[PATCH] broken A5/3-4 cipher support

--- src/gsm/a5.c | 143 +++++++++++++++++++++++++++++++++++++--------------- tests/a5/a5_test.c | 75 ++++++++++++++++++++++----- tests/a5/a5_test.ok | 24 +++++++++ 3 files changed, 188 insertions(+), 54 deletions(-) diff --git a/src/gsm/a5.c b/src/gsm/a5.c index de821e8..e8c86a2 100644 --- a/src/gsm/a5.c +++ b/src/gsm/a5.c @@ -38,46 +38,7 @@ #include <string.h> #include <osmocom/gsm/a5.h> - -/*! \brief Main method to generate a A5/x cipher stream - * \param[in] n Which A5/x method to use - * \param[in] key 8 byte array for the key (as received from the SIM) - * \param[in] fn Frame number - * \param[out] dl Pointer to array of ubits to return Downlink cipher stream - * \param[out] ul Pointer to array of ubits to return Uplink cipher stream - * \returns 0 for success, -ENOTSUP for invalid cipher selection. - * - * Currently A5/[0-2] are supported. - * Either (or both) of dl/ul can be NULL if not needed. - */ -int -osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) -{ - switch (n) - { - case 0: - if (dl) - memset(dl, 0x00, 114); - if (ul) - memset(ul, 0x00, 114); - break; - - case 1: - osmo_a5_1(key, fn, dl, ul); - break; - - case 2: - osmo_a5_2(key, fn, dl, ul); - break; - - default: - /* a5/[3..7] not supported here/yet */ - return -ENOTSUP; - } - - return 0; -} - +#include <osmocom/gsm/kasumi.h> /* ------------------------------------------------------------------------ */ /* A5/1&2 common stuff */ @@ -368,4 +329,106 @@ osmo_a5_2(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) } } +/* ------------------------------------------------------------------------ */ +/* A5/3&4 */ +/* ------------------------------------------------------------------------ */ + +/*! \brief Generate a GSM A5/4 cipher stream + * \param[in] key 16 byte array for the key (as received from the SIM) + * \param[in] fn Frame number + * \param[out] dl Pointer to array of ubits to return Downlink cipher stream + * \param[out] ul Pointer to array of ubits to return Uplink cipher stream + * \param[in] fn_correct true if fn is a real GSM frame number and thus requires internal conversion + * + * Either (or both) of dl/ul should be NULL if not needed. + * + * Implementation based on specifications from 3GPP TS 55.216, 3GPP TR 55.919 and ETSI TS 135 202 + * with slight simplifications (CE hardcoded to 0). + */ +void +_a5_4(const uint8_t *ck, uint32_t fn, ubit_t *dl, ubit_t *ul) +{ + uint8_t i, gamma[32], uplink[15]; + uint32_t fn_count = osmo_a5_fn_count(fn); + + if (ul) { + _kasumi_kgcore(0xF, 0, fn_count, 0, ck, gamma, 228); + for(i = 0; i < 15; i++) uplink[i] = (gamma[i + 14] << 2) + (gamma[i + 15] >> 6); + osmo_pbit2ubit(ul, uplink, 114); + } + if (dl) { + _kasumi_kgcore(0xF, 0, fn_count, 0, ck, gamma, 114); + osmo_pbit2ubit(dl, gamma, 114); + } +} + +/*! \brief Generate a GSM A5/3 cipher stream + * \param[in] key 8 byte array for the key (as received from the SIM) + * \param[in] fn Frame number + * \param[out] dl Pointer to array of ubits to return Downlink cipher stream + * \param[out] ul Pointer to array of ubits to return Uplink cipher stream + * \param[in] fn_correct true if fn is a real GSM frame number and thus requires internal conversion + * + * Either (or both) of dl/ul should be NULL if not needed. + * + * Implementation based on specifications from 3GPP TS 55.216, 3GPP TR 55.919 and ETSI TS 135 202 + * with slight simplifications (CE hardcoded to 0). + */ +void +_a5_3(const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) +{ + uint8_t ck[16]; + memcpy(ck, key, 8); + memcpy(ck + 8, key, 8); + /* internal function require 128 bit key so we expand by concatenating supplied 64 bit key */ + _a5_4(ck, fn, dl, ul); +} + +/*! \brief Main method to generate a A5/x cipher stream + * \param[in] n Which A5/x method to use + * \param[in] key 8 byte array for the key (as received from the SIM) + * \param[in] fn Frame number + * \param[out] dl Pointer to array of ubits to return Downlink cipher stream + * \param[out] ul Pointer to array of ubits to return Uplink cipher stream + * \returns 0 for success, -ENOTSUP for invalid cipher selection. + * + * Currently A5/[0-4] are supported. + * Either (or both) of dl/ul can be NULL if not needed. + */ +int +osmo_a5(int n, const uint8_t *key, uint32_t fn, ubit_t *dl, ubit_t *ul) +{ + switch (n) + { + case 0: + if (dl) + memset(dl, 0x00, 114); + if (ul) + memset(ul, 0x00, 114); + break; + + case 1: + osmo_a5_1(key, fn, dl, ul); + break; + + case 2: + osmo_a5_2(key, fn, dl, ul); + break; + + case 3: + _a5_3(key, fn, dl, ul); + break; + + case 4: + _a5_4(key, fn, dl, ul); + break; + + default: + /* a5/[5..7] not supported here/yet */ + return -ENOTSUP; + } + + return 0; +} + /*! @} */ diff --git a/tests/a5/a5_test.c b/tests/a5/a5_test.c index 14436f1..a6b799e 100644 --- a/tests/a5/a5_test.c +++ b/tests/a5/a5_test.c @@ -2,6 +2,7 @@ #include <stdlib.h> #include <stdint.h> #include <string.h> +#include <stdbool.h> #include <osmocom/core/bits.h> #include <osmocom/core/utils.h> @@ -36,24 +37,56 @@ static const uint8_t ul[] = { 0x80, 0xba, 0xab, 0xc0, 0x59, 0x26, 0x40, }; -static const char * -binstr(ubit_t *d, int n) +static inline uint32_t osmo_a5_fn(uint32_t fn_count) { - static char str[256]; - int i; + int t1 = fn_count >> 11; + int t2 = fn_count & 0x1f; + int t3 = (fn_count >> 5) & 0x3f; + return (t1 * 26 * 51) + ((t3 - t2 + 26) % 26) * 51 + t3; +} - for (i=0; i<n; i++) - str[i] = d[i] ? '1' : '0'; +static inline bool print_a5(int n, int k, const char * dir, const ubit_t * out, const char * block) +{ + uint8_t len = 114 / 8 + 1, buf[len], res[len]; + printf("A5/%d - %s: %s => ", n, dir, osmo_ubit_dump(out, 114)); + osmo_hexparse(block, res, len); + osmo_ubit2pbit(buf, out, 114); + if (0 != memcmp(buf, res, len)) { + printf("FAIL\nGOT: [%d] %s\nEXP: [%d] %s\n", k, osmo_hexdump_nospc(buf, len), k, osmo_hexdump_nospc(res, len)); + return false; + } + printf("OK\n"); + return true; +} - str[i] = '\0'; +static inline bool test_a53(const char * kc, uint32_t count, const char * block1, const char * block2) +{ + ubit_t dlout[114], ulout[114]; + uint8_t key[8]; + + osmo_hexparse(kc, key, 8); + osmo_a5(3, key, osmo_a5_fn(count), dlout, NULL); + osmo_a5(3, key, osmo_a5_fn(count), NULL, ulout); - return str; + return print_a5(3, 8, "DL", dlout, block1) & print_a5(3, 8, "UL", ulout, block2); } +static inline bool test_a54(const char * kc, uint32_t count, const char * block1, const char * block2) +{ + ubit_t dlout[114], ulout[114]; + uint8_t key[16]; + + osmo_hexparse(kc, key, 16); + osmo_a5(4, key, osmo_a5_fn(count), dlout, NULL); + osmo_a5(4, key, osmo_a5_fn(count), NULL, ulout); + + return print_a5(4, 8, "DL", dlout, block1) & print_a5(4, 8, "UL", ulout, block2); +} + + int main(int argc, char **argv) { - ubit_t exp[114]; - ubit_t out[114]; + ubit_t exp[114], out[114]; int n, i; for (n=0; n<3; n++) { @@ -66,13 +99,13 @@ int main(int argc, char **argv) osmo_a5(n, key, fn, out, NULL); - printf("A5/%d - DL: %s", n, binstr(out, 114)); + printf("A5/%d - DL: %s", n, osmo_ubit_dump(out, 114)); if (!memcmp(exp, out, 114)) printf(" => OK\n"); else { printf(" => BAD\n"); - printf(" Expected: %s", binstr(out, 114)); + printf(" Expected: %s", osmo_ubit_dump(out, 114)); fprintf(stderr, "[!] A5/%d DL failed", n); exit(1); } @@ -82,17 +115,31 @@ int main(int argc, char **argv) osmo_a5(n, key, fn, NULL, out); - printf("A5/%d - UL: %s", n, binstr(out, 114)); + printf("A5/%d - UL: %s", n, osmo_ubit_dump(out, 114)); if (!memcmp(exp, out, 114)) printf(" => OK\n"); else { printf(" => BAD\n"); - printf(" Expected: %s", binstr(out, 114)); + printf(" Expected: %s", osmo_ubit_dump(out, 114)); fprintf(stderr, "[!] A5/%d UL failed", n); exit(1); } } +// test vectors from 3GPP TS 55.217 and TS 55.218 + test_a53("2BD6459F82C5BC00", 0x24F20F, "889EEAAF9ED1BA1ABBD8436232E440", "5CA3406AA244CF69CF047AADA2DF40"); + test_a53("952C49104881FF48", 0x061272, "FB4D5FBCEE13A33389285686E9A5C0", "25090378E0540457C57E367662E440"); + test_a53("EFA8B2229E720C2A", 0x33FD3F, "0E4015755A336469C3DD8680E30340", "6F10669E2B4E18B042431A28E47F80"); + test_a53("952C49104881FF48", 0x061527, "AB7DB38A573A325DAA76E4CB800A40", "4C4B594FEA9D00FE8978B7B7BC1080"); + test_a53("3451F23A43BD2C87", 0x0E418C, "75F7C4C51560905DFBA05E46FB54C0", "192C95353CDF979E054186DF15BF00"); + test_a53("CAA2639BE82435CF", 0x2FF229, "301437E4D4D6565D4904C631606EC0", "F0A3B8795E264D3E1A82F684353DC0"); + test_a53("7AE67E87400B9FA6", 0x2F24E5, "F794290FEF643D2EA348A7796A2100", "CB6FA6C6B8A705AF9FEFE975818500"); + test_a53("58AF69935540698B", 0x05446B, "749CA4E6B691E5A598C461D5FE4740", "31C9E444CD04677ADAA8A082ADBC40"); + test_a53("017F81E5F236FE62", 0x156B26, "2A6976761E60CC4E8F9F52160276C0", "A544D8475F2C78C35614128F1179C0"); + test_a53("1ACA8B448B767B39", 0x0BC3B5, "A4F70DC5A2C9707F5FA1C60EB10640", "7780B597B328C1400B5C74823E8500"); + test_a54("3D43C388C9581E337FF1F97EB5C1F85E", 0x35D2CF, "A2FE3034B6B22CC4E33C7090BEC340", "170D7497432FF897B91BE8AECBA880"); + test_a54("A4496A64DF4F399F3B4506814A3E07A1", 0x212777, "89CDEE360DF9110281BCF57755A040", "33822C0C779598C9CBFC49183AF7C0"); + return 0; } diff --git a/tests/a5/a5_test.ok b/tests/a5/a5_test.ok index 4497e14..cefcdb6 100644 --- a/tests/a5/a5_test.ok +++ b/tests/a5/a5_test.ok @@ -4,3 +4,27 @@ A5/1 - DL: 110010111010001001010101011101100001011101011101001110110001110001111 A5/1 - UL: 110110010000001101011110000011110010101011101100000100111001101000000101110101001010100001111011101100010110010010 => OK A5/2 - DL: 010001011001110010001000110000111000001010110111111111111011001110011000110100101111100101101110000011110001010010 => OK A5/2 - UL: 111100000011101010101100110111101110001101011011010111100110010110000000101110101010101111000000010110010010011001 => OK +A5/3 - DL: 100010001001111011101010101011111001111011010001101110100001101010111011110110000100001101100010001100101110010001 => OK +A5/3 - UL: 010111001010001101000000011010101010001001000100110011110110100111001111000001000111101010101101101000101101111101 => OK +A5/3 - DL: 111110110100110101011111101111001110111000010011101000110011001110001001001010000101011010000110111010011010010111 => OK +A5/3 - UL: 001001010000100100000011011110001110000001010100000001000101011111000101011111100011011001110110011000101110010001 => OK +A5/3 - DL: 000011100100000000010101011101010101101000110011011001000110100111000011110111011000011010000000111000110000001101 => OK +A5/3 - UL: 011011110001000001100110100111100010101101001110000110001011000001000010010000110001101000101000111001000111111110 => OK +A5/3 - DL: 101010110111110110110011100010100101011100111010001100100101110110101010011101101110010011001011100000000000101001 => OK +A5/3 - UL: 010011000100101101011001010011111110101010011101000000001111111010001001011110001011011110110111101111000001000010 => OK +A5/3 - DL: 011101011111011111000100110001010001010101100000100100000101110111111011101000000101111001000110111110110101010011 => OK +A5/3 - UL: 000110010010110010010101001101010011110011011111100101111001111000000101010000011000011011011111000101011011111100 => OK +A5/3 - DL: 001100000001010000110111111001001101010011010110010101100101110101001001000001001100011000110001011000000110111011 => OK +A5/3 - UL: 111100001010001110111000011110010101111000100110010011010011111000011010100000101111011010000100001101010011110111 => OK +A5/3 - DL: 111101111001010000101001000011111110111101100100001111010010111010100011010010001010011101111001011010100010000100 => OK +A5/3 - UL: 110010110110111110100110110001101011100010100111000001011010111110011111111011111110100101110101100000011000010100 => OK +A5/3 - DL: 011101001001110010100100111001101011011010010001111001011010010110011000110001000110000111010101111111100100011101 => OK +A5/3 - UL: 001100011100100111100100010001001100110100000100011001110111101011011010101010001010000010000010101011011011110001 => OK +A5/3 - DL: 001010100110100101110110011101100001111001100000110011000100111010001111100111110101001000010110000000100111011011 => OK +A5/3 - UL: 101001010100010011011000010001110101111100101100011110001100001101010110000101000001001010001111000100010111100111 => OK +A5/3 - DL: 101001001111011100001101110001011010001011001001011100000111111101011111101000011100011000001110101100010000011001 => OK +A5/3 - UL: 011101111000000010110101100101111011001100101000110000010100000000001011010111000111010010000010001111101000010100 => OK +A5/4 - DL: 101000101111111000110000001101001011011010110010001011001100010011100011001111000111000010010000101111101100001101 => OK +A5/4 - UL: 000101110000110101110100100101110100001100101111111110001001011110111001000110111110100010101110110010111010100010 => OK +A5/4 - DL: 100010011100110111101110001101100000110111111001000100010000001010000001101111001111010101110111010101011010000001 => OK +A5/4 - UL: 001100111000001000101100000011000111011110010101100110001100100111001011111111000100100100011000001110101111011111 => OK -- 1.9.1 --------------070906000208070902060208--