PL/SQL: quoting problems (double quotes within PL/SQL, howto?)

Question

Hello,
I have a big problem with that: I just cannot use execute immediate to do what I want.
The goal is that another user than sysdba needs to be able to open/close the wallet (we are sysdba and our client doesn't want us to be able to open the wallet, and we don't want the client to have sysdba), so I take advantage of the fact that procedures are executed by default with the privileges of the user which writes it. So, I try and create a PL/SQL procedure as sys and grant execute rights to the client user.
To open/close a wallet, the command is:
alter system set encryption wallet open/close identified by "thepasshere";
Note the double quotes... They are the problem here (passwords are mixed case and contain special characters). Right now, the only solution I came up with is:
create or replace procedure open_wallet (passwd in varchar2) is
begin
execute immediate 'alter system set encryption wallet open identified by "' || passwd || '";';
end;
But that's vulnerable to code injection... So, instead, I tried:
create or replace procedure open_wallet (passwd in varchar2) is
cmd varchar2(512);
begin
cmd != 'alter system set encryption wallet open identified by ":1"';
execute immediate cmd using passwd;
end;
which yields "ORA-00911: invalid character" - uh?
Now, if I try:
create or replace procedure open_wallet (passwd in varchar2) is
cmd varchar(512);
begin
cmd := 'alter system set encryption wallet open identified by :1;';
execute immediate cmd using passwd;
end;
it answers "ORA-28357: password required to open the wallet"
Aaargh! I see no way around that :(
Is there a solution at all?

Answer 1

Did you try including the double quotes in the password bind value? Either when you pass the value in or by adding it in the routine.
create or replace procedure open_wallet (passwd in varchar2) is
cmd varchar(512);
pass varchar(512);
begin
cmd := 'alter system set encryption wallet open identified by :1;';
pass := '"' || passwd || '"';
execute immediate cmd using pass;
end;