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Merge branch 'const-memeq' 

Introduce constant time memory comparing functions for cryptographic purposes,
and a tool to test such functions or crypto transforms relying on them.
This commit is contained in:
Martin Willi 2015-04-14 11:57:17 +02:00
parent b17f0beda8 161a015782
commit aa9b74931f
42 changed files with 580 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
scripts/.gitignore vendored
View File

@ -15,3 +15,4 @@ pubkey_speed
settings-test
thread_analysis
tls_test
timeattack

4
scripts/Makefile.am
View File

@ -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

418
scripts/timeattack.c Normal file
View File

@ -0,0 +1,418 @@
#include <stdio.h>
#include <time.h>
#include <library.h>
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;
}
CALLBACK(attack_memeq5, bool,
u_char *subj, u_char *data, size_t len)
{
return memeq_const(subj, data, len);
}
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 },
{ "memeq5", attack_memeq5 },
};
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_chunk1, bool,
u_char *subj, u_char *data, size_t len)
{
return chunk_equals(chunk_create(subj, len), chunk_create(data, len));
}
CALLBACK(attack_chunk2, bool,
u_char *subj, u_char *data, size_t len)
{
return chunk_equals_const(chunk_create(subj, len), chunk_create(data, len));
}
static bool attack_chunk(char *name, u_int iterations, u_int distance)
{
struct {
char *name;
attackfn_t fn;
} attacks[] = {
{ "chunk1", attack_chunk1 },
{ "chunk2", attack_chunk2 },
};
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 <attack> <iterations> <distance>\n", argv[0]);
fprintf(stderr, " <attack>: memeq[1-5] / chunk[1-2] / aead / signer\n");
fprintf(stderr, " <iterations>: number of invocations * 1000\n");
fprintf(stderr, " <distance>: 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]));
}
if (strpfx(argv[1], "chunk"))
{
return !attack_chunk(argv[1], atoi(argv[2]), atoi(argv[3]));
}
return !attack_transform(argv[1], atoi(argv[2]), atoi(argv[3]));
}

2
src/libcharon/encoding/message.c
View File

@ -2625,7 +2625,7 @@ METHOD(message_t, parse_body, status_t,
other_hash = hash_payload->get_hash(hash_payload);
DBG3(DBG_ENC, "HASH received %B\nHASH expected %B",
&other_hash, &hash);
if (!chunk_equals(hash, other_hash))
if (!chunk_equals_const(hash, other_hash))
{
DBG1(DBG_ENC, "received HASH payload does not match");
chunk_free(&hash);

2
src/libcharon/network/receiver.c
View File

@ -247,7 +247,7 @@ static bool cookie_verify(private_receiver_t *this, message_t *message,
{
return FALSE;
}
if (chunk_equals(reference, cookie))
if (chunk_equals_const(reference, cookie))
{
chunk_free(&reference);
return TRUE;

5
src/libcharon/plugins/eap_aka/eap_aka_server.c
View File

@ -425,7 +425,7 @@ static status_t process_challenge(private_eap_aka_server_t *this,
enumerator->destroy(enumerator);
/* compare received RES against stored XRES */
if (!chunk_equals(res, this->xres))
if (!chunk_equals_const(res, this->xres))
{
DBG1(DBG_IKE, "received RES does not match XRES");
return FAILED;
@ -486,7 +486,7 @@ static status_t process_reauthentication(private_eap_aka_server_t *this,
this->crypto->clear_keys(this->crypto);
return challenge(this, out);
}
if (!chunk_equals(counter, this->counter))
if (!chunk_equals_const(counter, this->counter))
{
DBG1(DBG_IKE, "received counter does not match");
return FAILED;
@ -730,4 +730,3 @@ eap_aka_server_t *eap_aka_server_create(identification_t *server,
return &this->public;
}

3
src/libcharon/plugins/eap_aka_3gpp2/eap_aka_3gpp2_card.c
View File

@ -87,7 +87,7 @@ METHOD(simaka_card_t, get_quintuplet, status_t,
{
return FAILED;
}
if (!memeq(mac, xmac, AKA_MAC_LEN))
if (!memeq_const(mac, xmac, AKA_MAC_LEN))
{
DBG1(DBG_IKE, "received MAC does not match XMAC");
DBG3(DBG_IKE, "MAC %b\nXMAC %b", mac, AKA_MAC_LEN, xmac, AKA_MAC_LEN);
@ -184,4 +184,3 @@ eap_aka_3gpp2_card_t *eap_aka_3gpp2_card_create(eap_aka_3gpp2_functions_t *f)
return &this->public;
}

3
src/libcharon/plugins/eap_aka_3gpp2/eap_aka_3gpp2_provider.c
View File

@ -158,7 +158,7 @@ METHOD(simaka_provider_t, resync, bool,
{
return FALSE;
}
if (!memeq(macs, xmacs, AKA_MAC_LEN))
if (!memeq_const(macs, xmacs, AKA_MAC_LEN))
{
DBG1(DBG_IKE, "received MACS does not match XMACS");
DBG3(DBG_IKE, "MACS %b XMACS %b",
@ -205,4 +205,3 @@ eap_aka_3gpp2_provider_t *eap_aka_3gpp2_provider_create(
return &this->public;
}

3
src/libcharon/plugins/eap_md5/eap_md5.c
View File

@ -193,7 +193,7 @@ METHOD(eap_method_t, process_server, status_t,
}
response = chunk_create(data.ptr + 6, data.ptr[5]);
if (response.len < expected.len ||
!memeq(response.ptr, expected.ptr, expected.len))
!memeq_const(response.ptr, expected.ptr, expected.len))
{
chunk_free(&expected);
DBG1(DBG_IKE, "EAP-MD5 verification failed");
@ -299,4 +299,3 @@ eap_md5_t *eap_md5_create_peer(identification_t *server, identification_t *peer)
return &this->public;
}

7
src/libcharon/plugins/eap_mschapv2/eap_mschapv2.c
View File

@ -812,7 +812,7 @@ static status_t process_peer_success(private_eap_mschapv2_t *this,
goto error;
}
if (!chunk_equals(this->auth_response, auth_string))
if (!chunk_equals_const(this->auth_response, auth_string))
{
DBG1(DBG_IKE, "EAP-MS-CHAPv2 verification failed");
goto error;
@ -1087,8 +1087,8 @@ static status_t process_server_response(private_eap_mschapv2_t *this,
userid->destroy(userid);
chunk_clear(&nt_hash);
if (memeq(res->response.nt_response, this->nt_response.ptr,
this->nt_response.len))
if (memeq_const(res->response.nt_response, this->nt_response.ptr,
this->nt_response.len))
{
chunk_t hex;
char msg[AUTH_RESPONSE_LEN + sizeof(SUCCESS_MESSAGE)];
@ -1267,4 +1267,3 @@ eap_mschapv2_t *eap_mschapv2_create_peer(identification_t *server, identificatio
return &this->public;
}

3
src/libcharon/plugins/eap_sim/eap_sim_peer.c
View File

@ -310,7 +310,7 @@ static status_t process_challenge(private_eap_sim_peer_t *this,
/* excepting two or three RAND, each 16 bytes. We require two valid
* and different RANDs */
if ((rands.len != 2 * SIM_RAND_LEN && rands.len != 3 * SIM_RAND_LEN) ||
memeq(rands.ptr, rands.ptr + SIM_RAND_LEN, SIM_RAND_LEN))
memeq_const(rands.ptr, rands.ptr + SIM_RAND_LEN, SIM_RAND_LEN))
{
DBG1(DBG_IKE, "no valid AT_RAND received");
if (!create_client_error(this, SIM_INSUFFICIENT_CHALLENGES, out))
@ -734,4 +734,3 @@ eap_sim_peer_t *eap_sim_peer_create(identification_t *server,
return &this->public;
}

3
src/libcharon/plugins/eap_sim/eap_sim_server.c
View File

@ -262,7 +262,7 @@ static status_t process_reauthentication(private_eap_sim_server_t *this,
this->crypto->clear_keys(this->crypto);
return initiate(this, out);
}
if (!chunk_equals(counter, this->counter))
if (!chunk_equals_const(counter, this->counter))
{
DBG1(DBG_IKE, "received counter does not match");
return FAILED;
@ -644,4 +644,3 @@ eap_sim_server_t *eap_sim_server_create(identification_t *server,
return &this->public;
}

3
src/libcharon/plugins/eap_sim_file/eap_sim_file_card.c
View File

@ -52,7 +52,7 @@ METHOD(simaka_card_t, get_triplet, bool,
c_rand, SIM_RAND_LEN, c_sres, SIM_SRES_LEN, c_kc, SIM_KC_LEN);
if (id->matches(id, cand))
{
if (memeq(c_rand, rand, SIM_RAND_LEN))
if (memeq_const(c_rand, rand, SIM_RAND_LEN))
{
DBG2(DBG_CFG, " => triplet matches");
memcpy(sres, c_sres, SIM_SRES_LEN);
@ -105,4 +105,3 @@ eap_sim_file_card_t *eap_sim_file_card_create(eap_sim_file_triplets_t *triplets)
return &this->public;
}

2
src/libcharon/plugins/xauth_generic/xauth_generic.c
View File

@ -180,7 +180,7 @@ METHOD(xauth_method_t, process_server, status_t,
SHARED_EAP, this->server, this->peer);
while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
{
if (chunk_equals(shared->get_key(shared), pass))
if (chunk_equals_const(shared->get_key(shared), pass))
{
status = SUCCESS;
break;

2
src/libcharon/sa/ikev1/authenticators/psk_v1_authenticator.c
View File

@ -124,7 +124,7 @@ METHOD(authenticator_t, process, status_t,
return FAILED;
}
free(dh.ptr);
if (chunk_equals(hash, hash_payload->get_hash(hash_payload)))
if (chunk_equals_const(hash, hash_payload->get_hash(hash_payload)))
{
free(hash.ptr);
if (!this->hybrid)

2
src/libcharon/sa/ikev2/authenticators/eap_authenticator.c
View File

@ -464,7 +464,7 @@ static bool verify_auth(private_eap_authenticator_t *this, message_t *message,
return FALSE;
}
recv_auth_data = auth_payload->get_data(auth_payload);
if (!auth_data.len || !chunk_equals(auth_data, recv_auth_data))
if (!auth_data.len || !chunk_equals_const(auth_data, recv_auth_data))
{
DBG1(DBG_IKE, "verification of AUTH payload with%s EAP MSK failed",
this->msk.ptr ? "" : "out");

2
src/libcharon/sa/ikev2/authenticators/psk_authenticator.c
View File

@ -123,7 +123,7 @@ METHOD(authenticator_t, process, status_t,
{
continue;
}
if (auth_data.len && chunk_equals(auth_data, recv_auth_data))
if (auth_data.len && chunk_equals_const(auth_data, recv_auth_data))
{
DBG1(DBG_IKE, "authentication of '%Y' with %N successful",
other_id, auth_method_names, AUTH_PSK);

2
src/libcharon/sa/ikev2/tasks/ike_mobike.c
View File

@ -537,7 +537,7 @@ METHOD(task_t, process_i, status_t,
cookie2 = this->cookie2;
this->cookie2 = chunk_empty;
process_payloads(this, message);
if (!chunk_equals(cookie2, this->cookie2))
if (!chunk_equals_const(cookie2, this->cookie2))
{
chunk_free(&cookie2);
DBG1(DBG_IKE, "COOKIE2 mismatch, closing IKE_SA");

7
src/libimcv/plugins/imv_attestation/imv_attestation_process.c
View File

@ -181,7 +181,7 @@ bool imv_attestation_process(pa_tnc_attr_t *attr, imv_msg_t *out_msg,
DBG1(DBG_IMV, "verifying AIK with keyid %#B", &keyid);
keyid_hex = chunk_to_hex(keyid, NULL, FALSE);
if (session->get_device_id(session, &device_id) &&
chunk_equals(keyid_hex, device_id))
chunk_equals_const(keyid_hex, device_id))
{
trusted = session->get_device_trust(session);
}
@ -290,7 +290,7 @@ bool imv_attestation_process(pa_tnc_attr_t *attr, imv_msg_t *out_msg,
/* check hashes from database against measurements */
e = pts_db->create_file_hash_enumerator(pts_db,
pts->get_platform_id(pts),
pts->get_platform_id(pts),
algo, is_dir, arg_int);
if (!e)
{
@ -446,7 +446,7 @@ bool imv_attestation_process(pa_tnc_attr_t *attr, imv_msg_t *out_msg,
return FALSE;
}
if (!chunk_equals(pcr_comp, pcr_composite))
if (!chunk_equals_const(pcr_comp, pcr_composite))
{
DBG1(DBG_IMV, "received PCR Composite does not match "
"constructed one");
@ -564,4 +564,3 @@ quote_error:
}
return TRUE;
}

9
src/libimcv/pts/components/ita/ita_comp_ima.c
View File

@ -307,7 +307,7 @@ static bool check_boot_aggregate(pts_pcr_t *pcrs, chunk_t measurement,
}
if (pcr_ok)
{
success = chunk_equals(boot_aggregate, measurement);
success = chunk_equals_const(boot_aggregate, measurement);
DBG1(DBG_PTS, "boot aggregate value is %scorrect",
success ? "":"in");
return success;
@ -693,7 +693,7 @@ METHOD(pts_component_t, verify, status_t,
status = FAILED;
break;
}
if (chunk_equals(measurement, hash))
if (chunk_equals_const(measurement, hash))
{
status = SUCCESS;
break;
@ -748,7 +748,7 @@ METHOD(pts_component_t, verify, status_t,
has_pcr_info = evidence->get_pcr_info(evidence, &pcr_before, &pcr_after);
if (has_pcr_info)
{
if (!chunk_equals(pcr_before, pcrs->get(pcrs, pcr)))
if (!chunk_equals_const(pcr_before, pcrs->get(pcrs, pcr)))
{
DBG1(DBG_PTS, "PCR %2u: pcr_before is not equal to register value",
pcr);
@ -876,7 +876,7 @@ METHOD(pts_component_t, destroy, void,
DESTROY_IF(this->bios_list);
DESTROY_IF(this->ima_list);
this->name->destroy(this->name);
free(this);
}
}
@ -911,4 +911,3 @@ pts_component_t *pts_ita_comp_ima_create(uint32_t depth,
return &this->public;
}

3
src/libimcv/pts/components/ita/ita_comp_tboot.c
View File

@ -249,7 +249,7 @@ METHOD(pts_component_t, verify, status_t,
has_pcr_info = evidence->get_pcr_info(evidence, &pcr_before, &pcr_after);
if (has_pcr_info)
{
if (!chunk_equals(pcr_before, pcrs->get(pcrs, extended_pcr)))
if (!chunk_equals_const(pcr_before, pcrs->get(pcrs, extended_pcr)))
{
DBG1(DBG_PTS, "PCR %2u: pcr_before is not equal to register value",
extended_pcr);
@ -354,4 +354,3 @@ pts_component_t *pts_ita_comp_tboot_create(u_int32_t depth,
return &this->public;
}

2
src/libimcv/pts/components/ita/ita_comp_tgrub.c
View File

@ -141,7 +141,7 @@ METHOD(pts_component_t, verify, status_t,
has_pcr_info = evidence->get_pcr_info(evidence, &pcr_before, &pcr_after);
if (has_pcr_info)
{
if (!chunk_equals(pcr_before, pcrs->get(pcrs, extended_pcr)))
if (!chunk_equals_const(pcr_before, pcrs->get(pcrs, extended_pcr)))
{
DBG1(DBG_PTS, "PCR %2u: pcr_before is not equal to pcr value");
}

4
src/libimcv/pts/pts_database.c
View File

@ -187,7 +187,7 @@ METHOD(pts_database_t, add_file_measurement, status_t,
}
if (e->enumerate(e, &hash_id, &hash_value))
{
if (!chunk_equals(measurement, hash_value))
if (!chunk_equals_const(measurement, hash_value))
{
/* update hash measurement value */
if (this->db->execute(this->db, &hash_id,
@ -289,7 +289,7 @@ METHOD(pts_database_t, check_comp_measurement, status_t,
while (e->enumerate(e, &hash))
{
if (chunk_equals(hash, measurement))
if (chunk_equals_const(hash, measurement))
{
status = SUCCESS;
break;

8
src/libimcv/pts/pts_file_meas.c
View File

@ -133,7 +133,7 @@ METHOD(pts_file_meas_t, check, bool,
{
while (e->enumerate(e, &hash))
{
if (chunk_equals(entry->measurement, hash))
if (chunk_equals_const(entry->measurement, hash))
{
status = SUCCESS;
break;
@ -223,7 +223,7 @@ METHOD(pts_file_meas_t, verify, bool,
}
}
/* no PTS measurement returned for this filename */
/* no PTS measurement returned for this filename */
if (!found)
{
success = FALSE;
@ -234,7 +234,7 @@ METHOD(pts_file_meas_t, verify, bool,
if (found && !match)
{
if (chunk_equals(measurement, entry->measurement))
if (chunk_equals_const(measurement, entry->measurement))
{
match = TRUE;
DBG2(DBG_PTS, " %#B for '%s' is ok",
@ -252,7 +252,7 @@ METHOD(pts_file_meas_t, verify, bool,
&entry->measurement, entry->filename);
enumerator->destroy(enumerator);
}
return success;
}

2
src/libpttls/sasl/sasl_plain/sasl_plain.c
View File

@ -86,7 +86,7 @@ METHOD(sasl_mechanism_t, process_server, status_t,
DBG1(DBG_CFG, "no shared secret found for '%Y'", this->client);
return FAILED;
}
if (!chunk_equals(shared->get_key(shared), password))
if (!chunk_equals_const(shared->get_key(shared), password))
{
DBG1(DBG_CFG, "shared secret for '%Y' does not match", this->client);
shared->destroy(shared);

2
src/libradius/radius_message.c
View File

@ -536,7 +536,7 @@ METHOD(radius_message_t, verify, bool,
/* verify Response-Authenticator */
if (!hasher->get_hash(hasher, msg, NULL) ||
!hasher->get_hash(hasher, secret, buf) ||
!memeq(buf, res_auth, HASH_SIZE_MD5))
!memeq_const(buf, res_auth, HASH_SIZE_MD5))
{
DBG1(DBG_CFG, "RADIUS Response-Authenticator verification failed");
return FALSE;

3
src/libstrongswan/crypto/signers/mac_signer.c
View File

@ -85,7 +85,7 @@ METHOD(signer_t, verify_signature, bool,
return FALSE;
}
return this->mac->get_mac(this->mac, data, mac) &&
memeq(signature.ptr, mac, this->truncation);
memeq_const(signature.ptr, mac, this->truncation);
}
METHOD(signer_t, get_key_size, size_t,
@ -136,4 +136,3 @@ signer_t *mac_signer_create(mac_t *mac, size_t len)
return &this->public;
}

2
src/libstrongswan/plugins/af_alg/af_alg_signer.c
View File

@ -138,7 +138,7 @@ METHOD(signer_t, verify_signature, bool,
{
return FALSE;
}
return memeq(signature.ptr, sig, signature.len);
return memeq_const(signature.ptr, sig, signature.len);
}
METHOD(signer_t, get_key_size, size_t,

2
src/libstrongswan/plugins/ccm/ccm_aead.c
View File

@ -256,7 +256,7 @@ static bool verify_icv(private_ccm_aead_t *this, chunk_t plain, chunk_t assoc,
char buf[this->icv_size];
return create_icv(this, plain, assoc, iv, buf) &&
memeq(buf, icv, this->icv_size);
memeq_const(buf, icv, this->icv_size);
}
METHOD(aead_t, encrypt, bool,

2
src/libstrongswan/plugins/gcm/gcm_aead.c
View File

@ -276,7 +276,7 @@ static bool verify_icv(private_gcm_aead_t *this, chunk_t assoc, chunk_t crypt,
char tmp[this->icv_size];
return create_icv(this, assoc, crypt, j, tmp) &&
memeq(tmp, icv, this->icv_size);
memeq_const(tmp, icv, this->icv_size);
}
METHOD(aead_t, encrypt, bool,

5
src/libstrongswan/plugins/gmp/gmp_rsa_public_key.c
View File

@ -187,7 +187,7 @@ static bool verify_emsa_pkcs1_signature(private_gmp_rsa_public_key_t *this,
" %u bytes", em.len, data.len);
goto end;
}
success = memeq(em.ptr, data.ptr, data.len);
success = memeq_const(em.ptr, data.ptr, data.len);
}
else
{ /* IKEv2 and X.509 certificate signatures */
@ -258,7 +258,7 @@ static bool verify_emsa_pkcs1_signature(private_gmp_rsa_public_key_t *this,
goto end_parser;
}
hasher->destroy(hasher);
success = memeq(object.ptr, hash.ptr, hash.len);
success = memeq_const(object.ptr, hash.ptr, hash.len);
free(hash.ptr);
break;
}
@ -500,4 +500,3 @@ gmp_rsa_public_key_t *gmp_rsa_public_key_load(key_type_t type, va_list args)
return &this->public;
}

2
src/libstrongswan/plugins/openssl/openssl_pkcs7.c
View File

@ -305,7 +305,7 @@ static bool verify_digest(CMS_ContentInfo *cms, CMS_SignerInfo *si, int hash_oid
}
hasher->destroy(hasher);
if (!chunk_equals(digest, hash))
if (!chunk_equals_const(digest, hash))
{
free(hash.ptr);
DBG1(DBG_LIB, "invalid messageDigest");

2
src/libstrongswan/plugins/openssl/openssl_rsa_public_key.c
View File

@ -74,7 +74,7 @@ static bool verify_emsa_pkcs1_signature(private_openssl_rsa_public_key_t *this,
RSA_PKCS1_PADDING);
if (len != -1)
{
valid = chunk_equals(data, chunk_create(buf, len));
valid = chunk_equals_const(data, chunk_create(buf, len));
}
free(buf);
}

2
src/libstrongswan/plugins/pkcs12/pkcs12_decode.c
View File

@ -356,7 +356,7 @@ static bool verify_mac(hash_algorithm_t hash, chunk_t salt,
{
break;
}
if (chunk_equals(mac, calculated))
if (chunk_equals_const(mac, calculated))
{
success = TRUE;
break;

2
src/libstrongswan/plugins/pkcs7/pkcs7_signed_data.c
View File

@ -269,7 +269,7 @@ METHOD(enumerator_t, enumerate, bool,
hasher->destroy(hasher);
DBG3(DBG_LIB, "hash: %B", &hash);
valid = chunk_equals(chunk, hash);
valid = chunk_equals_const(chunk, hash);
free(hash.ptr);
if (!valid)
{

27
src/libstrongswan/tests/suites/test_chunk.c
View File

@ -60,6 +60,32 @@ START_TEST(test_chunk_equals)
}
END_TEST
/*******************************************************************************
* equals_const
*/
START_TEST(test_chunk_equals_const)
{
chunk_t chunk = chunk_from_str("chunk");
chunk_t chunk_a, chunk_b;
chunk_a = chunk_empty;
chunk_b = chunk_empty;
ck_assert(!chunk_equals_const(chunk_a, chunk_b));
chunk_a = chunk;
ck_assert(!chunk_equals_const(chunk_a, chunk_b));
chunk_b = chunk;
ck_assert(chunk_equals_const(chunk_a, chunk_b));
chunk_b = chunk_from_str("asdf");
ck_assert(!chunk_equals_const(chunk_a, chunk_b));
chunk_b = chunk_from_str("chunk");
ck_assert(chunk_equals_const(chunk_a, chunk_b));
}
END_TEST
/*******************************************************************************
* chunk_compare test
*/
@ -1013,6 +1039,7 @@ Suite *chunk_suite_create()
tc = tcase_create("equals");
tcase_add_test(tc, test_chunk_equals);
tcase_add_test(tc, test_chunk_equals_const);
suite_add_tcase(s, tc);
tc = tcase_create("chunk_compare");

47
src/libstrongswan/tests/suites/test_utils.c
View File

@ -306,6 +306,48 @@ START_TEST(test_memxor_aligned)
}
END_TEST
/*******************************************************************************
* memeq/const
*/
static struct {
char *a;
char *b;
size_t n;
bool res;
} memeq_data[] = {
{NULL, NULL, 0, TRUE},
{"a", "b", 0, TRUE},
{"", "", 1, TRUE},
{"abcdefgh", "abcdefgh", 8, TRUE},
{"a", "b", 1, FALSE},
{"A", "a", 1, FALSE},
{"\0a", "\0b", 2, FALSE},
{"abc", "abd", 3, FALSE},
{"abc", "dbd", 3, FALSE},
{"abcdefgh", "abcdffgh", 8, FALSE},
{"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz",
"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz", 52, TRUE},
{"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz",
"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyy", 52, FALSE},
{"bbcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz",
"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz", 52, FALSE},
};
START_TEST(test_memeq)
{
ck_assert(memeq(memeq_data[_i].a, memeq_data[_i].b,
memeq_data[_i].n) == memeq_data[_i].res);
}
END_TEST
START_TEST(test_memeq_const)
{
ck_assert(memeq_const(memeq_data[_i].a, memeq_data[_i].b,
memeq_data[_i].n) == memeq_data[_i].res);
}
END_TEST
/*******************************************************************************
* memstr
*/
@ -779,6 +821,11 @@ Suite *utils_suite_create()
tcase_add_test(tc, test_memxor_aligned);
suite_add_tcase(s, tc);
tc = tcase_create("memeq");
tcase_add_loop_test(tc, test_memeq, 0, countof(memeq_data));
tcase_add_loop_test(tc, test_memeq_const, 0, countof(memeq_data));
suite_add_tcase(s, tc);
tc = tcase_create("memstr");
tcase_add_loop_test(tc, test_memstr, 0, countof(memstr_data));
suite_add_tcase(s, tc);

13
src/libstrongswan/utils/chunk.h
View File

@ -309,6 +309,19 @@ static inline bool chunk_equals(chunk_t a, chunk_t b)
a.len == b.len && memeq(a.ptr, b.ptr, a.len);
}
/**
* Compare two chunks for equality, constant time for cryptographic purposes.
*
* Note that this function is constant time only for chunks with the same
* length, i.e. it does not protect against guessing the length of one of the
* chunks.
*/
static inline bool chunk_equals_const(chunk_t a, chunk_t b)
{
return a.ptr != NULL && b.ptr != NULL &&
a.len == b.len && memeq_const(a.ptr, b.ptr, a.len);
}
/**
* Compare two chunks (given as pointers) for equality (useful as callback),
* NULL chunks are never equal.

19
src/libstrongswan/utils/utils.c
View File

@ -109,6 +109,25 @@ void memwipe_noinline(void *ptr, size_t n)
memwipe_inline(ptr, n);
}
/**
* Described in header.
*/
bool memeq_const(const void *x, const void *y, size_t len)
{
const u_char *a, *b;
u_int bad = 0;
size_t i;
a = (const u_char*)x;
b = (const u_char*)y;
for (i = 0; i < len; i++)
{
bad |= a[i] != b[i];
}
return !bad;
}
/**
* Described in header.
*/

5
src/libstrongswan/utils/utils.h
View File

@ -184,6 +184,11 @@ static inline bool memeq(const void *x, const void *y, size_t len)
return memcmp(x, y, len) == 0;
}
/**
* Same as memeq(), but with a constant runtime, safe for cryptographic use.
*/
bool memeq_const(const void *x, const void *y, size_t len);
/**
* Calling memcpy() with NULL pointers, even with n == 0, results in undefined
* behavior according to the C standard. This version is guaranteed to not

2
src/libtls/tls_peer.c
View File

@ -641,7 +641,7 @@ static status_t process_finished(private_tls_peer_t *this, bio_reader_t *reader)
this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
return NEED_MORE;
}
if (!chunk_equals(received, chunk_from_thing(buf)))
if (!chunk_equals_const(received, chunk_from_thing(buf)))
{
DBG1(DBG_TLS, "received server finished invalid");
this->alert->add(this->alert, TLS_FATAL, TLS_DECRYPT_ERROR);

2
src/libtls/tls_server.c
View File

@ -607,7 +607,7 @@ static status_t process_finished(private_tls_server_t *this,
this->alert->add(this->alert, TLS_FATAL, TLS_INTERNAL_ERROR);
return NEED_MORE;
}
if (!chunk_equals(received, chunk_from_thing(buf)))
if (!chunk_equals_const(received, chunk_from_thing(buf)))
{
DBG1(DBG_TLS, "received client finished invalid");
this->alert->add(this->alert, TLS_FATAL, TLS_DECRYPT_ERROR);