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Merge pull request #62 from PQClean/functestunalign

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Un-align input byte arrays to catch assumptions about data alignment
This commit is contained in:
Thom Wiggers 2019-02-28 15:57:06 +01:00 committed by GitHub
commit f3e38dbfb2
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 74 additions and 26 deletions
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53
test/crypto_kem/functest.c
View File

@ -42,21 +42,45 @@ static int check_canary(const unsigned char *d) {
}
static int test_keys(void) {
unsigned char key_a[CRYPTO_BYTES + 16], key_b[CRYPTO_BYTES + 16];
unsigned char pk[CRYPTO_PUBLICKEYBYTES + 16];
unsigned char sendb[CRYPTO_CIPHERTEXTBYTES + 16];
unsigned char sk_a[CRYPTO_SECRETKEYBYTES + 16];
/*
* This is most likely going to be aligned by the compiler.
* 16 extra bytes for canary
* 1 extra byte for unalignment
*/
unsigned char key_a_aligned[CRYPTO_BYTES + 16 + 1];
unsigned char key_b_aligned[CRYPTO_BYTES + 16 + 1];
unsigned char pk_aligned[CRYPTO_PUBLICKEYBYTES + 16 + 1];
unsigned char sendb_aligned[CRYPTO_CIPHERTEXTBYTES + 16 + 1];
unsigned char sk_a_aligned[CRYPTO_SECRETKEYBYTES + 16 + 1];
/*
* Make sure all pointers are odd.
* This ensures that the implementation does not assume anything about the
* data alignment. For example this would catch if an implementation
* directly uses these pointers to load into vector registers using movdqa.
*/
unsigned char *key_a = (unsigned char *) ((uintptr_t) key_a_aligned|(uintptr_t) 1);
unsigned char *key_b = (unsigned char *) ((uintptr_t) key_b_aligned|(uintptr_t) 1);
unsigned char *pk = (unsigned char *) ((uintptr_t) pk_aligned|(uintptr_t) 1);
unsigned char *sendb = (unsigned char *) ((uintptr_t) sendb_aligned|(uintptr_t) 1);
unsigned char *sk_a = (unsigned char *) ((uintptr_t) sk_a_aligned|(uintptr_t) 1);
/*
* Write 8 byte canary before and after the actual memory regions.
* This is used to validate that the implementation does not assume
* anything about the placement of data in memory
* (e.g., assuming that the pk is always behind the sk)
*/
write_canary(key_a);
write_canary(key_a + sizeof(key_a) - 8);
write_canary(key_a + CRYPTO_BYTES + 8);
write_canary(key_b);
write_canary(key_b + sizeof(key_b) - 8);
write_canary(key_b + CRYPTO_BYTES + 8);
write_canary(pk);
write_canary(pk + sizeof(pk) - 8);
write_canary(pk + CRYPTO_PUBLICKEYBYTES + 8);
write_canary(sendb);
write_canary(sendb + sizeof(sendb) - 8);
write_canary(sendb + CRYPTO_CIPHERTEXTBYTES + 8);
write_canary(sk_a);
write_canary(sk_a + sizeof(sk_a) - 8);
write_canary(sk_a + CRYPTO_SECRETKEYBYTES + 8);
int i;
@ -75,11 +99,12 @@ static int test_keys(void) {
return -1;
}
if (check_canary(key_a) || check_canary(key_a + sizeof(key_a) - 8) ||
check_canary(key_b) || check_canary(key_b + sizeof(key_b) - 8) ||
check_canary(pk) || check_canary(pk + sizeof(pk) - 8) ||
check_canary(sendb) || check_canary(sendb + sizeof(sendb) - 8) ||
check_canary(sk_a) || check_canary(sk_a + sizeof(sk_a) - 8)) {
// Validate that the implementation did not touch the canary
if (check_canary(key_a) || check_canary(key_a + CRYPTO_BYTES + 8) ||
check_canary(key_b) || check_canary(key_b + CRYPTO_BYTES + 8 ) ||
check_canary(pk) || check_canary(pk + CRYPTO_PUBLICKEYBYTES + 8 ) ||
check_canary(sendb) || check_canary(sendb + CRYPTO_CIPHERTEXTBYTES + 8 ) ||
check_canary(sk_a) || check_canary(sk_a + CRYPTO_SECRETKEYBYTES + 8 )) {
printf("ERROR canary overwritten\n");
return -1;
}

47
test/crypto_sign/functest.c
View File

@ -43,24 +43,46 @@ static int check_canary(const unsigned char *d) {
}
static int test_sign(void) {
unsigned char pk[CRYPTO_PUBLICKEYBYTES + 16];
unsigned char sk[CRYPTO_SECRETKEYBYTES + 16];
unsigned char sm[MLEN + CRYPTO_BYTES + 16];
unsigned char m[MLEN + 16];
/*
* This is most likely going to be aligned by the compiler.
* 16 extra bytes for canary
* 1 extra byte for unalignment
*/
unsigned char pk_aligned[CRYPTO_PUBLICKEYBYTES + 16 + 1];
unsigned char sk_aligned[CRYPTO_SECRETKEYBYTES + 16 + 1];
unsigned char sm_aligned[MLEN + CRYPTO_BYTES + 16 + 1];
unsigned char m_aligned[MLEN + 16 + 1];
/*
* Make sure all pointers are odd.
* This ensures that the implementation does not assume anything about the
* data alignment. For example this would catch if an implementation
* directly uses these pointers to load into vector registers using movdqa.
*/
unsigned char *pk = (unsigned char *) ((uintptr_t) pk_aligned|(uintptr_t) 1);
unsigned char *sk = (unsigned char *) ((uintptr_t) sk_aligned|(uintptr_t) 1);
unsigned char *sm = (unsigned char *) ((uintptr_t) sm_aligned|(uintptr_t) 1);
unsigned char *m = (unsigned char *) ((uintptr_t) m_aligned|(uintptr_t) 1);
unsigned long long mlen;
unsigned long long smlen;
int returncode;
int i;
/*
* Write 8 byte canary before and after the actual memory regions.
* This is used to validate that the implementation does not assume
* anything about the placement of data in memory
* (e.g., assuming that the pk is always behind the sk)
*/
write_canary(pk);
write_canary(pk + sizeof(pk) - 8);
write_canary(pk + CRYPTO_PUBLICKEYBYTES + 8);
write_canary(sk);
write_canary(sk + sizeof(sk) - 8);
write_canary(sk + CRYPTO_SECRETKEYBYTES + 8);
write_canary(sm);
write_canary(sm + sizeof(sm) - 8);
write_canary(sm + MLEN + CRYPTO_BYTES + 8);
write_canary(m);
write_canary(m + sizeof(m) - 8);
write_canary(m + MLEN + 8);
for (i = 0; i < NTESTS; i++) {
RETURNS_ZERO(crypto_sign_keypair(pk + 8, sk + 8));
@ -78,10 +100,11 @@ static int test_sign(void) {
}
return 1;
}
if (check_canary(pk) || check_canary(pk + sizeof(pk) - 8) ||
check_canary(sk) || check_canary(sk + sizeof(sk) - 8) ||
check_canary(sm) || check_canary(sm + sizeof(sm) - 8) ||
check_canary(m) || check_canary(m + sizeof(m) - 8)) {
// Validate that the implementation did not touch the canary
if (check_canary(pk) || check_canary(pk + CRYPTO_PUBLICKEYBYTES + 8) ||
check_canary(sk) || check_canary(sk + CRYPTO_SECRETKEYBYTES + 8) ||
check_canary(sm) || check_canary(sm + MLEN + CRYPTO_BYTES + 8) ||
check_canary(m) || check_canary(m + MLEN + 8)) {
printf("ERROR canary overwritten\n");
return 1;
}