mbedtls

mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2026-04-04 11:36:06 +02:00

Files

Mateusz Starzyk efec38bb29 Extend CCM corner cases tests.

Add tests covering skipped update() or update_ad()
for empty plaintext/ciphertext and empty auth data.

Test vector for P=0, A=0 generated using python's
cryptography.hazmat library.

Python script used for test vector generation:
```
import os
from cryptography.hazmat.primitives.ciphers.aead import AESCCM

def encrypt(key, iv, plaintext, associated_data):

    key = bytes.fromhex(key)
    iv = bytes.fromhex(iv)
    plaintext = bytes.fromhex(plaintext)
    associated_data = bytes.fromhex(associated_data)

    aesccm = AESCCM(key)
    ct = aesccm.encrypt(iv, plaintext, associated_data)
    return ct.hex()

def decrypt(key, associated_data, iv, ciphertext):

    key = bytes.fromhex(key)
    associated_data = bytes.fromhex(associated_data)
    iv = bytes.fromhex(iv)
    ciphertext = bytes.fromhex(ciphertext)

    aesccm = AESCCM(key)
    pt = aesccm.decrypt(iv, ciphertext, associated_data)
    return pt.hex()

key = "54caf96ef6d448734700aadab50faf7a"
plaintext = ""
iv = "a3803e752ae849c910d8da36af"
aad = ""

encrypted = encrypt(key, iv, plaintext, aad)

print(f"key: {key}")
print(f"iv: {iv}")
print(f"encrypted: {encrypted}")

print("--------------------------------------")

decrypted = decrypt(
    key,
    aad,
    iv,
    encrypted
)

print(f"decrypted: {decrypted}")
```

Results:
```
key: 54caf96ef6d448734700aadab50faf7a
iv: a3803e752ae849c910d8da36af
encrypted: eba8347baa6d61f87b67c2dd7c6d2053
--------------------------------------
decrypted:
```

Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>

2021-09-06 12:09:34 +02:00