Как я могу получить secretKey для расшифровки?

Мне нужна помощь для получения secretKey, чтобы я мог уже зашифрованный файл перевести в нормальный текст. Вот пример кода который нужно расшифровать:

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package h8;

import android.content.SharedPreferences;
import android.util.Base64;
import android.util.Log;
import com.applovin.mediation.MaxReward;
import java.security.KeyFactory;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.X509EncodedKeySpec;

/* compiled from: IidStore */
public class b {

    /* renamed from: c  reason: collision with root package name */
    public static final String[] f8989c = {"*", "FCM", "GCM", MaxReward.DEFAULT_LABEL};

    /* renamed from: a  reason: collision with root package name */
    public final SharedPreferences f8990a;

    /* renamed from: b  reason: collision with root package name */
    public final String f8991b;

    /* JADX WARNING: Code restructure failed: missing block: B:9:0x0046, code lost:
        if (r0.isEmpty() != false) goto L_0x0048;
     */
    /* Code decompiled incorrectly, please refer to instructions dump. */
    public b(w5.c r4) {
        throw new UnsupportedOperationException("Method not decompiled: h8.b.<init>(w5.c):void");
    }

    public final String a() {
        PublicKey publicKey;
        synchronized (this.f8990a) {
            String str = null;
            String string = this.f8990a.getString("|S||P|", null);
            if (string == null) {
                return null;
            }
            try {
                publicKey = KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(Base64.decode(string, 8)));
            } catch (IllegalArgumentException | NoSuchAlgorithmException | InvalidKeySpecException e10) {
                Log.w("ContentValues", "Invalid key stored " + e10);
                publicKey = null;
            }
            if (publicKey == null) {
                return null;
            }
            try {
                byte[] digest = MessageDigest.getInstance("SHA1").digest(publicKey.getEncoded());
                digest[0] = (byte) (((digest[0] & 15) + 112) & 255);
                str = Base64.encodeToString(digest, 0, 8, 11);
            } catch (NoSuchAlgorithmException unused) {
                Log.w("ContentValues", "Unexpected error, device missing required algorithms");
            }
            return str;
        }
    }
}