You said that for medium, you used PKCS#7. However, according to this, you didn't implement it correctly. You are supposed to pad the plaintext before encryption. Looking at example files, and the disassembly, it appears that you pad after encryption.
You said that for medium, you used PKCS#7. However, according to this, you didn't implement it correctly. You are supposed to pad the plaintext before encryption. Looking at example files, and the disassembly, it appears that you pad after encryption.