`PListParser#base64decode` does not expect data to be multiline

[vsalavatov]

The plist file for proxy settings on MacOS may store some fields using multiline base64 encoding (<data>). For an example of how it may look, please see https://forum.latenightsw.com/t/how-do-i-base64-decode-and-encode-multiple-lines/759 (not a proxy preferences plist file, but it looks the same). The <data> contains the base64-encoded sequence split by newlines and tabulations.

It makes the method incorrectly parse the data or throw an exception (IndexOutOfBoundsException) because the length of the base64 sequence is not divisible by 4 because of the extra characters. It makes the OsxProxySearchStrategy strategy fail with an exception.

Probably, to make it more robust, all "space" characters should be filtered out.

[akuhtz]

@vsalavatov Can you provide the base64-encoded data that causes the exception?

[vsalavatov]

The issue was reported by a user, and I don't have the data at hand. I'll try to reproduce the issue myself later and post it here. It was some proxy credential stored in <data>, if I'm not mistaken.

[vsalavatov]

STR:

1. install wireguard client on mac
2. add an empty tunnel, it will automatically have some private key
3. it will appear in /Library/Preferences/SystemConfiguration/preferences.plist, see Details below
   Details

I cannot share the whole file, but this is the added entry

<key>733706DB-942B-4451-9F70-65379770E441</key>
        <dict>
            <key>DNS</key>
            <dict>
                <key>__INACTIVE__</key>
                <true/>
            </dict>
            <key>IPv4</key>
            <dict>
                <key>ConfigMethod</key>
                <string>VPN</string>
            </dict>
            <key>IPv6</key>
            <dict>
                <key>ConfigMethod</key>
                <string>Automatic</string>
            </dict>
            <key>Interface</key>
            <dict>
                <key>SubType</key>
                <string>com.wireguard.macos</string>
                <key>Type</key>
                <string>VPN</string>
            </dict>
            <key>Proxies</key>
            <dict>
                <key>FTPPassive</key>
                <integer>1</integer>
                <key>__INACTIVE__</key>
                <true/>
            </dict>
            <key>SMB</key>
            <dict/>
            <key>UserDefinedName</key>
            <string>kekos</string>
            <key>VPN</key>
            <dict>
                <key>AuthenticationMethod</key>
                <string>Password</string>
                <key>DesignatedRequirement</key>
                <string>(anchor apple generic and certificate leaf[field.1.2.840.113635.100.6.1.9] /* exists */ or anchor apple generic and certificate 1[field.1.2.840.113635.100.6.2.6] /* exists */ and certificate leaf[field.1.2.840.113635.100.6.1.13] /* exists */ and certificate leaf[subject.OU] = L82V4Y2P3C) and identifier "com.wireguard.macos.network-extension"</string>
                <key>DisconnectOnFastUserSwitch</key>
                <integer>0</integer>
                <key>DisconnectOnIdle</key>
                <integer>0</integer>
                <key>DisconnectOnIdleTimer</key>
                <integer>0</integer>
                <key>DisconnectOnLogout</key>
                <integer>0</integer>
                <key>DisconnectOnSleep</key>
                <integer>0</integer>
                <key>DisconnectOnWake</key>
                <integer>0</integer>
                <key>DisconnectOnWakeTimer</key>
                <integer>0</integer>
                <key>NEProviderBundleIdentifier</key>
                <string>com.wireguard.macos.network-extension</string>
                <key>OnDemandEnabled</key>
                <false/>
                <key>PasswordReference</key>
                <data>
                c3N1aQAAACCHGRyjD8kR1ISaAAUCtSEiAAAAAAAAAAAA
                AAAAAAAABmRibm0AAAAmfi9MaWJyYXJ5L0tleWNoYWlu
                cy9sb2dpbi5rZXljaGFpbi1kYgBpdGVtAAAASoAAAAAA
                AAAra2Vrb3M6IDhEREVGQTYwLThFRUItNDdGNS1CMjE5
                LTg3Njc0MDc2MEE0NgAAABNjb20ud2lyZWd1YXJkLm1h
                Y29z
                </data>
                <key>RemoteAddress</key>
                <string>Unspecified</string>
            </dict>
            <key>com.wireguard.macos</key>
            <dict>
                <key>UID</key>
                <integer>501</integer>
            </dict>
        </dict>

The system default strategy fails to parse the file:

[akuhtz]

@vsalavatov Many thanks for the data to reproduce the issue. As I don't have access to a Mac at the moment, could you try with the latest 1.1.5-SNAPSHOT version if the error is fixed? https://oss.sonatype.org/content/repositories/snapshots/org/bidib/com/github/markusbernhardt/proxy-vole/1.1.5-SNAPSHOT/

I will do a release if it works.

[vsalavatov]

It works! Thanks for such a fast fix! 🔥

[akuhtz]

@vsalavatov Thanks for your support 👍 Release 1.1.5 is published to central maven repo.