - GF2Vector otherVec = (GF2Vector)other; - if (length != otherVec.length) - { - throw new ArithmeticException("length mismatch"); - } - - int[] vec = IntUtils.clone(((GF2Vector)other).v); - - for (int i = vec.length - 1; i >= 0; i--) - { - vec[i] ^= v[i]; - } - - return new GF2Vector(length, vec); - } - - /** - * Multiply this vector with a permutation. - * - * @param p the permutation - * @return <tt>this*p = p*this</tt> - */ - public Vector multiply(Permutation p) - { - int[] pVec = p.getVector(); - if (length != pVec.length) - { - throw new ArithmeticException("length mismatch"); - } - - GF2Vector result = new GF2Vector(length); - - for (int i = 0; i < pVec.length; i++) - { - int e = v[pVec[i] >> 5] & (1 << (pVec[i] & 0x1f)); - if (e != 0) - { - result.v[i >> 5] |= 1 << (i & 0x1f); - } - } - - return result; - } - - /** - * Return a new vector consisting of the elements of this vector with the - * indices given by the set <tt>setJ</tt>. - * - * @param setJ the set of indices of elements to extract - * @return the new {@link GF2Vector} - * <tt>[this_setJ[0], this_setJ[1], ..., this_setJ[#setJ-1]]</tt> - */ - public GF2Vector extractVector(int[] setJ) - { - int k = setJ.length; - if (setJ[k - 1] > length) - { - throw new ArithmeticException("invalid index set"); - } - - GF2Vector result = new GF2Vector(k); - - for (int i = 0; i < k; i++) - { - int e = v[setJ[i] >> 5] & (1 << (setJ[i] & 0x1f)); - if (e != 0) - { - result.v[i >> 5] |= 1 << (i & 0x1f); - } - } - - return result; - } - - /** - * Return a new vector consisting of the first <tt>k</tt> elements of this - * vector. - * - * @param k the number of elements to extract - * @return a new {@link GF2Vector} consisting of the first <tt>k</tt> - * elements of this vector - */ - public GF2Vector extractLeftVector(int k) - { - if (k > length) - { - throw new ArithmeticException("invalid length"); - } - - if (k == length) - { - return new GF2Vector(this); - } - - GF2Vector result = new GF2Vector(k); - - int q = k >> 5; - int r = k & 0x1f; - - System.arraycopy(v, 0, result.v, 0, q); - if (r != 0) - { - result.v[q] = v[q] & ((1 << r) - 1); - } - - return result; - } - - /** - * Return a new vector consisting of the last <tt>k</tt> elements of this - * vector. - * - * @param k the number of elements to extract - * @return a new {@link GF2Vector} consisting of the last <tt>k</tt> - * elements of this vector - */ - public GF2Vector extractRightVector(int k) - { - if (k > length) - { - throw new ArithmeticException("invalid length"); - } - - if (k == length) - { - return new GF2Vector(this); - } - - GF2Vector result = new GF2Vector(k); - - int q = (length - k) >> 5; - int r = (length - k) & 0x1f; - int length = (k + 31) >> 5; - - int ind = q; - // if words have to be shifted - if (r != 0) - { - // process all but last word - for (int i = 0; i < length - 1; i++) - { - result.v[i] = (v[ind++] >>> r) | (v[ind] << (32 - r)); - } - // process last word - result.v[length - 1] = v[ind++] >>> r; - if (ind < v.length) - { - result.v[length - 1] |= v[ind] << (32 - r); - } - } - else - { - // no shift necessary - System.arraycopy(v, q, result.v, 0, length); - } - - return result; - } - - /** - * Rewrite this vector as a vector over <tt>GF(2<sup>m</sup>)</tt> with - * <tt>t</tt> elements. - * - * @param field the finite field <tt>GF(2<sup>m</sup>)</tt> - * @return the converted vector over <tt>GF(2<sup>m</sup>)</tt> - */ - public GF2mVector toExtensionFieldVector(GF2mField field) - { - int m = field.getDegree(); - if ((length % m) != 0) - { - throw new ArithmeticException("conversion is impossible"); - } - - int t = length / m; - int[] result = new int[t]; - int count = 0; - for (int i = t - 1; i >= 0; i--) - { - for (int j = field.getDegree() - 1; j >= 0; j--) - { - int q = count >>> 5; - int r = count & 0x1f; - - int e = (v[q] >>> r) & 1; - if (e == 1) - { - result[i] ^= 1 << j; - } - count++; - } - } - return new GF2mVector(field, result); - } - - /** - * Check if the given object is equal to this vector. - * - * @param other vector - * @return the result of the comparison - */ - public boolean equals(Object other) - { - - if (!(other instanceof GF2Vector)) - { - return false; - } - GF2Vector otherVec = (GF2Vector)other; - - return (length == otherVec.length) && IntUtils.equals(v, otherVec.v); - } - - /** - * @return the hash code of this vector - */ - public int hashCode() - { - int hash = length; - hash = hash * 31 + v.hashCode(); - return hash; - } - - /** - * @return a human readable form of this vector - */ - public String toString() - { - StringBuffer buf = new StringBuffer(); - for (int i = 0; i < length; i++) - { - if ((i != 0) && ((i & 0x1f) == 0)) - { - buf.append(' '); - } - int q = i >> 5; - int r = i & 0x1f; - int bit = v[q] & (1 << r); - if (bit == 0) - { - buf.append('0'); - } - else - { - buf.append('1'); - } - } - return buf.toString(); - } - -} |