3 * Copyright (c) 2006, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
20 int asn1_get_next(const u8 *buf, size_t len, struct asn1_hdr *hdr)
25 os_memset(hdr, 0, sizeof(*hdr));
29 hdr->identifier = *pos++;
30 hdr->class = hdr->identifier >> 6;
31 hdr->constructed = !!(hdr->identifier & (1 << 5));
33 if ((hdr->identifier & 0x1f) == 0x1f) {
37 wpa_printf(MSG_DEBUG, "ASN.1: Identifier "
42 wpa_printf(MSG_MSGDUMP, "ASN.1: Extended tag data: "
44 hdr->tag = (hdr->tag << 7) | (tmp & 0x7f);
47 hdr->tag = hdr->identifier & 0x1f;
52 wpa_printf(MSG_DEBUG, "ASN.1: Reserved length "
56 tmp &= 0x7f; /* number of subsequent octets */
59 wpa_printf(MSG_DEBUG, "ASN.1: Too long length field");
64 wpa_printf(MSG_DEBUG, "ASN.1: Length "
68 hdr->length = (hdr->length << 8) | *pos++;
71 /* Short form - length 0..127 in one octet */
75 if (end < pos || hdr->length > (unsigned int) (end - pos)) {
76 wpa_printf(MSG_DEBUG, "ASN.1: Contents underflow");
85 int asn1_parse_oid(const u8 *buf, size_t len, struct asn1_oid *oid)
91 os_memset(oid, 0, sizeof(*oid));
103 val = (val << 7) | (tmp & 0x7f);
104 } while (tmp & 0x80);
106 if (oid->len >= ASN1_MAX_OID_LEN) {
107 wpa_printf(MSG_DEBUG, "ASN.1: Too long OID value");
112 * The first octet encodes the first two object
113 * identifier components in (X*40) + Y formula.
116 oid->oid[0] = val / 40;
119 oid->oid[1] = val - oid->oid[0] * 40;
122 oid->oid[oid->len++] = val;
129 int asn1_get_oid(const u8 *buf, size_t len, struct asn1_oid *oid,
134 if (asn1_get_next(buf, len, &hdr) < 0 || hdr.length == 0)
137 if (hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_OID) {
138 wpa_printf(MSG_DEBUG, "ASN.1: Expected OID - found class %d "
139 "tag 0x%x", hdr.class, hdr.tag);
143 *next = hdr.payload + hdr.length;
145 return asn1_parse_oid(hdr.payload, hdr.length, oid);
149 void asn1_oid_to_str(struct asn1_oid *oid, char *buf, size_t len)
160 for (i = 0; i < oid->len; i++) {
161 ret = os_snprintf(pos, buf + len - pos,
163 i == 0 ? "" : ".", oid->oid[i]);
164 if (ret < 0 || ret >= buf + len - pos)
172 static u8 rotate_bits(u8 octet)
178 for (i = 0; i < 8; i++) {
189 unsigned long asn1_bit_string_to_long(const u8 *buf, size_t len)
191 unsigned long val = 0;
194 /* BER requires that unused bits are zero, so we can ignore the number
199 val |= rotate_bits(*pos++);
201 val |= ((unsigned long) rotate_bits(*pos++)) << 8;
203 val |= ((unsigned long) rotate_bits(*pos++)) << 16;
205 val |= ((unsigned long) rotate_bits(*pos++)) << 24;
207 wpa_printf(MSG_DEBUG, "X509: %s - some bits ignored "
208 "(BIT STRING length %lu)",
209 __func__, (unsigned long) len);