blob: 04d5320490f274c6267b6eb43dadce6706ae9875 [file] [log] [blame]
/*
* ASN.1 DER parsing
* Copyright (c) 2006-2014, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "utils/wpabuf.h"
#include "asn1.h"
const struct asn1_oid asn1_sha1_oid = {
.oid = { 1, 3, 14, 3, 2, 26 },
.len = 6
};
const struct asn1_oid asn1_sha256_oid = {
.oid = { 2, 16, 840, 1, 101, 3, 4, 2, 1 },
.len = 9
};
const struct asn1_oid asn1_ec_public_key_oid = {
.oid = { 1, 2, 840, 10045, 2, 1 },
.len = 6
};
const struct asn1_oid asn1_prime256v1_oid = {
.oid = { 1, 2, 840, 10045, 3, 1, 7 },
.len = 7
};
const struct asn1_oid asn1_secp384r1_oid = {
.oid = { 1, 3, 132, 0, 34 },
.len = 5
};
const struct asn1_oid asn1_secp521r1_oid = {
.oid = { 1, 3, 132, 0, 35 },
.len = 5
};
const struct asn1_oid asn1_brainpoolP256r1_oid = {
.oid = { 1, 3, 36, 3, 3, 2, 8, 1, 1, 7 },
.len = 10
};
const struct asn1_oid asn1_brainpoolP384r1_oid = {
.oid = { 1, 3, 36, 3, 3, 2, 8, 1, 1, 11 },
.len = 10
};
const struct asn1_oid asn1_brainpoolP512r1_oid = {
.oid = { 1, 3, 36, 3, 3, 2, 8, 1, 1, 13 },
.len = 10
};
const struct asn1_oid asn1_aes_siv_cmac_aead_256_oid = {
.oid = { 1, 2, 840, 113549, 1, 9, 16, 3, 22 },
.len = 9
};
const struct asn1_oid asn1_aes_siv_cmac_aead_384_oid = {
.oid = { 1, 2, 840, 113549, 1, 9, 16, 3, 23 },
.len = 9
};
const struct asn1_oid asn1_aes_siv_cmac_aead_512_oid = {
.oid = { 1, 2, 840, 113549, 1, 9, 16, 3, 24 },
.len = 9
};
const struct asn1_oid asn1_pbkdf2_oid = {
.oid = { 1, 2, 840, 113549, 1, 5, 12 },
.len = 7
};
const struct asn1_oid asn1_pbkdf2_hmac_sha256_oid = {
.oid = { 1, 2, 840, 113549, 2, 9 },
.len = 6
};
const struct asn1_oid asn1_pbkdf2_hmac_sha384_oid = {
.oid = { 1, 2, 840, 113549, 2, 10 },
.len = 6
};
const struct asn1_oid asn1_pbkdf2_hmac_sha512_oid = {
.oid = { 1, 2, 840, 113549, 2, 11 },
.len = 6
};
const struct asn1_oid asn1_dpp_config_params_oid = {
.oid = { 1, 3, 6, 1, 4, 1, 40808, 1, 2, 1 },
.len = 10
};
const struct asn1_oid asn1_dpp_asymmetric_key_package_oid = {
.oid = { 1, 3, 6, 1, 4, 1, 40808, 1, 2, 2 },
.len = 10
};
static int asn1_valid_der_boolean(struct asn1_hdr *hdr)
{
/* Enforce DER requirements for a single way of encoding a BOOLEAN */
if (hdr->length != 1) {
wpa_printf(MSG_DEBUG, "ASN.1: Unexpected BOOLEAN length (%u)",
hdr->length);
return 0;
}
if (hdr->payload[0] != 0 && hdr->payload[0] != 0xff) {
wpa_printf(MSG_DEBUG,
"ASN.1: Invalid BOOLEAN value 0x%x (DER requires 0 or 0xff)",
hdr->payload[0]);
return 0;
}
return 1;
}
static int asn1_valid_der(struct asn1_hdr *hdr)
{
if (hdr->class != ASN1_CLASS_UNIVERSAL)
return 1;
if (hdr->tag == ASN1_TAG_BOOLEAN && !asn1_valid_der_boolean(hdr))
return 0;
if (hdr->tag == ASN1_TAG_NULL && hdr->length != 0)
return 0;
/* Check for allowed primitive/constructed values */
if (hdr->constructed &&
(hdr->tag == ASN1_TAG_BOOLEAN ||
hdr->tag == ASN1_TAG_INTEGER ||
hdr->tag == ASN1_TAG_NULL ||
hdr->tag == ASN1_TAG_OID ||
hdr->tag == ANS1_TAG_RELATIVE_OID ||
hdr->tag == ASN1_TAG_REAL ||
hdr->tag == ASN1_TAG_ENUMERATED ||
hdr->tag == ASN1_TAG_BITSTRING ||
hdr->tag == ASN1_TAG_OCTETSTRING ||
hdr->tag == ASN1_TAG_NUMERICSTRING ||
hdr->tag == ASN1_TAG_PRINTABLESTRING ||
hdr->tag == ASN1_TAG_T61STRING ||
hdr->tag == ASN1_TAG_VIDEOTEXSTRING ||
hdr->tag == ASN1_TAG_VISIBLESTRING ||
hdr->tag == ASN1_TAG_IA5STRING ||
hdr->tag == ASN1_TAG_GRAPHICSTRING ||
hdr->tag == ASN1_TAG_GENERALSTRING ||
hdr->tag == ASN1_TAG_UNIVERSALSTRING ||
hdr->tag == ASN1_TAG_UTF8STRING ||
hdr->tag == ASN1_TAG_BMPSTRING ||
hdr->tag == ASN1_TAG_CHARACTERSTRING ||
hdr->tag == ASN1_TAG_UTCTIME ||
hdr->tag == ASN1_TAG_GENERALIZEDTIME ||
hdr->tag == ASN1_TAG_TIME))
return 0;
if (!hdr->constructed &&
(hdr->tag == ASN1_TAG_SEQUENCE ||
hdr->tag == ASN1_TAG_SET))
return 0;
return 1;
}
int asn1_get_next(const u8 *buf, size_t len, struct asn1_hdr *hdr)
{
const u8 *pos, *end;
u8 tmp;
os_memset(hdr, 0, sizeof(*hdr));
pos = buf;
end = buf + len;
if (pos >= end) {
wpa_printf(MSG_DEBUG, "ASN.1: No room for Identifier");
return -1;
}
hdr->identifier = *pos++;
hdr->class = hdr->identifier >> 6;
hdr->constructed = !!(hdr->identifier & (1 << 5));
if ((hdr->identifier & 0x1f) == 0x1f) {
size_t ext_len = 0;
hdr->tag = 0;
if (pos == end || (*pos & 0x7f) == 0) {
wpa_printf(MSG_DEBUG,
"ASN.1: Invalid extended tag (first octet has to be included with at least one nonzero bit for the tag value)");
return -1;
}
do {
if (pos >= end) {
wpa_printf(MSG_DEBUG, "ASN.1: Identifier "
"underflow");
return -1;
}
ext_len++;
tmp = *pos++;
wpa_printf(MSG_MSGDUMP, "ASN.1: Extended tag data: "
"0x%02x", tmp);
hdr->tag = (hdr->tag << 7) | (tmp & 0x7f);
} while (tmp & 0x80);
wpa_printf(MSG_MSGDUMP, "ASN.1: Extended Tag: 0x%x (len=%zu)",
hdr->tag, ext_len);
if ((hdr->class != ASN1_CLASS_PRIVATE && hdr->tag < 31) ||
ext_len * 7 > sizeof(hdr->tag) * 8) {
wpa_printf(MSG_DEBUG,
"ASN.1: Invalid or unsupported (too large) extended Tag: 0x%x (len=%zu)",
hdr->tag, ext_len);
return -1;
}
} else
hdr->tag = hdr->identifier & 0x1f;
if (pos >= end) {
wpa_printf(MSG_DEBUG, "ASN.1: No room for Length");
return -1;
}
tmp = *pos++;
if (tmp & 0x80) {
if (tmp == 0xff) {
wpa_printf(MSG_DEBUG, "ASN.1: Reserved length "
"value 0xff used");
return -1;
}
tmp &= 0x7f; /* number of subsequent octets */
hdr->length = 0;
if (tmp == 0 || pos == end || *pos == 0) {
wpa_printf(MSG_DEBUG,
"ASN.1: Definite long form of the length does not start with a nonzero value");
return -1;
}
if (tmp > 4) {
wpa_printf(MSG_DEBUG, "ASN.1: Too long length field");
return -1;
}
while (tmp--) {
if (pos >= end) {
wpa_printf(MSG_DEBUG, "ASN.1: Length "
"underflow");
return -1;
}
hdr->length = (hdr->length << 8) | *pos++;
}
if (hdr->length < 128) {
wpa_printf(MSG_DEBUG,
"ASN.1: Definite long form of the length used with too short length");
return -1;
}
} else {
/* Short form - length 0..127 in one octet */
hdr->length = tmp;
}
if (end < pos || hdr->length > (unsigned int) (end - pos)) {
wpa_printf(MSG_DEBUG, "ASN.1: Contents underflow");
return -1;
}
hdr->payload = pos;
if (!asn1_valid_der(hdr)) {
asn1_print_hdr(hdr, "ASN.1: Invalid DER encoding: ");
return -1;
}
return 0;
}
void asn1_print_hdr(const struct asn1_hdr *hdr, const char *title)
{
wpa_printf(MSG_DEBUG, "%sclass %d constructed %d tag 0x%x",
title, hdr->class, hdr->constructed, hdr->tag);
}
void asn1_unexpected(const struct asn1_hdr *hdr, const char *title)
{
wpa_printf(MSG_DEBUG, "%s - found class %d constructed %d tag 0x%x",
title, hdr->class, hdr->constructed, hdr->tag);
}
int asn1_parse_oid(const u8 *buf, size_t len, struct asn1_oid *oid)
{
const u8 *pos, *end;
unsigned long val;
u8 tmp;
os_memset(oid, 0, sizeof(*oid));
pos = buf;
end = buf + len;
while (pos < end) {
val = 0;
do {
if (pos >= end)
return -1;
tmp = *pos++;
val = (val << 7) | (tmp & 0x7f);
} while (tmp & 0x80);
if (oid->len >= ASN1_MAX_OID_LEN) {
wpa_printf(MSG_DEBUG, "ASN.1: Too long OID value");
return -1;
}
if (oid->len == 0) {
/*
* The first octet encodes the first two object
* identifier components in (X*40) + Y formula.
* X = 0..2.
*/
oid->oid[0] = val / 40;
if (oid->oid[0] > 2)
oid->oid[0] = 2;
oid->oid[1] = val - oid->oid[0] * 40;
oid->len = 2;
} else
oid->oid[oid->len++] = val;
}
return 0;
}
int asn1_get_oid(const u8 *buf, size_t len, struct asn1_oid *oid,
const u8 **next)
{
struct asn1_hdr hdr;
if (asn1_get_next(buf, len, &hdr) < 0 || hdr.length == 0 ||
!asn1_is_oid(&hdr)) {
asn1_unexpected(&hdr, "ASN.1: Expected OID");
return -1;
}
*next = hdr.payload + hdr.length;
return asn1_parse_oid(hdr.payload, hdr.length, oid);
}
void asn1_oid_to_str(const struct asn1_oid *oid, char *buf, size_t len)
{
char *pos = buf;
size_t i;
int ret;
if (len == 0)
return;
buf[0] = '\0';
for (i = 0; i < oid->len; i++) {
ret = os_snprintf(pos, buf + len - pos,
"%s%lu",
i == 0 ? "" : ".", oid->oid[i]);
if (os_snprintf_error(buf + len - pos, ret))
break;
pos += ret;
}
buf[len - 1] = '\0';
}
static u8 rotate_bits(u8 octet)
{
int i;
u8 res;
res = 0;
for (i = 0; i < 8; i++) {
res <<= 1;
if (octet & 1)
res |= 1;
octet >>= 1;
}
return res;
}
unsigned long asn1_bit_string_to_long(const u8 *buf, size_t len)
{
unsigned long val = 0;
const u8 *pos = buf;
/* BER requires that unused bits are zero, so we can ignore the number
* of unused bits */
pos++;
if (len >= 2)
val |= rotate_bits(*pos++);
if (len >= 3)
val |= ((unsigned long) rotate_bits(*pos++)) << 8;
if (len >= 4)
val |= ((unsigned long) rotate_bits(*pos++)) << 16;
if (len >= 5)
val |= ((unsigned long) rotate_bits(*pos++)) << 24;
if (len >= 6)
wpa_printf(MSG_DEBUG, "X509: %s - some bits ignored "
"(BIT STRING length %lu)",
__func__, (unsigned long) len);
return val;
}
int asn1_oid_equal(const struct asn1_oid *a, const struct asn1_oid *b)
{
size_t i;
if (a->len != b->len)
return 0;
for (i = 0; i < a->len; i++) {
if (a->oid[i] != b->oid[i])
return 0;
}
return 1;
}
int asn1_get_integer(const u8 *buf, size_t len, int *integer, const u8 **next)
{
struct asn1_hdr hdr;
size_t left;
const u8 *pos;
int value;
if (asn1_get_next(buf, len, &hdr) < 0 || hdr.length == 0 ||
!asn1_is_integer(&hdr)) {
asn1_unexpected(&hdr, "ASN.1: Expected INTEGER");
return -1;
}
*next = hdr.payload + hdr.length;
pos = hdr.payload;
left = hdr.length;
if (left > sizeof(value)) {
wpa_printf(MSG_DEBUG, "ASN.1: Too large INTEGER (len %u)",
hdr.length);
return -1;
}
value = 0;
while (left) {
value <<= 8;
value |= *pos++;
left--;
}
*integer = value;
return 0;
}
int asn1_get_sequence(const u8 *buf, size_t len, struct asn1_hdr *hdr,
const u8 **next)
{
if (asn1_get_next(buf, len, hdr) < 0 || !asn1_is_sequence(hdr)) {
asn1_unexpected(hdr, "ASN.1: Expected SEQUENCE");
return -1;
}
if (next)
*next = hdr->payload + hdr->length;
return 0;
}
int asn1_get_alg_id(const u8 *buf, size_t len, struct asn1_oid *oid,
const u8 **params, size_t *params_len, const u8 **next)
{
const u8 *pos = buf, *end = buf + len;
struct asn1_hdr hdr;
/*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL}
*/
if (asn1_get_sequence(pos, end - pos, &hdr, next) < 0 ||
asn1_get_oid(hdr.payload, hdr.length, oid, &pos) < 0)
return -1;
if (params && params_len) {
*params = pos;
*params_len = hdr.payload + hdr.length - pos;
}
return 0;
}
void asn1_put_integer(struct wpabuf *buf, int val)
{
u8 bin[4];
int zeros;
WPA_PUT_BE32(bin, val);
zeros = 0;
while (zeros < 3 && bin[zeros] == 0)
zeros++;
wpabuf_put_u8(buf, ASN1_TAG_INTEGER);
wpabuf_put_u8(buf, 4 - zeros);
wpabuf_put_data(buf, &bin[zeros], 4 - zeros);
}
static void asn1_put_len(struct wpabuf *buf, size_t len)
{
if (len <= 0x7f) {
wpabuf_put_u8(buf, len);
} else if (len <= 0xff) {
wpabuf_put_u8(buf, 0x80 | 1);
wpabuf_put_u8(buf, len);
} else if (len <= 0xffff) {
wpabuf_put_u8(buf, 0x80 | 2);
wpabuf_put_be16(buf, len);
} else if (len <= 0xffffff) {
wpabuf_put_u8(buf, 0x80 | 3);
wpabuf_put_be24(buf, len);
} else {
wpabuf_put_u8(buf, 0x80 | 4);
wpabuf_put_be32(buf, len);
}
}
void asn1_put_octet_string(struct wpabuf *buf, const struct wpabuf *val)
{
wpabuf_put_u8(buf, ASN1_TAG_OCTETSTRING);
asn1_put_len(buf, wpabuf_len(val));
wpabuf_put_buf(buf, val);
}
void asn1_put_oid(struct wpabuf *buf, const struct asn1_oid *oid)
{
u8 *len;
size_t i;
if (oid->len < 2)
return;
wpabuf_put_u8(buf, ASN1_TAG_OID);
len = wpabuf_put(buf, 1);
wpabuf_put_u8(buf, 40 * oid->oid[0] + oid->oid[1]);
for (i = 2; i < oid->len; i++) {
unsigned long val = oid->oid[i];
u8 bytes[8];
int idx = 0;
while (val) {
bytes[idx] = (idx ? 0x80 : 0x00) | (val & 0x7f);
idx++;
val >>= 7;
}
if (idx == 0) {
bytes[idx] = 0;
idx = 1;
}
while (idx > 0) {
idx--;
wpabuf_put_u8(buf, bytes[idx]);
}
}
*len = (u8 *) wpabuf_put(buf, 0) - len - 1;
}
void asn1_put_hdr(struct wpabuf *buf, u8 class, int constructed, u8 tag,
size_t len)
{
wpabuf_put_u8(buf, class << 6 | (constructed ? 0x20 : 0x00) | tag);
asn1_put_len(buf, len);
}
void asn1_put_sequence(struct wpabuf *buf, const struct wpabuf *payload)
{
asn1_put_hdr(buf, ASN1_CLASS_UNIVERSAL, 1, ASN1_TAG_SEQUENCE,
wpabuf_len(payload));
wpabuf_put_buf(buf, payload);
}
void asn1_put_set(struct wpabuf *buf, const struct wpabuf *payload)
{
asn1_put_hdr(buf, ASN1_CLASS_UNIVERSAL, 1, ASN1_TAG_SET,
wpabuf_len(payload));
wpabuf_put_buf(buf, payload);
}
void asn1_put_utf8string(struct wpabuf *buf, const char *val)
{
asn1_put_hdr(buf, ASN1_CLASS_UNIVERSAL, 0, ASN1_TAG_UTF8STRING,
os_strlen(val));
wpabuf_put_str(buf, val);
}
struct wpabuf * asn1_build_alg_id(const struct asn1_oid *oid,
const struct wpabuf *params)
{
struct wpabuf *buf;
size_t len;
/*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL}
*/
len = 100;
if (params)
len += wpabuf_len(params);
buf = wpabuf_alloc(len);
if (!buf)
return NULL;
asn1_put_oid(buf, oid);
if (params)
wpabuf_put_buf(buf, params);
return asn1_encaps(buf, ASN1_CLASS_UNIVERSAL, ASN1_TAG_SEQUENCE);
}
struct wpabuf * asn1_encaps(struct wpabuf *buf, u8 class, u8 tag)
{
struct wpabuf *res;
if (!buf)
return NULL;
res = wpabuf_alloc(10 + wpabuf_len(buf));
if (res) {
asn1_put_hdr(res, class, 1, tag, wpabuf_len(buf));
wpabuf_put_buf(res, buf);
}
wpabuf_clear_free(buf);
return res;
}