diff options
Diffstat (limited to 'fuzzer-verify.c')
| -rw-r--r-- | fuzzer-verify.c | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/fuzzer-verify.c b/fuzzer-verify.c index bbef524..a0ad086 100644 --- a/fuzzer-verify.c +++ b/fuzzer-verify.c @@ -2,6 +2,7 @@ #include "session.h" #include "fuzz-wrapfd.h" #include "debug.h" +#include "dss.h" static void setup_fuzzer(void) { fuzz_common_setup(); @@ -27,21 +28,35 @@ int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { if (setjmp(fuzz.jmp) == 0) { sign_key *key = new_sign_key(); - enum signkey_type type = DROPBEAR_SIGNKEY_ANY; - if (buf_get_pub_key(fuzz.input, key, &type) == DROPBEAR_SUCCESS) { - if (buf_verify(fuzz.input, key, verifydata) == DROPBEAR_SUCCESS) { + enum signkey_type keytype = DROPBEAR_SIGNKEY_ANY; + if (buf_get_pub_key(fuzz.input, key, &keytype) == DROPBEAR_SUCCESS) { + enum signature_type sigtype; + if (keytype == DROPBEAR_SIGNKEY_RSA) { + /* Flip a coin to decide rsa signature type */ + int flag = buf_getbyte(fuzz.input); + if (flag & 0x01) { + sigtype = DROPBEAR_SIGNATURE_RSA_SHA256; + } else { + sigtype = DROPBEAR_SIGNATURE_RSA_SHA1; + } + } else { + sigtype = signature_type_from_signkey(keytype); + } + if (buf_verify(fuzz.input, key, sigtype, verifydata) == DROPBEAR_SUCCESS) { /* The fuzzer is capable of generating keys with a signature to match. We don't want false positives if the key is bogus, since a client/server wouldn't be trusting a bogus key anyway */ int boguskey = 0; - if (type == DROPBEAR_SIGNKEY_DSS) { + if (keytype == DROPBEAR_SIGNKEY_DSS) { /* So far have seen dss keys with bad p/q/g domain parameters */ - int pprime, qprime; - assert(mp_prime_is_prime(key->dsskey->p, 5, &pprime) == MP_OKAY); - assert(mp_prime_is_prime(key->dsskey->q, 18, &qprime) == MP_OKAY); - boguskey = !(pprime && qprime); - /* Could also check g**q mod p == 1 */ + int pprime, qprime, trials; + trials = mp_prime_rabin_miller_trials(mp_count_bits(key->dsskey->p)); + assert(mp_prime_is_prime(key->dsskey->p, trials, &pprime) == MP_OKAY); + trials = mp_prime_rabin_miller_trials(mp_count_bits(key->dsskey->q)); + assert(mp_prime_is_prime(key->dsskey->q, trials, &qprime) == MP_OKAY); + boguskey = !(pprime && qprime); + /* Could also check g**q mod p == 1 */ } if (!boguskey) { |