-- AES implementation
-- By KillaVanilla
-- Made require-able by hugeblank

local out = {}

local sbox = {
[0]=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}

local inv_sbox = {
[0]=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}

local Rcon = {
[0]=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}

-- Finite-field multiplication lookup tables:

local mul_2 = {
[0]=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,
}

local mul_3 = {
[0]=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,
}

local mul_9 = {
[0]=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,
}

local mul_11 = {
[0]=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,
}

local mul_13 = {
[0]=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,
}

local mul_14 = {
[0]=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,
}

local bxor = bit.bxor
local insert = table.insert

local function copy(input)
	local c = {}
	for i, v in pairs(input) do
		c[i] = v
	end
	return c
end

local function subBytes(input, invert)
	for i=1, #input do
		if not (sbox[input[i]] and inv_sbox[input[i]]) then
			error("subBytes: input["..i.."] > 0xFF")
		end
		if invert then
			input[i] = inv_sbox[input[i]]
		else
			input[i] = sbox[input[i]]
		end
	end
	return input
end

local function shiftRows(input)
	local copy = {}
	-- Row 1: No change
	copy[1] = input[1]
	copy[2] = input[2]
	copy[3] = input[3]
	copy[4] = input[4]
	-- Row 2: Offset 1
	copy[5] = input[6]
	copy[6] = input[7]
	copy[7] = input[8]
	copy[8] = input[5]
	-- Row 3: Offset 2
	copy[9] = input[11]
	copy[10] = input[12]
	copy[11] = input[9]
	copy[12] = input[10]
	-- Row 4: Offset 3
	copy[13] = input[16]
	copy[14] = input[13]
	copy[15] = input[14]
	copy[16] = input[15]
	return copy
end

local function invShiftRows(input)
	local copy = {}
	-- Row 1: No change
	copy[1] = input[1]
	copy[2] = input[2]
	copy[3] = input[3]
	copy[4] = input[4]
	-- Row 2: Offset 1
	copy[5] = input[8]
	copy[6] = input[5]
	copy[7] = input[6]
	copy[8] = input[7]
	-- Row 3: Offset 2
	copy[9] = input[11]
	copy[10] = input[12]
	copy[11] = input[9]
	copy[12] = input[10]
	-- Row 4: Offset 3
	copy[13] = input[14]
	copy[14] = input[15]
	copy[15] = input[16]
	copy[16] = input[13]
	return copy
end

local function finite_field_mul(a,b) -- Multiply two numbers in GF(256), assuming that polynomials are 8 bits wide
	local product = 0
	local mulA, mulB = a,b
	for i=1, 8 do
		--print("FFMul: MulA: "..mulA.." MulB: "..mulB)
		if mulA == 0 or mulB == 0 then
			break
		end
		if bit.band(1, mulB) > 0 then
			product = bxor(product, mulA)
		end
		mulB = bit.brshift(mulB, 1)
		local carry = bit.band(0x80, mulA)
		mulA = bit.band(0xFF, bit.blshift(mulA, 1))
		if carry > 0 then
			mulA = bxor( mulA, 0x1B )
		end
	end
	return product
end

local function mixColumn(column)
	local output = {}
	--print("MixColumn: #column: "..#column)
	output[1] = bxor( mul_2[column[1]], bxor( mul_3[column[2]], bxor( column[3], column[4] ) ) )
	output[2] = bxor( column[1], bxor( mul_2[column[2]], bxor( mul_3[column[3]], column[4] ) ) )
	output[3] = bxor( column[1], bxor( column[2], bxor( mul_2[column[3]], mul_3[column[4]] ) ) )
	output[4] = bxor( mul_3[column[1]], bxor( column[2], bxor( column[3], mul_2[column[4]] ) ) )
	return output
end

local function invMixColumn(column)
	local output = {}
	--print("InvMixColumn: #column: "..#column)
	output[1] = bxor( mul_14[column[1]], bxor( mul_11[column[2]], bxor( mul_13[column[3]], mul_9[column[4]] ) ) )
	output[2] = bxor( mul_9[column[1]], bxor( mul_14[column[2]], bxor( mul_11[column[3]], mul_13[column[4]] ) ) )
	output[3] = bxor( mul_13[column[1]], bxor( mul_9[column[2]], bxor( mul_14[column[3]], mul_11[column[4]] ) ) )
	output[4] = bxor( mul_11[column[1]], bxor( mul_13[column[2]], bxor( mul_9[column[3]], mul_14[column[4]] ) ) )
	return output
end

local function mixColumns(input, invert)
	--print("MixColumns: #input: "..#input)
	-- Ooops. I mixed the ROWS instead of the COLUMNS on accident.
	local output = {}
	--[[
	local c1 = { input[1], input[2], input[3], input[4] }
	local c2 = { input[5], input[6], input[7], input[8] }
	local c3 = { input[9], input[10], input[11], input[12] }
	local c4 = { input[13], input[14], input[15], input[16] }
	]]
	local c1 = { input[1], input[5], input[9], input[13] }
	local c2 = { input[2], input[6], input[10], input[14] }
	local c3 = { input[3], input[7], input[11], input[15] }
	local c4 = { input[4], input[8], input[12], input[16] }
	if invert then
		c1 = invMixColumn(c1)
		c2 = invMixColumn(c2)
		c3 = invMixColumn(c3)
		c4 = invMixColumn(c4)
	else
		c1 = mixColumn(c1)
		c2 = mixColumn(c2)
		c3 = mixColumn(c3)
		c4 = mixColumn(c4)
	end
	--[[
	output[1] = c1[1]
	output[2] = c1[2]
	output[3] = c1[3]
	output[4] = c1[4]
	
	output[5] = c2[1]
	output[6] = c2[2]
	output[7] = c2[3]
	output[8] = c2[4]
	
	output[9] = c3[1]
	output[10] = c3[2]
	output[11] = c3[3]
	output[12] = c3[4]
	
	output[13] = c4[1]
	output[14] = c4[2]
	output[15] = c4[3]
	output[16] = c4[4]
	]]
	
	output[1] = c1[1]
	output[5] = c1[2]
	output[9] = c1[3]
	output[13] = c1[4]
	
	output[2] = c2[1]
	output[6] = c2[2]
	output[10] = c2[3]
	output[14] = c2[4]
	
	output[3] = c3[1]
	output[7] = c3[2]
	output[11] = c3[3]
	output[15] = c3[4]
	
	output[4] = c4[1]
	output[8] = c4[2]
	output[12] = c4[3]
	output[16] = c4[4]
	
	return output
end

local function addRoundKey(input, exp_key, round)
	local output = {}
	for i=1, 16 do
		assert(input[i], "input["..i.."]=nil!")
		assert(exp_key[ ((round-1)*16)+i ], "round_key["..(((round-1)*16)+i).."]=nil!")
		output[i] = bxor( input[i], exp_key[ ((round-1)*16)+i ] )
	end
	return output
end

out.key_schedule = function(enc_key)
	local function core(in1, in2, in3, in4, i)
		local s1 = in2
		local s2 = in3
		local s3 = in4
		local s4 = in1
		s1 = bxor(sbox[s1], Rcon[i])
		s2 = sbox[s2]
		s3 = sbox[s3]
		s4 = sbox[s4]
		return s1, s2, s3, s4
	end
	
	local n, b, key_type = 0, 0, 0
	
	-- Len | n | b |
	-- 128 |16 |176|
	-- 192 |24 |208|
	-- 256 |32 |240|
	
	-- Determine keysize:
	
	if #enc_key < 16 then
		error("Encryption key is too small; key size must be more than 16 bytes.")
	elseif #enc_key >= 16 and #enc_key < 24 then
		n = 16
		b = 176
		--key_type = 1
	elseif #enc_key >= 24 and #enc_key < 32 then
		n = 24
		b = 208
		--key_type = 2
	else
		n = 32
		b = 240
		--key_type = 3
	end
	
	local exp_key = {}
	local rcon_iter = 1
	for i=1, n do
		exp_key[i] = enc_key[i]
	end
	while #exp_key < b do
		local t1 = exp_key[#exp_key]
		local t2 = exp_key[#exp_key-1]
		local t3 = exp_key[#exp_key-2]
		local t4 = exp_key[#exp_key-3]
		t1, t2, t3, t4 = core(t1, t2, t3, t4, rcon_iter)
		rcon_iter = rcon_iter+1
		t1 = bxor(t1, exp_key[#exp_key-(n-1)])
		t2 = bxor(t2, exp_key[#exp_key-(n-2)])
		t3 = bxor(t3, exp_key[#exp_key-(n-3)])
		t4 = bxor(t4, exp_key[#exp_key-(n-4)])
		insert(exp_key, t1)
		insert(exp_key, t2)
		insert(exp_key, t3)
		insert(exp_key, t4)
		for i=1, 3 do
			t1 = bxor(exp_key[#exp_key], exp_key[#exp_key-(n-1)])
			t2 = bxor(exp_key[#exp_key-1], exp_key[#exp_key-(n-2)])
			t3 = bxor(exp_key[#exp_key-2], exp_key[#exp_key-(n-3)])
			t4 = bxor(exp_key[#exp_key-3], exp_key[#exp_key-(n-4)])
			insert(exp_key, t1)
			insert(exp_key, t2)
			insert(exp_key, t3)
			insert(exp_key, t4)
		end
		if key_type == 3 then -- If we're processing a 256 bit key...
			-- Take the previous 4 bytes of the expanded key, run them through the sbox,
			-- then XOR them with the previous n bytes of the expanded key, then output them
			-- as the next 4 bytes of expanded key.
			t1 = bxor(sbox[exp_key[#exp_key]], exp_key[#exp_key-(n-1)])
			t2 = bxor(sbox[exp_key[#exp_key-1]], exp_key[#exp_key-(n-2)])
			t3 = bxor(sbox[exp_key[#exp_key-2]], exp_key[#exp_key-(n-3)])
			t4 = bxor(sbox[exp_key[#exp_key-3]], exp_key[#exp_key-(n-4)])
			insert(exp_key, t1)
			insert(exp_key, t2)
			insert(exp_key, t3)
			insert(exp_key, t4)
		end
		if key_type == 2 or key_type == 3 then -- If we're processing a 192-bit or 256-bit key..
			local i = 2
			if key_type == 3 then
				i = 3
			end
			for j=1, i do
				t1 = bxor(exp_key[#exp_key], exp_key[#exp_key-(n-1)])
				t2 = bxor(exp_key[#exp_key-1], exp_key[#exp_key-(n-2)])
				t3 = bxor(exp_key[#exp_key-2], exp_key[#exp_key-(n-3)])
				t4 = bxor(exp_key[#exp_key-3], exp_key[#exp_key-(n-4)])
				insert(exp_key, t1)
				insert(exp_key, t2)
				insert(exp_key, t3)
				insert(exp_key, t4)
			end
		end
	end
	return exp_key
end

-- Transform a string of bytes into 16 byte blocks, adding padding to ensure that each block contains 16 bytes.
-- For example:
-- "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" (contains 28 0xFF bytes)
-- Is transformed into this:
-- {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF}, {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0,0,0,0} (16 0xFF bytes, followed by 12 0xFF bytes and 4 0x00 bytes for padding)

out.breakIntoBlocks  = function(data)
	if type(data) ~= "string" then
		error("breakIntoBlocks: data is not a string", 2)
	end
	while (#data % 16) ~= 0 do
		data = data.."\0"
	end
	local blocks = {}
	local blockNum = 1
	local output = {}
	for i=1, #data, 16 do
		blocks[blockNum] = {}
		for j=1, 16 do
			blocks[blockNum][j] = string.byte(data, ((blockNum-1)*16)+j, ((blockNum-1)*16)+j)
		end
		blockNum = blockNum+1
	end
	return blocks
end

-- Transform a string into a series of blocks.

-- For example, to get a key from a string:
-- local key = strToBlocks(keyStr)
-- key = key[1]

out.strToBlocks = function(str)
	local rawBytestream = {}
	local blocks = {}
	for i=1, #str do
		rawBytestream[i] = string.byte(str, i, i)
	end
	for i=1, math.ceil(#rawBytestream / 16) do
		blocks[i] = {}
		for j=1, 16 do
			blocks[i][j] = rawBytestream[ ((i-1)*16)+j ] or 0
		end
	end
	return blocks
end

-- Encrypt / Decrypt individual blocks:

out.encrypt_block = function(data, key)
	local exp_key = out.key_schedule(key)
	local state = data
	local nr = 0
	
	if #exp_key == 176 then -- Key type 1 (128-bits)
		nr = 10
	elseif #exp_key == 208 then -- Key type 2 (192-bits)
		nr = 12
	elseif #exp_key == 240 then -- Key type 3 (256-bits)
		nr = 14
	else
		error("encrypt_block: Unknown key size?", 2)
	end
	
	-- Inital round:
	state = addRoundKey(state, exp_key, 1)
	
	-- Repeat (Nr-1) times:
	for round_num = 2, nr-1 do	
		state = subBytes(state)
		state = shiftRows(state)
		state = mixColumns(state)
		state = addRoundKey(state, exp_key, round_num)
	end
	
	-- Final round (No mixColumns()):
	state = subBytes(state)
	state = shiftRows(state)
	state = addRoundKey(state, exp_key, nr)
	return state
end

out.decrypt_block = function(data, key)
	local exp_key = out.key_schedule(key)
	local state = data
	local nr = 0
	
	if #exp_key == 176 then -- Key type 1 (128-bits)
		nr = 10
	elseif #exp_key == 208 then -- Key type 2 (192-bits)
		nr = 12
	elseif #exp_key == 240 then -- Key type 3 (256-bits)
		nr = 14
	else
		error("decrypt_block: Unknown key size?", 2)
	end
	
	-- Inital round:
	state = addRoundKey(state, exp_key, nr)
	
	-- Repeat (Nr-1) times:
	for round_num = nr-1, 2, -1 do
		state = invShiftRows(state)
		state = subBytes(state, true)
		state = addRoundKey(state, exp_key, round_num)
		state = mixColumns(state, true)
	end
	
	-- Final round (No mixColumns()):
	state = invShiftRows(state)
	state = subBytes(state, true)
	state = addRoundKey(state, exp_key, 1)
	return state
end

out.encrypt_block_customExpKey = function(data, exp_key--[[, key_type]]) -- Encrypt blocks, but using a precalculated expanded key instead of performing the key expansion on every step like with the normal encrypt_block(2) call
	local state = data
	local nr = 0
	if #exp_key == 176 then -- Key type 1 (128-bits)
		nr = 10
	elseif #exp_key == 208 then -- Key type 2 (192-bits)
		nr = 12
	elseif #exp_key == 240 then -- Key type 3 (256-bits)
		nr = 14
	else
		error("encrypt_block: Unknown key size?", 2)
	end
	
	-- Inital round:
	state = addRoundKey(state, exp_key, 1)
	
	-- Repeat (Nr-1) times:
	for round_num = 2, nr-1 do	
		state = subBytes(state)
		state = shiftRows(state)
		state = mixColumns(state)
		state = addRoundKey(state, exp_key, round_num)
	end
	
	-- Final round (No mixColumns()):
	state = subBytes(state)
	state = shiftRows(state)
	state = addRoundKey(state, exp_key, nr)
	return state
end

out.decrypt_block_customExpKey = function(data, exp_key--[[, key_type]])
	local state = data
	local nr = 0
	if #exp_key == 176 then -- Key type 1 (128-bits)
		nr = 10
	elseif #exp_key == 208 then -- Key type 2 (192-bits)
		nr = 12
	elseif #exp_key == 240 then -- Key type 3 (256-bits)
		nr = 14
	else
		error("decrypt_block: Unknown key size?", 2)
	end
	
	-- Inital round:
	state = addRoundKey(state, exp_key, nr)
	
	-- Repeat (Nr-1) times:
	for round_num = nr-1, 2, -1 do
		state = invShiftRows(state)
		state = subBytes(state, true)
		state = addRoundKey(state, exp_key, round_num)
		state = mixColumns(state, true)
	end
	
	-- Final round (No mixColumns()):
	state = invShiftRows(state)
	state = subBytes(state, true)
	state = addRoundKey(state, exp_key, 1)
	return state
end

-- Encrypt / Decrypt bytestreams (tables of bytes):

-- ECB (electronic codebook) Mode (not secure, do not use):

out.encrypt_bytestream_ecb = function(data, key)
	local blocks = {}
	local outputBytestream = {}
	local exp_key = out.key_schedule(key)
	for i=1, #data, 16 do
		local block = {}
		for j=1, 16 do
			block[j] = data[i+(j-1)] or 0
		end
		block = out.encrypt_block_customExpKey(block, exp_key)
		for j=1, 16 do
			table.insert(outputBytestream, block[j])
		end
		os.queueEvent("")
		os.pullEvent("")
	end
	return outputBytestream
end

out.decrypt_bytestream_ecb = function(data, key)
	local outputBytestream = {}
	local exp_key = out.key_schedule(key)
	for i=1, #data, 16 do
		local block = {}
		for j=1, 16 do
			block[j] = data[i+(j-1)] or 0
		end
		block = out.decrypt_block_customExpKey(block, exp_key)
		for j=1, 16 do
			table.insert(outputBytestream, block[j])
		end
		os.queueEvent("")
		os.pullEvent("")
	end
	for i=#outputBytestream, 1, -1 do
		if outputBytestream[i] ~= 0 then
			break
		else
			outputBytestream[i] = nil
		end
	end
	return outputBytestream
end

-- CBC (cipher-block chaining) mode:

out.encrypt_bytestream = function(data, key, init_vector)
	local blocks = { init_vector }
	local outputBytestream = {}
	local exp_key = out.key_schedule(key)
	if not init_vector then
		error("encrypt_bytestream: No initalization vector was passed.", 2)
	end
	for i=1, #data do
		if data[i] == nil or data[i] >= 256 then
			if type(data[i]) == "number" then
				error("encrypt_bytestream: Invalid data at i="..i.." data[i]="..data[i], 2)
			else
				error("encrypt_bytestream: Invalid data at i="..i.." data[i]="..type(data[i]), 2)
			end
		end
	end
	local s = os.clock()
	for i=1, math.ceil(#data/16) do
		local block = {}
		if not blocks[i] then
			error("encrypt_bytestream: blocks["..i.."] is nil! Input size: "..#data, 2)
		end
		for j=1, 16 do
			block[j] = data[((i-1)*16)+j] or 0
			block[j] = bxor(block[j], blocks[i][j]) -- XOR this block with the previous one
		end
		--print("#bytes: "..#block)
		block = out.encrypt_block_customExpKey(block, exp_key)
		table.insert(blocks, block)
		for j=1, 16 do
			insert(outputBytestream, block[j])
		end
        if os.clock() - s >= 2.5 then
            os.queueEvent("")
            os.pullEvent("")
            s = os.clock()
        end
	end
	return outputBytestream
end

out.decrypt_bytestream = function(data, key, init_vector)
	local blocks = { init_vector }
	local outputBytestream = {}
	local exp_key = out.key_schedule(key)
	if not init_vector then
		error("decrypt_bytestream: No initalization vector was passed.", 2)
	end
	local s = os.clock()
	for i=1, math.ceil(#data/16) do
		local block = {}
		if not blocks[i] then
			error("decrypt_bytestream: blocks["..i.."] is nil! Input size: "..#data, 2)
		end
		for j=1, 16 do
			block[j] = data[((i-1)*16)+j] or 0
		end
		table.insert(blocks, block)
		local dec_block = out.decrypt_block_customExpKey(block, exp_key)
		for j=1, 16 do
			dec_block[j] = bxor(dec_block[j], blocks[i][j]) -- We use XOR on the plaintext, not the ciphertext
			table.insert(outputBytestream, dec_block[j])
		end
        if os.clock() - s >= 2.5 then
            os.queueEvent("")
            os.pullEvent("")
            s = os.clock()
        end
	end
	-- Remove padding:
	for i=#outputBytestream, #outputBytestream-15, -1 do
		if outputBytestream[i] ~= 0 then
			break
		else
			outputBytestream[i] = nil
		end
	end
	return outputBytestream
end

-- Encrypt / Decrypt strings:

out.encrypt_str = function(data, key, iv)
	local byteStream = {}
	for i=1, #data do
		table.insert(byteStream, string.byte(data, i, i))
	end
	local output_bytestream = {}
	if iv then
		output_bytestream = out.encrypt_bytestream(byteStream, key, iv)
	else
		output_bytestream = out.encrypt_bytestream_ecb(byteStream, key)
	end
	local output = ""
	for i=1, #output_bytestream do
		output = output..string.char(output_bytestream[i])
	end
	return output
end

out.decrypt_str = function(data, key, iv)
	local byteStream = {}
	for i=1, #data do
		table.insert(byteStream, string.byte(data, i, i))
	end
	local output_bytestream = {}
	if iv then
		output_bytestream = out.decrypt_bytestream(byteStream, key, iv)
	else
		output_bytestream = out.decrypt_bytestream_ecb(byteStream, key)
	end
	local output = ""
	for i=1, #output_bytestream do
		output = output..string.char(output_bytestream[i])
	end
	return output
end

out.davies_meyer = function(data, h0)
	local last_h = h0
    for dm_iter=1, 16 do
        for i=1, math.ceil(#data/16) do
            local block = {}
            for j=1, 16 do
                block[j] = data[((i-1)*16)+j] or 0
            end
            local block = encrypt_block(last_h, block)
            for j=1, 16 do
                block[j] = bxor(block[j], last_h[j]) -- XOR h[i-1] with h[i].
            end
            last_h = block
            os.queueEvent("")
            os.pullEvent("")
        end
    end
	return last_h
end

local function increment_ctr(blk)
	local cpy = {}
	for i=1, 16 do
		cpy[i] = blk[i] or 0
	end
	cpy[1] = cpy[1] + incAmt
	for i=2, 16 do
		if cpy[i-1] <= 255 then
			break
		end
		local carry = cpy[i-1] - 255
		cpy[i] = cpy[i]+carry
	end
	return cpy
end

local counter_mode_context = {
	key = {},
	ctr = {},
	stream_cache = {}, -- Use "leftover" bytes from generate() here.
	set_key = function(self, key)
		if type(key) == "string" then
			if #key < 16 then
				error("set_key: Key length ("..#key..") must be at least 16 characters!", 2)
			end
			for i=1, 16 do
				self.key[i] = string.byte(key, i, i)
			end
		elseif type(key) == "table" then
			if #key < 16 then
				error("set_key: Key length ("..#key..") must be at least 16 bytes!", 2)
			end
			for i=1, 16 do
				if type(key[i]) ~= "number" or key[i] > 255 or key[i] < 0 then
					if type(key[i]) == "nil" then
						error("set_key: Value key["..i.."] is invalid: nil", 2)
					else
						error("set_key: Value key["..i.."] is invalid: "..key[i], 2)
					end
				end
				self.key[i] = key[i]
			end
		else
			error("set_key: Key type is not supported: "..type(key), 2)
		end
	end,
	set_ctr = function(self, ctr)
		if type(ctr) == "string" then
			if #ctr < 16 then
				error("set_ctr: Counter length ("..#ctr..") must be at least 16 characters!", 2)
			end
			for i=1, 16 do
				self.ctr[i] = string.byte(ctr, i, i)
			end
		elseif type(ctr) == "table" then
			if #ctr < 16 then
				error("set_ctr: Counter length ("..#ctr..") must be at least 16 bytes!", 2)
			end
			for i=1, 16 do
				if type(ctr[i]) ~= "number" or ctr[i] > 255 or ctr[i] < 0 then
					if type(ctr[i]) == "nil" then
						error("set_ctr: Value ctr["..i.."] is invalid: nil", 2)
					else
						error("set_ctr: Value ctr["..i.."] is invalid: "..ctr[i], 2)
					end
				end
				self.ctr[i] = ctr[i]
			end
		elseif type(ctr) == "number" then
			local b1 = bit.band( ctr, 0xFF )
			local b2 = bit.band( bit.brshift(bit.band( ctr, 0xFF00 ), 8), 0xFF )
			local b3 = bit.band( bit.brshift(bit.band( ctr, 0xFF0000 ), 16), 0xFF )
			local b4 = bit.band( bit.brshift(bit.band( ctr, 0xFF000000 ), 24), 0xFF )
			self.ctr = {}
			for i=1, 16 do
				self.ctr[i] = 0
			end
			self.ctr[1] = b1
			self.ctr[2] = b2
			self.ctr[3] = b3
			self.ctr[4] = b4
		else
			error("set_ctr: Counter type is not supported: "..type(ctr), 2)
		end
	end,
	generate = function(self, bytes)
		local genBytes = {}
		if #self.stream_cache >= bytes then
			for i=1, bytes do
				table.insert(genBytes, table.remove(self.stream_cache))
			end
		else
			for i=1, #self.stream_cache do
				table.insert(genBytes, table.remove(self.stream_cache))
			end
			local blocksToGenerate = math.ceil((bytes - #genBytes) / 16)
			for i=1, blocksToGenerate-1 do
				self.ctr = increment_ctr(self.ctr)
				local block = out.encrypt_block(self.ctr, self.key)
				for i=1, 16 do
					table.insert(genBytes, block[i])
				end
			end
			self.ctr = increment_ctr(self.ctr)
			local block = out.encrypt_block(self.ctr, self.key)
			for i=1, (bytes - #genBytes) do
				table.insert(genBytes, table.remove(block))
			end
			for i=1, #block do
				table.insert(self.stream_cache, table.remove(block))
			end
		end
		return genBytes
	end,
}

out.new_ctrMode = function(key, iv)
	local context = {
		stream_cache = {},
		key = {},
		iv = {},
		__index = counter_mode_context,
	}
	setmetatable(context, context)
	context:set_key(key)
	context:set_ctr(iv)
	return context
end

return out