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-rw-r--r--core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2mMatrix.java377
1 files changed, 0 insertions, 377 deletions
diff --git a/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2mMatrix.java b/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2mMatrix.java
deleted file mode 100644
index 8dfdb9b1..00000000
--- a/core/src/main/java/org/bouncycastle/pqc/math/linearalgebra/GF2mMatrix.java
+++ /dev/null
@@ -1,377 +0,0 @@
-package org.bouncycastle.pqc.math.linearalgebra;
-
-/**
- * This class describes some operations with matrices over finite field <i>GF(2<sup>m</sup>)</i>
- * with small <i>m</i> (1&lt; m &lt;32).
- *
- * @see Matrix
- */
-public class GF2mMatrix
- extends Matrix
-{
-
- /**
- * finite field GF(2^m)
- */
- protected GF2mField field;
-
- /**
- * For the matrix representation the array of type int[][] is used, thus
- * every element of the array keeps one element of the matrix (element from
- * finite field GF(2^m))
- */
- protected int[][] matrix;
-
- /**
- * Constructor.
- *
- * @param field a finite field GF(2^m)
- * @param enc byte[] matrix in byte array form
- */
- public GF2mMatrix(GF2mField field, byte[] enc)
- {
-
- this.field = field;
-
- // decode matrix
- int d = 8;
- int count = 1;
- while (field.getDegree() > d)
- {
- count++;
- d += 8;
- }
-
- if (enc.length < 5)
- {
- throw new IllegalArgumentException(
- " Error: given array is not encoded matrix over GF(2^m)");
- }
-
- this.numRows = ((enc[3] & 0xff) << 24) ^ ((enc[2] & 0xff) << 16)
- ^ ((enc[1] & 0xff) << 8) ^ (enc[0] & 0xff);
-
- int n = count * this.numRows;
-
- if ((this.numRows <= 0) || (((enc.length - 4) % n) != 0))
- {
- throw new IllegalArgumentException(
- " Error: given array is not encoded matrix over GF(2^m)");
- }
-
- this.numColumns = (enc.length - 4) / n;
-
- matrix = new int[this.numRows][this.numColumns];
- count = 4;
- for (int i = 0; i < this.numRows; i++)
- {
- for (int j = 0; j < this.numColumns; j++)
- {
- for (int jj = 0; jj < d; jj += 8)
- {
- matrix[i][j] ^= (enc[count++] & 0x000000ff) << jj;
- }
- if (!this.field.isElementOfThisField(matrix[i][j]))
- {
- throw new IllegalArgumentException(
- " Error: given array is not encoded matrix over GF(2^m)");
- }
- }
- }
- }
-
- /**
- * Copy constructor.
- *
- * @param other another {@link GF2mMatrix}
- */
- public GF2mMatrix(GF2mMatrix other)
- {
- numRows = other.numRows;
- numColumns = other.numColumns;
- field = other.field;
- matrix = new int[numRows][];
- for (int i = 0; i < numRows; i++)
- {
- matrix[i] = IntUtils.clone(other.matrix[i]);
- }
- }
-
- /**
- * Constructor.
- *
- * @param field a finite field GF(2^m)
- * @param matrix the matrix as int array. Only the reference is copied.
- */
- protected GF2mMatrix(GF2mField field, int[][] matrix)
- {
- this.field = field;
- this.matrix = matrix;
- numRows = matrix.length;
- numColumns = matrix[0].length;
- }
-
- /**
- * @return a byte array encoding of this matrix
- */
- public byte[] getEncoded()
- {
- int d = 8;
- int count = 1;
- while (field.getDegree() > d)
- {
- count++;
- d += 8;
- }
-
- byte[] bf = new byte[this.numRows * this.numColumns * count + 4];
- bf[0] = (byte)(this.numRows & 0xff);
- bf[1] = (byte)((this.numRows >>> 8) & 0xff);
- bf[2] = (byte)((this.numRows >>> 16) & 0xff);
- bf[3] = (byte)((this.numRows >>> 24) & 0xff);
-
- count = 4;
- for (int i = 0; i < this.numRows; i++)
- {
- for (int j = 0; j < this.numColumns; j++)
- {
- for (int jj = 0; jj < d; jj += 8)
- {
- bf[count++] = (byte)(matrix[i][j] >>> jj);
- }
- }
- }
-
- return bf;
- }
-
- /**
- * Check if this is the zero matrix (i.e., all entries are zero).
- *
- * @return <tt>true</tt> if this is the zero matrix
- */
- public boolean isZero()
- {
- for (int i = 0; i < numRows; i++)
- {
- for (int j = 0; j < numColumns; j++)
- {
- if (matrix[i][j] != 0)
- {
- return false;
- }
- }
- }
- return true;
- }
-
- /**
- * Compute the inverse of this matrix.
- *
- * @return the inverse of this matrix (newly created).
- */
- public Matrix computeInverse()
- {
- if (numRows != numColumns)
- {
- throw new ArithmeticException("Matrix is not invertible.");
- }
-
- // clone this matrix
- int[][] tmpMatrix = new int[numRows][numRows];
- for (int i = numRows - 1; i >= 0; i--)
- {
- tmpMatrix[i] = IntUtils.clone(matrix[i]);
- }
-
- // initialize inverse matrix as unit matrix
- int[][] invMatrix = new int[numRows][numRows];
- for (int i = numRows - 1; i >= 0; i--)
- {
- invMatrix[i][i] = 1;
- }
-
- // simultaneously compute Gaussian reduction of tmpMatrix and unit
- // matrix
- for (int i = 0; i < numRows; i++)
- {
- // if diagonal element is zero
- if (tmpMatrix[i][i] == 0)
- {
- boolean foundNonZero = false;
- // find a non-zero element in the same column
- for (int j = i + 1; j < numRows; j++)
- {
- if (tmpMatrix[j][i] != 0)
- {
- // found it, swap rows ...
- foundNonZero = true;
- swapColumns(tmpMatrix, i, j);
- swapColumns(invMatrix, i, j);
- // ... and quit searching
- j = numRows;
- continue;
- }
- }
- // if no non-zero element was found
- if (!foundNonZero)
- {
- // the matrix is not invertible
- throw new ArithmeticException("Matrix is not invertible.");
- }
- }
-
- // normalize i-th row
- int coef = tmpMatrix[i][i];
- int invCoef = field.inverse(coef);
- multRowWithElementThis(tmpMatrix[i], invCoef);
- multRowWithElementThis(invMatrix[i], invCoef);
-
- // normalize all other rows
- for (int j = 0; j < numRows; j++)
- {
- if (j != i)
- {
- coef = tmpMatrix[j][i];
- if (coef != 0)
- {
- int[] tmpRow = multRowWithElement(tmpMatrix[i], coef);
- int[] tmpInvRow = multRowWithElement(invMatrix[i], coef);
- addToRow(tmpRow, tmpMatrix[j]);
- addToRow(tmpInvRow, invMatrix[j]);
- }
- }
- }
- }
-
- return new GF2mMatrix(field, invMatrix);
- }
-
- private static void swapColumns(int[][] matrix, int first, int second)
- {
- int[] tmp = matrix[first];
- matrix[first] = matrix[second];
- matrix[second] = tmp;
- }
-
- private void multRowWithElementThis(int[] row, int element)
- {
- for (int i = row.length - 1; i >= 0; i--)
- {
- row[i] = field.mult(row[i], element);
- }
- }
-
- private int[] multRowWithElement(int[] row, int element)
- {
- int[] result = new int[row.length];
- for (int i = row.length - 1; i >= 0; i--)
- {
- result[i] = field.mult(row[i], element);
- }
- return result;
- }
-
- /**
- * Add one row to another.
- *
- * @param fromRow the addend
- * @param toRow the row to add to
- */
- private void addToRow(int[] fromRow, int[] toRow)
- {
- for (int i = toRow.length - 1; i >= 0; i--)
- {
- toRow[i] = field.add(fromRow[i], toRow[i]);
- }
- }
-
- public Matrix rightMultiply(Matrix a)
- {
- throw new RuntimeException("Not implemented.");
- }
-
- public Matrix rightMultiply(Permutation perm)
- {
- throw new RuntimeException("Not implemented.");
- }
-
- public Vector leftMultiply(Vector vector)
- {
- throw new RuntimeException("Not implemented.");
- }
-
- public Vector rightMultiply(Vector vector)
- {
- throw new RuntimeException("Not implemented.");
- }
-
- /**
- * Checks if given object is equal to this matrix. The method returns false
- * whenever the given object is not a matrix over GF(2^m).
- *
- * @param other object
- * @return true or false
- */
- public boolean equals(Object other)
- {
-
- if (other == null || !(other instanceof GF2mMatrix))
- {
- return false;
- }
-
- GF2mMatrix otherMatrix = (GF2mMatrix)other;
-
- if ((!this.field.equals(otherMatrix.field))
- || (otherMatrix.numRows != this.numColumns)
- || (otherMatrix.numColumns != this.numColumns))
- {
- return false;
- }
-
- for (int i = 0; i < this.numRows; i++)
- {
- for (int j = 0; j < this.numColumns; j++)
- {
- if (this.matrix[i][j] != otherMatrix.matrix[i][j])
- {
- return false;
- }
- }
- }
-
- return true;
- }
-
- public int hashCode()
- {
- int hash = (this.field.hashCode() * 31 + numRows) * 31 + numColumns;
- for (int i = 0; i < this.numRows; i++)
- {
- for (int j = 0; j < this.numColumns; j++)
- {
- hash = hash * 31 + matrix[i][j];
- }
- }
- return hash;
- }
-
- public String toString()
- {
- String str = this.numRows + " x " + this.numColumns + " Matrix over "
- + this.field.toString() + ": \n";
-
- for (int i = 0; i < this.numRows; i++)
- {
- for (int j = 0; j < this.numColumns; j++)
- {
- str = str + this.field.elementToStr(matrix[i][j]) + " : ";
- }
- str = str + "\n";
- }
-
- return str;
- }
-
-}
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