2 files changed, 10 insertions, 10 deletions

diff --git a/toxencryptsave/toxencryptsave.c b/toxencryptsave/toxencryptsave.c
index e2f28a58..e6150ce2 100644
--- a/toxencryptsave/toxencryptsave.c
+++ b/toxencryptsave/toxencryptsave.c
@@ -82,7 +82,7 @@ bool tox_get_salt(const uint8_t *data, uint8_t *salt)
  *
  * returns true on success
  */
-bool tox_derive_key_from_pass(uint8_t *passphrase, size_t pplength, TOX_PASS_KEY *out_key,
+bool tox_derive_key_from_pass(const uint8_t *passphrase, size_t pplength, TOX_PASS_KEY *out_key,
                               TOX_ERR_KEY_DERIVATION *error)
 {
     uint8_t salt[crypto_pwhash_scryptsalsa208sha256_SALTBYTES];
@@ -93,10 +93,10 @@ bool tox_derive_key_from_pass(uint8_t *passphrase, size_t pplength, TOX_PASS_KEY
 /* Same as above, except with use the given salt for deterministic key derivation.
  * The salt must be TOX_PASS_SALT_LENGTH bytes in length.
  */
-bool tox_derive_key_with_salt(uint8_t *passphrase, size_t pplength, uint8_t *salt, TOX_PASS_KEY *out_key,
+bool tox_derive_key_with_salt(const uint8_t *passphrase, size_t pplength, const uint8_t *salt, TOX_PASS_KEY *out_key,
                               TOX_ERR_KEY_DERIVATION *error)
 {
-    if (pplength == 0 || !passphrase || !salt || !out_key) {
+    if (!salt || !out_key || (!passphrase && pplength != 0)) {
         SET_ERROR_PARAMETER(error, TOX_ERR_KEY_DERIVATION_NULL);
         return 0;
     }
@@ -180,7 +180,7 @@ bool tox_pass_key_encrypt(const uint8_t *data, size_t data_len, const TOX_PASS_K
  *
  * returns true on success
  */
-bool tox_pass_encrypt(const uint8_t *data, size_t data_len, uint8_t *passphrase, size_t pplength, uint8_t *out,
+bool tox_pass_encrypt(const uint8_t *data, size_t data_len, const uint8_t *passphrase, size_t pplength, uint8_t *out,
                       TOX_ERR_ENCRYPTION *error)
 {
     TOX_PASS_KEY key;
@@ -252,10 +252,10 @@ bool tox_pass_key_decrypt(const uint8_t *data, size_t length, const TOX_PASS_KEY
  *
  * returns true on success
  */
-bool tox_pass_decrypt(const uint8_t *data, size_t length, uint8_t *passphrase, size_t pplength, uint8_t *out,
+bool tox_pass_decrypt(const uint8_t *data, size_t length, const uint8_t *passphrase, size_t pplength, uint8_t *out,
                       TOX_ERR_DECRYPTION *error)
 {
-    if (length <= TOX_PASS_ENCRYPTION_EXTRA_LENGTH || pplength == 0) {
+    if (length <= TOX_PASS_ENCRYPTION_EXTRA_LENGTH) {
         SET_ERROR_PARAMETER(error, TOX_ERR_DECRYPTION_INVALID_LENGTH);
         return 0;
     }
diff --git a/toxencryptsave/toxencryptsave.h b/toxencryptsave/toxencryptsave.h
index c077d899..9e28b48e 100644
--- a/toxencryptsave/toxencryptsave.h
+++ b/toxencryptsave/toxencryptsave.h
@@ -143,7 +143,7 @@ typedef enum TOX_ERR_DECRYPTION {
  *
  * returns true on success
  */
-bool tox_pass_encrypt(const uint8_t *data, size_t data_len, uint8_t *passphrase, size_t pplength, uint8_t *out,
+bool tox_pass_encrypt(const uint8_t *data, size_t data_len, const uint8_t *passphrase, size_t pplength, uint8_t *out,
                       TOX_ERR_ENCRYPTION *error);
 
 
@@ -155,7 +155,7 @@ bool tox_pass_encrypt(const uint8_t *data, size_t data_len, uint8_t *passphrase,
  *
  * returns true on success
  */
-bool tox_pass_decrypt(const uint8_t *data, size_t length, uint8_t *passphrase, size_t pplength, uint8_t *out,
+bool tox_pass_decrypt(const uint8_t *data, size_t length, const uint8_t *passphrase, size_t pplength, uint8_t *out,
                       TOX_ERR_DECRYPTION *error);
 
 
@@ -183,13 +183,13 @@ typedef struct {
  *
  * returns true on success
  */
-bool tox_derive_key_from_pass(uint8_t *passphrase, size_t pplength, TOX_PASS_KEY *out_key,
+bool tox_derive_key_from_pass(const uint8_t *passphrase, size_t pplength, TOX_PASS_KEY *out_key,
                               TOX_ERR_KEY_DERIVATION *error);
 
 /* Same as above, except use the given salt for deterministic key derivation.
  * The salt must be TOX_PASS_SALT_LENGTH bytes in length.
  */
-bool tox_derive_key_with_salt(uint8_t *passphrase, size_t pplength, uint8_t *salt, TOX_PASS_KEY *out_key,
+bool tox_derive_key_with_salt(const uint8_t *passphrase, size_t pplength, const uint8_t *salt, TOX_PASS_KEY *out_key,
                               TOX_ERR_KEY_DERIVATION *error);
 
 /* This retrieves the salt used to encrypt the given data, which can then be passed to