📄 Radikant-ASN1-C
A lightweight and fast ASN.1 DER encoder/decoder prototype library written in C, with no external dependencies. OpenSSL 24.1 Million items/sec Radikant: 262.5 Million items/sec. OpenSSL is significalty slower because has a different safe and agnostic internal structure.
Encoding
asn1_encoder_t ctx;
asn1_encoder_init(&ctx, buffer, sizeof(buffer));
const uint8_t hello_str[] = "hello";
asn1_encode_octet_string(&ctx, hello_str, sizeof(hello_str) - 1);
asn1_encode_integer(&ctx, -123);
size_t content_len = sizeof(buffer) - ctx.current_pos;
asn1_encode_tag_and_length(&ctx, ASN1_TAG_SEQUENCE, content_len);
const uint8_t* data = asn1_encoder_get_data(&ctx, &final_len);
Encoded 13 bytes:
30 0B 02 02 FF 85 04 05 68 65 6C 6C 6F
Dumping encoded structure:
0 : Tag=0x30 (SEQUENCE) Length=11
0 : Tag=0x02 (INTEGER) Length=2
Value: -123 (0xffffffffffffff85)
4 : Tag=0x04 (OCTET STRING) Length=5
Data: 68:65:6C:6C:6F:
Decoding
asn1_decoder_t ctx;
asn1_decoder_init(&ctx, encoded_data, final_len);
asn1_decoder_t seq_ctx;
asn1_decoder_enter_constructed(&ctx, &seq_ctx, ASN1_TAG_SEQUENCE);
int64_t int_val;
asn1_decode_integer(&seq_ctx, &int_val);
const uint8_t* str_data;
size_t str_len;
asn1_decode_string_like(&seq_ctx, ASN1_TAG_OCTET_STRING, &str_data, &str_len);
Decoding encoded structure:
- Read INTEGER: -123
- Read OCTET STRING: 'hello'
Encode/decode test successful.
Parse Cert
asn1_decoder_t ctx;
asn1_decoder_init(&ctx, github_der, sizeof(github_der));
asn1_error_t err = asn1_dump_recursive(&ctx, stdout, 0);
===================================
Parsing Github.com Certificate...
===================================
Certificate (SEQUENCE):
TBSCertificate (SEQUENCE):
Version: [0] EXPLICIT
Value: 2 (v3)
Serial Number: 00:AB:66:86:B5:62:7B:E8:05:96:82:13:30:12:86:49:F5
Algorithm: ecdsa-with-SHA256 (1.2.840.10045.4.3.2)
Issuer:
countryName (2.5.4.6)
Value: 'GB'
stateOrProvinceName (2.5.4.8)
Value: 'Greater Manchester'
localityName (2.5.4.7)
Value: 'Salford'
organizationName (2.5.4.10)
Value: 'Sectigo Limited'
commonName (2.5.4.3)
Value: 'Sectigo ECC Domain Validation Secure Server CA'
Validity:
Not Before: '250205000000Z'
Not After : '260205235959Z'
Subject:
commonName (2.5.4.3)
Value: 'github.com'
Subject Public Key Info:
Algorithm: ecPublicKey (1.2.840.10045.2.1)
Parameters: (Skipped)
Public Key (Unused Bits: 0):
04:20:34:5C:46:FF:2C:CB:F8:24:9A:AE:F0:BB:2F:77:
A9:1F:97:21:36:71:BA:C2:26:18:C5:1E:43:FD:9D:49:
E0:CC:46:9C:85:FC:29:B4:F9:7C:28:0B:A3:2C:C7:5C:
BF:6F:E7:46:DD:04:8A:BA:CB:80:2D:37:88:0D:EE:06:
D6
Extensions: [3] EXPLICIT
Extension OID: authorityKeyIdentifier (2.5.29.35)
Value (OCTET STRING):
30:16:80:14:F6:85:0A:3B:11:86:E1:04:7D:0E:AA:0B:2C:D2:EE:CC:64:7B:7B:AE
Extension OID: subjectKeyIdentifier (2.5.29.14)
Value (OCTET STRING):
04:14:53:C8:7F:DE:9E:98:4E:C7:4D:D6:BC:DE:AB:95:3E:30:3D:3D:D1:C8
Extension OID: keyUsage (2.5.29.15)
Critical: TRUE
Value (OCTET STRING): 03:02:07:80
Extension OID: basicConstraints (2.5.29.19)
Critical: TRUE
Value (OCTET STRING): 30:00
Extension OID: extendedKeyUsage (2.5.29.37)
Value (OCTET STRING):
30:14:06:08:2B:06:01:05:05:07:03:01:06:08:2B:06:01:05:05:07:03:02
Extension OID: certificatePolicies (2.5.29.32)
Value (OCTET STRING):
30:40:30:34:06:0B:2B:06:01:04:01:B2:31:01:02:02:
07:30:25:30:23:06:08:2B:06:01:05:05:07:02:01:16:
17:68:74:74:70:73:3A:2F:2F:73:65:63:74:69:67:6F:
2E:63:6F:6D:2F:43:50:53:30:08:06:06:67:81:0C:01:
02:01
Extension OID: authorityInfoAccess (1.3.6.1.5.5.7.1.1)
Value (OCTET STRING):
30:76:30:4F:06:08:2B:06:01:05:05:07:30:02:86:43:
68:74:74:70:3A:2F:2F:63:72:74:2E:73:65:63:74:69:
67:6F:2E:63:6F:6D:2F:53:65:63:74:69:67:6F:45:43:
43:44:6F:6D:61:69:6E:56:61:6C:69:64:61:74:69:6F:
6E:53:65:63:75:72:65:53:65:72:76:65:72:43:41:2E:
63:72:74:30:23:06:08:2B:06:01:05:05:07:30:01:86:
17:68:74:74:70:3A:2F:2F:6F:63:73:70:2E:73:65:63:
74:69:67:6F:2E:63:6F:6D
Extension OID: SCT List (Sectigo) (1.3.6.1.4.1.22112.2.4.2)
Value (OCTET STRING):
04:82:01:6A:01:68:00:75:00:96:97:64:BF:55:58:97:
AD:F7:43:87:68:37:08:42:77:E9:F0:3A:D5:F6:A4:F3:
36:6E:46:A4:3F:0F:CA:A9:C6:00:00:01:94:D3:6B:94:
4B:00:00:04:03:00:46:30:44:02:20:3B:8B:AA:3E:2E:
94:23:B7:A0:1E:12:39:6D:1E:1B:3F:4E:21:02:9C:77:
74:C5:37:9E:AF:FD:EF:0F:5C:60:B0:02:20:62:51:B0:
46:8B:7E:4A:A1:01:0A:CF:FF:7E:BC:7F:60:74:CF:C2:
8C:7D:40:B7:72:EC:68:D3:2D:61:DF:70:C0:00:77:00:
19:86:D4:C7:28:AA:6F:FE:BA:03:6F:78:2A:4D:01:91:
AA:CE:2D:72:31:0F:AE:CE:5D:70:41:2D:25:4C:C7:D4:
00:00:01:94:D3:6B:93:ED:00:00:04:03:00:48:30:46:
02:21:00:E5:AC:89:F1:EC:9F:B7:31:FA:A0:C4:1D:BE:
16:FA:B7:74:C9:64:D6:A8:F8:72:13:B0:FF:E1:E4:61:
57:C6:D0:02:21:00:C4:FE:24:A0:10:7D:4B:88:74:11:
B1:7E:BC:AB:1A:BC:2C:38:3D:E9:46:CD:6D:C8:0C:B2:
91:D3:C6:46:0B:13:00:76:00:CB:38:F7:15:89:7C:84:
A1:44:5F:5B:C1:DD:FB:C9:6E:F2:9A:59:CD:47:0A:69:
05:85:B0:CB:14:C3:14:58:E7:00:00:01:94:D3:6B:94:
25:00:00:04:03:00:47:30:45:02:21:00:D4:62:96:F7:
66:A0:0C:53:49:21:8A:CC:1F:78:1A:25:D5:EC:74:85:
69:51:C6:4E:7F:11:F5:16:4B:1B:B8:B1:02:20:52:42:
7E:C9:48:36:17:39:DD:0D:13:20:C2:47:75:C1:4E:5B:
6B:60:1B:8B:41:03:57:4B:F3:CD:6D:5D:B3:27
Extension OID: subjectAltName (2.5.29.17)
Value (decoded SubjectAltName):
DNS Name: 'github.com'
DNS Name: 'www.github.com'
Algorithm: ecdsa-with-SHA256 (1.2.840.10045.4.3.2)
Signature Value (Unused Bits: 0):
30:44:02:20:71:8C:A7:6E:C1:04:12:75:DF:9E:A5:09:
ED:96:63:2C:D8:22:9F:DF:00:E3:50:33:70:24:78:4F:
DF:CA:6D:2C:02:20:6D:55:F3:77:62:02:19:FA:77:87:
11:FC:1C:46:18:73:E2:E0:E9:73:C1:7E:B4:A9:AD:71:
E5:89:4A:27:0C:90
===================================
Successfully parsed certificate.