synta 0.1.2

ASN.1 parser, decoder, and encoder library with DER/BER support and C FFI
Documentation 
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

#!/usr/bin/env python3
"""
Example 9: PKCS#12 archive parsing.

Demonstrates: load_pkcs12_certificates, load_pkcs12_keys, load_pkcs12.

Test vectors:
  tests/vectors/test_bundle_nopass.p12  (no password, 1+ certs)
  tests/vectors/test_bundle_pass.p12    (password-protected)
  tests/vectors/test_bundle_2certs.p12  (2 certs, no password)
  tests/vectors/cryptography/…/pkcs12/cert-none-key-none.p12
                                        (1 cert + 1 unencrypted key, no password)
  tests/vectors/cryptography/…/pkcs12/cert-key-aes256cbc.p12
                                        (1 cert + 1 AES-256-CBC encrypted key,
                                         password = b"cryptography")
"""

import pathlib
import synta

VECTORS = pathlib.Path(__file__).parent.parent / "tests" / "vectors"
CRYPTO_PKCS12 = (
    VECTORS
    / "cryptography"
    / "vectors"
    / "cryptography_vectors"
    / "pkcs12"
)


def section(title):
    print(f"\n{'─' * 60}\n{title}\n{'─' * 60}")


def demo_no_password():
    section("load_pkcs12_certificates — no password")
    path = VECTORS / "test_bundle_nopass.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    certs = synta.load_pkcs12_certificates(data, None)
    print(f"  Loaded {len(certs)} certificate(s) from no-password archive")
    for i, cert in enumerate(certs):
        print(f"  [{i}] subject={cert.subject}  sig_alg={cert.signature_algorithm}")


def demo_two_certs():
    section("load_pkcs12_certificates — two certificates, no password")
    path = VECTORS / "test_bundle_2certs.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    certs = synta.load_pkcs12_certificates(data, None)
    print(f"  Loaded {len(certs)} certificate(s)")
    for i, cert in enumerate(certs):
        print(f"  [{i}] subject={cert.subject}")


def demo_with_password():
    section("load_pkcs12_certificates — AES-256-CBC encrypted, with password")
    path = VECTORS / "test_bundle_pass.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    try:
        certs = synta.load_pkcs12_certificates(data, b"synta")
        print(f"  Loaded {len(certs)} certificate(s) with correct password")
        for i, cert in enumerate(certs):
            print(f"  [{i}] subject={cert.subject}")
    except ValueError as e:
        # May fail if the openssl feature is not compiled in
        print(f"  ValueError: {e}")
        print("  (Encrypted PKCS#12 requires the 'openssl' feature to be enabled)")


def demo_wrong_password():
    section("ValueError for wrong password")
    path = VECTORS / "test_bundle_pass.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    try:
        synta.load_pkcs12_certificates(data, b"wrong_password")
        print("  No error raised (unexpected — perhaps openssl feature not enabled)")
    except ValueError as e:
        print(f"  ValueError (wrong password): {e}")


def demo_keys_unencrypted():
    section("load_pkcs12_keys — unencrypted keyBag (cert-none-key-none.p12)")
    path = CRYPTO_PKCS12 / "cert-none-key-none.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    keys = synta.load_pkcs12_keys(data)
    print(f"  Loaded {len(keys)} key(s)")
    for i, key_der in enumerate(keys):
        # Each blob is a DER-encoded OneAsymmetricKey (PKCS#8) SEQUENCE (tag 0x30)
        print(f"  [{i}] PKCS#8 DER: {len(key_der)} bytes, tag=0x{key_der[0]:02x}")


def demo_both_unencrypted():
    section("load_pkcs12 — cert + unencrypted key in one call")
    path = CRYPTO_PKCS12 / "cert-none-key-none.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    certs, keys = synta.load_pkcs12(data)
    print(f"  Certificates: {len(certs)}, Keys: {len(keys)}")
    for i, cert in enumerate(certs):
        print(f"  cert[{i}] subject={cert.subject}")
    for i, key_der in enumerate(keys):
        print(f"  key[{i}]  PKCS#8 DER: {len(key_der)} bytes")


def demo_keys_encrypted():
    section("load_pkcs12_keys — AES-256-CBC shrouded keyBag (cert-key-aes256cbc.p12)")
    path = CRYPTO_PKCS12 / "cert-key-aes256cbc.p12"
    if not path.exists():
        print(f"  Skipped: {path} not found")
        return
    data = path.read_bytes()
    try:
        keys = synta.load_pkcs12_keys(data, b"cryptography")
        print(f"  Loaded {len(keys)} decrypted key(s)")
        for i, key_der in enumerate(keys):
            print(f"  [{i}] PKCS#8 DER: {len(key_der)} bytes, tag=0x{key_der[0]:02x}")
    except ValueError as e:
        print(f"  ValueError: {e}")
        print("  (Encrypted keys require the 'openssl' feature to be enabled)")


def main():
    print("=" * 60)
    print("Example 9: PKCS#12 archive parsing")
    print("=" * 60)
    demo_no_password()
    demo_two_certs()
    demo_with_password()
    demo_wrong_password()
    demo_keys_unencrypted()
    demo_both_unencrypted()
    demo_keys_encrypted()
    print("\nAll PKCS#12 examples completed.")


if __name__ == "__main__":
    main()