0. Check the version of OpenSSL.
1. Check the correctness of implementation of md5.
2. Compute hash of empty string. Save it as binary to hash.bin. 
3. Use enc command and transform hash.bin to base64. 
4. Check padding of "000", "0000","00000",... transformed to base64.
5. How hash is changed if 1 bit of message is changed? Check! 
6. Compute sha1 hash of shattered-1.pdf and shattered-2.pdf. Open both files and see differences.
7. Check integrity of https://www.openssl.org/source/ file.
8. Encrypt arbitrary string using AES128 ECB with key K derived from password. 
9. Check ciphertext when key 1 bit of plaintext was changed.
10. Encrypt file.txt of many (>100x) 11111111....  to file.ecb using ecb mode. Do you see any pattern?
11. Transform file file.ecb to base64. Do you see any pattern?
12. Repeat 11. with cbc mode. Do you see any pattern? Remove salt.
13. Encrypt 15 ("123456789012345") and 16  (with AES) bytes of characters ("1234567890123456").