clinical-analysis-api / app /crypto_utils.py
MakPr016
Updated files + Dockerfile
a2543e1
"""
Encryption utilities using NaCl (libsodium)
"""
import base64
import gzip
import json
from nacl.secret import SecretBox
from nacl.utils import random
class CryptoManager:
def __init__(self, secret_key_hex: str):
"""
Initialize with hex key string from .env
Converts 64-character hex string to 32 bytes
"""
if not secret_key_hex:
raise ValueError("Secret key is required")
if len(secret_key_hex) == 64:
self.secret_key = bytes.fromhex(secret_key_hex)
elif len(secret_key_hex) == 32:
print(f"⚠️ WARNING: Key is only 32 characters (16 bytes)")
print(f" Should be 64 hex characters for 32 bytes")
self.secret_key = secret_key_hex.encode('utf-8')
else:
raise ValueError(f"Secret key must be 64 hex characters (got {len(secret_key_hex)})")
if len(self.secret_key) != 32:
raise ValueError(f"Secret key must be 32 bytes (got {len(self.secret_key)} bytes)")
self.box = SecretBox(self.secret_key)
print(f"✓ CryptoManager initialized (key: {len(self.secret_key)} bytes)")
def encrypt(self, plaintext: bytes, nonce: bytes = None) -> bytes:
"""Encrypt plaintext bytes"""
if nonce is None:
nonce = random(SecretBox.NONCE_SIZE)
return self.box.encrypt(plaintext, nonce)
def decrypt(self, ciphertext: str, nonce: str) -> bytes:
"""Decrypt base64-encoded ciphertext with base64-encoded nonce"""
try:
ciphertext_bytes = base64.b64decode(ciphertext)
nonce_bytes = base64.b64decode(nonce)
return self.box.decrypt(ciphertext_bytes, nonce_bytes)
except Exception as e:
raise ValueError(f"Decryption failed. {e}")
def encrypt_json(self, data: dict) -> dict:
"""
Encrypt JSON data with compression
Returns dict with base64-encoded ciphertext and nonce
"""
json_data = json.dumps(data).encode('utf-8')
compressed = gzip.compress(json_data, compresslevel=6)
compressed_b64 = base64.b64encode(compressed).decode('utf-8')
nonce = random(SecretBox.NONCE_SIZE)
ciphertext = self.box.encrypt(compressed_b64.encode('utf-8'), nonce)
return {
"ciphertext": base64.b64encode(ciphertext.ciphertext).decode('utf-8'),
"nonce": base64.b64encode(nonce).decode('utf-8')
}
def decrypt_json(self, ciphertext: str, nonce: str) -> dict:
"""
Decrypt and decompress JSON data
"""
try:
decrypted = self.decrypt(ciphertext, nonce)
compressed_b64 = decrypted.decode('utf-8')
compressed_bytes = base64.b64decode(compressed_b64)
decompressed = gzip.decompress(compressed_bytes)
return json.loads(decompressed.decode('utf-8'))
except Exception as e:
raise ValueError(f"Decryption/decompression failed. {e}")