GAuthDecrypt is Swift library for extraction two-factor authentication secret keys from export QR codes of Google Authenticator app. At the input is a string read from a qr code, at the output is an array of objects of the GAuthOTP type. I used it on my 2FA app check it Open2FA

You can use Swift Package Manager and specify dependency in Package.swift by adding this:

dependencies: [
    .package(url: "https://github.com/AginSquash/GAuthDecrypt.git", .upToNextMinor(from: "2.0.0"))
]

Or click File -> Add Packages. In search form enter https://github.com/AginSquash/GAuthDecrypt.git and click "Copy Dependency" button.

let stringFromGoogleAuthApp = "otpauth-migration://offline?data=CjEKCkhlbGxvId6tvu8SGEV4YW1wbGU6YWxpY2VAZ29vZ2xlLmNvbRoHRXhhbXBsZTAC"
let decrypted = GAuthDecryptFrom(input: stringFromGoogleAuthApp) // decrypted type is Optional<[GAuthOTP]>
print(decrypted![0]) 
/*
    type: .totp, 
    algorithm: .unspecified, 
    name: "Example:[email protected]", 
    secret: "JBSWY3DPEHPK3PXP", 
    issuer: "Example", 
    counter: 0, 
    digitsRawValue: 0) 
*/

All dependencies in this project are added through SPM. Links to them:

• https://github.com/apple/swift-protobuf
• https://github.com/norio-nomura/Base32

Copyright (C) 2023 Vladislav Vrublevsky [email protected]

This software is provided 'as-is', without any express or implied warranty.

In no event will the authors be held liable for any damages arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

• The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation is required.
• Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
• This notice may not be removed or altered from any source or binary distribution.
• Redistributions of any form whatsoever must retain the following acknowledgment: 'This product includes software developed by the "Vladislav Vrublevsky" (AginSquash).'