Diffstat (limited to 'gammu/emb/gammu/depend/siemens/chiffre.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | gammu/emb/gammu/depend/siemens/chiffre.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/gammu/emb/gammu/depend/siemens/chiffre.c b/gammu/emb/gammu/depend/siemens/chiffre.c new file mode 100644 index 0000000..65a06ba --- a/dev/null +++ b/gammu/emb/gammu/depend/siemens/chiffre.c @@ -0,0 +1,223 @@ +/* xsiemens.c */ +/* Siemens service code generator */ +/* (C) Ivan Gorinov, 30.09.2002 */ + +#include "chiffre.h" + +unsigned char key1[4] = {0x57, 0xF9, 0x3A, 0xC1}; /* Level 1 key */ +unsigned char key2[4] = {0xA4, 0xD3, 0x67, 0x9C}; /* Level 2 key */ + +/* 4-bit substitution boxes */ +unsigned char sbox_h[0x10] = +{0x09, 0x02, 0x04, 0x06, 0x08, 0x07, 0x05, 0x03, 0x01, 0x00, + 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F}; +unsigned char sbox_l[0x10] = +{0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00, + 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F}; + +unsigned char sbox[0x100]; /* 8-bit substitution box */ + +char digit[] = "0123456789ABCDEF"; + +/* Convert hex digit to binary value */ +int from_hex(int c) +{ + int i; + + for(i = 0; i < 0x10; i++) if(c == digit[i]) break; + if (i >= 0x10) i = -1; + return i; +} + +/* Convert binary value to string (decimal) */ +int bin2dec(char *s, int n, unsigned long l) +{ + int c, i, j; + + j = n; + s[j] = 0; + for(i = 0; i < n; i++) { + c = l % 10; + l /= 10; + c = digit[c]; + s[--j] = c; + } + return j; +} + +/* Convert two 4-bit boxes to one 8-bit */ +int initbox(void) +{ + int i, j, k, x; + + k = 0; + for(i = 0; i < 0x10; i++) { + x = sbox_h[i] << 4; + for(j = 0; j < 0x10; j++) { + sbox[k] = sbox_l[j] | x; + k++; + } + } + return 0; +} + +/* Substitution */ +void subst(unsigned char *b, unsigned char *a, int n) +{ + int i; + + for(i = 0; i < n; i++) b[i] = sbox[a[i]]; +} + +/* Xor N bytes with Z, inverting every odd byte */ +void xxstr(unsigned char *b, unsigned char *a, int n, int z) +{ + int i; + + for(i = 0; i < n; i++) { + if(i & 1) { + b[i] = (~a[i]) ^ z; + } else { + b[i] = a[i] ^ z; + } + } +} + +/* Encryption (1 iteration) */ +void ec_f(unsigned char *a, int n, int z) +{ + unsigned char bc[0x20], bs[0x10], bx[0x10]; + int n2, i; + + for(i = 0; i < n; i++) bc[i] = a[i]; + n2 = n >> 1; + subst(bs, a, n2); + xxstr(bx, bs, n2, z); + for(i = 0; i < n2; i++) { + a[i] = bx[i] ^ bc[i+n2]; + a[i+n2] = bc[i]; + } +} + +void ec_f_bak(unsigned char *a, int n, int z) +{ + unsigned char bc[0x20], bs[0x10], bx[0x10]; + int n2, i; + + n2 = n >> 1; + for(i = 0; i < n2; i++) bc[i+n2] = a[i]; + subst(bs, bc + n2, n2); + xxstr(bx, bs, n2, z); + for(i = 0; i < n2; i++) bc[i] = bx[i] ^ a[i+n2]; + for(i = 0; i < n; i++) a[i] = bc[i]; +} + +/* Decryption (1 iteration) */ +void dc_f(unsigned char *a, int n, int z) +{ + unsigned char bc[0x20], bs[0x10], bx[0x10]; + int n2, i; + + for(i = 0; i < n; i++) bc[i] = a[i]; + n2 = n >> 1; + subst(bs, a + n2, n2); + xxstr(bx, bs, n2, z); + for(i = 0; i < n2; i++) { + a[i] = bc[i+n2]; + a[i+n2] = bx[i] ^ bc[i]; + } +} + +/* Encryption (IMSI -> code) */ +void ss_encrypt(unsigned char *a, int n, unsigned char *key) +{ + int i; + + for(i = 0; i < 4; i++) ec_f_bak(a, n, key[i]); +} + +/* Decryption (code -> IMSI) */ +void ss_decrypt(unsigned char *a, int n, unsigned char *key) +{ + int i; + + for(i = 0; i < 4; i++) dc_f(a, n, key[3-i]); +} + +int siemens_code(char *str_imsi, char *str_code, int level) +{ + unsigned char array[8]; + unsigned char xcode[8]; + unsigned char test[8]; + unsigned long l0, l1; + unsigned char *key; + int x, c, i, j; + + if(!str_code) return -1; + str_code[0] = 0; + + initbox(); + + switch(level) { + case 1: key = key1; break; + case 2: key = key2; break; + default: return -1; + } + + /* Check the length of IMSI */ + for(i = 0; i < 32; i++) if(!str_imsi[i]) break; + if(i == 0) return -1; + if(i >= 32) return -1; + + /* Convert last 12 digits to 6 bytes [2-7] */ + for(j = 7; j >= 2; j--) { + if (i == 0) { + c = 0x0F; + } else { + c = str_imsi[--i]; + c = from_hex(c); + if(c < 0) return -1; + } + x = c; + if(i == 0) { + c = 0x0F; + } else { + c = str_imsi[--i]; + c = from_hex(c); + if(c < 0) return -1; + } + x = (x << 4) | c; + array[j] = x; + } + + /* This byte is never checked by firmware */ + array[1] = 0; + + /* Byte [0] <- checksum */ + x = 0; + for(i = 1; i < 8; i++) x ^= array[i]; + array[0] = x; + + for(i = 0; i < 8; i++) xcode[i] = array[i]; + + /* Make the code */ + ss_encrypt(xcode, 8, key); + + /* The test */ + for(i = 0; i < 8; i++) test[i] = xcode[i]; + ss_decrypt(test, 8, key); + for(i = 0; i < 8; i++) if(test[i] != array[i]) break; + if(i < 8) return -1; + + /* Convert to strings */ + l0 = 0; + for(i = 3; i >= 0; i--) l0 = (l0 << 8) | xcode[i]; + + l1 = 0; + for(i = 7; i >= 4; i--) l1 = (l1 << 8) | xcode[i]; + + bin2dec(str_code, 10, l0); + bin2dec(str_code + 10, 10, l1); + + return 0; +} |