package Ciphers; import java.math.BigInteger; import java.util.Scanner; /** * This class is build to demonstrate the application of the AES-algorithm on a single 128-Bit block * of data. */ public class AES { /** * Precalculated values for x to the power of 2 in Rijndaels galois field. Used as 'RCON' during * the key expansion. */ private static final int[] RCON = { 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d }; /** * Rijndael S-box Substitution table used for encryption in the subBytes step, as well as the key * expansion. */ private static final int[] SBOX = { 0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0, 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75, 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84, 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8, 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73, 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB, 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08, 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E, 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF, 0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16 }; /** * Inverse Rijndael S-box Substitution table used for decryption in the subBytesDec step. */ private static final int[] INVERSE_SBOX = { 0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB, 0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB, 0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E, 0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25, 0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92, 0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84, 0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06, 0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B, 0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73, 0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E, 0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B, 0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4, 0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F, 0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF, 0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61, 0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D }; /** * Precalculated lookup table for galois field multiplication by 2 used in the MixColums step * during encryption. */ private static final int[] MULT2 = { 0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a, 0x1c, 0x1e, 0x20, 0x22, 0x24, 0x26, 0x28, 0x2a, 0x2c, 0x2e, 0x30, 0x32, 0x34, 0x36, 0x38, 0x3a, 0x3c, 0x3e, 0x40, 0x42, 0x44, 0x46, 0x48, 0x4a, 0x4c, 0x4e, 0x50, 0x52, 0x54, 0x56, 0x58, 0x5a, 0x5c, 0x5e, 0x60, 0x62, 0x64, 0x66, 0x68, 0x6a, 0x6c, 0x6e, 0x70, 0x72, 0x74, 0x76, 0x78, 0x7a, 0x7c, 0x7e, 0x80, 0x82, 0x84, 0x86, 0x88, 0x8a, 0x8c, 0x8e, 0x90, 0x92, 0x94, 0x96, 0x98, 0x9a, 0x9c, 0x9e, 0xa0, 0xa2, 0xa4, 0xa6, 0xa8, 0xaa, 0xac, 0xae, 0xb0, 0xb2, 0xb4, 0xb6, 0xb8, 0xba, 0xbc, 0xbe, 0xc0, 0xc2, 0xc4, 0xc6, 0xc8, 0xca, 0xcc, 0xce, 0xd0, 0xd2, 0xd4, 0xd6, 0xd8, 0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xee, 0xf0, 0xf2, 0xf4, 0xf6, 0xf8, 0xfa, 0xfc, 0xfe, 0x1b, 0x19, 0x1f, 0x1d, 0x13, 0x11, 0x17, 0x15, 0x0b, 0x09, 0x0f, 0x0d, 0x03, 0x01, 0x07, 0x05, 0x3b, 0x39, 0x3f, 0x3d, 0x33, 0x31, 0x37, 0x35, 0x2b, 0x29, 0x2f, 0x2d, 0x23, 0x21, 0x27, 0x25, 0x5b, 0x59, 0x5f, 0x5d, 0x53, 0x51, 0x57, 0x55, 0x4b, 0x49, 0x4f, 0x4d, 0x43, 0x41, 0x47, 0x45, 0x7b, 0x79, 0x7f, 0x7d, 0x73, 0x71, 0x77, 0x75, 0x6b, 0x69, 0x6f, 0x6d, 0x63, 0x61, 0x67, 0x65, 0x9b, 0x99, 0x9f, 0x9d, 0x93, 0x91, 0x97, 0x95, 0x8b, 0x89, 0x8f, 0x8d, 0x83, 0x81, 0x87, 0x85, 0xbb, 0xb9, 0xbf, 0xbd, 0xb3, 0xb1, 0xb7, 0xb5, 0xab, 0xa9, 0xaf, 0xad, 0xa3, 0xa1, 0xa7, 0xa5, 0xdb, 0xd9, 0xdf, 0xdd, 0xd3, 0xd1, 0xd7, 0xd5, 0xcb, 0xc9, 0xcf, 0xcd, 0xc3, 0xc1, 0xc7, 0xc5, 0xfb, 0xf9, 0xff, 0xfd, 0xf3, 0xf1, 0xf7, 0xf5, 0xeb, 0xe9, 0xef, 0xed, 0xe3, 0xe1, 0xe7, 0xe5 }; /** * Precalculated lookup table for galois field multiplication by 3 used in the MixColums step * during encryption. */ private static final int[] MULT3 = { 0x00, 0x03, 0x06, 0x05, 0x0c, 0x0f, 0x0a, 0x09, 0x18, 0x1b, 0x1e, 0x1d, 0x14, 0x17, 0x12, 0x11, 0x30, 0x33, 0x36, 0x35, 0x3c, 0x3f, 0x3a, 0x39, 0x28, 0x2b, 0x2e, 0x2d, 0x24, 0x27, 0x22, 0x21, 0x60, 0x63, 0x66, 0x65, 0x6c, 0x6f, 0x6a, 0x69, 0x78, 0x7b, 0x7e, 0x7d, 0x74, 0x77, 0x72, 0x71, 0x50, 0x53, 0x56, 0x55, 0x5c, 0x5f, 0x5a, 0x59, 0x48, 0x4b, 0x4e, 0x4d, 0x44, 0x47, 0x42, 0x41, 0xc0, 0xc3, 0xc6, 0xc5, 0xcc, 0xcf, 0xca, 0xc9, 0xd8, 0xdb, 0xde, 0xdd, 0xd4, 0xd7, 0xd2, 0xd1, 0xf0, 0xf3, 0xf6, 0xf5, 0xfc, 0xff, 0xfa, 0xf9, 0xe8, 0xeb, 0xee, 0xed, 0xe4, 0xe7, 0xe2, 0xe1, 0xa0, 0xa3, 0xa6, 0xa5, 0xac, 0xaf, 0xaa, 0xa9, 0xb8, 0xbb, 0xbe, 0xbd, 0xb4, 0xb7, 0xb2, 0xb1, 0x90, 0x93, 0x96, 0x95, 0x9c, 0x9f, 0x9a, 0x99, 0x88, 0x8b, 0x8e, 0x8d, 0x84, 0x87, 0x82, 0x81, 0x9b, 0x98, 0x9d, 0x9e, 0x97, 0x94, 0x91, 0x92, 0x83, 0x80, 0x85, 0x86, 0x8f, 0x8c, 0x89, 0x8a, 0xab, 0xa8, 0xad, 0xae, 0xa7, 0xa4, 0xa1, 0xa2, 0xb3, 0xb0, 0xb5, 0xb6, 0xbf, 0xbc, 0xb9, 0xba, 0xfb, 0xf8, 0xfd, 0xfe, 0xf7, 0xf4, 0xf1, 0xf2, 0xe3, 0xe0, 0xe5, 0xe6, 0xef, 0xec, 0xe9, 0xea, 0xcb, 0xc8, 0xcd, 0xce, 0xc7, 0xc4, 0xc1, 0xc2, 0xd3, 0xd0, 0xd5, 0xd6, 0xdf, 0xdc, 0xd9, 0xda, 0x5b, 0x58, 0x5d, 0x5e, 0x57, 0x54, 0x51, 0x52, 0x43, 0x40, 0x45, 0x46, 0x4f, 0x4c, 0x49, 0x4a, 0x6b, 0x68, 0x6d, 0x6e, 0x67, 0x64, 0x61, 0x62, 0x73, 0x70, 0x75, 0x76, 0x7f, 0x7c, 0x79, 0x7a, 0x3b, 0x38, 0x3d, 0x3e, 0x37, 0x34, 0x31, 0x32, 0x23, 0x20, 0x25, 0x26, 0x2f, 0x2c, 0x29, 0x2a, 0x0b, 0x08, 0x0d, 0x0e, 0x07, 0x04, 0x01, 0x02, 0x13, 0x10, 0x15, 0x16, 0x1f, 0x1c, 0x19, 0x1a }; /** * Precalculated lookup table for galois field multiplication by 9 used in the MixColums step * during decryption. */ private static final int[] MULT9 = { 0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f, 0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77, 0x90, 0x99, 0x82, 0x8b, 0xb4, 0xbd, 0xa6, 0xaf, 0xd8, 0xd1, 0xca, 0xc3, 0xfc, 0xf5, 0xee, 0xe7, 0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04, 0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c, 0xab, 0xa2, 0xb9, 0xb0, 0x8f, 0x86, 0x9d, 0x94, 0xe3, 0xea, 0xf1, 0xf8, 0xc7, 0xce, 0xd5, 0xdc, 0x76, 0x7f, 0x64, 0x6d, 0x52, 0x5b, 0x40, 0x49, 0x3e, 0x37, 0x2c, 0x25, 0x1a, 0x13, 0x08, 0x01, 0xe6, 0xef, 0xf4, 0xfd, 0xc2, 0xcb, 0xd0, 0xd9, 0xae, 0xa7, 0xbc, 0xb5, 0x8a, 0x83, 0x98, 0x91, 0x4d, 0x44, 0x5f, 0x56, 0x69, 0x60, 0x7b, 0x72, 0x05, 0x0c, 0x17, 0x1e, 0x21, 0x28, 0x33, 0x3a, 0xdd, 0xd4, 0xcf, 0xc6, 0xf9, 0xf0, 0xeb, 0xe2, 0x95, 0x9c, 0x87, 0x8e, 0xb1, 0xb8, 0xa3, 0xaa, 0xec, 0xe5, 0xfe, 0xf7, 0xc8, 0xc1, 0xda, 0xd3, 0xa4, 0xad, 0xb6, 0xbf, 0x80, 0x89, 0x92, 0x9b, 0x7c, 0x75, 0x6e, 0x67, 0x58, 0x51, 0x4a, 0x43, 0x34, 0x3d, 0x26, 0x2f, 0x10, 0x19, 0x02, 0x0b, 0xd7, 0xde, 0xc5, 0xcc, 0xf3, 0xfa, 0xe1, 0xe8, 0x9f, 0x96, 0x8d, 0x84, 0xbb, 0xb2, 0xa9, 0xa0, 0x47, 0x4e, 0x55, 0x5c, 0x63, 0x6a, 0x71, 0x78, 0x0f, 0x06, 0x1d, 0x14, 0x2b, 0x22, 0x39, 0x30, 0x9a, 0x93, 0x88, 0x81, 0xbe, 0xb7, 0xac, 0xa5, 0xd2, 0xdb, 0xc0, 0xc9, 0xf6, 0xff, 0xe4, 0xed, 0x0a, 0x03, 0x18, 0x11, 0x2e, 0x27, 0x3c, 0x35, 0x42, 0x4b, 0x50, 0x59, 0x66, 0x6f, 0x74, 0x7d, 0xa1, 0xa8, 0xb3, 0xba, 0x85, 0x8c, 0x97, 0x9e, 0xe9, 0xe0, 0xfb, 0xf2, 0xcd, 0xc4, 0xdf, 0xd6, 0x31, 0x38, 0x23, 0x2a, 0x15, 0x1c, 0x07, 0x0e, 0x79, 0x70, 0x6b, 0x62, 0x5d, 0x54, 0x4f, 0x46 }; /** * Precalculated lookup table for galois field multiplication by 11 used in the MixColums step * during decryption. */ private static final int[] MULT11 = { 0x00, 0x0b, 0x16, 0x1d, 0x2c, 0x27, 0x3a, 0x31, 0x58, 0x53, 0x4e, 0x45, 0x74, 0x7f, 0x62, 0x69, 0xb0, 0xbb, 0xa6, 0xad, 0x9c, 0x97, 0x8a, 0x81, 0xe8, 0xe3, 0xfe, 0xf5, 0xc4, 0xcf, 0xd2, 0xd9, 0x7b, 0x70, 0x6d, 0x66, 0x57, 0x5c, 0x41, 0x4a, 0x23, 0x28, 0x35, 0x3e, 0x0f, 0x04, 0x19, 0x12, 0xcb, 0xc0, 0xdd, 0xd6, 0xe7, 0xec, 0xf1, 0xfa, 0x93, 0x98, 0x85, 0x8e, 0xbf, 0xb4, 0xa9, 0xa2, 0xf6, 0xfd, 0xe0, 0xeb, 0xda, 0xd1, 0xcc, 0xc7, 0xae, 0xa5, 0xb8, 0xb3, 0x82, 0x89, 0x94, 0x9f, 0x46, 0x4d, 0x50, 0x5b, 0x6a, 0x61, 0x7c, 0x77, 0x1e, 0x15, 0x08, 0x03, 0x32, 0x39, 0x24, 0x2f, 0x8d, 0x86, 0x9b, 0x90, 0xa1, 0xaa, 0xb7, 0xbc, 0xd5, 0xde, 0xc3, 0xc8, 0xf9, 0xf2, 0xef, 0xe4, 0x3d, 0x36, 0x2b, 0x20, 0x11, 0x1a, 0x07, 0x0c, 0x65, 0x6e, 0x73, 0x78, 0x49, 0x42, 0x5f, 0x54, 0xf7, 0xfc, 0xe1, 0xea, 0xdb, 0xd0, 0xcd, 0xc6, 0xaf, 0xa4, 0xb9, 0xb2, 0x83, 0x88, 0x95, 0x9e, 0x47, 0x4c, 0x51, 0x5a, 0x6b, 0x60, 0x7d, 0x76, 0x1f, 0x14, 0x09, 0x02, 0x33, 0x38, 0x25, 0x2e, 0x8c, 0x87, 0x9a, 0x91, 0xa0, 0xab, 0xb6, 0xbd, 0xd4, 0xdf, 0xc2, 0xc9, 0xf8, 0xf3, 0xee, 0xe5, 0x3c, 0x37, 0x2a, 0x21, 0x10, 0x1b, 0x06, 0x0d, 0x64, 0x6f, 0x72, 0x79, 0x48, 0x43, 0x5e, 0x55, 0x01, 0x0a, 0x17, 0x1c, 0x2d, 0x26, 0x3b, 0x30, 0x59, 0x52, 0x4f, 0x44, 0x75, 0x7e, 0x63, 0x68, 0xb1, 0xba, 0xa7, 0xac, 0x9d, 0x96, 0x8b, 0x80, 0xe9, 0xe2, 0xff, 0xf4, 0xc5, 0xce, 0xd3, 0xd8, 0x7a, 0x71, 0x6c, 0x67, 0x56, 0x5d, 0x40, 0x4b, 0x22, 0x29, 0x34, 0x3f, 0x0e, 0x05, 0x18, 0x13, 0xca, 0xc1, 0xdc, 0xd7, 0xe6, 0xed, 0xf0, 0xfb, 0x92, 0x99, 0x84, 0x8f, 0xbe, 0xb5, 0xa8, 0xa3 }; /** * Precalculated lookup table for galois field multiplication by 13 used in the MixColums step * during decryption. */ private static final int[] MULT13 = { 0x00, 0x0d, 0x1a, 0x17, 0x34, 0x39, 0x2e, 0x23, 0x68, 0x65, 0x72, 0x7f, 0x5c, 0x51, 0x46, 0x4b, 0xd0, 0xdd, 0xca, 0xc7, 0xe4, 0xe9, 0xfe, 0xf3, 0xb8, 0xb5, 0xa2, 0xaf, 0x8c, 0x81, 0x96, 0x9b, 0xbb, 0xb6, 0xa1, 0xac, 0x8f, 0x82, 0x95, 0x98, 0xd3, 0xde, 0xc9, 0xc4, 0xe7, 0xea, 0xfd, 0xf0, 0x6b, 0x66, 0x71, 0x7c, 0x5f, 0x52, 0x45, 0x48, 0x03, 0x0e, 0x19, 0x14, 0x37, 0x3a, 0x2d, 0x20, 0x6d, 0x60, 0x77, 0x7a, 0x59, 0x54, 0x43, 0x4e, 0x05, 0x08, 0x1f, 0x12, 0x31, 0x3c, 0x2b, 0x26, 0xbd, 0xb0, 0xa7, 0xaa, 0x89, 0x84, 0x93, 0x9e, 0xd5, 0xd8, 0xcf, 0xc2, 0xe1, 0xec, 0xfb, 0xf6, 0xd6, 0xdb, 0xcc, 0xc1, 0xe2, 0xef, 0xf8, 0xf5, 0xbe, 0xb3, 0xa4, 0xa9, 0x8a, 0x87, 0x90, 0x9d, 0x06, 0x0b, 0x1c, 0x11, 0x32, 0x3f, 0x28, 0x25, 0x6e, 0x63, 0x74, 0x79, 0x5a, 0x57, 0x40, 0x4d, 0xda, 0xd7, 0xc0, 0xcd, 0xee, 0xe3, 0xf4, 0xf9, 0xb2, 0xbf, 0xa8, 0xa5, 0x86, 0x8b, 0x9c, 0x91, 0x0a, 0x07, 0x10, 0x1d, 0x3e, 0x33, 0x24, 0x29, 0x62, 0x6f, 0x78, 0x75, 0x56, 0x5b, 0x4c, 0x41, 0x61, 0x6c, 0x7b, 0x76, 0x55, 0x58, 0x4f, 0x42, 0x09, 0x04, 0x13, 0x1e, 0x3d, 0x30, 0x27, 0x2a, 0xb1, 0xbc, 0xab, 0xa6, 0x85, 0x88, 0x9f, 0x92, 0xd9, 0xd4, 0xc3, 0xce, 0xed, 0xe0, 0xf7, 0xfa, 0xb7, 0xba, 0xad, 0xa0, 0x83, 0x8e, 0x99, 0x94, 0xdf, 0xd2, 0xc5, 0xc8, 0xeb, 0xe6, 0xf1, 0xfc, 0x67, 0x6a, 0x7d, 0x70, 0x53, 0x5e, 0x49, 0x44, 0x0f, 0x02, 0x15, 0x18, 0x3b, 0x36, 0x21, 0x2c, 0x0c, 0x01, 0x16, 0x1b, 0x38, 0x35, 0x22, 0x2f, 0x64, 0x69, 0x7e, 0x73, 0x50, 0x5d, 0x4a, 0x47, 0xdc, 0xd1, 0xc6, 0xcb, 0xe8, 0xe5, 0xf2, 0xff, 0xb4, 0xb9, 0xae, 0xa3, 0x80, 0x8d, 0x9a, 0x97 }; /** * Precalculated lookup table for galois field multiplication by 14 used in the MixColums step * during decryption. */ private static final int[] MULT14 = { 0x00, 0x0e, 0x1c, 0x12, 0x38, 0x36, 0x24, 0x2a, 0x70, 0x7e, 0x6c, 0x62, 0x48, 0x46, 0x54, 0x5a, 0xe0, 0xee, 0xfc, 0xf2, 0xd8, 0xd6, 0xc4, 0xca, 0x90, 0x9e, 0x8c, 0x82, 0xa8, 0xa6, 0xb4, 0xba, 0xdb, 0xd5, 0xc7, 0xc9, 0xe3, 0xed, 0xff, 0xf1, 0xab, 0xa5, 0xb7, 0xb9, 0x93, 0x9d, 0x8f, 0x81, 0x3b, 0x35, 0x27, 0x29, 0x03, 0x0d, 0x1f, 0x11, 0x4b, 0x45, 0x57, 0x59, 0x73, 0x7d, 0x6f, 0x61, 0xad, 0xa3, 0xb1, 0xbf, 0x95, 0x9b, 0x89, 0x87, 0xdd, 0xd3, 0xc1, 0xcf, 0xe5, 0xeb, 0xf9, 0xf7, 0x4d, 0x43, 0x51, 0x5f, 0x75, 0x7b, 0x69, 0x67, 0x3d, 0x33, 0x21, 0x2f, 0x05, 0x0b, 0x19, 0x17, 0x76, 0x78, 0x6a, 0x64, 0x4e, 0x40, 0x52, 0x5c, 0x06, 0x08, 0x1a, 0x14, 0x3e, 0x30, 0x22, 0x2c, 0x96, 0x98, 0x8a, 0x84, 0xae, 0xa0, 0xb2, 0xbc, 0xe6, 0xe8, 0xfa, 0xf4, 0xde, 0xd0, 0xc2, 0xcc, 0x41, 0x4f, 0x5d, 0x53, 0x79, 0x77, 0x65, 0x6b, 0x31, 0x3f, 0x2d, 0x23, 0x09, 0x07, 0x15, 0x1b, 0xa1, 0xaf, 0xbd, 0xb3, 0x99, 0x97, 0x85, 0x8b, 0xd1, 0xdf, 0xcd, 0xc3, 0xe9, 0xe7, 0xf5, 0xfb, 0x9a, 0x94, 0x86, 0x88, 0xa2, 0xac, 0xbe, 0xb0, 0xea, 0xe4, 0xf6, 0xf8, 0xd2, 0xdc, 0xce, 0xc0, 0x7a, 0x74, 0x66, 0x68, 0x42, 0x4c, 0x5e, 0x50, 0x0a, 0x04, 0x16, 0x18, 0x32, 0x3c, 0x2e, 0x20, 0xec, 0xe2, 0xf0, 0xfe, 0xd4, 0xda, 0xc8, 0xc6, 0x9c, 0x92, 0x80, 0x8e, 0xa4, 0xaa, 0xb8, 0xb6, 0x0c, 0x02, 0x10, 0x1e, 0x34, 0x3a, 0x28, 0x26, 0x7c, 0x72, 0x60, 0x6e, 0x44, 0x4a, 0x58, 0x56, 0x37, 0x39, 0x2b, 0x25, 0x0f, 0x01, 0x13, 0x1d, 0x47, 0x49, 0x5b, 0x55, 0x7f, 0x71, 0x63, 0x6d, 0xd7, 0xd9, 0xcb, 0xc5, 0xef, 0xe1, 0xf3, 0xfd, 0xa7, 0xa9, 0xbb, 0xb5, 0x9f, 0x91, 0x83, 0x8d }; /** * Subroutine of the Rijndael key expansion. */ public static BigInteger scheduleCore(BigInteger t, int rconCounter) { StringBuilder rBytes = new StringBuilder(t.toString(16)); // Add zero padding while (rBytes.length() < 8) { rBytes.insert(0, "0"); } // rotate the first 16 bits to the back String rotatingBytes = rBytes.substring(0, 2); String fixedBytes = rBytes.substring(2); rBytes = new StringBuilder(fixedBytes + rotatingBytes); // apply S-Box to all 8-Bit Substrings for (int i = 0; i < 4; i++) { StringBuilder currentByteBits = new StringBuilder(rBytes.substring(i * 2, (i + 1) * 2)); int currentByte = Integer.parseInt(currentByteBits.toString(), 16); currentByte = SBOX[currentByte]; // add the current RCON value to the first byte if (i == 0) { currentByte = currentByte ^ RCON[rconCounter]; } currentByteBits = new StringBuilder(Integer.toHexString(currentByte)); // Add zero padding while (currentByteBits.length() < 2) { currentByteBits.insert(0, '0'); } // replace bytes in original string rBytes = new StringBuilder(rBytes.substring(0, i * 2) + currentByteBits + rBytes.substring((i + 1) * 2)); } // t = new BigInteger(rBytes, 16); // return t; return new BigInteger(rBytes.toString(), 16); } /** * Returns an array of 10 + 1 round keys that are calculated by using Rijndael key schedule * * @return array of 10 + 1 round keys */ public static BigInteger[] keyExpansion(BigInteger initialKey) { BigInteger[] roundKeys = { initialKey, new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), new BigInteger("0"), }; // initialize rcon iteration int rconCounter = 1; for (int i = 1; i < 11; i++) { // get the previous 32 bits the key BigInteger t = roundKeys[i - 1].remainder(new BigInteger("100000000", 16)); // split previous key into 8-bit segments BigInteger[] prevKey = { roundKeys[i - 1].remainder(new BigInteger("100000000", 16)), roundKeys[i - 1] .remainder(new BigInteger("10000000000000000", 16)) .divide(new BigInteger("100000000", 16)), roundKeys[i - 1] .remainder(new BigInteger("1000000000000000000000000", 16)) .divide(new BigInteger("10000000000000000", 16)), roundKeys[i - 1].divide(new BigInteger("1000000000000000000000000", 16)), }; // run schedule core t = scheduleCore(t, rconCounter); rconCounter += 1; // Calculate partial round key BigInteger t0 = t.xor(prevKey[3]); BigInteger t1 = t0.xor(prevKey[2]); BigInteger t2 = t1.xor(prevKey[1]); BigInteger t3 = t2.xor(prevKey[0]); // Join round key segments t2 = t2.multiply(new BigInteger("100000000", 16)); t1 = t1.multiply(new BigInteger("10000000000000000", 16)); t0 = t0.multiply(new BigInteger("1000000000000000000000000", 16)); roundKeys[i] = t0.add(t1).add(t2).add(t3); } return roundKeys; } /** * representation of the input 128-bit block as an array of 8-bit integers. * * @param block of 128-bit integers * @return array of 8-bit integers */ public static int[] splitBlockIntoCells(BigInteger block) { int[] cells = new int[16]; StringBuilder blockBits = new StringBuilder(block.toString(2)); // Append leading 0 for full "128-bit" string while (blockBits.length() < 128) { blockBits.insert(0, '0'); } // split 128 to 8 bit cells for (int i = 0; i < cells.length; i++) { String cellBits = blockBits.substring(8 * i, 8 * (i + 1)); cells[i] = Integer.parseInt(cellBits, 2); } return cells; } /** * Returns the 128-bit BigInteger representation of the input of an array of 8-bit integers. * * @param cells that we need to merge * @return block of merged cells */ public static BigInteger mergeCellsIntoBlock(int[] cells) { StringBuilder blockBits = new StringBuilder(); for (int i = 0; i < 16; i++) { StringBuilder cellBits = new StringBuilder(Integer.toBinaryString(cells[i])); // Append leading 0 for full "8-bit" strings while (cellBits.length() < 8) { cellBits.insert(0, '0'); } blockBits.append(cellBits); } return new BigInteger(blockBits.toString(), 2); } /** * @return ciphertext XOR key */ public static BigInteger addRoundKey(BigInteger ciphertext, BigInteger key) { return ciphertext.xor(key); } /** * substitutes 8-Bit long substrings of the input using the S-Box and returns the result. * * @return subtraction Output */ public static BigInteger subBytes(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); for (int i = 0; i < 16; i++) { cells[i] = SBOX[cells[i]]; } return mergeCellsIntoBlock(cells); } /** * substitutes 8-Bit long substrings of the input using the inverse S-Box for decryption and * returns the result. * * @return subtraction Output */ public static BigInteger subBytesDec(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); for (int i = 0; i < 16; i++) { cells[i] = INVERSE_SBOX[cells[i]]; } return mergeCellsIntoBlock(cells); } /** * Cell permutation step. Shifts cells within the rows of the input and returns the result. */ public static BigInteger shiftRows(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); int[] output = new int[16]; // do nothing in the first row output[0] = cells[0]; output[4] = cells[4]; output[8] = cells[8]; output[12] = cells[12]; // shift the second row backwards by one cell output[1] = cells[5]; output[5] = cells[9]; output[9] = cells[13]; output[13] = cells[1]; // shift the third row backwards by two cell output[2] = cells[10]; output[6] = cells[14]; output[10] = cells[2]; output[14] = cells[6]; // shift the forth row backwards by tree cell output[3] = cells[15]; output[7] = cells[3]; output[11] = cells[7]; output[15] = cells[11]; return mergeCellsIntoBlock(output); } /** * Cell permutation step for decryption . Shifts cells within the rows of the input and returns * the result. */ public static BigInteger shiftRowsDec(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); int[] output = new int[16]; // do nothing in the first row output[0] = cells[0]; output[4] = cells[4]; output[8] = cells[8]; output[12] = cells[12]; // shift the second row forwards by one cell output[1] = cells[13]; output[5] = cells[1]; output[9] = cells[5]; output[13] = cells[9]; // shift the third row forwards by two cell output[2] = cells[10]; output[6] = cells[14]; output[10] = cells[2]; output[14] = cells[6]; // shift the forth row forwards by tree cell output[3] = cells[7]; output[7] = cells[11]; output[11] = cells[15]; output[15] = cells[3]; return mergeCellsIntoBlock(output); } /** * Applies the Rijndael MixColumns to the input and returns the result. */ public static BigInteger mixColumns(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); int[] outputCells = new int[16]; for (int i = 0; i < 4; i++) { int[] row = {cells[i * 4], cells[i * 4 + 1], cells[i * 4 + 2], cells[i * 4 + 3]}; outputCells[i * 4] = MULT2[row[0]] ^ MULT3[row[1]] ^ row[2] ^ row[3]; outputCells[i * 4 + 1] = row[0] ^ MULT2[row[1]] ^ MULT3[row[2]] ^ row[3]; outputCells[i * 4 + 2] = row[0] ^ row[1] ^ MULT2[row[2]] ^ MULT3[row[3]]; outputCells[i * 4 + 3] = MULT3[row[0]] ^ row[1] ^ row[2] ^ MULT2[row[3]]; } return mergeCellsIntoBlock(outputCells); } /** * Applies the inverse Rijndael MixColumns for decryption to the input and returns the result. */ public static BigInteger mixColumnsDec(BigInteger ciphertext) { int[] cells = splitBlockIntoCells(ciphertext); int[] outputCells = new int[16]; for (int i = 0; i < 4; i++) { int[] row = {cells[i * 4], cells[i * 4 + 1], cells[i * 4 + 2], cells[i * 4 + 3]}; outputCells[i * 4] = MULT14[row[0]] ^ MULT11[row[1]] ^ MULT13[row[2]] ^ MULT9[row[3]]; outputCells[i * 4 + 1] = MULT9[row[0]] ^ MULT14[row[1]] ^ MULT11[row[2]] ^ MULT13[row[3]]; outputCells[i * 4 + 2] = MULT13[row[0]] ^ MULT9[row[1]] ^ MULT14[row[2]] ^ MULT11[row[3]]; outputCells[i * 4 + 3] = MULT11[row[0]] ^ MULT13[row[1]] ^ MULT9[row[2]] ^ MULT14[row[3]]; } return mergeCellsIntoBlock(outputCells); } /** * Encrypts the plaintext with the key and returns the result * * @param plainText which we want to encrypt * @param key the key for encrypt * @return EncryptedText */ public static BigInteger encrypt(BigInteger plainText, BigInteger key) { BigInteger[] roundKeys = keyExpansion(key); // Initial round plainText = addRoundKey(plainText, roundKeys[0]); // Main rounds for (int i = 1; i < 10; i++) { plainText = subBytes(plainText); plainText = shiftRows(plainText); plainText = mixColumns(plainText); plainText = addRoundKey(plainText, roundKeys[i]); } // Final round plainText = subBytes(plainText); plainText = shiftRows(plainText); plainText = addRoundKey(plainText, roundKeys[10]); return plainText; } /** * Decrypts the ciphertext with the key and returns the result * * @param cipherText The Encrypted text which we want to decrypt * @return decryptedText */ public static BigInteger decrypt(BigInteger cipherText, BigInteger key) { BigInteger[] roundKeys = keyExpansion(key); // Invert final round cipherText = addRoundKey(cipherText, roundKeys[10]); cipherText = shiftRowsDec(cipherText); cipherText = subBytesDec(cipherText); // Invert main rounds for (int i = 9; i > 0; i--) { cipherText = addRoundKey(cipherText, roundKeys[i]); cipherText = mixColumnsDec(cipherText); cipherText = shiftRowsDec(cipherText); cipherText = subBytesDec(cipherText); } // Invert initial round cipherText = addRoundKey(cipherText, roundKeys[0]); return cipherText; } public static void main(String[] args) { try (Scanner input = new Scanner(System.in)) { System.out.println("Enter (e) letter for encrpyt or (d) letter for decrypt :"); char choice = input.nextLine().charAt(0); String in; switch (choice) { case 'E', 'e' -> { System.out.println("Choose a plaintext block (128-Bit Integer in base 16):"); in = input.nextLine(); BigInteger plaintext = new BigInteger(in, 16); System.out.println("Choose a Key (128-Bit Integer in base 16):"); in = input.nextLine(); BigInteger encryptionKey = new BigInteger(in, 16); System.out.println( "The encrypted message is: \n" + encrypt(plaintext, encryptionKey).toString(16)); } case 'D', 'd' -> { System.out.println("Enter your ciphertext block (128-Bit Integer in base 16):"); in = input.nextLine(); BigInteger ciphertext = new BigInteger(in, 16); System.out.println("Choose a Key (128-Bit Integer in base 16):"); in = input.nextLine(); BigInteger decryptionKey = new BigInteger(in, 16); System.out.println( "The deciphered message is:\n" + decrypt(ciphertext, decryptionKey).toString(16)); } default -> System.out.println("** End **"); } } } }