Exemple #1
0
// GenerateDecryptionKeys creates a white-boxed version of AES with given key for decryption, with any non-determinism
// generated by seed. Opts specifies what type of input and output masks we put on the construction and should be in
// common.{IndependentMasks, SameMasks, MatchingMasks}.
func GenerateDecryptionKeys(key, seed []byte, opts common.KeyGenerationOpts) (out Construction, inputMask, outputMask matrix.Matrix) {
	rs := random.NewSource("Chow Decryption", seed)

	constr := saes.Construction{key}
	roundKeys := constr.StretchedKey()

	// Last key needs to be unshifted for decryption to work right.
	constr.UnShiftRows(roundKeys[10])

	skinny := func(pos int) table.Byte {
		return common.InvTBox{constr, 0x00, roundKeys[0][pos]}
	}

	wide := func(round, pos int) table.Word {
		if round == 0 {
			return table.ComposedToWord{
				common.InvTBox{Constr: constr, KeyByte1: roundKeys[10][pos], KeyByte2: roundKeys[9][pos]},
				common.InvTyiTable(pos % 4),
			}
		} else {
			return table.ComposedToWord{
				common.InvTBox{Constr: constr, KeyByte2: roundKeys[9-round][pos]},
				common.InvTyiTable(pos % 4),
			}
		}
	}

	generateKeys(&rs, opts, &out, &inputMask, &outputMask, common.UnShiftRows, skinny, wide)

	return
}
Exemple #2
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// GenerateDecryptionKeys creates a white-boxed version of the AES key `key` for decryption, with any non-determinism
// generated by `seed`.  The `opts` argument works the same as above.
func GenerateDecryptionKeys(key, seed []byte, opts KeyGenerationOpts) (out Construction, inputMask, outputMask matrix.Matrix) {
	constr := saes.Construction{key}
	roundKeys := constr.StretchedKey()

	// Last key needs to be unshifted for decryption to work right.
	constr.UnShiftRows(roundKeys[10])

	skinny := func(pos int) table.Byte {
		return InvTBox{constr, 0x00, roundKeys[0][pos]}
	}

	wide := func(round, pos int) table.Word {
		if round == 0 {
			return table.ComposedToWord{
				InvTBox{constr, roundKeys[10][pos], roundKeys[9][pos]},
				InvTyiTable(pos % 4),
			}
		} else {
			return table.ComposedToWord{
				InvTBox{constr, 0x00, roundKeys[9-round][pos]},
				InvTyiTable(pos % 4),
			}
		}
	}

	generateKeys(seed, opts, &out, &inputMask, &outputMask, unshiftRows, skinny, wide)

	return
}
Exemple #3
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func (sr shiftrows) Decode(in [16]byte) (out [16]byte) {
	constr := saes.Construction{}

	copy(out[:], in[:])
	constr.UnShiftRows(out[:])

	return
}
Exemple #4
0
// GenerateDecryptionKeys creates a white-boxed version of the AES key `key` for decryption, with any non-determinism
// generated by `seed`.
func GenerateDecryptionKeys(key, seed []byte, opts common.KeyGenerationOpts) (out Construction, inputMask, outputMask matrix.Matrix) {
	rs := random.NewSource("Xiao Decryption", seed)

	constr := saes.Construction{key}
	roundKeys := constr.StretchedKey()

	// Apply UnShiftRows to round keys 10.
	constr.UnShiftRows(roundKeys[10])

	hidden := func(round, pos int) table.DoubleToWord {
		if round == 0 {
			return tBoxMixCol{
				[2]table.Byte{
					common.InvTBox{constr, roundKeys[10][pos+0], roundKeys[9][pos+0]},
					common.InvTBox{constr, roundKeys[10][pos+1], roundKeys[9][pos+1]},
				},
				unMixColumns,
				sideFromPos(pos),
			}
		} else if 0 < round && round < 9 {
			return tBoxMixCol{
				[2]table.Byte{
					common.InvTBox{constr, 0x00, roundKeys[9-round][pos+0]},
					common.InvTBox{constr, 0x00, roundKeys[9-round][pos+1]},
				},
				unMixColumns,
				sideFromPos(pos),
			}
		} else {
			return tBox{
				[2]table.Byte{
					common.InvTBox{constr, 0x00, roundKeys[0][pos+0]},
					common.InvTBox{constr, 0x00, roundKeys[0][pos+1]},
				},
				sideFromPos(pos),
			}
		}
	}

	common.GenerateMasks(&rs, opts, &inputMask, &outputMask)
	generateRoundMaterial(&rs, &out, hidden)
	generateBarriers(&rs, &out, &inputMask, &outputMask, &unShiftRows)

	return out, inputMask, outputMask
}