diff options
Diffstat (limited to 'core/src/main/java/org/spongycastle/crypto/modes/gcm/GCMUtil.java')
| -rw-r--r-- | core/src/main/java/org/spongycastle/crypto/modes/gcm/GCMUtil.java | 457 |
1 files changed, 457 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/modes/gcm/GCMUtil.java b/core/src/main/java/org/spongycastle/crypto/modes/gcm/GCMUtil.java new file mode 100644 index 00000000..77be4b87 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/modes/gcm/GCMUtil.java @@ -0,0 +1,457 @@ +package org.spongycastle.crypto.modes.gcm; + +import org.spongycastle.util.Arrays; +import org.spongycastle.util.Pack; + +abstract class GCMUtil +{ + private static final int E1 = 0xe1000000; + private static final byte E1B = (byte)0xe1; + private static final long E1L = (E1 & 0xFFFFFFFFL) << 24; + + private static int[] generateLookup() + { + int[] lookup = new int[256]; + + for (int c = 0; c < 256; ++c) + { + int v = 0; + for (int i = 7; i >= 0; --i) + { + if ((c & (1 << i)) != 0) + { + v ^= (E1 >>> (7 - i)); + } + } + lookup[c] = v; + } + + return lookup; + } + + private static final int[] LOOKUP = generateLookup(); + + static byte[] oneAsBytes() + { + byte[] tmp = new byte[16]; + tmp[0] = (byte)0x80; + return tmp; + } + + static int[] oneAsInts() + { + int[] tmp = new int[4]; + tmp[0] = 1 << 31; + return tmp; + } + + static long[] oneAsLongs() + { + long[] tmp = new long[2]; + tmp[0] = 1L << 63; + return tmp; + } + + static byte[] asBytes(int[] x) + { + byte[] z = new byte[16]; + Pack.intToBigEndian(x, z, 0); + return z; + } + + static void asBytes(int[] x, byte[] z) + { + Pack.intToBigEndian(x, z, 0); + } + + static byte[] asBytes(long[] x) + { + byte[] z = new byte[16]; + Pack.longToBigEndian(x, z, 0); + return z; + } + + static void asBytes(long[] x, byte[] z) + { + Pack.longToBigEndian(x, z, 0); + } + + static int[] asInts(byte[] x) + { + int[] z = new int[4]; + Pack.bigEndianToInt(x, 0, z); + return z; + } + + static void asInts(byte[] x, int[] z) + { + Pack.bigEndianToInt(x, 0, z); + } + + static long[] asLongs(byte[] x) + { + long[] z = new long[2]; + Pack.bigEndianToLong(x, 0, z); + return z; + } + + static void asLongs(byte[] x, long[] z) + { + Pack.bigEndianToLong(x, 0, z); + } + + static void multiply(byte[] x, byte[] y) + { + byte[] r0 = Arrays.clone(x); + byte[] r1 = new byte[16]; + + for (int i = 0; i < 16; ++i) + { + byte bits = y[i]; + for (int j = 7; j >= 0; --j) + { + if ((bits & (1 << j)) != 0) + { + xor(r1, r0); + } + + if (shiftRight(r0) != 0) + { + r0[0] ^= E1B; + } + } + } + + System.arraycopy(r1, 0, x, 0, 16); + } + + static void multiply(int[] x, int[] y) + { + int[] r0 = Arrays.clone(x); + int[] r1 = new int[4]; + + for (int i = 0; i < 4; ++i) + { + int bits = y[i]; + for (int j = 31; j >= 0; --j) + { + if ((bits & (1 << j)) != 0) + { + xor(r1, r0); + } + + if (shiftRight(r0) != 0) + { + r0[0] ^= E1; + } + } + } + + System.arraycopy(r1, 0, x, 0, 4); + } + + static void multiply(long[] x, long[] y) + { + long[] r0 = new long[]{ x[0], x[1] }; + long[] r1 = new long[2]; + + for (int i = 0; i < 2; ++i) + { + long bits = y[i]; + for (int j = 63; j >= 0; --j) + { + if ((bits & (1L << j)) != 0) + { + xor(r1, r0); + } + + if (shiftRight(r0) != 0) + { + r0[0] ^= E1L; + } + } + } + + x[0] = r1[0]; + x[1] = r1[1]; + } + + // P is the value with only bit i=1 set + static void multiplyP(int[] x) + { + if (shiftRight(x) != 0) + { + x[0] ^= E1; + } + } + + static void multiplyP(int[] x, int[] y) + { + if (shiftRight(x, y) != 0) + { + y[0] ^= E1; + } + } + + // P is the value with only bit i=1 set + static void multiplyP8(int[] x) + { +// for (int i = 8; i != 0; --i) +// { +// multiplyP(x); +// } + + int c = shiftRightN(x, 8); + x[0] ^= LOOKUP[c >>> 24]; + } + + static void multiplyP8(int[] x, int[] y) + { + int c = shiftRightN(x, 8, y); + y[0] ^= LOOKUP[c >>> 24]; + } + + static byte shiftRight(byte[] x) + { +// int c = 0; +// for (int i = 0; i < 16; ++i) +// { +// int b = x[i] & 0xff; +// x[i] = (byte)((b >>> 1) | c); +// c = (b & 1) << 7; +// } +// return (byte)c; + + int i = 0, c = 0; + do + { + int b = x[i] & 0xff; + x[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + x[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + x[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + x[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + } + while (i < 16); + return (byte)c; + } + + static byte shiftRight(byte[] x, byte[] z) + { +// int c = 0; +// for (int i = 0; i < 16; ++i) +// { +// int b = x[i] & 0xff; +// z[i] = (byte) ((b >>> 1) | c); +// c = (b & 1) << 7; +// } +// return (byte) c; + + int i = 0, c = 0; + do + { + int b = x[i] & 0xff; + z[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + z[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + z[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + b = x[i] & 0xff; + z[i++] = (byte)((b >>> 1) | c); + c = (b & 1) << 7; + } + while (i < 16); + return (byte)c; + } + + static int shiftRight(int[] x) + { +// int c = 0; +// for (int i = 0; i < 4; ++i) +// { +// int b = x[i]; +// x[i] = (b >>> 1) | c; +// c = b << 31; +// } +// return c; + + int b = x[0]; + x[0] = b >>> 1; + int c = b << 31; + b = x[1]; + x[1] = (b >>> 1) | c; + c = b << 31; + b = x[2]; + x[2] = (b >>> 1) | c; + c = b << 31; + b = x[3]; + x[3] = (b >>> 1) | c; + return b << 31; + } + + static int shiftRight(int[] x, int[] z) + { +// int c = 0; +// for (int i = 0; i < 4; ++i) +// { +// int b = x[i]; +// z[i] = (b >>> 1) | c; +// c = b << 31; +// } +// return c; + + int b = x[0]; + z[0] = b >>> 1; + int c = b << 31; + b = x[1]; + z[1] = (b >>> 1) | c; + c = b << 31; + b = x[2]; + z[2] = (b >>> 1) | c; + c = b << 31; + b = x[3]; + z[3] = (b >>> 1) | c; + return b << 31; + } + + static long shiftRight(long[] x) + { + long b = x[0]; + x[0] = b >>> 1; + long c = b << 63; + b = x[1]; + x[1] = (b >>> 1) | c; + return b << 63; + } + + static long shiftRight(long[] x, long[] z) + { + long b = x[0]; + z[0] = b >>> 1; + long c = b << 63; + b = x[1]; + z[1] = (b >>> 1) | c; + return b << 63; + } + + static int shiftRightN(int[] x, int n) + { +// int c = 0, nInv = 32 - n; +// for (int i = 0; i < 4; ++i) +// { +// int b = x[i]; +// x[i] = (b >>> n) | c; +// c = b << nInv; +// } +// return c; + + int b = x[0], nInv = 32 - n; + x[0] = b >>> n; + int c = b << nInv; + b = x[1]; + x[1] = (b >>> n) | c; + c = b << nInv; + b = x[2]; + x[2] = (b >>> n) | c; + c = b << nInv; + b = x[3]; + x[3] = (b >>> n) | c; + return b << nInv; + } + + static int shiftRightN(int[] x, int n, int[] z) + { +// int c = 0, nInv = 32 - n; +// for (int i = 0; i < 4; ++i) +// { +// int b = x[i]; +// z[i] = (b >>> n) | c; +// c = b << nInv; +// } +// return c; + + int b = x[0], nInv = 32 - n; + z[0] = b >>> n; + int c = b << nInv; + b = x[1]; + z[1] = (b >>> n) | c; + c = b << nInv; + b = x[2]; + z[2] = (b >>> n) | c; + c = b << nInv; + b = x[3]; + z[3] = (b >>> n) | c; + return b << nInv; + } + + static void xor(byte[] x, byte[] y) + { + int i = 0; + do + { + x[i] ^= y[i]; ++i; + x[i] ^= y[i]; ++i; + x[i] ^= y[i]; ++i; + x[i] ^= y[i]; ++i; + } + while (i < 16); + } + + static void xor(byte[] x, byte[] y, int yOff, int yLen) + { + while (yLen-- > 0) + { + x[yLen] ^= y[yOff + yLen]; + } + } + + static void xor(byte[] x, byte[] y, byte[] z) + { + int i = 0; + do + { + z[i] = (byte)(x[i] ^ y[i]); ++i; + z[i] = (byte)(x[i] ^ y[i]); ++i; + z[i] = (byte)(x[i] ^ y[i]); ++i; + z[i] = (byte)(x[i] ^ y[i]); ++i; + } + while (i < 16); + } + + static void xor(int[] x, int[] y) + { + x[0] ^= y[0]; + x[1] ^= y[1]; + x[2] ^= y[2]; + x[3] ^= y[3]; + } + + static void xor(int[] x, int[] y, int[] z) + { + z[0] = x[0] ^ y[0]; + z[1] = x[1] ^ y[1]; + z[2] = x[2] ^ y[2]; + z[3] = x[3] ^ y[3]; + } + + static void xor(long[] x, long[] y) + { + x[0] ^= y[0]; + x[1] ^= y[1]; + } + + static void xor(long[] x, long[] y, long[] z) + { + z[0] = x[0] ^ y[0]; + z[1] = x[1] ^ y[1]; + } +} |