diff --git a/examples/knx-linux/CMakeLists.txt b/examples/knx-linux/CMakeLists.txt index c669c13..ba97c10 100644 --- a/examples/knx-linux/CMakeLists.txt +++ b/examples/knx-linux/CMakeLists.txt @@ -4,7 +4,10 @@ set(LIBRARIES_FROM_REFERENCES "") add_executable(knx-linux ../../src/knx/address_table_object.cpp ../../src/knx/address_table_object.h - ../../src/knx/apdu.cpp + ../../src/knx/aes.c + ../../src/knx/aes.h + ../../src/knx/aes.hpp + ../../src/knx/apdu.cpp ../../src/knx/apdu.h ../../src/knx/application_layer.cpp ../../src/knx/application_layer.h diff --git a/examples/knx-linux/main.cpp b/examples/knx-linux/main.cpp index dbca23d..1e9d84c 100644 --- a/examples/knx-linux/main.cpp +++ b/examples/knx-linux/main.cpp @@ -46,6 +46,130 @@ long lastsend = 0; #define MIN knx.getGroupObject(3) #define RESET knx.getGroupObject(4) +int ceil(float num) { + int inum = (int)num; + if (num == (float)inum) { + return inum; + } + return inum + 1; +} + +int toBase32(uint8_t* in, long length, uint8_t*& out, bool usePadding) +{ + char base32StandardAlphabet[] = {"ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"}; + char standardPaddingChar = '='; + + int result = 0; + int count = 0; + int bufSize = 8; + int index = 0; + int size = 0; // size of temporary array + uint8_t* temp = NULL; + + if (length < 0 || length > 268435456LL) + { + return 0; + } + + size = 8 * ceil(length / 4.0); // Calculating size of temporary array. Not very precise. + temp = (uint8_t*)malloc(size); // Allocating temporary array. + + if (length > 0) + { + int buffer = in[0]; + int next = 1; + int bitsLeft = 8; + + while (count < bufSize && (bitsLeft > 0 || next < length)) + { + if (bitsLeft < 5) + { + if (next < length) + { + buffer <<= 8; + buffer |= in[next] & 0xFF; + next++; + bitsLeft += 8; + } + else + { + int pad = 5 - bitsLeft; + buffer <<= pad; + bitsLeft += pad; + } + } + index = 0x1F & (buffer >> (bitsLeft -5)); + + bitsLeft -= 5; + temp[result] = (uint8_t)base32StandardAlphabet[index]; + result++; + } + } + + if (usePadding) + { + int pads = (result % 8); + if (pads > 0) + { + pads = (8 - pads); + for (int i = 0; i < pads; i++) + { + temp[result] = standardPaddingChar; + result++; + } + } + } + + out = (uint8_t*)malloc(result); + memcpy(out, temp, result); + free(temp); + + return result; +} + +int fromBase32(uint8_t* in, long length, uint8_t*& out) +{ + int result = 0; // Length of the array of decoded values. + int buffer = 0; + int bitsLeft = 0; + uint8_t* temp = NULL; + + temp = (uint8_t*)malloc(length); // Allocating temporary array. + + for (int i = 0; i < length; i++) + { + uint8_t ch = in[i]; + + // ignoring some characters: ' ', '\t', '\r', '\n', '=' + if (ch == 0xA0 || ch == 0x09 || ch == 0x0A || ch == 0x0D || ch == 0x3D) continue; + + // recovering mistyped: '0' -> 'O', '1' -> 'L', '8' -> 'B' + if (ch == 0x30) { ch = 0x4F; } else if (ch == 0x31) { ch = 0x4C; } else if (ch == 0x38) { ch = 0x42; } + + + // look up one base32 symbols: from 'A' to 'Z' or from 'a' to 'z' or from '2' to '7' + if ((ch >= 0x41 && ch <= 0x5A) || (ch >= 0x61 && ch <= 0x7A)) { ch = ((ch & 0x1F) - 1); } + else if (ch >= 0x32 && ch <= 0x37) { ch -= (0x32 - 26); } + else { free(temp); return 0; } + + buffer <<= 5; + buffer |= ch; + bitsLeft += 5; + if (bitsLeft >= 8) + { + temp[result] = (unsigned char)((unsigned int)(buffer >> (bitsLeft - 8)) & 0xFF); + result++; + bitsLeft -= 8; + } + } + + out = (uint8_t*)malloc(result); + memcpy(out, temp, result); + free(temp); + + return result; +} + void measureTemp() { long now = millis(); @@ -119,6 +243,14 @@ int main(int argc, char **argv) { printf("main() start.\n"); + uint8_t inPlain[] { 0x00, 0xFA, 0x01, 0x02, 0x03, 0x04, // KNX Serial + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F}; // Key + uint8_t* outEncoded = NULL; + + uint8_t len = toBase32(inPlain, sizeof(inPlain), outEncoded, false); + + printf("FDSK(len: %d): %s\n", len, outEncoded); + // Prevent swapping of this process struct sched_param sp; memset(&sp, 0, sizeof(sp)); diff --git a/src/knx/aes.c b/src/knx/aes.c new file mode 100644 index 0000000..eaf2b69 --- /dev/null +++ b/src/knx/aes.c @@ -0,0 +1,569 @@ +/* + +This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode. +Block size can be chosen in aes.h - available choices are AES128, AES192, AES256. + +The implementation is verified against the test vectors in: + National Institute of Standards and Technology Special Publication 800-38A 2001 ED + +ECB-AES128 +---------- + + plain-text: + 6bc1bee22e409f96e93d7e117393172a + ae2d8a571e03ac9c9eb76fac45af8e51 + 30c81c46a35ce411e5fbc1191a0a52ef + f69f2445df4f9b17ad2b417be66c3710 + + key: + 2b7e151628aed2a6abf7158809cf4f3c + + resulting cipher + 3ad77bb40d7a3660a89ecaf32466ef97 + f5d3d58503b9699de785895a96fdbaaf + 43b1cd7f598ece23881b00e3ed030688 + 7b0c785e27e8ad3f8223207104725dd4 + + +NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0) + You should pad the end of the string with zeros if this is not the case. + For AES192/256 the key size is proportionally larger. + +*/ + + +/*****************************************************************************/ +/* Includes: */ +/*****************************************************************************/ +#include // CBC mode, for memset +#include "aes.h" + +/*****************************************************************************/ +/* Defines: */ +/*****************************************************************************/ +// The number of columns comprising a state in AES. This is a constant in AES. Value=4 +#define Nb 4 + +#if defined(AES256) && (AES256 == 1) + #define Nk 8 + #define Nr 14 +#elif defined(AES192) && (AES192 == 1) + #define Nk 6 + #define Nr 12 +#else + #define Nk 4 // The number of 32 bit words in a key. + #define Nr 10 // The number of rounds in AES Cipher. +#endif + +// jcallan@github points out that declaring Multiply as a function +// reduces code size considerably with the Keil ARM compiler. +// See this link for more information: https://github.com/kokke/tiny-AES-C/pull/3 +#ifndef MULTIPLY_AS_A_FUNCTION + #define MULTIPLY_AS_A_FUNCTION 0 +#endif + + + + +/*****************************************************************************/ +/* Private variables: */ +/*****************************************************************************/ +// state - array holding the intermediate results during decryption. +typedef uint8_t state_t[4][4]; + + + +// The lookup-tables are marked const so they can be placed in read-only storage instead of RAM +// The numbers below can be computed dynamically trading ROM for RAM - +// This can be useful in (embedded) bootloader applications, where ROM is often limited. +static const uint8_t sbox[256] = { + //0 1 2 3 4 5 6 7 8 9 A B C D E F + 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 }; + +static const uint8_t rsbox[256] = { + 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 }; + +// The round constant word array, Rcon[i], contains the values given by +// x to the power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) +static const uint8_t Rcon[11] = { + 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 }; + +/* + * Jordan Goulder points out in PR #12 (https://github.com/kokke/tiny-AES-C/pull/12), + * that you can remove most of the elements in the Rcon array, because they are unused. + * + * From Wikipedia's article on the Rijndael key schedule @ https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon + * + * "Only the first some of these constants are actually used – up to rcon[10] for AES-128 (as 11 round keys are needed), + * up to rcon[8] for AES-192, up to rcon[7] for AES-256. rcon[0] is not used in AES algorithm." + */ + + +/*****************************************************************************/ +/* Private functions: */ +/*****************************************************************************/ +/* +static uint8_t getSBoxValue(uint8_t num) +{ + return sbox[num]; +} +*/ +#define getSBoxValue(num) (sbox[(num)]) +/* +static uint8_t getSBoxInvert(uint8_t num) +{ + return rsbox[num]; +} +*/ +#define getSBoxInvert(num) (rsbox[(num)]) + +// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states. +static void KeyExpansion(uint8_t* RoundKey, const uint8_t* Key) +{ + unsigned i, j, k; + uint8_t tempa[4]; // Used for the column/row operations + + // The first round key is the key itself. + for (i = 0; i < Nk; ++i) + { + RoundKey[(i * 4) + 0] = Key[(i * 4) + 0]; + RoundKey[(i * 4) + 1] = Key[(i * 4) + 1]; + RoundKey[(i * 4) + 2] = Key[(i * 4) + 2]; + RoundKey[(i * 4) + 3] = Key[(i * 4) + 3]; + } + + // All other round keys are found from the previous round keys. + for (i = Nk; i < Nb * (Nr + 1); ++i) + { + { + k = (i - 1) * 4; + tempa[0]=RoundKey[k + 0]; + tempa[1]=RoundKey[k + 1]; + tempa[2]=RoundKey[k + 2]; + tempa[3]=RoundKey[k + 3]; + + } + + if (i % Nk == 0) + { + // This function shifts the 4 bytes in a word to the left once. + // [a0,a1,a2,a3] becomes [a1,a2,a3,a0] + + // Function RotWord() + { + const uint8_t u8tmp = tempa[0]; + tempa[0] = tempa[1]; + tempa[1] = tempa[2]; + tempa[2] = tempa[3]; + tempa[3] = u8tmp; + } + + // SubWord() is a function that takes a four-byte input word and + // applies the S-box to each of the four bytes to produce an output word. + + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + + tempa[0] = tempa[0] ^ Rcon[i/Nk]; + } +#if defined(AES256) && (AES256 == 1) + if (i % Nk == 4) + { + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + } +#endif + j = i * 4; k=(i - Nk) * 4; + RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0]; + RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1]; + RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2]; + RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3]; + } +} + +void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key) +{ + KeyExpansion(ctx->RoundKey, key); +} +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) +void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv) +{ + KeyExpansion(ctx->RoundKey, key); + memcpy (ctx->Iv, iv, AES_BLOCKLEN); +} +void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv) +{ + memcpy (ctx->Iv, iv, AES_BLOCKLEN); +} +#endif + +// This function adds the round key to state. +// The round key is added to the state by an XOR function. +static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey) +{ + uint8_t i,j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j]; + } + } +} + +// The SubBytes Function Substitutes the values in the +// state matrix with values in an S-box. +static void SubBytes(state_t* state) +{ + uint8_t i, j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxValue((*state)[j][i]); + } + } +} + +// The ShiftRows() function shifts the rows in the state to the left. +// Each row is shifted with different offset. +// Offset = Row number. So the first row is not shifted. +static void ShiftRows(state_t* state) +{ + uint8_t temp; + + // Rotate first row 1 columns to left + temp = (*state)[0][1]; + (*state)[0][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[3][1]; + (*state)[3][1] = temp; + + // Rotate second row 2 columns to left + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to left + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[3][3]; + (*state)[3][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[1][3]; + (*state)[1][3] = temp; +} + +static uint8_t xtime(uint8_t x) +{ + return ((x<<1) ^ (((x>>7) & 1) * 0x1b)); +} + +// MixColumns function mixes the columns of the state matrix +static void MixColumns(state_t* state) +{ + uint8_t i; + uint8_t Tmp, Tm, t; + for (i = 0; i < 4; ++i) + { + t = (*state)[i][0]; + Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ; + Tm = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm); (*state)[i][0] ^= Tm ^ Tmp ; + Tm = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm); (*state)[i][1] ^= Tm ^ Tmp ; + Tm = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm); (*state)[i][2] ^= Tm ^ Tmp ; + Tm = (*state)[i][3] ^ t ; Tm = xtime(Tm); (*state)[i][3] ^= Tm ^ Tmp ; + } +} + +// Multiply is used to multiply numbers in the field GF(2^8) +// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary +// The compiler seems to be able to vectorize the operation better this way. +// See https://github.com/kokke/tiny-AES-c/pull/34 +#if MULTIPLY_AS_A_FUNCTION +static uint8_t Multiply(uint8_t x, uint8_t y) +{ + return (((y & 1) * x) ^ + ((y>>1 & 1) * xtime(x)) ^ + ((y>>2 & 1) * xtime(xtime(x))) ^ + ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ + ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */ + } +#else +#define Multiply(x, y) \ + ( ((y & 1) * x) ^ \ + ((y>>1 & 1) * xtime(x)) ^ \ + ((y>>2 & 1) * xtime(xtime(x))) ^ \ + ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ \ + ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))) \ + +#endif + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +// MixColumns function mixes the columns of the state matrix. +// The method used to multiply may be difficult to understand for the inexperienced. +// Please use the references to gain more information. +static void InvMixColumns(state_t* state) +{ + int i; + uint8_t a, b, c, d; + for (i = 0; i < 4; ++i) + { + a = (*state)[i][0]; + b = (*state)[i][1]; + c = (*state)[i][2]; + d = (*state)[i][3]; + + (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09); + (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d); + (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b); + (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e); + } +} + + +// The SubBytes Function Substitutes the values in the +// state matrix with values in an S-box. +static void InvSubBytes(state_t* state) +{ + uint8_t i, j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxInvert((*state)[j][i]); + } + } +} + +static void InvShiftRows(state_t* state) +{ + uint8_t temp; + + // Rotate first row 1 columns to right + temp = (*state)[3][1]; + (*state)[3][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[0][1]; + (*state)[0][1] = temp; + + // Rotate second row 2 columns to right + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to right + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[1][3]; + (*state)[1][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[3][3]; + (*state)[3][3] = temp; +} +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + +// Cipher is the main function that encrypts the PlainText. +static void Cipher(state_t* state, const uint8_t* RoundKey) +{ + uint8_t round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(0, state, RoundKey); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr rounds are executed in the loop below. + // Last one without MixColumns() + for (round = 1; ; ++round) + { + SubBytes(state); + ShiftRows(state); + if (round == Nr) { + break; + } + MixColumns(state); + AddRoundKey(round, state, RoundKey); + } + // Add round key to last round + AddRoundKey(Nr, state, RoundKey); +} + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +static void InvCipher(state_t* state, const uint8_t* RoundKey) +{ + uint8_t round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(Nr, state, RoundKey); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr rounds are executed in the loop below. + // Last one without InvMixColumn() + for (round = (Nr - 1); ; --round) + { + InvShiftRows(state); + InvSubBytes(state); + AddRoundKey(round, state, RoundKey); + if (round == 0) { + break; + } + InvMixColumns(state); + } + +} +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ +#if defined(ECB) && (ECB == 1) + + +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf) +{ + // The next function call encrypts the PlainText with the Key using AES algorithm. + Cipher((state_t*)buf, ctx->RoundKey); +} + +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf) +{ + // The next function call decrypts the PlainText with the Key using AES algorithm. + InvCipher((state_t*)buf, ctx->RoundKey); +} + + +#endif // #if defined(ECB) && (ECB == 1) + + + + + +#if defined(CBC) && (CBC == 1) + + +static void XorWithIv(uint8_t* buf, const uint8_t* Iv) +{ + uint8_t i; + for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size + { + buf[i] ^= Iv[i]; + } +} + +void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length) +{ + uintptr_t i; + uint8_t *Iv = ctx->Iv; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + XorWithIv(buf, Iv); + Cipher((state_t*)buf, ctx->RoundKey); + Iv = buf; + buf += AES_BLOCKLEN; + } + /* store Iv in ctx for next call */ + memcpy(ctx->Iv, Iv, AES_BLOCKLEN); +} + +void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length) +{ + uintptr_t i; + uint8_t storeNextIv[AES_BLOCKLEN]; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + memcpy(storeNextIv, buf, AES_BLOCKLEN); + InvCipher((state_t*)buf, ctx->RoundKey); + XorWithIv(buf, ctx->Iv); + memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN); + buf += AES_BLOCKLEN; + } + +} + +#endif // #if defined(CBC) && (CBC == 1) + + + +#if defined(CTR) && (CTR == 1) + +/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */ +void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length) +{ + uint8_t buffer[AES_BLOCKLEN]; + + unsigned i; + int bi; + for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi) + { + if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */ + { + + memcpy(buffer, ctx->Iv, AES_BLOCKLEN); + Cipher((state_t*)buffer,ctx->RoundKey); + + /* Increment Iv and handle overflow */ + for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) + { + /* inc will overflow */ + if (ctx->Iv[bi] == 255) + { + ctx->Iv[bi] = 0; + continue; + } + ctx->Iv[bi] += 1; + break; + } + bi = 0; + } + + buf[i] = (buf[i] ^ buffer[bi]); + } +} + +#endif // #if defined(CTR) && (CTR == 1) + diff --git a/src/knx/aes.h b/src/knx/aes.h new file mode 100644 index 0000000..0d3b2e0 --- /dev/null +++ b/src/knx/aes.h @@ -0,0 +1,90 @@ +#ifndef _AES_H_ +#define _AES_H_ + +#include + +// #define the macros below to 1/0 to enable/disable the mode of operation. +// +// CBC enables AES encryption in CBC-mode of operation. +// CTR enables encryption in counter-mode. +// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously. + +// The #ifndef-guard allows it to be configured before #include'ing or at compile time. +#ifndef CBC + #define CBC 1 +#endif + +#ifndef ECB + #define ECB 1 +#endif + +#ifndef CTR + #define CTR 1 +#endif + + +#define AES128 1 +//#define AES192 1 +//#define AES256 1 + +#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only + +#if defined(AES256) && (AES256 == 1) + #define AES_KEYLEN 32 + #define AES_keyExpSize 240 +#elif defined(AES192) && (AES192 == 1) + #define AES_KEYLEN 24 + #define AES_keyExpSize 208 +#else + #define AES_KEYLEN 16 // Key length in bytes + #define AES_keyExpSize 176 +#endif + +struct AES_ctx +{ + uint8_t RoundKey[AES_keyExpSize]; +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) + uint8_t Iv[AES_BLOCKLEN]; +#endif +}; + +void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key); +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) +void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, const uint8_t* iv); +void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv); +#endif + +#if defined(ECB) && (ECB == 1) +// buffer size is exactly AES_BLOCKLEN bytes; +// you need only AES_init_ctx as IV is not used in ECB +// NB: ECB is considered insecure for most uses +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf); + +#endif // #if defined(ECB) && (ECB == !) + + +#if defined(CBC) && (CBC == 1) +// buffer size MUST be mutile of AES_BLOCKLEN; +// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme +// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv() +// no IV should ever be reused with the same key +void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); +void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); + +#endif // #if defined(CBC) && (CBC == 1) + + +#if defined(CTR) && (CTR == 1) + +// Same function for encrypting as for decrypting. +// IV is incremented for every block, and used after encryption as XOR-compliment for output +// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme +// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv() +// no IV should ever be reused with the same key +void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); + +#endif // #if defined(CTR) && (CTR == 1) + + +#endif // _AES_H_ diff --git a/src/knx/aes.hpp b/src/knx/aes.hpp new file mode 100644 index 0000000..ade1642 --- /dev/null +++ b/src/knx/aes.hpp @@ -0,0 +1,12 @@ +#ifndef _AES_HPP_ +#define _AES_HPP_ + +#ifndef __cplusplus +#error Do not include the hpp header in a c project! +#endif //__cplusplus + +extern "C" { +#include "aes.h" +} + +#endif //_AES_HPP_ diff --git a/src/knx/application_layer.cpp b/src/knx/application_layer.cpp index abe340c..39932a6 100644 --- a/src/knx/application_layer.cpp +++ b/src/knx/application_layer.cpp @@ -423,7 +423,8 @@ void ApplicationLayer::systemNetworkParameterReadResponse(Priority priority, Hop //apdu.printPDU(); - dataSystemBroadcastRequest(AckDontCare, hopType, SystemPriority, apdu); + //dataSystemBroadcastRequest(AckDontCare, hopType, SystemPriority, apdu); + dataBroadcastRequest(AckDontCare, hopType, SystemPriority, apdu); } //TODO: ApplicationLayer::domainAddressSerialNumberWriteRequest() diff --git a/src/knx/data_link_layer.cpp b/src/knx/data_link_layer.cpp index a8421e8..d457850 100644 --- a/src/knx/data_link_layer.cpp +++ b/src/knx/data_link_layer.cpp @@ -108,10 +108,15 @@ void DataLinkLayer::frameRecieved(CemiFrame& frame) if (addrType == GroupAddress && destination == 0) { +#if !defined(USE_TP) if (systemBroadcast == SysBroadcast) _networkLayer.systemBroadcastIndication(ack, type, npdu, priority, source); else _networkLayer.broadcastIndication(ack, type, npdu, priority, source); +#else + _networkLayer.systemBroadcastIndication(ack, type, npdu, priority, source); + _networkLayer.broadcastIndication(ack, type, npdu, priority, source); +#endif } else { diff --git a/src/knx/device_object.cpp b/src/knx/device_object.cpp index 888fabd..2930b8e 100644 --- a/src/knx/device_object.cpp +++ b/src/knx/device_object.cpp @@ -10,7 +10,7 @@ DeviceObject::DeviceObject() { //Default to KNXA (0xFA) - uint8_t serialNumber[] = {0x00, 0xFA, 0x00, 0x00, 0x00, 0x00}; + uint8_t serialNumber[] = {0x00, 0xFA, 0x01, 0x02, 0x03, 0x04}; uint8_t hardwareType[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; Property* properties[] = diff --git a/src/knx/ip_data_link_layer.cpp b/src/knx/ip_data_link_layer.cpp index 7219508..8e2a0f0 100644 --- a/src/knx/ip_data_link_layer.cpp +++ b/src/knx/ip_data_link_layer.cpp @@ -70,6 +70,17 @@ void IpDataLinkLayer::loop() _platform.sendBytesUniCast(hpai.ipAddress(), hpai.ipPortNumber(), searchResponse.data(), searchResponse.totalLength()); break; } + /* + case SearchRequestSecure: + { + KnxIpSearchRequest searchRequest(buffer, len); + KnxIpSearchResponse searchResponse(_ipParameters, _deviceObject); + searchResponse.serviceTypeIdentifier(SearchResponseSecure); + + auto hpai = searchRequest.hpai(); + _platform.sendBytesUniCast(hpai.ipAddress(), hpai.ipPortNumber(), searchResponse.data(), searchResponse.totalLength()); + break; + }*/ default: print("Unhandled service identifier: "); println(code, HEX); @@ -108,4 +119,4 @@ bool IpDataLinkLayer::sendBytes(uint8_t* bytes, uint16_t length) return _platform.sendBytesMultiCast(bytes, length); } -#endif \ No newline at end of file +#endif diff --git a/src/knx/knx_ip_frame.h b/src/knx/knx_ip_frame.h index 3f21a15..38bbdd7 100644 --- a/src/knx/knx_ip_frame.h +++ b/src/knx/knx_ip_frame.h @@ -23,6 +23,8 @@ enum KnxIpServiceType ConnectionStateResponse = 0x208, DisconnectRequest = 0x209, DisconnectResponse = 0x20A, + SearchRequestSecure = 0x20B, + SearchResponseSecure = 0x20C, DeviceConfigurationRequest = 0x310, DeviceConfigurationAck = 0x311, TunnelingRequest = 0x420, @@ -55,4 +57,4 @@ class KnxIpFrame uint8_t* _data = 0; uint16_t _dataLength; }; -#endif \ No newline at end of file +#endif diff --git a/src/knx/knx_ip_search_response.cpp b/src/knx/knx_ip_search_response.cpp index ba3968e..d051416 100644 --- a/src/knx/knx_ip_search_response.cpp +++ b/src/knx/knx_ip_search_response.cpp @@ -22,8 +22,8 @@ KnxIpSearchResponse::KnxIpSearchResponse(IpParameterObject& parameters, DeviceOb _deviceInfo.indiviudalAddress(parameters.propertyValue(PID_KNX_INDIVIDUAL_ADDRESS)); _deviceInfo.projectInstallationIdentifier(parameters.propertyValue(PID_PROJECT_INSTALLATION_ID)); _deviceInfo.serialNumber(deviceObject.propertyData(PID_SERIAL_NUMBER)); - //_deviceInfo.routingMulticastAddress(parameters.propertyValue(PID_ROUTING_MULTICAST_ADDRESS)); - _deviceInfo.routingMulticastAddress(0); + _deviceInfo.routingMulticastAddress(parameters.propertyValue(PID_ROUTING_MULTICAST_ADDRESS)); + //_deviceInfo.routingMulticastAddress(0); uint8_t mac_address[LEN_MAC_ADDRESS] = {0}; Property* prop = parameters.property(PID_MAC_ADDRESS); @@ -59,4 +59,4 @@ KnxIpSupportedServiceDIB& KnxIpSearchResponse::supportedServices() { return _supportedServices; } -#endif \ No newline at end of file +#endif diff --git a/src/knx/knx_types.h b/src/knx/knx_types.h index 046a4b3..7d46976 100644 --- a/src/knx/knx_types.h +++ b/src/knx/knx_types.h @@ -150,4 +150,7 @@ enum ApduType PropertyValueWrite = 0x3d7, PropertyDescriptionRead = 0x3d8, PropertyDescriptionResponse = 0x3d9, + + // Secure Service + SecureService = 0x3F1 }; diff --git a/src/knx/secure_application_layer.cpp b/src/knx/secure_application_layer.cpp index 47578c0..81fd7e9 100644 --- a/src/knx/secure_application_layer.cpp +++ b/src/knx/secure_application_layer.cpp @@ -6,8 +6,18 @@ #include "bau.h" #include "string.h" #include "bits.h" +#include "aes.hpp" #include +const uint8_t SecureDataPdu = 0; +const uint8_t SecureServiceRequest = 2; +const uint8_t SecureServiceResponse = 3; + +uint8_t lastValidSequenceNumberTool = 0; + +// Our FDSK +uint8_t SecureApplicationLayer::_key[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F }; + SecureApplicationLayer::SecureApplicationLayer(AssociationTableObject& assocTable, BusAccessUnit& bau): ApplicationLayer(assocTable, bau) { @@ -104,3 +114,413 @@ void SecureApplicationLayer::dataConnectedRequest(uint16_t tsap, Priority priori // apdu must be valid until it was confirmed ApplicationLayer::dataConnectedRequest(tsap, priority, apdu); } + +class TpTelegram +{ +public: + TpTelegram() + { + + } + + ~TpTelegram() + { + if (_data) + delete[] _data; + } + + void parseByteArray(uint8_t *buf) + { + _ctrlField = buf[0]; + _ctrlFieldExt = buf[1]; + _srcAddr = buf[2] << 8 | buf[3]; + _dstAddr = buf[4] << 8 | buf[5]; + _dataLen = buf[6]; + + // Copy starting from TPCI octet + _dataLen += 1; + _data = new uint8_t (_dataLen); + memcpy(_data, &buf[7], _dataLen); + } + + uint16_t SrcAddr() + { + return _srcAddr; + } + + uint16_t DstAddr() + { + return _dstAddr; + } + + uint8_t Tpci() + { + uint8_t tpci; + + tpci = (_data[0] & 0xFC) >> 2; + + return tpci; + } + + uint16_t Apci() + { + uint16_t apci; + + if (_dataLen > 1) + { + apci = (_data[0] & 0x03) << 8 | _data[1]; + } + else + { + apci = (_data[0] & 0x03); + } + + return apci; + } + + uint8_t* Apdu() + { + return _data; + } + + uint16_t ApduLen() + { + return _dataLen; + } + + uint8_t* Asdu() + { + return _data + 2; + } + + uint16_t AsduLen() + { + return _dataLen - 2; + } + + bool isSecureTelegram() + { + return Apci() == SecureService; + } + +private: + uint8_t _ctrlField; + uint8_t _ctrlFieldExt; + uint16_t _srcAddr; + uint16_t _dstAddr; + uint8_t _dataLen; + uint8_t* _data; + +}; + +uint32_t SecureApplicationLayer::calcAuthOnlyMac(uint8_t* apdu, uint8_t apduLength, uint8_t* key, uint8_t* iv, uint8_t* ctr0) +{ + uint16_t bufLen = 2 + apduLength; // 2 bytes for the length field (uint16_t) + // AES-128 operates on blocks of 16 bytes, add padding + uint16_t bufLenPadded = (bufLen + 15) / 16 * 16; + uint8_t buffer[bufLenPadded]; + // Make sure to have zeroes everywhere, because of the padding + memset(buffer, 0x00, bufLenPadded); + + uint8_t* pBuf = buffer; + + pBuf = pushWord(apduLength, pBuf); + pBuf = pushByteArray(apdu, apduLength, pBuf); + + // Use zeroes as IV for first round + uint8_t zeroIv[16] = {0x00}; + + struct AES_ctx ctx1; + AES_init_ctx_iv(&ctx1, key, zeroIv); + // Now encrypt first block B0 + AES_CBC_encrypt_buffer(&ctx1, iv, 16); + // Encrypt remaining buffer + AES_CBC_encrypt_buffer(&ctx1, buffer, bufLenPadded); + + struct AES_ctx ctx2; + AES_init_ctx_iv(&ctx2, key, ctr0); + AES_CTR_xcrypt_buffer(&ctx2, buffer, 4); // 4 bytes only for the MAC + + uint32_t mac; + popInt(mac, &buffer[0]); + + return mac; +} + +uint32_t SecureApplicationLayer::calcConfAuthMac(uint8_t* associatedData, uint16_t associatedDataLength, + uint8_t* apdu, uint8_t apduLength, + uint8_t* key, uint8_t* iv) +{ + uint16_t bufLen = 2 + associatedDataLength + apduLength; // 2 bytes for the length field (uint16_t) + // AES-128 operates on blocks of 16 bytes, add padding + uint16_t bufLenPadded = (bufLen + 15) / 16 * 16; + uint8_t buffer[bufLenPadded]; + // Make sure to have zeroes everywhere, because of the padding + memset(buffer, 0x00, bufLenPadded); + + uint8_t* pBuf = buffer; + + pBuf = pushWord(associatedDataLength, pBuf); + pBuf = pushByteArray(associatedData, associatedDataLength, pBuf); + pBuf = pushByteArray(apdu, apduLength, pBuf); + + // Use zeroes as IV for first round + uint8_t zeroIv[16] = {0x00}; + + struct AES_ctx ctx; + AES_init_ctx_iv(&ctx, key, zeroIv); + // Now encrypt first block B0 + AES_CBC_encrypt_buffer(&ctx, iv, 16); + // Encrypt remaining buffer + AES_CBC_encrypt_buffer(&ctx, buffer, bufLenPadded); + + uint32_t mac; + popInt(mac, &buffer[bufLenPadded - 16]); // bufLenPadded has a guaranteed minimum size of 16 bytes + + return mac; +} + +void SecureApplicationLayer::block0(uint8_t* buffer, uint8_t* seqNum, uint16_t indSrcAddr, uint16_t dstAddr, bool dstAddrIsGroupAddr, uint8_t extFrameFormat, uint8_t tpci, uint8_t apci, uint8_t payloadLength) +{ + uint8_t* pBuf = buffer; + pBuf = pushByteArray(seqNum, 6, pBuf); + pBuf = pushWord(indSrcAddr, pBuf); + pBuf = pushWord(dstAddr, pBuf); + pBuf = pushByte(0x00, pBuf); // FT: frametype + pBuf = pushByte( (dstAddrIsGroupAddr ? 0x80 : 0x00) | (extFrameFormat & 0xf), pBuf); // AT: address type + pBuf = pushByte(tpci, pBuf); // TPCI + pBuf = pushByte(apci, pBuf); // APCI // draft spec shows something different! + pBuf = pushByte(0x00, pBuf); // Reserved: fixed 0x00 (really?) + pBuf = pushByte(payloadLength, pBuf); // Payload length +} + +void SecureApplicationLayer::blockCtr0(uint8_t* buffer, uint8_t* seqNum, uint16_t indSrcAddr, uint16_t dstAddr, bool dstAddrIsGroupAddr) +{ + uint8_t* pBuf = buffer; + pBuf = pushByteArray(seqNum, 6, pBuf); + pBuf = pushWord(indSrcAddr, pBuf); + pBuf = pushWord(dstAddr, pBuf); + pBuf = pushInt(0x00000000, pBuf); + pBuf = pushByte(0x01, pBuf); +} + +uint64_t SecureApplicationLayer::lastValidSequenceNumber(bool toolAcces, uint16_t srcAddr) +{ + if (toolAcces) + { + return lastValidSequenceNumberTool; + } + + // TODO + return 0; +} + +bool SecureApplicationLayer::decrypt(uint8_t* plainApdu, uint16_t srcAddr, uint16_t dstAddr, uint8_t tpci, uint8_t* secureAsdu, uint16_t secureAdsuLength) +{ + uint8_t extendedFrameFormat = 0; + + const uint8_t* pBuf; + uint8_t scf; + + pBuf = popByte(scf, secureAsdu); + + bool toolAccess = ((scf & 0x80) == 0x80); + bool systemBroadcast = ((scf & 0x08) == 0x08); + uint8_t sai = (scf >> 4) & 0x07; // sai can only be 0x0 (CCM auth only) or 0x1 (CCM with auth+conf), other values are reserved + bool authOnly = ( sai == 0); + uint8_t service = (scf & 0x07); // only 0x0 (S-A_Data-PDU), 0x2 (S-A_Sync_Req-PDU) or 0x3 (S-A_Sync_Rsp-PDU) are valid values + + uint8_t seqNum[6]; + pBuf = popByteArray(seqNum, 6, pBuf); + + if (service == SecureDataPdu) + { + uint64_t receivedSeqNumber = ((uint64_t)seqNum[0] << 40) | ((uint64_t)seqNum[1] << 32) | ((uint64_t)seqNum[2] << 24) | + ((uint64_t)seqNum[3] << 16) | ((uint64_t)seqNum[4] << 8) | (uint64_t)seqNum[5]; + uint64_t expectedSeqNumber = lastValidSequenceNumber(toolAccess, srcAddr) + 1; + + if (receivedSeqNumber < expectedSeqNumber) + { + // security failure + print("security failure: received seqNum: "); + print(receivedSeqNumber, HEX); + print(" < expected seqNum: "); + print(expectedSeqNumber, HEX); + return false; + } + } + + uint16_t apduLength = secureAdsuLength - 1 - 6 - 4; // secureAdsuLength - sizeof(scf) - sizeof(seqNum) - sizeof(mac) + pBuf = popByteArray(plainApdu, apduLength, pBuf); + + // Clear IV buffer + uint8_t iv[16] = {0x00}; + // Create first block B0 for AES CBC MAC calculation, used as IV later + block0(iv, seqNum, srcAddr, dstAddr, false, extendedFrameFormat, tpci | (SecureService >> 8), SecureService & 0x00FF, apduLength); + + // Clear block counter0 buffer + uint8_t ctr0[16] = {0x00}; + // Create first block for block counter 0 + blockCtr0(ctr0, seqNum, srcAddr, dstAddr, false); + + uint32_t mac; + pBuf = popInt(mac, pBuf); + + if (authOnly) + { + // APDU is already plain, no decryption needed + + // Only check the MAC + uint32_t calculatedMac = calcAuthOnlyMac(plainApdu, apduLength, _key, iv, ctr0); + if (calculatedMac != mac) + { + // security failure + print("security failure: calculated MAC: "); + print(calculatedMac, HEX); + print(" != received MAC: "); + print(mac, HEX); + + return false; + } + } + else + { + // APDU is encrypted and needs decryption + + uint16_t bufLen = 4 + apduLength; + // AES-128 operates on blocks of 16 bytes, add padding + //uint16_t bufLenPadded = (bufLen + 15) / 16 * 16; + //uint8_t buffer[bufLenPadded]; + uint8_t buffer[bufLen]; + // Make sure to have zeroes everywhere, because of the padding + //memset(buffer, 0x00, bufLenPadded); + + pushInt(mac, &buffer[0]); + pushByteArray(plainApdu, apduLength, &buffer[4]); // apdu is still encrypted + + struct AES_ctx ctx; + AES_init_ctx_iv(&ctx, _key, ctr0); + //AES_CTR_xcrypt_buffer(&ctx, buffer, bufLenPadded); + AES_CTR_xcrypt_buffer(&ctx, buffer, bufLen); + + uint32_t decryptedMac; + popInt(decryptedMac, &buffer[0]); + popByteArray(plainApdu, apduLength, &buffer[4]); // apdu is now decrypted (overwritten) + + // Do calculations for Auth+Conf + uint8_t associatedData[1] = {scf}; + uint32_t calculatedMac = calcConfAuthMac(associatedData, sizeof(associatedData), plainApdu, apduLength, _key, iv); + if (calculatedMac != decryptedMac) + { + // security failure + print("security failure: calculated MAC: "); + print(calculatedMac, HEX); + print(" != decrypted MAC: "); + print(decryptedMac, HEX); + return false; + } + } + + return true; +} + +/* +void SecureApplicationLayer::test_datasecure_decrypt() +{ + TpTelegram t; + t.parseByteArray(secureTelegram); + + if (t.isSecureTelegram()) + { + uint16_t apduLength = t.AsduLen() - 1 - 6 - 4; // secureAdsuLength - sizeof(scf) - sizeof(seqNum) - sizeof(mac) + uint8_t apdu[apduLength]; + + if (decrypt(apdu, t.SrcAddr(), t.DstAddr(), t.Tpci(), t.Asdu(), t.AsduLen())) + { + std::cout << "Plain APDU: "; + for (uint8_t i = 0; i< apduLength; i++) + { + std::cout << std::hex << static_cast(apdu[i]) << " "; + } + std::cout << std::endl; + } + } + else + { + std::cout << "Telegram is not secured!" << std::endl; + } +} +*/ +void SecureApplicationLayer::encrypt(uint8_t* buffer, uint16_t srcAddr, uint16_t dstAddr, uint8_t tpci, uint8_t* apdu, uint16_t apduLength) +{ + uint8_t scf = 0x90; + uint8_t seqNum[6] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x04}; + bool authOnly = false; + uint8_t extendedFrameFormat = 0; + + // Clear IV buffer + uint8_t iv[16] = {0x00}; + // Create first block B0 for AES CBC MAC calculation, used as IV later + block0(iv, seqNum, srcAddr, dstAddr, false, extendedFrameFormat, tpci | (SecureService >> 8), SecureService & 0x00FF, apduLength); + + // Clear block counter0 buffer + uint8_t ctr0[16] = {0x00}; + // Create first block for block counter 0 + blockCtr0(ctr0, seqNum, srcAddr, dstAddr, false); + + if (authOnly) + { + // Do calculations for AuthOnly + uint32_t tmpMac = calcAuthOnlyMac(apdu, apduLength, _key, iv, ctr0); + } + else + { + // Do calculations for Auth+Conf + uint8_t associatedData[1] = {scf}; + uint32_t mac = calcConfAuthMac(associatedData, sizeof(associatedData), apdu, apduLength, _key, iv); + + pushInt(mac, buffer); + pushByteArray(apdu, apduLength, &buffer[4]); + + struct AES_ctx ctx; + AES_init_ctx_iv(&ctx, _key, ctr0); + AES_CTR_xcrypt_buffer(&ctx, buffer, apduLength + 4); // APDU + MAC (4 bytes) + } +} + +/* +void SecureApplicationLayer::test_datasecure_encrypt() +{ + TpTelegram t; + t.parseByteArray(plainTelegram); + + if (!t.isSecureTelegram()) + { + uint16_t bufLen = 4 + t.ApduLen(); + // AES-128 operates on blocks of 16 bytes, add padding + //uint16_t bufLenPadded = (bufLen + 15) / 16 * 16; + //uint8_t buffer[bufLenPadded]; + uint8_t buffer[bufLen]; + // Make sure to have zeroes everywhere, because of the padding + //memset(buffer, 0x00, bufLenPadded); + + encrypt(buffer, t.SrcAddr(), t.DstAddr(), t.Tpci(), t.Apdu(), t.ApduLen()); + + std::cout << "Secure Data: "; + for (uint8_t i = 0; i< t.ApduLen(); i++) + { + std::cout << std::hex << static_cast(buffer[4+i]) << " "; + } + std::cout << std::endl; + + uint32_t mac; + popInt(mac, &buffer[0]); + + std::cout << std::hex << "MAC: " << mac << std::endl; + } + else + { + std::cout << "Telegram is secured!" << std::endl; + } +} +*/ diff --git a/src/knx/secure_application_layer.h b/src/knx/secure_application_layer.h index 35f4ebf..10c990d 100644 --- a/src/knx/secure_application_layer.h +++ b/src/knx/secure_application_layer.h @@ -50,4 +50,18 @@ class SecureApplicationLayer : public ApplicationLayer virtual void dataConnectedRequest(uint16_t tsap, Priority priority, APDU& apdu); // apdu must be valid until it was confirmed private: + uint32_t calcAuthOnlyMac(uint8_t* apdu, uint8_t apduLength, uint8_t* key, uint8_t* iv, uint8_t* ctr0); + uint32_t calcConfAuthMac(uint8_t* associatedData, uint16_t associatedDataLength, uint8_t* apdu, uint8_t apduLength, uint8_t* key, uint8_t* iv); + + void block0(uint8_t* buffer, uint8_t* seqNum, uint16_t indSrcAddr, uint16_t dstAddr, bool dstAddrIsGroupAddr, uint8_t extFrameFormat, uint8_t tpci, uint8_t apci, uint8_t payloadLength); + void blockCtr0(uint8_t* buffer, uint8_t* seqNum, uint16_t indSrcAddr, uint16_t dstAddr, bool dstAddrIsGroupAddr); + + uint64_t lastValidSequenceNumber(bool toolAcces, uint16_t srcAddr); + + bool decrypt(uint8_t* plainApdu, uint16_t srcAddr, uint16_t dstAddr, uint8_t tpci, uint8_t* secureAsdu, uint16_t secureAdsuLength); + void encrypt(uint8_t* buffer, uint16_t srcAddr, uint16_t dstAddr, uint8_t tpci, uint8_t* apdu, uint16_t apduLength); + + // Our FDSK + static uint8_t _key[]; + };