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[PATCH v2 01/15] Import Tiny AES128
by Anton Lundin 19 Dec '14

19 Dec '14

This imports Tiny AES128 from https://github.com/kokke/tiny-AES128-C for use in the decoding of OSTC3 firmwares. This aes-code is released into the public domain. Signed-off-by: Anton Lundin <glance(a)acc.umu.se> --- msvc/libdivecomputer.vcproj | 6 + src/Makefile.am | 1 + src/aes.c | 583 ++++++++++++++++++++++++++++++++++++++++++++ src/aes.h | 40 +++ 4 files changed, 630 insertions(+) create mode 100644 src/aes.c create mode 100644 src/aes.h diff --git a/msvc/libdivecomputer.vcproj b/msvc/libdivecomputer.vcproj index 2fea2b9..c8a2a8b 100644 --- a/msvc/libdivecomputer.vcproj +++ b/msvc/libdivecomputer.vcproj @@ -255,6 +255,9 @@ > </File> <File + RelativePath="..\src\aes.c" + > + <File RelativePath="..\src\hw_ostc3.c" > </File> @@ -561,6 +564,9 @@ > </File> <File + RelativePath="..\src\aes.h" + > + <File RelativePath="..\include\libdivecomputer\hw_ostc3.h" > </File> diff --git a/src/Makefile.am b/src/Makefile.am index 1f52841..821bc1b 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -44,6 +44,7 @@ libdivecomputer_la_SOURCES = \ ihex.h ihex.c \ hw_ostc.c hw_ostc_parser.c \ hw_frog.c \ + aes.h aes.c \ hw_ostc3.c \ cressi_edy.c cressi_edy_parser.c \ cressi_leonardo.c cressi_leonardo_parser.c \ diff --git a/src/aes.c b/src/aes.c new file mode 100644 index 0000000..4c7645f --- /dev/null +++ b/src/aes.c @@ -0,0 +1,583 @@ +/* + +This is an implementation of the AES128 algorithm, specifically ECB and CBC mode. + +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. + +*/ + + +/*****************************************************************************/ +/* Includes: */ +/*****************************************************************************/ +#include <stdint.h> +#include <string.h> // 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 +// The number of 32 bit words in a key. +#define Nk 4 +// Key length in bytes [128 bit] +#define KEYLEN 16 +// The number of rounds in AES Cipher. +#define Nr 10 + +// 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-AES128-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]; +static state_t* state; + +// The array that stores the round keys. +static uint8_t RoundKey[176]; + +// The Key input to the AES Program +static const uint8_t* Key; + +#if defined(CBC) && CBC + // Initial Vector used only for CBC mode + static uint8_t* Iv; +#endif + +// 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 th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) +// Note that i starts at 1, not 0). +static const uint8_t Rcon[255] = { + 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 }; + + +/*****************************************************************************/ +/* Private functions: */ +/*****************************************************************************/ +static uint8_t getSBoxValue(uint8_t num) +{ + return sbox[num]; +} + +static uint8_t getSBoxInvert(uint8_t num) +{ + return 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(void) +{ + uint32_t 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 < (Nb * (Nr + 1))); ++i) + { + for(j = 0; j < 4; ++j) + { + tempa[j]=RoundKey[(i-1) * 4 + j]; + } + if (i % Nk == 0) + { + // This function rotates the 4 bytes in a word to the left once. + // [a0,a1,a2,a3] becomes [a1,a2,a3,a0] + + // Function RotWord() + { + k = tempa[0]; + tempa[0] = tempa[1]; + tempa[1] = tempa[2]; + tempa[2] = tempa[3]; + tempa[3] = k; + } + + // 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]; + } + else if (Nk > 6 && 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]); + } + } + RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0]; + RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1]; + RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2]; + RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3]; + } +} + +// 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) +{ + 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(void) +{ + 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(void) +{ + 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(void) +{ + 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) +#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)))))); + } +#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 + +// 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(void) +{ + 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(void) +{ + 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(void) +{ + 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; +} + + +// Cipher is the main function that encrypts the PlainText. +static void Cipher(void) +{ + uint8_t round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(0); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr-1 rounds are executed in the loop below. + for(round = 1; round < Nr; ++round) + { + SubBytes(); + ShiftRows(); + MixColumns(); + AddRoundKey(round); + } + + // The last round is given below. + // The MixColumns function is not here in the last round. + SubBytes(); + ShiftRows(); + AddRoundKey(Nr); +} + +static void InvCipher(void) +{ + uint8_t round=0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(Nr); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr-1 rounds are executed in the loop below. + for(round=Nr-1;round>0;round--) + { + InvShiftRows(); + InvSubBytes(); + AddRoundKey(round); + InvMixColumns(); + } + + // The last round is given below. + // The MixColumns function is not here in the last round. + InvShiftRows(); + InvSubBytes(); + AddRoundKey(0); +} + +static void BlockCopy(uint8_t* output, uint8_t* input) +{ + uint8_t i; + for (i=0;i<KEYLEN;++i) + { + output[i] = input[i]; + } +} + + + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ +#if defined(ECB) && ECB + + +void AES128_ECB_encrypt(uint8_t* input, const uint8_t* key, uint8_t* output) +{ + // Copy input to output, and work in-memory on output + BlockCopy(output, input); + state = (state_t*)output; + + Key = key; + KeyExpansion(); + + // The next function call encrypts the PlainText with the Key using AES algorithm. + Cipher(); +} + +void AES128_ECB_decrypt(uint8_t* input, const uint8_t* key, uint8_t *output) +{ + // Copy input to output, and work in-memory on output + BlockCopy(output, input); + state = (state_t*)output; + + // The KeyExpansion routine must be called before encryption. + Key = key; + KeyExpansion(); + + InvCipher(); +} + + +#endif // #if defined(ECB) && ECB + + + + + +#if defined(CBC) && CBC + + +static void XorWithIv(uint8_t* buf) +{ + uint8_t i; + for(i = 0; i < KEYLEN; ++i) + { + buf[i] ^= Iv[i]; + } +} + +void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv) +{ + intptr_t i; + uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */ + + BlockCopy(output, input); + state = (state_t*)output; + + // Skip the key expansion if key is passed as 0 + if(0 != key) + { + Key = key; + KeyExpansion(); + } + + if(iv != 0) + { + Iv = (uint8_t*)iv; + } + + for(i = 0; i < length; i += KEYLEN) + { + XorWithIv(input); + BlockCopy(output, input); + state = (state_t*)output; + Cipher(); + Iv = output; + input += KEYLEN; + output += KEYLEN; + } + + if(remainders) + { + BlockCopy(output, input); + memset(output + remainders, 0, KEYLEN - remainders); /* add 0-padding */ + state = (state_t*)output; + Cipher(); + } +} + +void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv) +{ + intptr_t i; + uint8_t remainders = length % KEYLEN; /* Remaining bytes in the last non-full block */ + + BlockCopy(output, input); + state = (state_t*)output; + + // Skip the key expansion if key is passed as 0 + if(0 != key) + { + Key = key; + KeyExpansion(); + } + + // If iv is passed as 0, we continue to encrypt without re-setting the Iv + if(iv != 0) + { + Iv = (uint8_t*)iv; + } + + for(i = 0; i < length; i += KEYLEN) + { + BlockCopy(output, input); + state = (state_t*)output; + InvCipher(); + XorWithIv(output); + Iv = input; + input += KEYLEN; + output += KEYLEN; + } + + if(remainders) + { + BlockCopy(output, input); + memset(output+remainders, 0, KEYLEN - remainders); /* add 0-padding */ + state = (state_t*)output; + InvCipher(); + } +} + + +#endif // #if defined(CBC) && CBC + + diff --git a/src/aes.h b/src/aes.h new file mode 100644 index 0000000..708a09c --- /dev/null +++ b/src/aes.h @@ -0,0 +1,40 @@ +#ifndef _AES_H_ +#define _AES_H_ + +#include <stdint.h> + + +// #define the macros below to 1/0 to enable/disable the mode of operation. +// +// CBC enables AES128 encryption in CBC-mode of operation and handles 0-padding. +// ECB enables the basic ECB 16-byte block algorithm. Both 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 + + + +#if defined(ECB) && ECB + +void AES128_ECB_encrypt(uint8_t* input, const uint8_t* key, uint8_t *output); +void AES128_ECB_decrypt(uint8_t* input, const uint8_t* key, uint8_t *output); + +#endif // #if defined(ECB) && ECB + + +#if defined(CBC) && CBC + +void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv); +void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length, const uint8_t* key, const uint8_t* iv); + +#endif // #if defined(CBC) && CBC + + + +#endif //_AES_H_ -- 2.1.0

2 19

[PATCH 01/11] Import Tiny AES128
by Anton Lundin 19 Dec '14

19 Dec '14

This imports Tiny AES128 from https://github.com/kokke/tiny-AES128-C for use in the decoding of OSTC3 firmwares. This aes-code is released into the public domain. Signed-off-by: Anton Lundin <glance(a)acc.umu.se> --- msvc/libdivecomputer.vcproj | 6 + src/Makefile.am | 1 + src/aes.c | 486 ++++++++++++++++++++++++++++++++++++++++++++ src/aes.h | 16 ++ 4 files changed, 509 insertions(+) create mode 100644 src/aes.c create mode 100644 src/aes.h diff --git a/msvc/libdivecomputer.vcproj b/msvc/libdivecomputer.vcproj index 78a8190..10a4cf7 100644 --- a/msvc/libdivecomputer.vcproj +++ b/msvc/libdivecomputer.vcproj @@ -247,6 +247,9 @@ > </File> <File + RelativePath="..\src\aes.c" + > + <File RelativePath="..\src\hw_ostc3.c" > </File> @@ -537,6 +540,9 @@ > </File> <File + RelativePath="..\src\aes.h" + > + <File RelativePath="..\include\libdivecomputer\hw_ostc3.h" > </File> diff --git a/src/Makefile.am b/src/Makefile.am index 595f0c7..eb39a4b 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -43,6 +43,7 @@ libdivecomputer_la_SOURCES = \ ihex.h ihex.c \ hw_ostc.c hw_ostc_parser.c \ hw_frog.c \ + aes.h aes.c \ hw_ostc3.c \ cressi_edy.c cressi_edy_parser.c \ cressi_leonardo.c cressi_leonardo_parser.c \ diff --git a/src/aes.c b/src/aes.c new file mode 100644 index 0000000..000a067 --- /dev/null +++ b/src/aes.c @@ -0,0 +1,486 @@ +/* + +This is an implementation of the AES128 algorithm, specifically ECB mode. + +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 + 50fe67cc996d32b6da0937e99bafec60 + d9a4dada0892239f6b8b3d7680e15674 + a78819583f0308e7a6bf36b1386abf23 + c6d3416d29165c6fcb8e51a227ba994e + + +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. + +*/ + +#ifndef _AES_C_ +#define _AES_C_ + + +/*****************************************************************************/ +/* Includes: */ +/*****************************************************************************/ +#include <stdint.h> +#include "aes.h" + + +/*****************************************************************************/ +/* Defines: */ +/*****************************************************************************/ +// The number of columns comprising a state in AES. This is a constant in AES. Value=4 +#define Nb 4 +// The number of 32 bit words in a key. +#define Nk 4 +// Key length in bytes [128 bit] +#define keyln 16 +// The number of rounds in AES Cipher. +#define Nr 10 + + +/*****************************************************************************/ +/* Private variables: */ +/*****************************************************************************/ +// in - pointer to the CipherText to be decrypted. +// out - pointer to buffer to hold output of the decryption. +// state - array holding the intermediate results during decryption. +static uint8_t* in, *out, state[4][4]; + +// The array that stores the round keys. +static uint8_t RoundKey[176]; + +// The Key input to the AES Program +static uint8_t* Key; + +// 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 th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) +// Note that i starts at 1, not 0). +static const uint8_t Rcon[255] = { + 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 }; + + +/*****************************************************************************/ +/* Private functions: */ +/*****************************************************************************/ +static uint8_t getSBoxValue(uint8_t num) +{ + return sbox[num]; +} + +static uint8_t getSBoxInvert(uint8_t num) +{ + return 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() +{ + uint32_t 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 < (Nb * (Nr + 1))); ++i) + { + for(j = 0; j < 4; ++j) + { + tempa[j]=RoundKey[(i-1) * 4 + j]; + } + if (i % Nk == 0) + { + // This function rotates the 4 bytes in a word to the left once. + // [a0,a1,a2,a3] becomes [a1,a2,a3,a0] + + // Function RotWord() + { + k = tempa[0]; + tempa[0] = tempa[1]; + tempa[1] = tempa[2]; + tempa[2] = tempa[3]; + tempa[3] = k; + } + + // 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]; + } + else if (Nk > 6 && 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]); + } + } + RoundKey[i * 4 + 0] = RoundKey[(i - Nk) * 4 + 0] ^ tempa[0]; + RoundKey[i * 4 + 1] = RoundKey[(i - Nk) * 4 + 1] ^ tempa[1]; + RoundKey[i * 4 + 2] = RoundKey[(i - Nk) * 4 + 2] ^ tempa[2]; + RoundKey[i * 4 + 3] = RoundKey[(i - Nk) * 4 + 3] ^ tempa[3]; + } +} + +// 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) +{ + uint8_t i,j; + for(i=0;i<4;i++) + { + for(j = 0; j < 4; ++j) + { + state[j][i] ^= 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() +{ + uint8_t i, j; + for(i = 0; i < 4; ++i) + { + for(j = 0; j < 4; ++j) + { + state[i][j] = getSBoxValue(state[i][j]); + } + } +} + +// 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() +{ + uint8_t temp; + + // Rotate first row 1 columns to left + temp = state[1][0]; + state[1][0] = state[1][1]; + state[1][1] = state[1][2]; + state[1][2] = state[1][3]; + state[1][3] = temp; + + // Rotate second row 2 columns to left + temp = state[2][0]; + state[2][0] = state[2][2]; + state[2][2] = temp; + + temp = state[2][1]; + state[2][1] = state[2][3]; + state[2][3] = temp; + + // Rotate third row 3 columns to left + temp = state[3][0]; + state[3][0] = state[3][3]; + state[3][3] = state[3][2]; + state[3][2] = state[3][1]; + state[3][1] = 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() +{ + uint8_t i; + uint8_t Tmp,Tm,t; + for(i = 0; i < 4; ++i) + { + t = state[0][i]; + Tmp = state[0][i] ^ state[1][i] ^ state[2][i] ^ state[3][i] ; + Tm = state[0][i] ^ state[1][i] ; Tm = xtime(Tm); state[0][i] ^= Tm ^ Tmp ; + Tm = state[1][i] ^ state[2][i] ; Tm = xtime(Tm); state[1][i] ^= Tm ^ Tmp ; + Tm = state[2][i] ^ state[3][i] ; Tm = xtime(Tm); state[2][i] ^= Tm ^ Tmp ; + Tm = state[3][i] ^ t ; Tm = xtime(Tm); state[3][i] ^= Tm ^ Tmp ; + } +} + +// Multiplty is a macro used to multiply numbers in the field GF(2^8) +#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)))))) + + +// 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() +{ + int i; + uint8_t a,b,c,d; + for(i=0;i<4;i++) + { + + a = state[0][i]; + b = state[1][i]; + c = state[2][i]; + d = state[3][i]; + + + state[0][i] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09); + state[1][i] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d); + state[2][i] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b); + state[3][i] = 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() +{ + uint8_t i,j; + for(i=0;i<4;i++) + { + for(j=0;j<4;j++) + { + state[i][j] = getSBoxInvert(state[i][j]); + } + } +} + + +static void InvShiftRows() +{ + uint8_t temp; + + // Rotate first row 1 columns to right + temp=state[1][3]; + state[1][3]=state[1][2]; + state[1][2]=state[1][1]; + state[1][1]=state[1][0]; + state[1][0]=temp; + + // Rotate second row 2 columns to right + temp=state[2][0]; + state[2][0]=state[2][2]; + state[2][2]=temp; + + temp=state[2][1]; + state[2][1]=state[2][3]; + state[2][3]=temp; + + // Rotate third row 3 columns to right + temp=state[3][0]; + state[3][0]=state[3][1]; + state[3][1]=state[3][2]; + state[3][2]=state[3][3]; + state[3][3]=temp; +} + + +// Cipher is the main function that encrypts the PlainText. +static void Cipher() +{ + uint8_t i, j, round = 0; + + //Copy the input PlainText to state array. + for(i = 0; i < 4; ++i) + { + for(j = 0; j < 4 ; ++j) + { + state[j][i] = in[(i * 4) + j]; + } + } + + // Add the First round key to the state before starting the rounds. + AddRoundKey(0); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr-1 rounds are executed in the loop below. + for(round = 1; round < Nr; ++round) + { + SubBytes(); + ShiftRows(); + MixColumns(); + AddRoundKey(round); + } + + // The last round is given below. + // The MixColumns function is not here in the last round. + SubBytes(); + ShiftRows(); + AddRoundKey(Nr); + + // The encryption process is over. + // Copy the state array to output array. + for(i = 0; i < 4; ++i) + { + for(j = 0; j < 4; ++j) + { + out[(i * 4) + j] = state[j][i]; + } + } +} + +static void InvCipher() +{ + uint8_t i,j,round=0; + + //Copy the input CipherText to state array. + for(i=0;i<4;i++) + { + for(j=0;j<4;j++) + { + state[j][i] = in[i*4 + j]; + } + } + + // Add the First round key to the state before starting the rounds. + AddRoundKey(Nr); + + // There will be Nr rounds. + // The first Nr-1 rounds are identical. + // These Nr-1 rounds are executed in the loop below. + for(round=Nr-1;round>0;round--) + { + InvShiftRows(); + InvSubBytes(); + AddRoundKey(round); + InvMixColumns(); + } + + // The last round is given below. + // The MixColumns function is not here in the last round. + InvShiftRows(); + InvSubBytes(); + AddRoundKey(0); + + // The decryption process is over. + // Copy the state array to output array. + for(i=0;i<4;i++) + { + for(j=0;j<4;j++) + { + out[i*4+j]=state[j][i]; + } + } +} + + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ + +void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output) +{ + // Copy the Key and CipherText + Key = key; + in = input; + out = output; + + // The KeyExpansion routine must be called before encryption. + KeyExpansion(); + + // The next function call encrypts the PlainText with the Key using AES algorithm. + Cipher(); +} + +void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output) +{ + Key = key; + in = input; + out = output; + + KeyExpansion(); + + InvCipher(); +} + +#endif //_AES_C_ + + diff --git a/src/aes.h b/src/aes.h new file mode 100644 index 0000000..5fb2176 --- /dev/null +++ b/src/aes.h @@ -0,0 +1,16 @@ +#ifndef _AES_H_ +#define _AES_H_ + +#include <stdint.h> + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +void AES128_ECB_encrypt(uint8_t* input, uint8_t* key, uint8_t *output); +void AES128_ECB_decrypt(uint8_t* input, uint8_t* key, uint8_t *output); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ +#endif //_AES_H_ -- 1.9.1

2 41

DC setting api
by john＠vanostrand.com 18 Dec '14

18 Dec '14

3 3

Quick question before dig into this
by John Van Ostrand 10 Dec '14

10 Dec '14

Two friends brought over their Seiko-based DCs. One an Apeks Quantum and the other a Zeagle N2ition. The Zeagle cable was used. I tried both in Windows and Linux to import dives (subsurface) but as soon as the conversation took place the DCs switched from PC to Time mode. It occurred at the first LED flash on the cable. This looks like a protocol issue but before I dig into this I thought I'd ask and look for some advice. -- John Van Ostrand At large on sabbatical

2 1

[PATCH 1/2] Cochran: removed unneeded serial configuration and commands.
by John Van Ostrand 07 Dec '14

07 Dec '14

The Cochran serial configuration and commands duplicated what Analyst did when communicating with the DC. These are unneeded and were removed. Signed-off-by: John Van Ostrand <john(a)vanostrand.com> --- src/cochran_commander.c | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/src/cochran_commander.c b/src/cochran_commander.c index 5f7b8f3..dc9b3d5 100644 --- a/src/cochran_commander.c +++ b/src/cochran_commander.c @@ -82,7 +82,6 @@ cochran_packet (cochran_device_t *device, dc_event_progress_t *progress, if (high_speed) { serial_sleep(device->port, 45); - // Weird but I only get the right result when I do it twice // Rates are odd, like 825600 for the EMC, 115200 for commander rc = serial_configure(device->port, device->data.conf.high_baud, 8, SERIAL_PARITY_NONE, 2, SERIAL_FLOWCONTROL_NONE); @@ -91,14 +90,6 @@ cochran_packet (cochran_device_t *device, dc_event_progress_t *progress, free (device); return DC_STATUS_IO; } - - rc = serial_configure(device->port, device->data.conf.high_baud, 8, - SERIAL_PARITY_NONE, 2, SERIAL_FLOWCONTROL_NONE); - if (rc == -1) { - ERROR (abstract->context, "Failed to set the high baud rate."); - free (device); - return DC_STATUS_IO; - } } // Receive the answer from the device. @@ -146,14 +137,8 @@ cochran_commander_serial_setup (cochran_device_t *device, dc_context_t *context) serial_set_queue_size(device->port, 4096, 4096); // Make sure everything is in a sane state. - // Mimicing Analyst software with excessive flushes serial_flush (device->port, SERIAL_QUEUE_OUTPUT); serial_flush (device->port, SERIAL_QUEUE_INPUT); - serial_flush (device->port, SERIAL_QUEUE_INPUT); - serial_flush (device->port, SERIAL_QUEUE_INPUT); - serial_flush (device->port, SERIAL_QUEUE_INPUT); - serial_flush (device->port, SERIAL_QUEUE_INPUT); - serial_flush (device->port, SERIAL_QUEUE_INPUT); serial_set_break(device->port, 1); serial_sleep(device->port, 16); -- 1.9.3

1 1

C# and libdivecomputer
by libdivecomputer＠henrik.synth.no 01 Dec '14

01 Dec '14

loicmichel wrote: > > Dear Anton Lundin, > > I'm used to program in C# and have zaro experience with C. > > Are you aware of any c# code to link to the libdivecomputer ? > > I can't figure out from the example how to download and use data from > a VEO2 computer. > > Thanks for help, > There's a libdivecomputer DLL here: http://www.libdivecomputer.org/builds/divinglog/ Maybe that's useful? Cheers, Henrik

4 9

Roadmap for the v0.5 release
by Jef Driesen 01 Dec '14

01 Dec '14

Hi, I originally planned to release version 0.5 around the end of September. Looks like I've been a bit optimistic there. Anyway, instead of committing on a new deadline, I'll just give an overview of all the things that are in the pipeline. First of all, there are 4 completely new backends in development: * Suunto EON steel (done) * Citizen Hyper Aqualand (done) * Cochran Commander and EMC * Divesystem Orca and iDive There are also a few other new features being worked on: * Firmware updater for the HW OSTC3 and OSTC Sport * A more modular example application * Regular bugfixes here and there So these are the things I would like to finish first. There has been some discussion about a string based api, but I would like to postpone that after the v0.5 release. I might already consider adding a string based variant of the devinfo event (for the serial number and firmware version), but that will depend on how well everything else on my todo list goes. Jef

1 0

Re: Patches to add basic support for the Suunto EON Steel
by Jef Driesen 24 Nov '14

24 Nov '14

Linus, According to Dirk the plan is to have a subsurface beta ready before the eonsteel is available on the market. And thus is would be convenient to have a first version included in libdivecomputer. I'll do my best to meet that deadline. There has been quite some discussion on the new string based api for libdivecomputer. I'll need some more time to go through this whole discussion and give its some more thoughts. Therefore, I propose we target for a first version of the eonsteel backend without any of those string based api changes. So that's basically your 0001 patch. Those are not critical features, and trying to rush things is always a bad idea. So what I consider mandatory to fix before I'll commit your patches are: Naming conventions for entry point functions and the private device and parser structures. I know you don't like these long names, but that's the convention in the libdivecomputer codebase, and I'll insist on following existing practice. See the 0001 patch. Working build on Windows. I have attached a patch that does the necessary casts (and a few other things) to get the mingw and msvc builds to work. In most places, I simply added casts wherever the compiler complained, without checking whether that was the right thing to do. Many of those casts can probably avoided by using the correct type (unsigned instead of signed). Even the gcc compilers spits out tons of warnings, so you don't even need msvc to locate the type mismatches. BTW, if the goal is to demo a build to Suunto, then I think we should not only compile test on Windows, but actually try a Windows build too. They are probably using Windows. Proper integration with the libdivecomputer logging functions. The other ones I can live with and/or fix later. (more inline comments below) On 28-10-14 17:51, Linus Torvalds wrote: > On Tue, Oct 28, 2014 at 8:43 AM, Jef Driesen <jef(a)libdivecomputer.org> wrote: >> >> There are also some header files like unistd.h which don't exist on windows. > > Hmm. I wonder why I included them. > > Part of it is probably that the whole back-end started out as this > "suunto hacking tool" that did a lot of "print hex information of the > packets". That's also why there was no libdivecomputer infrastructure, > this thing was entirely stand-alone for just trying to gather traces > and recreate them, and figure out what the things did. No idea why you needed sys/types.h, fcntl.h, etc. Most of the other ones are also no longer necessary if the custom logging is removed. > I got no actual information from Suunto, but the fact that many things > are just text helped. Seeing filenames etc in the dumps etc.. And the > actual dive dumps have this interesting "each data has its type > associated with it, and each type has a human-readable type > descriptor". Which meant that I never needed to guess what the actual > data means - the problem was figuring out the odd marshaling of the > data, and the odd packet protocol. I guess everyone does printf logging at some point. Me too :-) >> Libdivecomputer doesn't log anything on its own. The actual logging is done >> by the application. That's on purpose. That's for example how subsurface is >> able to generate a libdivecomputer log directly from the GUI. I believe >> that's a very useful feature, which certainly doesn't sucks :-) > > So the logging I have is for protocol errors, or surprising things. > Not useful to users. It's more of a protocol verification, I would > *not* want it to show up in applications. The logged info doesn't need to be useful for the user. The user only needs some super easy way to get the log and then send it back to someone that does understand what's inside. There are also multiple loglevels, which the application can control. ERROR and WARNING are self explanatory. INFO is used for logging the communication protocol (e.g. raw data packets), and DEBUG is for whatever else you would like to log. >> Why do you need void pointers here? You're parsing a byte array, which is by >> definition an unsigned char array. So where do you get void pointers from? > > "void *" is the "random byte area" type. It's one of the things C++ > completely screwed up. It's very useful when you use the helper > function on random data (that may be embedded in structures etc, or > give pointers to "uint32_t" etc when you convert from little-endian to > big-endian etc. > > But if there are no cases of that left over, maybe you can convert > them all to "unsigned char *" .. I very rarely need void pointers. Probably only for very generic functions like memcpy and friends. For byte arrays unsigned char's are perfect, and they also avoid the whole void pointer arithmetic problem. >> I know it doesn't support a standard memory dump. But a dump of one dive is >> fine too. I can use the parser standalone. > > I hacked up subsurface to just dump the per-dive data to a > "dive-%08x.log" file. That's *fairly* close to what the computer does > internally, although this dumped data contains the date in the first > 32-bit word, which is what the parser expects. On the dive computer, > the date is encoded in the filename - see the > > dc_buffer_append(file, buf, 4); > > in eon_steel_device_foreach() where I append it to the data buffer > instead, since the parser doesn't have access to the filename. That looks very reasonable. Is it always a 32bit number? If it could be a 64bit timestamp, then it might be safer to reserve 8 bytes here. One Y2038 problem less :-) This timestamp is also a good candidate for use as the libdivecomputer fingerprint! > (The dive date is *also* encoded in the dive data, but in a very > inconvenient format with a dynamic type, so I wanted the data from the > filename for simplicity). > > So here are the dumps of the dives I have on that dive computer so > far, in that "parser format". > > That first dive is just me lowering the dive computer into the > neighbors pool. The other 21 dives are the ones we did in Bonaire. Your data files where too large for the list. I got them, but if you want I can still manually approve your mail. > Dirk has one of the Intel engineers create a contraption to lower the > thing into the pool multiple times, so that I can see what happens to > the directory listing when it no longer fits in one "readdir" reply > (the packets may be 64 bytes each, but they are chained up to be > replies that can apparently be up to 1kB in size - at least I haven't > seen anything bigger than that yet. And I don't know what happens when > the directory listing is bigger than that, because the 22 dives I have > so far create only about 460 bytes of "readdir reply"). A small pressure chamber might be even more convenient: no need to have a pool around. Jef

3 17

Re: Petrel data problems [was Re: Crash when opening log file]
by Jef Driesen 24 Nov '14

24 Nov '14

On 23-11-14 16:25, Dirk Hohndel wrote: > On Sun, Nov 23, 2014 at 11:39:55AM +0100, Henrik Brautaset Aronsen > wrote: >>> >>> I did a new fresh import from my Petrel on the latest master and >>> saved it. >>> This time the saved petrel2.xml [1] does not contain the empty >>> <cylinder >>> /> statements. But id does contain cylinders with something in them, >>> even >>> on gauge dives: >>> >>> <cylinder o2='52.0%' /> >>> <cylinder o2='18.0%' he='45.0%' /> > > I haven't used my Petrel in gauge mode (that's one heck of an expensive > gauge...). It would make sense that it doesn't support any gases in > that > mode, but libdivecomputer doesn't know that the Petrel was in gauge > mode > so it tells us about those gases as they are present in the dive > header. > I am making a lot of assumptions here - but since I know a little bit > about the Petrel data format I think these are reasonable assumptions. > > Jef, can you confirm this analysis? Yes, your analysis is correct. I just checked the documentation, and the gauge mode isn't mentioned anywhere. So either it's just missing in the documentation, or it's not recorded. The Petrel (and Predator too) is also one of the devices where the dive mode is stored in the sample data, and not the dive header. I assume that's done because you can switch between OC/CC during the dive. But that makes it also rather difficult to tell whether a dive is OC or CC (e.g. what should we do if there are mixed samples?). And thus what libdivecomputer does is just return all gas mixes. >>> I tried to do a data dump, but both subsurface and the >>> libdivecomputer >>> dump app doesn't cooperate: > > IIRC, the Petrel doesn't support dumps. > >> Result: Unsupported operation The Petrel protocol doesn't support memory dumps. The Petrel also supports the older Predator protocol. That one supports memory dumps, but is only capable of downloading the last 128K of memory. For protocols without support for memory dumps, I usually dump the individual dives, using this patch for the universal app: http://www.libdivecomputer.org/tmp/universal_dump_dives.patch Jef

1 0

Re: Petrel data problems [was Re: Crash when opening log file]
by Henrik Brautaset Aronsen 23 Nov '14

23 Nov '14

Henrik Brautaset Aronsen wrote: > Dirk Hohndel wrote: >> >> On November 22, 2014 9:52:42 PM Miika Turkia <miika.turkia(a)gmail.com> >> wrote: >> >> > > I'll need to poke at that and figure out what's happening. I'm quite >> > > pressed for time right now, hopefully I'll get to it after the >> weekend. >> > > >> > >> > The XML contains po2 values. Isn't that currently enough to make >> Subsruface >> > treat the dive as a CCR dive? >> >> I believe you are correct >> > > I did a new fresh import from my Petrel on the latest master and saved > it. This time the saved petrel2.xml [1] does not contain the empty > <cylinder /> statements. But id does contain cylinders with something > in them, even on gauge dives: > > <cylinder o2='52.0%' /> > <cylinder o2='18.0%' he='45.0%' /> > > I tried to do a data dump, but both subsurface and the libdivecomputer > dump app doesn't cooperate: > > $ examples/universal -l petrel2.log -m petrel2.bin -v -n "Shearwater > Petrel" /dev/tty.Petrel-SerialPort > DATETIME 2014-11-23T10:29:31Z (1416738571) > VERSION 0.5.0-devel (e307227b808186beccc00461103477156e97f5e4) > Opening the device (Shearwater Petrel, /dev/tty.Petrel-SerialPort). > INFO: Open: name=/dev/tty.Petrel-SerialPort > INFO: Configure: baudrate=115200, databits=8, parity=0, stopbits=1, > flowcontrol=0 > INFO: Timeout: value=3000 > INFO: Sleep: value=300 > INFO: Flush: queue=3, input=0, output=0 > Registering the event handler. > Registering the cancellation handler. > Downloading the memory dump. > universal.c:793: Error downloading the memory dump. > INFO: Write: size=9, data=FF0105002E902000C0 > Result: Unsupported operation > > (at this point, the Petrel immediately drops out of the upload dive mode) The same thing happens with the universal app from http://libdivecomputer.org/builds/macosx/ as well. Any ideas, Jef? $ ~/Downloads/universal -l petrel2.log -m petrel2.bin -v -n "Shearwater Petrel" /dev/tty.Petrel-SerialPort DATETIME 2014-11-23T10:37:18Z (1416739038) VERSION 0.5.0-devel (5e88cf749475377fe21d2dd2b4d60fce6542127c) Opening the device (Shearwater Petrel, /dev/tty.Petrel-SerialPort). INFO: Open: name=/dev/tty.Petrel-SerialPort INFO: Configure: baudrate=115200, databits=8, parity=0, stopbits=1, flowcontrol=0 INFO: Timeout: value=3000 INFO: Sleep: value=300 INFO: Flush: queue=3, input=0, output=0 Registering the event handler. Registering the cancellation handler. Downloading the memory dump. ../../source/examples/universal.c:802: Error downloading the memory dump. INFO: Write: size=9, data=FF0105002E902000C0 Result: Unsupported operation -H

1 0

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