ed25519: support empty password

Author: FooBarrior

mysql-test/suite/plugins/r/auth_ed25519.result

@@ -70,6 +70,20 @@ current_user()
 test1@localhost
 disconnect con1;
 connection default;
+create user test2@localhost identified via ed25519 using PASSWORD('');
+show grants for test2@localhost;
+Grants for test2@localhost
+GRANT USAGE ON *.* TO `test2`@`localhost` IDENTIFIED VIA ed25519 USING '4LH+dBF+G5W2CKTyId8xR3SyDqZoQjUNUVNxx8aWbG4'
+connect con2, localhost, test2,;
+select current_user();
+current_user()
+test2@localhost
+disconnect con2;
+connect(localhost,test2,wrong_pwd,test,MASTER_MYPORT,MASTER_MYSOCK);
+connect con3, localhost, test2, "wrong_pwd";
+ERROR 28000: Access denied for user 'test2'@'localhost' (using password: YES)
+connection default;
+drop user test2@localhost;
 drop user test1@localhost;
 uninstall plugin ed25519;
 select ed25519_password("foo");

mysql-test/suite/plugins/t/auth_ed25519.test

@@ -50,6 +50,18 @@ select current_user();
 disconnect con1;
 connection default;
 
+create user test2@localhost identified via ed25519 using PASSWORD('');
+show grants for test2@localhost;
+connect con2, localhost, test2,;
+select current_user();
+disconnect con2;
+
+replace_result $MASTER_MYSOCK MASTER_MYSOCK $MASTER_MYPORT MASTER_MYPORT;
+error ER_ACCESS_DENIED_ERROR;
+connect con3, localhost, test2, "wrong_pwd";
+connection default;
+drop user test2@localhost;
+
 drop user test1@localhost;
 uninstall plugin ed25519;
 error ER_CANT_INITIALIZE_UDF;

plugin/auth_ed25519/server_ed25519.c

@@ -64,7 +64,7 @@ static int compute_password_digest(const char *pw, size_t pwlen,
                                    char *d, size_t *dlen)
 {
   unsigned char pk[CRYPTO_PUBLICKEYBYTES];
-  if (*dlen < PASSWORD_LEN || pwlen == 0)
+  if (*dlen < PASSWORD_LEN)
     return 1;
   *dlen= PASSWORD_LEN;
   crypto_sign_keypair(pk, (unsigned char*)pw, pwlen);