/** 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; }