Check android keystore keypass for correctness

You can also check if the password is correct without attempting to change the password. I did it by listing the properties of the keystore with this command:

keytool -list -keystore <keystorefile> -storepass <passwordtocheck>

You can do it a couple of ways:

A. With keytool

If you run the command keytool -keypasswd -keystore <keystore> -alias <alias> -storepass <storepass> -keypass <keypass> -new <keypass> then you will get the error Keystore was tampered with, or password was incorrect if the keystore password is wrong, or the error Cannot recover key if the alias password is wrong. Unfortunately the return code is 1 in both cases, so you will need to do parsing of the program's output if you want to be smart about the type of error.

B. With a small Java program

Something along these lines:

KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());

try (FileInputStream fis = new FileInputStream(keystore)) {
    ks.load(fis, ksPw.toCharArray());
}

ks.getEntry(alias, new KeyStore.PasswordProtection(aliasPw.toCharArray()));

will fail at line 4 with a java.io.IOException if the key store password is wrong, or with a java.security.UnrecoverableKeyException at line 7 if the alias password is wrong.