How to generate package signature in Flutter (azure connection, msal)?

Question

How to generate signature in Flutter (azure connection, msal)?

       "redirect_uri" : "msauth://<YOUR_PACKAGE_NAME>/<YOUR_BASE64_URL_ENCODED_PACKAGE_SIGNATURE>",

What exactly is package signature and how to generate it in Flutter? I use this library: https://pub.dev/packages/flutter_azure_b2c

EDIT:

Should I use only keytool to generate?

echo y | keytool -genkeypair -dname "cn=Jones, ou=JavaSoft, o=Sun, c=PL" -alias business -keypass kpi135 -keystore C:/Workspace/android.js -storepass ab987c -validity 20000

I use this one: Generate SHA-1 for Flutter/React-Native/Android-Native app

but it is much longer than usual code I saw. I have SHA1 encoded and it is longer, is it correct to use?

i.e. my is like :

RTE6ASD6MDk6ODM6RUY6NjY6N0I6RjY6MkE6M0U6QzA6MTU6QzI6NkU6QkI6MTE6NEU6Qjc6MTc6MzI=

correct length

M61nf%2CaH69kCSmFY1ejcX83rNNc%3D

Answer 1

Apart from using keytool, you can also use signing report of gradle as suggested by Mostafa Radwan:

• Go to android folder: cd android
• Get the signinReport: ./gradlew signingReport and grab the SHA1 key

If the above steps don't work then you can try as suggested by
Loop_assembly:

daemon> signingReport

References: Flutter - Get SHA-1 Certificate - Android Studio 3.2.1 and Generate SHA-1 for Flutter/React-Native/Android-Native app