Python, Cryptography and Hazmat

Why Python is not taught in schools is beyond me? For me, it is the pocket calculator of the future and opens up a whole lot of scientific…

Python, Cryptography and Hazmat

Why Python is not taught in schools is beyond me? For me, it is the pocket calculator of the future and opens up a whole lot of scientific and engineering principles. So while the syntax of the language may be far from perfect and pure, it is the opportunities to integrate libraries such as Numpy, Pandas, and TensorFlow that opens up a new world of opportunity. And it runs on virtually every device you can imagine, and there’s more code around for it than with most of the programming languages.

For cybersecurity, we have great libraries such as cryptography. With this we can hash data can check the output against production systems. So, let’s take a quick look at this library. Overall it contains both “secure” primitives and a “hazmat” layer. The “hazmat” layer should always be treated with care, as it could contain security vulnerabilities. In this case, we will implement a number of hashing primitives with the “hazmat” layer.

Hazmat Hashing

In our first simple example, we will hash our data, and where we take any amount of data and produce a digital fingerprint for it. We normally either represent our data in terms of ASCII characters, hexadecimal values or Base-64 characters. As our hashes are just a whole string of binary values, we normally output hexadecimal or Base-64 values. These can be created using the binascii library, and where the a2b_hex() method converts from a hex string (ASCII) to a byte array, and b2a_hex() converts from a byte array to a hexadecimal string. At the core, though, Python is dealing with byte arrays, and we must convert our input values from strings into byte arrays, and then perform the hashing method on this byte array [here]:

from cryptography.hazmat.primitives import hashes
import binascii
import sys

st = "00"
hex=False
showhex="No"

def show_hash(name,type,data):
  digest = hashes.Hash(type)
  digest.update(data)
  res=digest.finalize()
  hex=binascii.b2a_hex(res).decode()
  b64=binascii.b2a_base64(res).decode()
  print (f"{name}: {hex} {b64}")

if (len(sys.argv)>1):
	st=str(sys.argv[1])

if (len(sys.argv)>1):
	showhex=str(sys.argv[2])

if (showhex=="yes"): hex=True

try:
	if (hex==True): data = binascii.a2b_hex(st)
	else: data=st.encode()


	print ("Data: ",st)
	print (" Hex: ",binascii.b2a_hex(data).decode())
	print()

	show_hash("Blake2p (64 bytes)",hashes.BLAKE2b(64),data)
	show_hash("Blake2s (32 bytes)",hashes.BLAKE2s(32),data)
	show_hash("MD5",hashes.MD5(),data)
	show_hash("SHA1",hashes.SHA1(),data)	
	show_hash("SHA224",hashes.SHA224(),data)
	show_hash("SHA256",hashes.SHA256(),data)
	show_hash("SHA384",hashes.SHA384(),data)
	show_hash("SHA3_224",hashes.SHA3_224(),data)
	show_hash("SHA3_256",hashes.SHA3_256(),data)
	show_hash("SHA3_384",hashes.SHA3_384(),data)
	show_hash("SHA3_512",hashes.SHA3_512(),data)
	show_hash("SHA512",hashes.SHA512(),data)
	show_hash("SHA512_224",hashes.SHA512_224(),data)
	show_hash("SHA512_256",hashes.SHA512_256(),data)
	show_hash("SHAKE128 (64 bytes)",hashes.SHAKE128(64),data)
	show_hash("SHAKE256 (64 bytes)",hashes.SHAKE256(64),data)

except Exception as e:
    print(e)

A sample run [here]:

Data:  The quick brown fox jumps over the lazy dog
 Hex:  54686520717569636b2062726f776e20666f78206a756d7073206f76657220746865206c617a7920646f67
Key:  key
 Hex:  6b6579

HMAC-Blake2p (64 bytes): 92294f92c0dfb9b00ec9ae8bd94d7e7d8a036b885a499f149dfe2fd2199394aaaf6b8894a1730cccb2cd050f9bcf5062a38b51b0dab33207f8ef35ae2c9df51b kilPksDfubAOya6L2U1+fYoDa4haSZ8Unf4v0hmTlKqva4iUoXMMzLLNBQ+bz1Bio4tRsNqzMgf47zWuLJ31Gw==

HMAC-Blake2s (32 bytes): f93215bb90d4af4c3061cd932fb169fb8bb8a91d0b4022baea1271e1323cd9a0 +TIVu5DUr0wwYc2TL7Fp+4u4qR0LQCK66hJx4TI82aA=

HMAC-MD5: 80070713463e7749b90c2dc24911e275 gAcHE0Y+d0m5DC3CSRHidQ==

HMAC-SHA1: de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9 3nybhbi3iqa8ino29wqQcBydtNk=

HMAC-SHA224: 88ff8b54675d39b8f72322e65ff945c52d96379988ada25639747e69 iP+LVGddObj3IyLmX/lFxS2WN5mIraJWOXR+aQ==

HMAC-SHA256: f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8 97yD9DBThCSxMpjmqm+xQ+9NWaFJRhdZl0edvC0aPNg=

HMAC-SHA384: d7f4727e2c0b39ae0f1e40cc96f60242d5b7801841cea6fc592c5d3e1ae50700582a96cf35e1e554995fe4e03381c237 1/RyfiwLOa4PHkDMlvYCQtW3gBhBzqb8WSxdPhrlBwBYKpbPNeHlVJlf5OAzgcI3

HMAC-SHA3_224: ff6fa8447ce10fb1efdccfe62caf8b640fe46c4fb1007912bf85100f /2+oRHzhD7Hv3M/mLK+LZA/kbE+xAHkSv4UQDw==

HMAC-SHA3_256: 8c6e0683409427f8931711b10ca92a506eb1fafa48fadd66d76126f47ac2c333 jG4Gg0CUJ/iTFxGxDKkqUG6x+vpI+t1m12Em9HrCwzM=

HMAC-SHA3_384: aa739ad9fcdf9be4a04f06680ade7a1bd1e01a0af64accb04366234cf9f6934a0f8589772f857681fcde8acc256091a2 qnOa2fzfm+SgTwZoCt56G9HgGgr2SsywQ2YjTPn2k0oPhYl3L4V2gfzeiswlYJGi

HMAC-SHA3_512: 237a35049c40b3ef5ddd960b3dc893d8284953b9a4756611b1b61bffcf53edd979f93547db714b06ef0a692062c609b70208ab8d4a280ceee40ed8100f293063 I3o1BJxAs+9d3ZYLPciT2ChJU7mkdWYRsbYb/89T7dl5+TVH23FLBu8KaSBixgm3AgirjUooDO7kDtgQDykwYw==

HMAC-SHA512: b42af09057bac1e2d41708e48a902e09b5ff7f12ab428a4fe86653c73dd248fb82f948a549f7b791a5b41915ee4d1ec3935357e4e2317250d0372afa2ebeeb3a tCrwkFe6weLUFwjkipAuCbX/fxKrQopP6GZTxz3SSPuC+UilSfe3kaW0GRXuTR7Dk1NX5OIxclDQNyr6Lr7rOg==

HMAC-SHA512_224: a1afb4f708cb63570639195121785ada3dc615989cc3c73f38e306a3 oa+09wjLY1cGORlRIXha2j3GFZicw8c/OOMGow==

HMAC-SHA512_256: 7fb65e03577da9151a1016e9c2e514d4d48842857f13927f348588173dca6d89 f7ZeA1d9qRUaEBbpwuUU1NSIQoV/E5J/NIWIFz3KbYk=

Here is the running code:

hashnew
A Python repl by billbuchananreplit.com

So, now we can hash data, let’s now add a secret key, in order to authenticate Bob to Alice and use HMAC (hash-based message authentication code).

Hazmat HMAC

HMAC supports the usage of a key to hash data. This key is kept secret between Bob and Alice, and can be used to authentication both the data and that the sender still knows the secret. Overall HMAC can be used with a range of different hashing methods, such as MD5, SHA-1, SHA-256 (SHA-2) and SHA-3:

In this case, we will implement a number of HMAC primitives with the “hazmat” layer, and use the hashing methods from before, but add a key [here]:

from cryptography.hazmat.primitives import hashes, hmac
import binascii
import sys

st = "00"
hex=False
showhex="No"
k="00"

def show_hash(name,type,data,key):
  digest = hmac.HMAC(key, type)
  digest.update(data)
  res=digest.finalize()
  hex=binascii.b2a_hex(res).decode()
  b64=binascii.b2a_base64(res).decode()
  print (f"HMAC-{name}: {hex} {b64}")

if (len(sys.argv)>1):
	st=str(sys.argv[1])

if (len(sys.argv)>2):
	showhex=str(sys.argv[2])
if (len(sys.argv)>3):
	k=str(sys.argv[3])

if (showhex=="yes"): hex=True

try:
	if (hex==True): data = binascii.a2b_hex(st)
	else: data=st.encode()

	if (hex==True): key = binascii.a2b_hex(k)
	else: key=k.encode()

	print ("Data: ",st)
	print (" Hex: ",binascii.b2a_hex(data).decode())
	print ("Key: ",k)
	print (" Hex: ",binascii.b2a_hex(key).decode())
	print()

	show_hash("Blake2p (64 bytes)",hashes.BLAKE2b(64),data,key)
	show_hash("Blake2s (32 bytes)",hashes.BLAKE2s(32),data,key)
	show_hash("MD5",hashes.MD5(),data,key)
	show_hash("SHA1",hashes.SHA1(),data,key)	
	show_hash("SHA224",hashes.SHA224(),data,key)
	show_hash("SHA256",hashes.SHA256(),data,key)
	show_hash("SHA384",hashes.SHA384(),data,key)
	show_hash("SHA3_224",hashes.SHA3_224(),data,key)
	show_hash("SHA3_256",hashes.SHA3_256(),data,key)
	show_hash("SHA3_384",hashes.SHA3_384(),data,key)
	show_hash("SHA3_512",hashes.SHA3_512(),data,key)
	show_hash("SHA512",hashes.SHA512(),data,key)
	show_hash("SHA512_224",hashes.SHA512_224(),data,key)
	show_hash("SHA512_256",hashes.SHA512_256(),data,key)

except Exception as e:
    print(e)

A sample run [here]:

Data:  The quick brown fox jumps over the lazy dog
 Hex:  54686520717569636b2062726f776e20666f78206a756d7073206f76657220746865206c617a7920646f67
Key:  key
 Hex:  6b6579

HMAC-Blake2p (64 bytes): 92294f92c0dfb9b00ec9ae8bd94d7e7d8a036b885a499f149dfe2fd2199394aaaf6b8894a1730cccb2cd050f9bcf5062a38b51b0dab33207f8ef35ae2c9df51b kilPksDfubAOya6L2U1+fYoDa4haSZ8Unf4v0hmTlKqva4iUoXMMzLLNBQ+bz1Bio4tRsNqzMgf47zWuLJ31Gw==

HMAC-Blake2s (32 bytes): f93215bb90d4af4c3061cd932fb169fb8bb8a91d0b4022baea1271e1323cd9a0 +TIVu5DUr0wwYc2TL7Fp+4u4qR0LQCK66hJx4TI82aA=

HMAC-MD5: 80070713463e7749b90c2dc24911e275 gAcHE0Y+d0m5DC3CSRHidQ==

HMAC-SHA1: de7c9b85b8b78aa6bc8a7a36f70a90701c9db4d9 3nybhbi3iqa8ino29wqQcBydtNk=

HMAC-SHA224: 88ff8b54675d39b8f72322e65ff945c52d96379988ada25639747e69 iP+LVGddObj3IyLmX/lFxS2WN5mIraJWOXR+aQ==

HMAC-SHA256: f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8 97yD9DBThCSxMpjmqm+xQ+9NWaFJRhdZl0edvC0aPNg=

HMAC-SHA384: d7f4727e2c0b39ae0f1e40cc96f60242d5b7801841cea6fc592c5d3e1ae50700582a96cf35e1e554995fe4e03381c237 1/RyfiwLOa4PHkDMlvYCQtW3gBhBzqb8WSxdPhrlBwBYKpbPNeHlVJlf5OAzgcI3

HMAC-SHA3_224: ff6fa8447ce10fb1efdccfe62caf8b640fe46c4fb1007912bf85100f /2+oRHzhD7Hv3M/mLK+LZA/kbE+xAHkSv4UQDw==

HMAC-SHA3_256: 8c6e0683409427f8931711b10ca92a506eb1fafa48fadd66d76126f47ac2c333 jG4Gg0CUJ/iTFxGxDKkqUG6x+vpI+t1m12Em9HrCwzM=

HMAC-SHA3_384: aa739ad9fcdf9be4a04f06680ade7a1bd1e01a0af64accb04366234cf9f6934a0f8589772f857681fcde8acc256091a2 qnOa2fzfm+SgTwZoCt56G9HgGgr2SsywQ2YjTPn2k0oPhYl3L4V2gfzeiswlYJGi

HMAC-SHA3_512: 237a35049c40b3ef5ddd960b3dc893d8284953b9a4756611b1b61bffcf53edd979f93547db714b06ef0a692062c609b70208ab8d4a280ceee40ed8100f293063 I3o1BJxAs+9d3ZYLPciT2ChJU7mkdWYRsbYb/89T7dl5+TVH23FLBu8KaSBixgm3AgirjUooDO7kDtgQDykwYw==

HMAC-SHA512: b42af09057bac1e2d41708e48a902e09b5ff7f12ab428a4fe86653c73dd248fb82f948a549f7b791a5b41915ee4d1ec3935357e4e2317250d0372afa2ebeeb3a tCrwkFe6weLUFwjkipAuCbX/fxKrQopP6GZTxz3SSPuC+UilSfe3kaW0GRXuTR7Dk1NX5OIxclDQNyr6Lr7rOg==

HMAC-SHA512_224: a1afb4f708cb63570639195121785ada3dc615989cc3c73f38e306a3 oa+09wjLY1cGORlRIXha2j3GFZicw8c/OOMGow==

HMAC-SHA512_256: 7fb65e03577da9151a1016e9c2e514d4d48842857f13927f348588173dca6d89 f7ZeA1d9qRUaEBbpwuUU1NSIQoV/E5J/NIWIFz3KbYk=

And here is the running code:

hashnew2
A Python repl by billbuchananreplit.com

Conclusions

And there you go … the pocket calculator of the 21st Century … Python. Go learn it!