add load/save from key instead of pw

auto_tests/encryptsave_test.c

@@ -25,6 +25,9 @@ unsigned char known_key[crypto_box_BEFORENMBYTES] = {0x29, 0x36, 0x1c, 0x9e, 0x6
 char* pw = "hunter2";
 unsigned int pwlen = 7;
 
+unsigned char known_key2[crypto_box_BEFORENMBYTES] = {0x7a, 0xfa, 0x95, 0x45, 0x36, 0x8a, 0xa2, 0x5c, 0x40, 0xfd, 0xc0, 0xe2, 0x35, 0x8, 0x7, 0x88, 0xfa, 0xf9, 0x37, 0x86, 0xeb, 0xff, 0x50, 0x4f, 0x3, 0xe2, 0xf6, 0xd9, 0xef, 0x9, 0x17, 0x1}; 
+// same as above, except standard opslimit instead of extra ops limit for test_known_kdf, and hash pw before kdf for compat
+
 /* cause I'm shameless */
 void accept_friend_request(Tox *m, const uint8_t *public_key, const uint8_t *data, uint16_t length, void *userdata)
 {
@@ -61,11 +64,13 @@ START_TEST(test_save_friend)
     tox_get_address(tox2, address);
     int test = tox_add_friend(tox1, address, (uint8_t *)"Gentoo", 7);
     ck_assert_msg(test == 0, "Failed to add friend error code: %i", test);
+
     uint32_t size = tox_encrypted_size(tox1);
     uint8_t data[size];
     test = tox_encrypted_save(tox1, data, "correcthorsebatterystaple", 25);
     ck_assert_msg(test == 0, "failed to encrypted save");
     ck_assert_msg(tox_is_save_encrypted(data) == 1, "magic number missing");
+
     Tox *tox3 = tox_new(0);
     test = tox_encrypted_load(tox3, data, size, "correcthorsebatterystaple", 25);
     ck_assert_msg(test == 0, "failed to encrypted load");
@@ -73,6 +78,41 @@ START_TEST(test_save_friend)
     test = tox_get_client_id(tox3, 0, address2);
     ck_assert_msg(test == 0, "no friends!");
     ck_assert_msg(memcmp(address, address2, TOX_CLIENT_ID_SIZE) == 0, "addresses don't match!");
+
+    size = tox_encrypted_size(tox3);
+    uint8_t data2[size];
+    uint8_t key[32 + crypto_box_BEFORENMBYTES];
+    memcpy(key, salt, 32); memcpy(key+32, known_key2, crypto_box_BEFORENMBYTES);
+    test = tox_encrypted_key_save(tox3, data2, key);
+    ck_assert_msg(test == 0, "failed to encrypted save the second");
+    ck_assert_msg(tox_is_save_encrypted(data2) == 1, "magic number the second missing");
+
+    // first test tox_encrypted_key_load
+    Tox* tox4 = tox_new(0);
+    test = tox_encrypted_key_load(tox4, data2, size, key);
+    ck_assert_msg(test == 0, "failed to encrypted load the second");
+    uint8_t address4[TOX_CLIENT_ID_SIZE];
+    test = tox_get_client_id(tox4, 0, address4);
+    ck_assert_msg(test == 0, "no friends! the second");
+    ck_assert_msg(memcmp(address, address2, TOX_CLIENT_ID_SIZE) == 0, "addresses don't match! the second");
+
+    // now test compaitibilty with tox_encrypted_load, first manually...
+    uint8_t out1[size], out2[size];
+    printf("Trying to decrypt from pw:\n");
+    uint32_t sz1 = tox_pass_decrypt(data2+TOX_ENC_SAVE_MAGIC_LENGTH, size-TOX_ENC_SAVE_MAGIC_LENGTH, pw, pwlen, out1);
+    uint32_t sz2 = tox_pass_key_decrypt(data2+TOX_ENC_SAVE_MAGIC_LENGTH, size-TOX_ENC_SAVE_MAGIC_LENGTH, key, out2);
+    ck_assert_msg(sz1 == sz2, "differing output sizes");
+    ck_assert_msg(memcmp(out1, out2, sz1) == 0, "differing output data");
+
+    // and now with the code in use (I only bothered with manually to debug this, and it seems a waste
+    // to remove the manual check now that it's there)
+    Tox* tox5 = tox_new(0);
+    test = tox_encrypted_load(tox5, data2, size, pw, pwlen);
+    ck_assert_msg(test == 0, "failed to encrypted load the third");
+    uint8_t address5[TOX_CLIENT_ID_SIZE];
+    test = tox_get_client_id(tox4, 0, address5);
+    ck_assert_msg(test == 0, "no friends! the third");
+    ck_assert_msg(memcmp(address, address2, TOX_CLIENT_ID_SIZE) == 0, "addresses don't match! the third");
 }
 END_TEST
 

toxencryptsave/toxencryptsave.c

@@ -175,6 +175,28 @@ int tox_encrypted_save(const Tox *tox, uint8_t *data, uint8_t *passphrase, uint3
     return tox_pass_encrypt(temp_data, temp_size, passphrase, pplength, data);
 }
 
+/* Save the messenger data encrypted with the given key from tox_derive_key.
+ * data must be at least tox_encrypted_size().
+ *
+ * returns 0 on success
+ * returns -1 on failure
+ */
+int tox_encrypted_key_save(const Tox* tox, uint8_t* data, uint8_t* key)
+{
+    /* first get plain save data */
+    uint32_t temp_size = tox_size(tox);
+    uint8_t temp_data[temp_size];
+    tox_save(tox, temp_data);
+
+    /* the output data consists of, in order: magic number, enc_data */
+    /* first add the magic number */
+    memcpy(data, TOX_ENC_SAVE_MAGIC_NUMBER, TOX_ENC_SAVE_MAGIC_LENGTH);
+    data += TOX_ENC_SAVE_MAGIC_LENGTH;
+
+    /* encrypt */
+    return tox_pass_key_encrypt(temp_data, temp_size, key, data);
+}
+
 /* This is the inverse of tox_pass_key_encrypt, also using only keys produced by
  * tox_derive_key_from_pass.
  *
@@ -260,6 +282,29 @@ int tox_encrypted_load(Tox *tox, const uint8_t *data, uint32_t length, uint8_t *
     return tox_load(tox, temp_data, decrypt_length);
 }
 
+/* Load the messenger from encrypted data of size length, with key from tox_derive_key.
+ *
+ * returns 0 on success
+ * returns -1 on failure
+ */
+int tox_encrypted_key_load(Tox *tox, const uint8_t *data, uint32_t length, uint8_t* key)
+{
+    if (memcmp(data, TOX_ENC_SAVE_MAGIC_NUMBER, TOX_ENC_SAVE_MAGIC_LENGTH) != 0)
+        return -1;
+
+    data += TOX_ENC_SAVE_MAGIC_LENGTH;
+    length -= TOX_ENC_SAVE_MAGIC_LENGTH;
+
+    uint32_t decrypt_length = length - TOX_PASS_ENCRYPTION_EXTRA_LENGTH;
+    uint8_t temp_data[decrypt_length];
+
+    if (tox_pass_key_decrypt(data, length, key, temp_data)
+            != decrypt_length)
+        return -1;
+    printf("tox key load: decryption passed\n");
+    return tox_load(tox, temp_data, decrypt_length);
+}
+
 /* Determines whether or not the given data is encrypted (by checking the magic number)
  *
  * returns 1 if it is encrypted

toxencryptsave/toxencryptsave.h

@@ -95,6 +95,14 @@ int tox_pass_encrypt(const uint8_t *data, uint32_t data_len, uint8_t *passphrase
  */
 int tox_encrypted_save(const Tox *tox, uint8_t *data, uint8_t *passphrase, uint32_t pplength);
 
+/* Save the messenger data encrypted with the given key from tox_derive_key.
+ * data must be at least tox_encrypted_size().
+ *
+ * returns 0 on success
+ * returns -1 on failure
+ */
+int tox_encrypted_key_save(const Tox* tox, uint8_t* data, uint8_t* key);
+
 /* This is the inverse of tox_pass_key_encrypt, also using only keys produced by
  * tox_derive_key_from_pass.
  *
@@ -121,6 +129,13 @@ int tox_pass_decrypt(const uint8_t *data, uint32_t length, uint8_t *passphrase,
  */
 int tox_encrypted_load(Tox *tox, const uint8_t *data, uint32_t length, uint8_t *passphrase, uint32_t pplength);
 
+/* Load the messenger from encrypted data of size length, with key from tox_derive_key.
+ *
+ * returns 0 on success
+ * returns -1 on failure
+ */
+int tox_encrypted_key_load(Tox *tox, const uint8_t *data, uint32_t length, uint8_t* key);
+
 /* Determines whether or not the given data is encrypted (by checking the magic number)
  *
  * returns 1 if it is encrypted