crypto_cipher_set_key cannot fail

In 5e4d53d535 we made it so that
crypto_cipher_set_key cannot fail. The call will now
always succeed, to returning a boolean for success/failure makes
no sense.

src/common/crypto.c

@@ -426,10 +426,7 @@ crypto_create_init_cipher(const char *key, int encrypt_mode)
     return NULL;
   }
 
-  if (crypto_cipher_set_key(crypto, key)) {
-    crypto_log_errors(LOG_WARN, "setting symmetric key");
-    goto error;
-  }
+  crypto_cipher_set_key(crypto, key);
 
   if (encrypt_mode)
     r = crypto_cipher_encrypt_init_cipher(crypto);
@@ -1252,16 +1249,14 @@ crypto_cipher_generate_key(crypto_cipher_env_t *env)
 
 /** Set the symmetric key for the cipher in <b>env</b> to the first
  * CIPHER_KEY_LEN bytes of <b>key</b>. Does not initialize the cipher.
- * Return 0 on success, -1 on failure.
  */
-int
+void
 crypto_cipher_set_key(crypto_cipher_env_t *env, const char *key)
 {
   tor_assert(env);
   tor_assert(key);
 
   memcpy(env->key, key, CIPHER_KEY_LEN);
-  return 0;
 }
 
 /** Generate an initialization vector for our AES-CTR cipher; store it

src/common/crypto.h

@@ -151,7 +151,7 @@ int crypto_pk_check_fingerprint_syntax(const char *s);
 
 /* symmetric crypto */
 int crypto_cipher_generate_key(crypto_cipher_env_t *env);
-int crypto_cipher_set_key(crypto_cipher_env_t *env, const char *key);
+void crypto_cipher_set_key(crypto_cipher_env_t *env, const char *key);
 void crypto_cipher_generate_iv(char *iv_out);
 int crypto_cipher_set_iv(crypto_cipher_env_t *env, const char *iv);
 const char *crypto_cipher_get_key(crypto_cipher_env_t *env);