diff --git a/scripts/.gitignore b/scripts/.gitignore index b876a3ac2..7883d9cca 100644 --- a/scripts/.gitignore +++ b/scripts/.gitignore @@ -15,3 +15,4 @@ pubkey_speed settings-test thread_analysis tls_test +timeattack diff --git a/scripts/Makefile.am b/scripts/Makefile.am index abc6d75dd..c5155efc2 100644 --- a/scripts/Makefile.am +++ b/scripts/Makefile.am @@ -5,7 +5,7 @@ AM_CPPFLAGS = \ noinst_PROGRAMS = bin2array bin2sql id2sql key2keyid keyid2sql oid2der \ thread_analysis dh_speed pubkey_speed crypt_burn hash_burn fetch \ - dnssec malloc_speed aes-test settings-test + dnssec malloc_speed aes-test settings-test timeattack if USE_TLS noinst_PROGRAMS += tls_test @@ -28,6 +28,7 @@ hash_burn_SOURCES = hash_burn.c malloc_speed_SOURCES = malloc_speed.c fetch_SOURCES = fetch.c dnssec_SOURCES = dnssec.c +timeattack_SOURCES = timeattack.c id2sql_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la key2keyid_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la keyid2sql_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la @@ -41,6 +42,7 @@ fetch_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la dnssec_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la aes_test_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la settings_test_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la +timeattack_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la key2keyid.o : $(top_builddir)/config.status diff --git a/scripts/timeattack.c b/scripts/timeattack.c new file mode 100644 index 000000000..0a53abae9 --- /dev/null +++ b/scripts/timeattack.c @@ -0,0 +1,365 @@ +#include +#include + +#include + +typedef bool (*attackfn_t)(void *subj, u_char *data, size_t len); + +static void start_timing(struct timespec *start) +{ + clock_gettime(CLOCK_PROCESS_CPUTIME_ID, start); +} + +static u_int64_t end_timing(struct timespec *start) +{ + struct timespec end; + + clock_gettime(CLOCK_THREAD_CPUTIME_ID, &end); + return (end.tv_nsec - start->tv_nsec) + + (end.tv_sec - start->tv_sec) * 1000000000; +} + +static int intcmp(const void *a, const void *b) +{ + return *(u_int64_t*)a - *(u_int64_t*)b; +} + +static u_int64_t median(u_int64_t *m, int count) +{ + qsort(m, count, sizeof(u_int64_t), intcmp); + return m[count / 2]; +} + +static bool timeattack(attackfn_t attackfn, void *subj, size_t dlen, + u_int iterations, u_int distance) +{ + struct timespec start; + u_char test[dlen]; + u_int64_t mini, maxi, t[256], m[256][10]; + float fastdist = 0, slowdist = 0; + int i, j, k, l, byte, limit, retry = 0; + int fastest = 0, slowest = 0; + + memset(test, 0, dlen); + + /* do some iterations to fill caches */ + for (i = 0; i < iterations; i++) + { + attackfn(subj, test, dlen); + } + + for (byte = 0; byte < dlen;) + { + memset(t, 0, sizeof(t)); + memset(m, 0, sizeof(m)); + + limit = iterations * (retry + 1); + + /* measure timing for all patterns in next byte */ + for (k = 0; k < 10; k++) + { + for (j = 0; j < 256; j++) + { + for (l = 0; l < 100; l++) + { + test[byte] = j; + start_timing(&start); + for (i = 0; i < limit; i++) + { + attackfn(subj, test, dlen); + } + m[j][k] += end_timing(&start); + } + } + } + + for (j = 0; j < 256; j++) + { + t[j] = median(m[j], countof(m[j])); + } + + /* find fastest/slowest runs */ + mini = ~0; + maxi = 0; + for (j = 0; j < 256; j++) + { + if (t[j] < mini) + { + mini = min(t[j], mini); + fastest = j; + } + if (t[j] > maxi) + { + maxi = max(t[j], maxi); + slowest = j; + } + } + /* calculate distance to next result */ + mini = ~0; + maxi = 0; + for (j = 0; j < 256; j++) + { + if (fastest != j && t[j] < mini) + { + mini = min(t[j], mini); + fastdist = (float)(t[j] - t[fastest]) / distance; + } + if (slowest != j && t[j] > maxi) + { + maxi = max(t[j], maxi); + slowdist = (float)(t[slowest] - t[j]) / distance; + } + } + if (fastdist > 1.0f) + { + fprintf(stderr, "byte %02d: %02x (fastest, dist %02.2f)\n", + byte, fastest, fastdist); + test[byte] = fastest; + retry = 0; + byte++; + } + else if (slowdist > 1.0f) + { + fprintf(stderr, "byte %02d: %02x (slowest, dist %02.2f)\n", + byte, slowest, slowdist); + test[byte] = slowest; + retry = 0; + byte++; + } + else + { + if (retry++ > 5 && byte > 0) + { + fprintf(stderr, "distance fastest %02.2f (%02x), " + "slowest %02.2f (%02x), stepping back\n", + fastdist, fastest, slowdist, slowest); + test[byte--] = 0; + } + else if (retry < 10) + { + fprintf(stderr, "distance fastest %02.2f (%02x), " + "slowest %02.2f (%02x), retrying (%d)\n", + fastdist, fastest, slowdist, slowest, retry); + } + else + { + printf("attack failed, giving up\n"); + return FALSE; + } + } + } + if (attackfn(subj, test, dlen)) + { + printf("attack successful with %b\n", test, dlen); + return TRUE; + } + printf("attack failed with %b\n", test, dlen); + return FALSE; +} + +CALLBACK(attack_memeq1, bool, + u_char *subj, u_char *data, size_t len) +{ + return memeq(data, subj, len); +} + +CALLBACK(attack_memeq2, bool, + u_char *subj, u_char *data, size_t len) +{ + return memeq(subj, data, len); +} + +CALLBACK(attack_memeq3, bool, + u_char *subj, u_char *data, size_t len) +{ + int i; + + for (i = 0; i < len; i++) + { + if (subj[i] != data[i]) + { + return FALSE; + } + } + return TRUE; +} + +CALLBACK(attack_memeq4, bool, + u_char *subj, u_char *data, size_t len) +{ + int i, m = 0; + + for (i = 0; i < len; i++) + { + m |= subj[i] != data[i]; + } + return !m; +} + +static bool attack_memeq(char *name, u_int iterations, u_int distance) +{ + struct { + char *name; + attackfn_t fn; + } attacks[] = { + { "memeq1", attack_memeq1 }, + { "memeq2", attack_memeq2 }, + { "memeq3", attack_memeq3 }, + { "memeq4", attack_memeq4 }, + }; + u_char exp[16]; + int i; + + srandom(time(NULL)); + for (i = 0; i < sizeof(exp); i++) + { + exp[i] = random(); + } + fprintf(stderr, "attacking %b\n", exp, sizeof(exp)); + + for (i = 0; i < countof(attacks); i++) + { + if (streq(name, attacks[i].name)) + { + return timeattack(attacks[i].fn, exp, sizeof(exp), + iterations, distance); + } + } + return FALSE; +} + +CALLBACK(attack_aead, bool, + aead_t *aead, u_char *data, size_t len) +{ + u_char iv[aead->get_iv_size(aead)]; + + memset(iv, 0, sizeof(iv)); + return aead->decrypt(aead, chunk_create(data, len), chunk_empty, + chunk_from_thing(iv), NULL); +} + +static bool attack_aeads(encryption_algorithm_t alg, size_t key_size, + u_int iterations, u_int distance) +{ + u_char buf[64]; + aead_t *aead; + bool res; + + aead = lib->crypto->create_aead(lib->crypto, alg, key_size, 0); + if (!aead) + { + fprintf(stderr, "creating AEAD %N failed\n", + encryption_algorithm_names, alg); + return FALSE; + } + memset(buf, 0xe3, sizeof(buf)); + if (!aead->set_key(aead, chunk_create(buf, aead->get_key_size(aead)))) + { + aead->destroy(aead); + return FALSE; + } + memset(buf, 0, aead->get_iv_size(aead)); + if (!aead->encrypt(aead, chunk_create(buf, 0), chunk_empty, + chunk_create(buf, aead->get_iv_size(aead)), NULL)) + { + aead->destroy(aead); + return FALSE; + } + fprintf(stderr, "attacking %b\n", buf, aead->get_icv_size(aead)); + + res = timeattack(attack_aead, aead, aead->get_icv_size(aead), + iterations, distance); + aead->destroy(aead); + return res; +} + +CALLBACK(attack_signer, bool, + signer_t *signer, u_char *data, size_t len) +{ + return signer->verify_signature(signer, chunk_empty, chunk_create(data, len)); +} + +static bool attack_signers(integrity_algorithm_t alg, + u_int iterations, u_int distance) +{ + u_char buf[64]; + signer_t *signer; + bool res; + + signer = lib->crypto->create_signer(lib->crypto, alg); + if (!signer) + { + fprintf(stderr, "creating signer %N failed\n", + integrity_algorithm_names, alg); + return FALSE; + } + memset(buf, 0xe3, sizeof(buf)); + if (!signer->set_key(signer, chunk_create(buf, signer->get_key_size(signer)))) + { + signer->destroy(signer); + return FALSE; + } + if (!signer->get_signature(signer, chunk_empty, buf)) + { + signer->destroy(signer); + return FALSE; + } + fprintf(stderr, "attacking %b\n", buf, signer->get_block_size(signer)); + + res = timeattack(attack_signer, signer, signer->get_block_size(signer), + iterations, distance); + signer->destroy(signer); + return res; +} + +static bool attack_transform(char *name, u_int iterations, u_int distance) +{ + const proposal_token_t *token; + + token = lib->proposal->get_token(lib->proposal, name); + if (!token) + { + fprintf(stderr, "algorithm '%s' unknown\n", name); + return FALSE; + } + + switch (token->type) + { + case ENCRYPTION_ALGORITHM: + if (encryption_algorithm_is_aead(token->algorithm)) + { + return attack_aeads(token->algorithm, token->keysize / 8, + iterations, distance); + } + fprintf(stderr, "can't attack a crypter\n"); + return FALSE; + case INTEGRITY_ALGORITHM: + return attack_signers(token->algorithm, iterations, distance); + default: + fprintf(stderr, "can't attack a %N\n", transform_type_names, token->type); + return FALSE; + } +} + +int main(int argc, char *argv[]) +{ + library_init(NULL, "timeattack"); + atexit(library_deinit); + lib->plugins->load(lib->plugins, getenv("PLUGINS") ?: PLUGINS); + + if (argc < 3) + { + fprintf(stderr, "usage: %s \n", argv[0]); + fprintf(stderr, " : memeq[1-4] / aead / signer\n"); + fprintf(stderr, " : number of invocations * 1000\n"); + fprintf(stderr, " : time difference in ns for a hit\n"); + fprintf(stderr, " example: %s memeq1 100 500\n", argv[0]); + fprintf(stderr, " example: %s aes128gcm16 100 4000\n", argv[0]); + return 1; + } + if (strpfx(argv[1], "memeq")) + { + return !attack_memeq(argv[1], atoi(argv[2]), atoi(argv[3])); + } + return !attack_transform(argv[1], atoi(argv[2]), atoi(argv[3])); +}