md5 sha256 sha512 sha224 sha384

In this project I recreated 5 different popular hash functions. Hash functions take in data and spit out a deterministic, fixed-length number, called a hash. Because it's nearly impossible to reverse-engineer the original message from these hashes, and slight differences in the message produce vastly different hashes, it has many uses in authentication and verification of information integrity. sha256 is used in the Bitcoin protocol. The real challenge of this project was debugging the algorithm, since it was impossible to tell what went wrong from reading the output. The painstaking attention to detail required to locate the errors taught me the value of clear, readable code that gets the job done right the first time.

Usage

Build with make or make re.

./ft_ssl [HASH_FUNCTION] -[MODE] [INPUT]

Hash functions:

md5
sha224
sha256
sha384
sha512

Modes:
-p write message on standard input
-q quiet mode--shows only the hash
-r reverse format--prints the hash first, then reprints the message after
-s take string instead of a file

Examples

$ ./ft_ssl md5 -s "haha"
MD5("haha")= 4e4d6c332b6fe62a63afe56171fd3725

$ echo "hehe" | ./ft_ssl md5
e4439267203fb5277d347e6cd6e440b5

$ ./ft_ssl sha224 example.txt
SHA224(example.txt)= adbc0e78670e40dbe3443227eedafacde89883a3229ad17b9079e762

$ ./ft_ssl sha512 -q example.txt
aced30a57ad9d56f272dce155e370ef7b5d2ef99c7aae6e5f9d0e1e62e4966163955b35a801cfe09f0d320a1b94a22c102bb174a66d2a1d974dba0072ffdc981

$ ./ft_ssl sha384 -r -s "example"
feeebf884f6dabe6eca8d68e373d6be488cdaa5eb764e895290336ffe9ff969686f2a9d362e9a8bbddf6e7b2e1455f2d "example"

./ft_ssl sha256 -p
my message
on stdin
my message
on stdin
e955158c7fe7ed9f5f77c86c200e902f7a88a5fc7f88235f370cb6e6127cf85d