Spaces:
Paused
Paused
File size: 20,514 Bytes
aaaaa79 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 |
"""
Certificate Authority Service
Provides PKI infrastructure for VPN client certificate management
"""
import os
import subprocess
import logging
from cryptography import x509
from cryptography.x509.oid import NameOID, ExtensionOID
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from datetime import datetime, timedelta
logger = logging.getLogger(__name__)
class CertificateAuthority:
"""Certificate Authority for VPN client certificates"""
def __init__(self, ca_dir='/etc/vpn-ca'):
self.ca_dir = ca_dir
self.ca_cert_path = os.path.join(ca_dir, 'ca.crt')
self.ca_key_path = os.path.join(ca_dir, 'ca.key')
self.crl_path = os.path.join(ca_dir, 'crl.pem')
self.serial_file = os.path.join(ca_dir, 'serial')
self.index_file = os.path.join(ca_dir, 'index.txt')
# Ensure CA directory exists
os.makedirs(ca_dir, mode=0o700, exist_ok=True)
# Initialize CA if not exists
if not os.path.exists(self.ca_cert_path):
self._create_root_ca()
# Initialize index file for certificate tracking
if not os.path.exists(self.index_file):
with open(self.index_file, 'w') as f:
f.write('') # Empty index file
def _create_root_ca(self):
"""Create root CA certificate and private key"""
try:
logger.info("Creating root CA certificate")
# Generate private key
private_key = rsa.generate_private_key(
public_exponent=65537,
key_size=4096
)
# Create certificate
subject = issuer = x509.Name([
x509.NameAttribute(NameOID.COUNTRY_NAME, "US"),
x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, "Virtual"),
x509.NameAttribute(NameOID.LOCALITY_NAME, "Internet"),
x509.NameAttribute(NameOID.ORGANIZATION_NAME, "VPN Service CA"),
x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, "Certificate Authority"),
x509.NameAttribute(NameOID.COMMON_NAME, "VPN Root CA"),
])
cert = x509.CertificateBuilder().subject_name(
subject
).issuer_name(
issuer
).public_key(
private_key.public_key()
).serial_number(
1
).not_valid_before(
datetime.utcnow()
).not_valid_after(
datetime.utcnow() + timedelta(days=3650) # 10 years
).add_extension(
x509.BasicConstraints(ca=True, path_length=None),
critical=True,
).add_extension(
x509.KeyUsage(
key_cert_sign=True,
crl_sign=True,
digital_signature=False,
key_encipherment=False,
key_agreement=False,
data_encipherment=False,
content_commitment=False,
encipher_only=False,
decipher_only=False
),
critical=True,
).add_extension(
x509.SubjectKeyIdentifier.from_public_key(private_key.public_key()),
critical=False,
).sign(private_key, hashes.SHA256())
# Save certificate and private key
with open(self.ca_cert_path, 'wb') as f:
f.write(cert.public_bytes(serialization.Encoding.PEM))
with open(self.ca_key_path, 'wb') as f:
f.write(private_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption()
))
# Set secure permissions
os.chmod(self.ca_key_path, 0o600)
os.chmod(self.ca_cert_path, 0o644)
# Initialize serial number file
with open(self.serial_file, 'w') as f:
f.write('02')
logger.info("Root CA certificate created successfully")
except Exception as e:
logger.error(f"Failed to create root CA: {e}")
raise
def generate_client_certificate(self, username, email, validity_days=365):
"""Generate client certificate for VPN authentication"""
try:
logger.info(f"Generating client certificate for {username}")
# Load CA certificate and private key
with open(self.ca_cert_path, 'rb') as f:
ca_cert = x509.load_pem_x509_certificate(f.read())
with open(self.ca_key_path, 'rb') as f:
ca_private_key = serialization.load_pem_private_key(f.read(), password=None)
# Generate client private key
client_private_key = rsa.generate_private_key(
public_exponent=65537,
key_size=2048
)
# Get next serial number
serial_number = self._get_next_serial()
# Create client certificate
subject = x509.Name([
x509.NameAttribute(NameOID.COUNTRY_NAME, "US"),
x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, "Virtual"),
x509.NameAttribute(NameOID.LOCALITY_NAME, "Internet"),
x509.NameAttribute(NameOID.ORGANIZATION_NAME, "VPN Service"),
x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, "VPN Clients"),
x509.NameAttribute(NameOID.COMMON_NAME, username),
x509.NameAttribute(NameOID.EMAIL_ADDRESS, email),
])
cert = x509.CertificateBuilder().subject_name(
subject
).issuer_name(
ca_cert.subject
).public_key(
client_private_key.public_key()
).serial_number(
serial_number
).not_valid_before(
datetime.utcnow()
).not_valid_after(
datetime.utcnow() + timedelta(days=validity_days)
).add_extension(
x509.BasicConstraints(ca=False, path_length=None),
critical=True,
).add_extension(
x509.KeyUsage(
key_cert_sign=False,
crl_sign=False,
digital_signature=True,
key_encipherment=True,
key_agreement=False,
data_encipherment=False,
content_commitment=False,
encipher_only=False,
decipher_only=False
),
critical=True,
).add_extension(
x509.ExtendedKeyUsage([
x509.oid.ExtendedKeyUsageOID.CLIENT_AUTH,
]),
critical=True,
).add_extension(
x509.SubjectKeyIdentifier.from_public_key(client_private_key.public_key()),
critical=False,
).add_extension(
x509.AuthorityKeyIdentifier.from_issuer_public_key(ca_cert.public_key()),
critical=False,
).sign(ca_private_key, hashes.SHA256())
# Update certificate index
self._update_certificate_index(cert, 'V') # V = Valid
logger.info(f"Client certificate generated successfully for {username} (Serial: {serial_number})")
return {
'certificate': cert.public_bytes(serialization.Encoding.PEM),
'private_key': client_private_key.private_bytes(
encoding=serialization.Encoding.PEM,
format=serialization.PrivateFormat.PKCS8,
encryption_algorithm=serialization.NoEncryption()
),
'serial_number': serial_number,
'not_valid_before': cert.not_valid_before,
'not_valid_after': cert.not_valid_after
}
except Exception as e:
logger.error(f"Failed to generate client certificate: {e}")
raise
def revoke_certificate(self, serial_number, reason='unspecified'):
"""Revoke a client certificate"""
try:
logger.info(f"Revoking certificate with serial {serial_number}")
# Update certificate index
self._update_certificate_index_status(serial_number, 'R', reason)
# Generate new CRL
self._generate_crl()
logger.info(f"Certificate {serial_number} revoked successfully")
except Exception as e:
logger.error(f"Failed to revoke certificate {serial_number}: {e}")
raise
def get_certificate_status(self, serial_number):
"""Get certificate status from index"""
try:
with open(self.index_file, 'r') as f:
for line in f:
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 3 and parts[3] == str(serial_number):
status = parts[0]
if status == 'V':
return 'valid'
elif status == 'R':
return 'revoked'
elif status == 'E':
return 'expired'
return 'unknown'
except Exception as e:
logger.error(f"Failed to get certificate status: {e}")
return 'unknown'
def list_certificates(self):
"""List all certificates in the index"""
try:
certificates = []
with open(self.index_file, 'r') as f:
for line in f:
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 6:
cert_info = {
'status': parts[0],
'expiry_date': parts[1],
'revocation_date': parts[2] if parts[2] else None,
'serial_number': parts[3],
'filename': parts[4],
'subject': parts[5]
}
certificates.append(cert_info)
return certificates
except Exception as e:
logger.error(f"Failed to list certificates: {e}")
return []
def _get_next_serial(self):
"""Get next serial number for certificate"""
try:
with open(self.serial_file, 'r') as f:
serial = int(f.read().strip(), 16)
except (FileNotFoundError, ValueError):
serial = 2
# Update serial file
with open(self.serial_file, 'w') as f:
f.write(f'{serial + 1:02X}')
return serial
def _update_certificate_index(self, cert, status):
"""Update certificate index with new certificate"""
try:
# Format: status \t expiry_date \t revocation_date \t serial \t filename \t subject
expiry_date = cert.not_valid_after.strftime('%y%m%d%H%M%SZ')
serial_hex = f'{cert.serial_number:02X}'
subject_str = cert.subject.rfc4514_string()
index_line = f"{status}\t{expiry_date}\t\t{serial_hex}\tunknown\t{subject_str}\n"
with open(self.index_file, 'a') as f:
f.write(index_line)
except Exception as e:
logger.error(f"Failed to update certificate index: {e}")
raise
def _update_certificate_index_status(self, serial_number, new_status, reason=None):
"""Update certificate status in index"""
try:
lines = []
updated = False
with open(self.index_file, 'r') as f:
lines = f.readlines()
for i, line in enumerate(lines):
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 4 and parts[3] == str(serial_number):
# Update status
parts[0] = new_status
if new_status == 'R' and reason:
# Add revocation date
parts[2] = datetime.utcnow().strftime('%y%m%d%H%M%SZ')
lines[i] = '\t'.join(parts) + '\n'
updated = True
break
if updated:
with open(self.index_file, 'w') as f:
f.writelines(lines)
except Exception as e:
logger.error(f"Failed to update certificate status: {e}")
raise
def _generate_crl(self):
"""Generate Certificate Revocation List"""
try:
logger.info("Generating Certificate Revocation List")
# Load CA certificate and private key
with open(self.ca_cert_path, 'rb') as f:
ca_cert = x509.load_pem_x509_certificate(f.read())
with open(self.ca_key_path, 'rb') as f:
ca_private_key = serialization.load_pem_private_key(f.read(), password=None)
# Get revoked certificates
revoked_certs = []
with open(self.index_file, 'r') as f:
for line in f:
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 4 and parts[0] == 'R':
serial_number = int(parts[3], 16)
revocation_date = datetime.strptime(parts[2], '%y%m%d%H%M%SZ')
revoked_cert = x509.RevokedCertificateBuilder().serial_number(
serial_number
).revocation_date(
revocation_date
).build()
revoked_certs.append(revoked_cert)
# Build CRL
crl_builder = x509.CertificateRevocationListBuilder().issuer_name(
ca_cert.subject
).last_update(
datetime.utcnow()
).next_update(
datetime.utcnow() + timedelta(days=30)
)
for revoked_cert in revoked_certs:
crl_builder = crl_builder.add_revoked_certificate(revoked_cert)
crl = crl_builder.sign(ca_private_key, hashes.SHA256())
# Save CRL
with open(self.crl_path, 'wb') as f:
f.write(crl.public_bytes(serialization.Encoding.PEM))
logger.info("CRL generated successfully")
except Exception as e:
logger.error(f"Failed to generate CRL: {e}")
raise
def get_ca_certificate(self):
"""Get CA certificate in PEM format"""
try:
with open(self.ca_cert_path, 'rb') as f:
return f.read()
except Exception as e:
logger.error(f"Failed to read CA certificate: {e}")
return None
def get_crl(self):
"""Get Certificate Revocation List"""
try:
if os.path.exists(self.crl_path):
with open(self.crl_path, 'rb') as f:
return f.read()
else:
# Generate CRL if it doesn't exist
self._generate_crl()
with open(self.crl_path, 'rb') as f:
return f.read()
except Exception as e:
logger.error(f"Failed to read CRL: {e}")
return None
def verify_certificate(self, cert_pem):
"""Verify a certificate against the CA"""
try:
# Load certificates
cert = x509.load_pem_x509_certificate(cert_pem)
with open(self.ca_cert_path, 'rb') as f:
ca_cert = x509.load_pem_x509_certificate(f.read())
# Verify signature
ca_public_key = ca_cert.public_key()
ca_public_key.verify(
cert.signature,
cert.tbs_certificate_bytes,
cert.signature_algorithm_oid._name
)
# Check validity period
now = datetime.utcnow()
if now < cert.not_valid_before or now > cert.not_valid_after:
return False, "Certificate expired or not yet valid"
# Check revocation status
status = self.get_certificate_status(cert.serial_number)
if status == 'revoked':
return False, "Certificate revoked"
return True, "Certificate valid"
except Exception as e:
logger.error(f"Certificate verification failed: {e}")
return False, str(e)
def cleanup_expired_certificates(self):
"""Clean up expired certificates from the index"""
try:
logger.info("Cleaning up expired certificates")
lines = []
updated_count = 0
with open(self.index_file, 'r') as f:
lines = f.readlines()
now = datetime.utcnow()
for i, line in enumerate(lines):
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 2 and parts[0] == 'V':
try:
expiry_date = datetime.strptime(parts[1], '%y%m%d%H%M%SZ')
if now > expiry_date:
# Mark as expired
parts[0] = 'E'
lines[i] = '\t'.join(parts) + '\n'
updated_count += 1
except ValueError:
continue
if updated_count > 0:
with open(self.index_file, 'w') as f:
f.writelines(lines)
logger.info(f"Marked {updated_count} certificates as expired")
except Exception as e:
logger.error(f"Failed to cleanup expired certificates: {e}")
def get_statistics(self):
"""Get CA statistics"""
try:
stats = {
'total_certificates': 0,
'valid_certificates': 0,
'revoked_certificates': 0,
'expired_certificates': 0
}
with open(self.index_file, 'r') as f:
for line in f:
if line.strip():
parts = line.strip().split('\t')
if len(parts) >= 1:
stats['total_certificates'] += 1
status = parts[0]
if status == 'V':
stats['valid_certificates'] += 1
elif status == 'R':
stats['revoked_certificates'] += 1
elif status == 'E':
stats['expired_certificates'] += 1
return stats
except Exception as e:
logger.error(f"Failed to get CA statistics: {e}")
return {
'total_certificates': 0,
'valid_certificates': 0,
'revoked_certificates': 0,
'expired_certificates': 0
}
|