/** Run unit tests for our public key crypto functions */
static void
test_crypto_pk(void)
{
crypto_pk_t *pk1 = NULL, *pk2 = NULL;
char *encoded = NULL;
char data1[1024], data2[1024], data3[1024];
size_t size;
int i, j, p, len;
/* Public-key ciphers */
pk1 = pk_generate(0);
pk2 = crypto_pk_new();
test_assert(pk1 && pk2);
test_assert(! crypto_pk_write_public_key_to_string(pk1, &encoded, &size));
test_assert(! crypto_pk_read_public_key_from_string(pk2, encoded, size));
test_eq(0, crypto_pk_cmp_keys(pk1, pk2));
/* comparison between keys and NULL */
tt_int_op(crypto_pk_cmp_keys(NULL, pk1), <, 0);
tt_int_op(crypto_pk_cmp_keys(NULL, NULL), ==, 0);
tt_int_op(crypto_pk_cmp_keys(pk1, NULL), >, 0);
test_eq(128, crypto_pk_keysize(pk1));
test_eq(1024, crypto_pk_num_bits(pk1));
test_eq(128, crypto_pk_keysize(pk2));
test_eq(1024, crypto_pk_num_bits(pk2));
test_eq(128, crypto_pk_public_encrypt(pk2, data1, sizeof(data1),
"Hello whirled.", 15,
PK_PKCS1_OAEP_PADDING));
test_eq(128, crypto_pk_public_encrypt(pk1, data2, sizeof(data1),
"Hello whirled.", 15,
PK_PKCS1_OAEP_PADDING));
/* oaep padding should make encryption not match */
test_memneq(data1, data2, 128);
test_eq(15, crypto_pk_private_decrypt(pk1, data3, sizeof(data3), data1, 128,
PK_PKCS1_OAEP_PADDING,1));
test_streq(data3, "Hello whirled.");
memset(data3, 0, 1024);
test_eq(15, crypto_pk_private_decrypt(pk1, data3, sizeof(data3), data2, 128,
PK_PKCS1_OAEP_PADDING,1));
test_streq(data3, "Hello whirled.");
/* Can't decrypt with public key. */
test_eq(-1, crypto_pk_private_decrypt(pk2, data3, sizeof(data3), data2, 128,
PK_PKCS1_OAEP_PADDING,1));
/* Try again with bad padding */
memcpy(data2+1, "XYZZY", 5); /* This has fails ~ once-in-2^40 */
test_eq(-1, crypto_pk_private_decrypt(pk1, data3, sizeof(data3), data2, 128,
PK_PKCS1_OAEP_PADDING,1));
/* File operations: save and load private key */
test_assert(! crypto_pk_write_private_key_to_filename(pk1,
get_fname("pkey1")));
/* failing case for read: can't read. */
test_assert(crypto_pk_read_private_key_from_filename(pk2,
get_fname("xyzzy")) < 0);
write_str_to_file(get_fname("xyzzy"), "foobar", 6);
/* Failing case for read: no key. */
test_assert(crypto_pk_read_private_key_from_filename(pk2,
get_fname("xyzzy")) < 0);
test_assert(! crypto_pk_read_private_key_from_filename(pk2,
get_fname("pkey1")));
test_eq(15, crypto_pk_private_decrypt(pk2, data3, sizeof(data3), data1, 128,
PK_PKCS1_OAEP_PADDING,1));
/* Now try signing. */
strlcpy(data1, "Ossifrage", 1024);
test_eq(128, crypto_pk_private_sign(pk1, data2, sizeof(data2), data1, 10));
test_eq(10,
crypto_pk_public_checksig(pk1, data3, sizeof(data3), data2, 128));
test_streq(data3, "Ossifrage");
/* Try signing digests. */
test_eq(128, crypto_pk_private_sign_digest(pk1, data2, sizeof(data2),
data1, 10));
test_eq(20,
crypto_pk_public_checksig(pk1, data3, sizeof(data3), data2, 128));
test_eq(0, crypto_pk_public_checksig_digest(pk1, data1, 10, data2, 128));
test_eq(-1, crypto_pk_public_checksig_digest(pk1, data1, 11, data2, 128));
/*XXXX test failed signing*/
/* Try encoding */
crypto_pk_free(pk2);
pk2 = NULL;
i = crypto_pk_asn1_encode(pk1, data1, 1024);
test_assert(i>0);
pk2 = crypto_pk_asn1_decode(data1, i);
test_assert(crypto_pk_cmp_keys(pk1,pk2) == 0);
/* Try with hybrid encryption wrappers. */
crypto_rand(data1, 1024);
for (i = 0; i < 2; ++i) {
for (j = 85; j < 140; ++j) {
memset(data2,0,1024);
memset(data3,0,1024);
p = (i==0)?PK_PKCS1_PADDING:PK_PKCS1_OAEP_PADDING;
len = crypto_pk_public_hybrid_encrypt(pk1,data2,sizeof(data2),
data1,j,p,0);
test_assert(len>=0);
len = crypto_pk_private_hybrid_decrypt(pk1,data3,sizeof(data3),
data2,len,p,1);
test_eq(len,j);
test_memeq(data1,data3,j);
}
}
/* Try copy_full */
crypto_pk_free(pk2);
pk2 = crypto_pk_copy_full(pk1);
test_assert(pk2 != NULL);
test_neq_ptr(pk1, pk2);
test_assert(crypto_pk_cmp_keys(pk1,pk2) == 0);
done:
if (pk1)
crypto_pk_free(pk1);
if (pk2)
crypto_pk_free(pk2);
tor_free(encoded);
}
/** Given an encrypted DH public key as generated by onion_skin_create,
* and the private key for this onion router, generate the reply (128-byte
* DH plus the first 20 bytes of shared key material), and store the
* next key_out_len bytes of key material in key_out.
*/
int
onion_skin_server_handshake(const char *onion_skin, /*ONIONSKIN_CHALLENGE_LEN*/
crypto_pk_env_t *private_key,
crypto_pk_env_t *prev_private_key,
char *handshake_reply_out, /*ONIONSKIN_REPLY_LEN*/
char *key_out,
size_t key_out_len)
{
char challenge[ONIONSKIN_CHALLENGE_LEN];
crypto_dh_env_t *dh = NULL;
ssize_t len;
char *key_material=NULL;
size_t key_material_len=0;
int i;
crypto_pk_env_t *k;
len = -1;
for (i=0;i<2;++i) {
k = i==0?private_key:prev_private_key;
if (!k)
break;
note_crypto_pk_op(DEC_ONIONSKIN);
len = crypto_pk_private_hybrid_decrypt(k, challenge,
onion_skin, ONIONSKIN_CHALLENGE_LEN,
PK_PKCS1_OAEP_PADDING,0);
if (len>0)
break;
}
if (len<0) {
log_info(LD_PROTOCOL,
"Couldn't decrypt onionskin: client may be using old onion key");
goto err;
} else if (len != DH_KEY_LEN) {
log_warn(LD_PROTOCOL, "Unexpected onionskin length after decryption: %ld",
(long)len);
goto err;
}
dh = crypto_dh_new();
if (crypto_dh_get_public(dh, handshake_reply_out, DH_KEY_LEN)) {
log_info(LD_GENERAL, "crypto_dh_get_public failed.");
goto err;
}
key_material_len = DIGEST_LEN+key_out_len;
key_material = tor_malloc(key_material_len);
len = crypto_dh_compute_secret(dh, challenge, DH_KEY_LEN,
key_material, key_material_len);
if (len < 0) {
log_info(LD_GENERAL, "crypto_dh_compute_secret failed.");
goto err;
}
/* send back H(K|0) as proof that we learned K. */
memcpy(handshake_reply_out+DH_KEY_LEN, key_material, DIGEST_LEN);
/* use the rest of the key material for our shared keys, digests, etc */
memcpy(key_out, key_material+DIGEST_LEN, key_out_len);
memset(challenge, 0, sizeof(challenge));
memset(key_material, 0, key_material_len);
tor_free(key_material);
crypto_dh_free(dh);
return 0;
err:
memset(challenge, 0, sizeof(challenge));
if (key_material) {
memset(key_material, 0, key_material_len);
tor_free(key_material);
}
if (dh) crypto_dh_free(dh);
return -1;
}
