Decrypt a Java AES encoded String in Dart

I need to decrypt an AES (PKCS#7) encoded string in my Flutter mobile application. The string is got from a QR Code, which has been generated from a Java application and contains the AES encoded …

Extract raw certificate from PKCS#7 file in JAVA

I would like to achieve the same what this openssl command performs, but programmatically in Java: openssl pkcs7 -in toBeExported.p7c -inform DER -out certificate.pem -print_certs which means that …