Add set_secret() and get_secret() for iOS impl.

[tmpfs]

Closes #187.

[brotskydotcom]

Your definitions of set_secret and get_secret are perfect.

But, like the macOS implementation, you should have set_password call set_secret like this:

    fn set_password(&self, password: &str) -> Result<()> {
        self.set_secret(password.as_bytes())
    }

and you should have get_password call get_secret like this:

    fn get_password(&self) -> Result<String> {
        let password_bytes = self.get_secret()?;
        decode_password(password_bytes.to_vec())
    }

[tmpfs]

Good call @brotskydotcom , thats done!

[brotskydotcom]

Excellent! Thank you so much!

[tmpfs]

I notice you convert to Vec<u8> when calling decode_password() but std::str::from_utf8 will take a slice so you can just pass to without the calls to to_vec().

Edit: so if you prefer std::str::from_utf8 to String::from_utf8 then we could avoid the allocations here make the code a bit tidier.

[brotskydotcom]

Can you please update README.md to add your name in the contributor's list?

[brotskydotcom]

I notice you convert to Vec<u8> when calling decode_password() but std::str::from_utf8 will take a slice so you can just pass to without the calls to to_vec().

Edit: so if you prefer std::str::from_utf8 to String::from_utf8 then we could avoid the allocations here.

Well the definition of decode_password is shared across platforms and most of the others have already done the vector conversion. But I still like the optimization you suggest in the iOS case, because password_bytes is already a Vec when it comes back from get_secret, so there's really no reason to have the .to_vec() redundant copy made. It should just be decode_password(password_bytes).

[brotskydotcom]

Just one last fix needed.

[brotskydotcom]

Whoops. Just noticed one more fix needed to get the example library working on iOS:

You need to change line 92 from

    use keyring::default::IosCredential;

to

    use keyring::ios::IosCredential;

[brotskydotcom]

Perfect, thanks for keeping at it!