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freebsd-skq/contrib/wpa_supplicant/x509v3.c
Sam Leffler 7700b89cce Import of WPA supplicant 0.5.8
2007-07-11 15:48:36 +00:00

1597 lines
39 KiB
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/*
* X.509v3 certificate parsing and processing (RFC 3280 profile)
* Copyright (c) 2006, Jouni Malinen <j@w1.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Alternatively, this software may be distributed under the terms of BSD
* license.
*
* See README and COPYING for more details.
*/
#include "includes.h"
#include "common.h"
#ifdef CONFIG_INTERNAL_X509
#include "asn1.h"
#include "crypto.h"
#include "x509v3.h"
static void x509_free_name(struct x509_name *name)
{
os_free(name->cn);
os_free(name->c);
os_free(name->l);
os_free(name->st);
os_free(name->o);
os_free(name->ou);
os_free(name->email);
name->cn = name->c = name->l = name->st = name->o = name->ou = NULL;
name->email = NULL;
}
/**
* x509_certificate_free - Free an X.509 certificate
* @cert: Certificate to be freed
*/
void x509_certificate_free(struct x509_certificate *cert)
{
if (cert == NULL)
return;
if (cert->next) {
wpa_printf(MSG_DEBUG, "X509: x509_certificate_free: cer=%p "
"was still on a list (next=%p)\n",
cert, cert->next);
}
x509_free_name(&cert->issuer);
x509_free_name(&cert->subject);
os_free(cert->public_key);
os_free(cert->sign_value);
os_free(cert);
}
/**
* x509_certificate_free - Free an X.509 certificate chain
* @cert: Pointer to the first certificate in the chain
*/
void x509_certificate_chain_free(struct x509_certificate *cert)
{
struct x509_certificate *next;
while (cert) {
next = cert->next;
cert->next = NULL;
x509_certificate_free(cert);
cert = next;
}
}
static int x509_str_compare(const char *a, const char *b)
{
if (!a && b)
return -1;
if (a && !b)
return 1;
if (!a && !b)
return 0;
return os_strcmp(a, b);
}
/**
* x509_name_compare - Compare X.509 certificate names
* @a: Certificate name
* @b: Certifiatte name
* Returns: <0, 0, or >0 based on whether a is less than, equal to, or
* greater than b
*/
int x509_name_compare(struct x509_name *a, struct x509_name *b)
{
int res;
if (!a && b)
return -1;
if (a && !b)
return 1;
if (!a && !b)
return 0;
res = x509_str_compare(a->cn, b->cn);
if (res)
return res;
res = x509_str_compare(a->c, b->c);
if (res)
return res;
res = x509_str_compare(a->l, b->l);
if (res)
return res;
res = x509_str_compare(a->st, b->st);
if (res)
return res;
res = x509_str_compare(a->o, b->o);
if (res)
return res;
res = x509_str_compare(a->ou, b->ou);
if (res)
return res;
res = x509_str_compare(a->email, b->email);
if (res)
return res;
return 0;
}
static int x509_parse_algorithm_identifier(
const u8 *buf, size_t len,
struct x509_algorithm_identifier *id, const u8 **next)
{
struct asn1_hdr hdr;
const u8 *pos, *end;
/*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL
* }
*/
if (asn1_get_next(buf, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(AlgorithmIdentifier) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
end = pos + hdr.length;
if (end > buf + len)
return -1;
*next = end;
if (asn1_get_oid(pos, end - pos, &id->oid, &pos))
return -1;
/* TODO: optional parameters */
return 0;
}
static int x509_parse_public_key(const u8 *buf, size_t len,
struct x509_certificate *cert,
const u8 **next)
{
struct asn1_hdr hdr;
const u8 *pos, *end;
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING
* }
*/
pos = buf;
end = buf + len;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(SubjectPublicKeyInfo) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
if (pos + hdr.length > end)
return -1;
end = pos + hdr.length;
*next = end;
if (x509_parse_algorithm_identifier(pos, end - pos,
&cert->public_key_alg, &pos))
return -1;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_BITSTRING) {
wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING "
"(subjectPublicKey) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
if (hdr.length < 1)
return -1;
pos = hdr.payload;
if (*pos) {
wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits",
*pos);
/*
* TODO: should this be rejected? X.509 certificates are
* unlikely to use such a construction. Now we would end up
* including the extra bits in the buffer which may also be
* ok.
*/
}
os_free(cert->public_key);
cert->public_key = os_malloc(hdr.length - 1);
if (cert->public_key == NULL) {
wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for "
"public key");
return -1;
}
os_memcpy(cert->public_key, pos + 1, hdr.length - 1);
cert->public_key_len = hdr.length - 1;
wpa_hexdump(MSG_MSGDUMP, "X509: subjectPublicKey",
cert->public_key, cert->public_key_len);
return 0;
}
static int x509_parse_name(const u8 *buf, size_t len, struct x509_name *name,
const u8 **next)
{
struct asn1_hdr hdr;
const u8 *pos, *end, *set_pos, *set_end, *seq_pos, *seq_end;
struct asn1_oid oid;
char **fieldp;
/*
* Name ::= CHOICE { RDNSequence }
* RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
* RelativeDistinguishedName ::= SET OF AttributeTypeAndValue
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue
* }
* AttributeType ::= OBJECT IDENTIFIER
* AttributeValue ::= ANY DEFINED BY AttributeType
*/
if (asn1_get_next(buf, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(Name / RDNSequencer) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
if (pos + hdr.length > buf + len)
return -1;
end = *next = pos + hdr.length;
while (pos < end) {
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SET) {
wpa_printf(MSG_DEBUG, "X509: Expected SET "
"(RelativeDistinguishedName) - found class "
"%d tag 0x%x", hdr.class, hdr.tag);
x509_free_name(name);
return -1;
}
set_pos = hdr.payload;
pos = set_end = hdr.payload + hdr.length;
if (asn1_get_next(set_pos, set_end - set_pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(AttributeTypeAndValue) - found class %d "
"tag 0x%x", hdr.class, hdr.tag);
x509_free_name(name);
return -1;
}
seq_pos = hdr.payload;
seq_end = hdr.payload + hdr.length;
if (asn1_get_oid(seq_pos, seq_end - seq_pos, &oid, &seq_pos)) {
x509_free_name(name);
return -1;
}
if (asn1_get_next(seq_pos, seq_end - seq_pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL) {
wpa_printf(MSG_DEBUG, "X509: Failed to parse "
"AttributeValue");
x509_free_name(name);
return -1;
}
/* RFC 3280:
* MUST: country, organization, organizational-unit,
* distinguished name qualifier, state or province name,
* common name, serial number.
* SHOULD: locality, title, surname, given name, initials,
* pseudonym, generation qualifier.
* MUST: domainComponent (RFC 2247).
*/
fieldp = NULL;
if (oid.len == 4 &&
oid.oid[0] == 2 && oid.oid[1] == 5 && oid.oid[2] == 4) {
/* id-at ::= 2.5.4 */
switch (oid.oid[3]) {
case 3:
/* commonName */
fieldp = &name->cn;
break;
case 6:
/* countryName */
fieldp = &name->c;
break;
case 7:
/* localityName */
fieldp = &name->l;
break;
case 8:
/* stateOrProvinceName */
fieldp = &name->st;
break;
case 10:
/* organizationName */
fieldp = &name->o;
break;
case 11:
/* organizationalUnitName */
fieldp = &name->ou;
break;
}
} else if (oid.len == 7 &&
oid.oid[0] == 1 && oid.oid[1] == 2 &&
oid.oid[2] == 840 && oid.oid[3] == 113549 &&
oid.oid[4] == 1 && oid.oid[5] == 9 &&
oid.oid[6] == 1) {
/* 1.2.840.113549.1.9.1 - e-mailAddress */
fieldp = &name->email;
}
if (fieldp == NULL) {
wpa_hexdump(MSG_DEBUG, "X509: Unrecognized OID",
(u8 *) oid.oid,
oid.len * sizeof(oid.oid[0]));
wpa_hexdump_ascii(MSG_MSGDUMP, "X509: Attribute Data",
hdr.payload, hdr.length);
continue;
}
os_free(*fieldp);
*fieldp = os_malloc(hdr.length + 1);
if (*fieldp == NULL) {
x509_free_name(name);
return -1;
}
os_memcpy(*fieldp, hdr.payload, hdr.length);
(*fieldp)[hdr.length] = '\0';
}
return 0;
}
/**
* x509_name_string - Convert an X.509 certificate name into a string
* @name: Name to convert
* @buf: Buffer for the string
* @len: Maximum buffer length
*/
void x509_name_string(struct x509_name *name, char *buf, size_t len)
{
char *pos, *end;
int ret;
if (len == 0)
return;
pos = buf;
end = buf + len;
if (name->c) {
ret = os_snprintf(pos, end - pos, "C=%s, ", name->c);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (name->st) {
ret = os_snprintf(pos, end - pos, "ST=%s, ", name->st);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (name->l) {
ret = os_snprintf(pos, end - pos, "L=%s, ", name->l);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (name->o) {
ret = os_snprintf(pos, end - pos, "O=%s, ", name->o);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (name->ou) {
ret = os_snprintf(pos, end - pos, "OU=%s, ", name->ou);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (name->cn) {
ret = os_snprintf(pos, end - pos, "CN=%s, ", name->cn);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
if (pos > buf + 1 && pos[-1] == ' ' && pos[-2] == ',') {
*pos-- = '\0';
*pos-- = '\0';
}
if (name->email) {
ret = os_snprintf(pos, end - pos, "/emailAddress=%s",
name->email);
if (ret < 0 || ret >= end - pos)
goto done;
pos += ret;
}
done:
end[-1] = '\0';
}
static int x509_parse_time(const u8 *buf, size_t len, u8 asn1_tag,
os_time_t *val)
{
const char *pos;
int year, month, day, hour, min, sec;
/*
* Time ::= CHOICE {
* utcTime UTCTime,
* generalTime GeneralizedTime
* }
*
* UTCTime: YYMMDDHHMMSSZ
* GeneralizedTime: YYYYMMDDHHMMSSZ
*/
pos = (const char *) buf;
switch (asn1_tag) {
case ASN1_TAG_UTCTIME:
if (len != 13 || buf[12] != 'Z') {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized "
"UTCTime format", buf, len);
return -1;
}
if (sscanf(pos, "%02d", &year) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse "
"UTCTime year", buf, len);
return -1;
}
if (year < 50)
year += 2000;
else
year += 1900;
pos += 2;
break;
case ASN1_TAG_GENERALIZEDTIME:
if (len != 15 || buf[14] != 'Z') {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Unrecognized "
"GeneralizedTime format", buf, len);
return -1;
}
if (sscanf(pos, "%04d", &year) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse "
"GeneralizedTime year", buf, len);
return -1;
}
pos += 4;
break;
default:
wpa_printf(MSG_DEBUG, "X509: Expected UTCTime or "
"GeneralizedTime - found tag 0x%x", asn1_tag);
return -1;
}
if (sscanf(pos, "%02d", &month) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
"(month)", buf, len);
return -1;
}
pos += 2;
if (sscanf(pos, "%02d", &day) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
"(day)", buf, len);
return -1;
}
pos += 2;
if (sscanf(pos, "%02d", &hour) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
"(hour)", buf, len);
return -1;
}
pos += 2;
if (sscanf(pos, "%02d", &min) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
"(min)", buf, len);
return -1;
}
pos += 2;
if (sscanf(pos, "%02d", &sec) != 1) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse Time "
"(sec)", buf, len);
return -1;
}
if (os_mktime(year, month, day, hour, min, sec, val) < 0) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to convert Time",
buf, len);
return -1;
}
return 0;
}
static int x509_parse_validity(const u8 *buf, size_t len,
struct x509_certificate *cert, const u8 **next)
{
struct asn1_hdr hdr;
const u8 *pos;
size_t plen;
/*
* Validity ::= SEQUENCE {
* notBefore Time,
* notAfter Time
* }
*
* RFC 3280, 4.1.2.5:
* CAs conforming to this profile MUST always encode certificate
* validity dates through the year 2049 as UTCTime; certificate
* validity dates in 2050 or later MUST be encoded as GeneralizedTime.
*/
if (asn1_get_next(buf, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(Validity) - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
plen = hdr.length;
if (pos + plen > buf + len)
return -1;
*next = pos + plen;
if (asn1_get_next(pos, plen, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
x509_parse_time(hdr.payload, hdr.length, hdr.tag,
&cert->not_before) < 0) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notBefore "
"Time", hdr.payload, hdr.length);
return -1;
}
pos = hdr.payload + hdr.length;
plen = *next - pos;
if (asn1_get_next(pos, plen, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
x509_parse_time(hdr.payload, hdr.length, hdr.tag,
&cert->not_after) < 0) {
wpa_hexdump_ascii(MSG_DEBUG, "X509: Failed to parse notAfter "
"Time", hdr.payload, hdr.length);
return -1;
}
wpa_printf(MSG_MSGDUMP, "X509: Validity: notBefore: %lu notAfter: %lu",
(unsigned long) cert->not_before,
(unsigned long) cert->not_after);
return 0;
}
static int x509_id_ce_oid(struct asn1_oid *oid)
{
/* id-ce arc from X.509 for standard X.509v3 extensions */
return oid->len >= 4 &&
oid->oid[0] == 2 /* joint-iso-ccitt */ &&
oid->oid[1] == 5 /* ds */ &&
oid->oid[2] == 29 /* id-ce */;
}
static int x509_parse_ext_key_usage(struct x509_certificate *cert,
const u8 *pos, size_t len)
{
struct asn1_hdr hdr;
/*
* KeyUsage ::= BIT STRING {
* digitalSignature (0),
* nonRepudiation (1),
* keyEncipherment (2),
* dataEncipherment (3),
* keyAgreement (4),
* keyCertSign (5),
* cRLSign (6),
* encipherOnly (7),
* decipherOnly (8) }
*/
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_BITSTRING ||
hdr.length < 1) {
wpa_printf(MSG_DEBUG, "X509: Expected BIT STRING in "
"KeyUsage; found %d tag 0x%x len %d",
hdr.class, hdr.tag, hdr.length);
return -1;
}
cert->extensions_present |= X509_EXT_KEY_USAGE;
cert->key_usage = asn1_bit_string_to_long(hdr.payload, hdr.length);
wpa_printf(MSG_DEBUG, "X509: KeyUsage 0x%lx", cert->key_usage);
return 0;
}
static int x509_parse_ext_basic_constraints(struct x509_certificate *cert,
const u8 *pos, size_t len)
{
struct asn1_hdr hdr;
unsigned long value;
size_t left;
/*
* BasicConstraints ::= SEQUENCE {
* cA BOOLEAN DEFAULT FALSE,
* pathLenConstraint INTEGER (0..MAX) OPTIONAL }
*/
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE in "
"BasicConstraints; found %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
cert->extensions_present |= X509_EXT_BASIC_CONSTRAINTS;
if (hdr.length == 0)
return 0;
if (asn1_get_next(hdr.payload, hdr.length, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL) {
wpa_printf(MSG_DEBUG, "X509: Failed to parse "
"BasicConstraints");
return -1;
}
if (hdr.tag == ASN1_TAG_BOOLEAN) {
if (hdr.length != 1) {
wpa_printf(MSG_DEBUG, "X509: Unexpected "
"Boolean length (%u) in BasicConstraints",
hdr.length);
return -1;
}
cert->ca = hdr.payload[0];
if (hdr.payload + hdr.length == pos + len) {
wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d",
cert->ca);
return 0;
}
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL) {
wpa_printf(MSG_DEBUG, "X509: Failed to parse "
"BasicConstraints");
return -1;
}
}
if (hdr.tag != ASN1_TAG_INTEGER) {
wpa_printf(MSG_DEBUG, "X509: Expected INTEGER in "
"BasicConstraints; found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
left = hdr.length;
value = 0;
while (left) {
value <<= 8;
value |= *pos++;
left--;
}
cert->path_len_constraint = value;
cert->extensions_present |= X509_EXT_PATH_LEN_CONSTRAINT;
wpa_printf(MSG_DEBUG, "X509: BasicConstraints - cA=%d "
"pathLenConstraint=%lu",
cert->ca, cert->path_len_constraint);
return 0;
}
static int x509_parse_extension_data(struct x509_certificate *cert,
struct asn1_oid *oid,
const u8 *pos, size_t len)
{
if (!x509_id_ce_oid(oid))
return 1;
/* TODO: add other extensions required by RFC 3280, Ch 4.2:
* certificate policies (section 4.2.1.5)
* the subject alternative name (section 4.2.1.7)
* name constraints (section 4.2.1.11)
* policy constraints (section 4.2.1.12)
* extended key usage (section 4.2.1.13)
* inhibit any-policy (section 4.2.1.15)
*/
switch (oid->oid[3]) {
case 15: /* id-ce-keyUsage */
return x509_parse_ext_key_usage(cert, pos, len);
case 19: /* id-ce-basicConstraints */
return x509_parse_ext_basic_constraints(cert, pos, len);
default:
return 1;
}
}
static int x509_parse_extension(struct x509_certificate *cert,
const u8 *pos, size_t len, const u8 **next)
{
const u8 *end;
struct asn1_hdr hdr;
struct asn1_oid oid;
int critical_ext = 0, res;
char buf[80];
/*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING
* }
*/
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in "
"Extensions: class %d tag 0x%x; expected SEQUENCE",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
*next = end = pos + hdr.length;
if (asn1_get_oid(pos, end - pos, &oid, &pos) < 0) {
wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data for "
"Extension (expected OID)");
return -1;
}
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
(hdr.tag != ASN1_TAG_BOOLEAN &&
hdr.tag != ASN1_TAG_OCTETSTRING)) {
wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header in "
"Extensions: class %d tag 0x%x; expected BOOLEAN "
"or OCTET STRING", hdr.class, hdr.tag);
return -1;
}
if (hdr.tag == ASN1_TAG_BOOLEAN) {
if (hdr.length != 1) {
wpa_printf(MSG_DEBUG, "X509: Unexpected "
"Boolean length (%u)", hdr.length);
return -1;
}
critical_ext = hdr.payload[0];
pos = hdr.payload;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
(hdr.class != ASN1_CLASS_UNIVERSAL &&
hdr.class != ASN1_CLASS_PRIVATE) ||
hdr.tag != ASN1_TAG_OCTETSTRING) {
wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 header "
"in Extensions: class %d tag 0x%x; "
"expected OCTET STRING",
hdr.class, hdr.tag);
return -1;
}
}
asn1_oid_to_str(&oid, buf, sizeof(buf));
wpa_printf(MSG_DEBUG, "X509: Extension: extnID=%s critical=%d",
buf, critical_ext);
wpa_hexdump(MSG_MSGDUMP, "X509: extnValue", hdr.payload, hdr.length);
res = x509_parse_extension_data(cert, &oid, hdr.payload, hdr.length);
if (res < 0)
return res;
if (res == 1 && critical_ext) {
wpa_printf(MSG_INFO, "X509: Unknown critical extension %s",
buf);
return -1;
}
return 0;
}
static int x509_parse_extensions(struct x509_certificate *cert,
const u8 *pos, size_t len)
{
const u8 *end;
struct asn1_hdr hdr;
/* Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension */
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Unexpected ASN.1 data "
"for Extensions: class %d tag 0x%x; "
"expected SEQUENCE", hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
end = pos + hdr.length;
while (pos < end) {
if (x509_parse_extension(cert, pos, end - pos, &pos)
< 0)
return -1;
}
return 0;
}
static int x509_parse_tbs_certificate(const u8 *buf, size_t len,
struct x509_certificate *cert,
const u8 **next)
{
struct asn1_hdr hdr;
const u8 *pos, *end;
size_t left;
char sbuf[128];
unsigned long value;
/* tbsCertificate TBSCertificate ::= SEQUENCE */
if (asn1_get_next(buf, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: tbsCertificate did not start "
"with a valid SEQUENCE - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
end = *next = pos + hdr.length;
/*
* version [0] EXPLICIT Version DEFAULT v1
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
if (asn1_get_next(pos, end - pos, &hdr) < 0)
return -1;
pos = hdr.payload;
if (hdr.class == ASN1_CLASS_CONTEXT_SPECIFIC) {
if (asn1_get_next(pos, end - pos, &hdr) < 0)
return -1;
if (hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_INTEGER) {
wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for "
"version field - found class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
if (hdr.length != 1) {
wpa_printf(MSG_DEBUG, "X509: Unexpected version field "
"length %u (expected 1)", hdr.length);
return -1;
}
pos = hdr.payload;
left = hdr.length;
value = 0;
while (left) {
value <<= 8;
value |= *pos++;
left--;
}
cert->version = value;
if (cert->version != X509_CERT_V1 &&
cert->version != X509_CERT_V2 &&
cert->version != X509_CERT_V3) {
wpa_printf(MSG_DEBUG, "X509: Unsupported version %d",
cert->version + 1);
return -1;
}
if (asn1_get_next(pos, end - pos, &hdr) < 0)
return -1;
} else
cert->version = X509_CERT_V1;
wpa_printf(MSG_MSGDUMP, "X509: Version X.509v%d", cert->version + 1);
/* serialNumber CertificateSerialNumber ::= INTEGER */
if (hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_INTEGER) {
wpa_printf(MSG_DEBUG, "X509: No INTEGER tag found for "
"serialNumber; class=%d tag=0x%x",
hdr.class, hdr.tag);
return -1;
}
pos = hdr.payload;
left = hdr.length;
while (left) {
cert->serial_number <<= 8;
cert->serial_number |= *pos++;
left--;
}
wpa_printf(MSG_MSGDUMP, "X509: serialNumber %lu", cert->serial_number);
/* signature AlgorithmIdentifier */
if (x509_parse_algorithm_identifier(pos, end - pos, &cert->signature,
&pos))
return -1;
/* issuer Name */
if (x509_parse_name(pos, end - pos, &cert->issuer, &pos))
return -1;
x509_name_string(&cert->issuer, sbuf, sizeof(sbuf));
wpa_printf(MSG_MSGDUMP, "X509: issuer %s", sbuf);
/* validity Validity */
if (x509_parse_validity(pos, end - pos, cert, &pos))
return -1;
/* subject Name */
if (x509_parse_name(pos, end - pos, &cert->subject, &pos))
return -1;
x509_name_string(&cert->subject, sbuf, sizeof(sbuf));
wpa_printf(MSG_MSGDUMP, "X509: subject %s", sbuf);
/* subjectPublicKeyInfo SubjectPublicKeyInfo */
if (x509_parse_public_key(pos, end - pos, cert, &pos))
return -1;
if (pos == end)
return 0;
if (cert->version == X509_CERT_V1)
return 0;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
" tag to parse optional tbsCertificate "
"field(s); parsed class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
if (hdr.tag == 1) {
/* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL */
wpa_printf(MSG_DEBUG, "X509: issuerUniqueID");
/* TODO: parse UniqueIdentifier ::= BIT STRING */
if (hdr.payload + hdr.length == end)
return 0;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
" tag to parse optional tbsCertificate "
"field(s); parsed class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
}
if (hdr.tag == 2) {
/* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL */
wpa_printf(MSG_DEBUG, "X509: subjectUniqueID");
/* TODO: parse UniqueIdentifier ::= BIT STRING */
if (hdr.payload + hdr.length == end)
return 0;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_CONTEXT_SPECIFIC) {
wpa_printf(MSG_DEBUG, "X509: Expected Context-Specific"
" tag to parse optional tbsCertificate "
"field(s); parsed class %d tag 0x%x",
hdr.class, hdr.tag);
return -1;
}
}
if (hdr.tag != 3) {
wpa_printf(MSG_DEBUG, "X509: Ignored unexpected "
"Context-Specific tag %d in optional "
"tbsCertificate fields", hdr.tag);
return 0;
}
/* extensions [3] EXPLICIT Extensions OPTIONAL */
if (cert->version != X509_CERT_V3) {
wpa_printf(MSG_DEBUG, "X509: X.509%d certificate and "
"Extensions data which are only allowed for "
"version 3", cert->version + 1);
return -1;
}
if (x509_parse_extensions(cert, hdr.payload, hdr.length) < 0)
return -1;
pos = hdr.payload + hdr.length;
if (pos < end) {
wpa_hexdump(MSG_DEBUG,
"X509: Ignored extra tbsCertificate data",
pos, end - pos);
}
return 0;
}
static int x509_rsadsi_oid(struct asn1_oid *oid)
{
return oid->len >= 4 &&
oid->oid[0] == 1 /* iso */ &&
oid->oid[1] == 2 /* member-body */ &&
oid->oid[2] == 840 /* us */ &&
oid->oid[3] == 113549 /* rsadsi */;
}
static int x509_pkcs_oid(struct asn1_oid *oid)
{
return oid->len >= 5 &&
x509_rsadsi_oid(oid) &&
oid->oid[4] == 1 /* pkcs */;
}
static int x509_digest_oid(struct asn1_oid *oid)
{
return oid->len >= 5 &&
x509_rsadsi_oid(oid) &&
oid->oid[4] == 2 /* digestAlgorithm */;
}
static int x509_sha1_oid(struct asn1_oid *oid)
{
return oid->len == 6 &&
oid->oid[0] == 1 /* iso */ &&
oid->oid[1] == 3 /* identified-organization */ &&
oid->oid[2] == 14 /* oiw */ &&
oid->oid[3] == 3 /* secsig */ &&
oid->oid[4] == 2 /* algorithms */ &&
oid->oid[5] == 26 /* id-sha1 */;
}
/**
* x509_certificate_parse - Parse a X.509 certificate in DER format
* @buf: Pointer to the X.509 certificate in DER format
* @len: Buffer length
* Returns: Pointer to the parsed certificate or %NULL on failure
*
* Caller is responsible for freeing the returned certificate by calling
* x509_certificate_free().
*/
struct x509_certificate * x509_certificate_parse(const u8 *buf, size_t len)
{
struct asn1_hdr hdr;
const u8 *pos, *end, *hash_start;
struct x509_certificate *cert;
cert = os_zalloc(sizeof(*cert) + len);
if (cert == NULL)
return NULL;
os_memcpy(cert + 1, buf, len);
cert->cert_start = (u8 *) (cert + 1);
cert->cert_len = len;
pos = buf;
end = buf + len;
/* RFC 3280 - X.509 v3 certificate / ASN.1 DER */
/* Certificate ::= SEQUENCE */
if (asn1_get_next(pos, len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Certificate did not start with "
"a valid SEQUENCE - found class %d tag 0x%x",
hdr.class, hdr.tag);
x509_certificate_free(cert);
return NULL;
}
pos = hdr.payload;
if (pos + hdr.length > end) {
x509_certificate_free(cert);
return NULL;
}
if (pos + hdr.length < end) {
wpa_hexdump(MSG_MSGDUMP, "X509: Ignoring extra data after DER "
"encoded certificate",
pos + hdr.length, end - pos + hdr.length);
end = pos + hdr.length;
}
hash_start = pos;
cert->tbs_cert_start = cert->cert_start + (hash_start - buf);
if (x509_parse_tbs_certificate(pos, end - pos, cert, &pos)) {
x509_certificate_free(cert);
return NULL;
}
cert->tbs_cert_len = pos - hash_start;
/* signatureAlgorithm AlgorithmIdentifier */
if (x509_parse_algorithm_identifier(pos, end - pos,
&cert->signature_alg, &pos)) {
x509_certificate_free(cert);
return NULL;
}
/* signatureValue BIT STRING */
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_BITSTRING) {
wpa_printf(MSG_DEBUG, "X509: Expected BITSTRING "
"(signatureValue) - found class %d tag 0x%x",
hdr.class, hdr.tag);
x509_certificate_free(cert);
return NULL;
}
if (hdr.length < 1) {
x509_certificate_free(cert);
return NULL;
}
pos = hdr.payload;
if (*pos) {
wpa_printf(MSG_DEBUG, "X509: BITSTRING - %d unused bits",
*pos);
/* PKCS #1 v1.5 10.2.1:
* It is an error if the length in bits of the signature S is
* not a multiple of eight.
*/
x509_certificate_free(cert);
return NULL;
}
os_free(cert->sign_value);
cert->sign_value = os_malloc(hdr.length - 1);
if (cert->sign_value == NULL) {
wpa_printf(MSG_DEBUG, "X509: Failed to allocate memory for "
"signatureValue");
x509_certificate_free(cert);
return NULL;
}
os_memcpy(cert->sign_value, pos + 1, hdr.length - 1);
cert->sign_value_len = hdr.length - 1;
wpa_hexdump(MSG_MSGDUMP, "X509: signature",
cert->sign_value, cert->sign_value_len);
return cert;
}
/**
* x509_certificate_check_signature - Verify certificate signature
* @issuer: Issuer certificate
* @cert: Certificate to be verified
* Returns: 0 if cert has a valid signature that was signed by the issuer,
* -1 if not
*/
int x509_certificate_check_signature(struct x509_certificate *issuer,
struct x509_certificate *cert)
{
struct crypto_public_key *pk;
u8 *data;
const u8 *pos, *end, *next, *da_end;
size_t data_len;
struct asn1_hdr hdr;
struct asn1_oid oid;
u8 hash[20];
size_t hash_len;
if (!x509_pkcs_oid(&cert->signature.oid) ||
cert->signature.oid.len != 7 ||
cert->signature.oid.oid[5] != 1 /* pkcs-1 */) {
wpa_printf(MSG_DEBUG, "X509: Unrecognized signature "
"algorithm");
return -1;
}
pk = crypto_public_key_import(issuer->public_key,
issuer->public_key_len);
if (pk == NULL)
return -1;
data_len = cert->sign_value_len;
data = os_malloc(data_len);
if (data == NULL) {
crypto_public_key_free(pk);
return -1;
}
if (crypto_public_key_decrypt_pkcs1(pk, cert->sign_value,
cert->sign_value_len, data,
&data_len) < 0) {
wpa_printf(MSG_DEBUG, "X509: Failed to decrypt signature");
crypto_public_key_free(pk);
os_free(data);
return -1;
}
crypto_public_key_free(pk);
wpa_hexdump(MSG_MSGDUMP, "X509: Signature data D", data, data_len);
/*
* PKCS #1 v1.5, 10.1.2:
*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm DigestAlgorithmIdentifier,
* digest Digest
* }
*
* DigestAlgorithmIdentifier ::= AlgorithmIdentifier
*
* Digest ::= OCTET STRING
*
*/
if (asn1_get_next(data, data_len, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(DigestInfo) - found class %d tag 0x%x",
hdr.class, hdr.tag);
os_free(data);
return -1;
}
pos = hdr.payload;
end = pos + hdr.length;
/*
* X.509:
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL
* }
*/
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_SEQUENCE) {
wpa_printf(MSG_DEBUG, "X509: Expected SEQUENCE "
"(AlgorithmIdentifier) - found class %d tag 0x%x",
hdr.class, hdr.tag);
os_free(data);
return -1;
}
da_end = hdr.payload + hdr.length;
if (asn1_get_oid(hdr.payload, hdr.length, &oid, &next)) {
wpa_printf(MSG_DEBUG, "X509: Failed to parse digestAlgorithm");
os_free(data);
return -1;
}
if (x509_sha1_oid(&oid)) {
if (cert->signature.oid.oid[6] !=
5 /* sha-1WithRSAEncryption */) {
wpa_printf(MSG_DEBUG, "X509: digestAlgorithm SHA1 "
"does not match with certificate "
"signatureAlgorithm (%lu)",
cert->signature.oid.oid[6]);
os_free(data);
return -1;
}
goto skip_digest_oid;
}
if (!x509_digest_oid(&oid)) {
wpa_printf(MSG_DEBUG, "X509: Unrecognized digestAlgorithm");
os_free(data);
return -1;
}
switch (oid.oid[5]) {
case 5: /* md5 */
if (cert->signature.oid.oid[6] != 4 /* md5WithRSAEncryption */)
{
wpa_printf(MSG_DEBUG, "X509: digestAlgorithm MD5 does "
"not match with certificate "
"signatureAlgorithm (%lu)",
cert->signature.oid.oid[6]);
os_free(data);
return -1;
}
break;
case 2: /* md2 */
case 4: /* md4 */
default:
wpa_printf(MSG_DEBUG, "X509: Unsupported digestAlgorithm "
"(%lu)", oid.oid[5]);
os_free(data);
return -1;
}
skip_digest_oid:
/* Digest ::= OCTET STRING */
pos = da_end;
end = data + data_len;
if (asn1_get_next(pos, end - pos, &hdr) < 0 ||
hdr.class != ASN1_CLASS_UNIVERSAL ||
hdr.tag != ASN1_TAG_OCTETSTRING) {
wpa_printf(MSG_DEBUG, "X509: Expected OCTETSTRING "
"(Digest) - found class %d tag 0x%x",
hdr.class, hdr.tag);
os_free(data);
return -1;
}
wpa_hexdump(MSG_MSGDUMP, "X509: Decrypted Digest",
hdr.payload, hdr.length);
switch (cert->signature.oid.oid[6]) {
case 4: /* md5WithRSAEncryption */
md5_vector(1, &cert->tbs_cert_start, &cert->tbs_cert_len,
hash);
hash_len = 16;
wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (MD5)",
hash, hash_len);
break;
case 5: /* sha-1WithRSAEncryption */
sha1_vector(1, &cert->tbs_cert_start, &cert->tbs_cert_len,
hash);
hash_len = 20;
wpa_hexdump(MSG_MSGDUMP, "X509: Certificate hash (SHA1)",
hash, hash_len);
break;
case 2: /* md2WithRSAEncryption */
case 11: /* sha256WithRSAEncryption */
case 12: /* sha384WithRSAEncryption */
case 13: /* sha512WithRSAEncryption */
default:
wpa_printf(MSG_INFO, "X509: Unsupported certificate signature "
"algorithm (%lu)", cert->signature.oid.oid[6]);
os_free(data);
return -1;
}
if (hdr.length != hash_len ||
os_memcmp(hdr.payload, hash, hdr.length) != 0) {
wpa_printf(MSG_INFO, "X509: Certificate Digest does not match "
"with calculated tbsCertificate hash");
os_free(data);
return -1;
}
os_free(data);
wpa_printf(MSG_DEBUG, "X509: Certificate Digest matches with "
"calculated tbsCertificate hash");
return 0;
}
static int x509_valid_issuer(const struct x509_certificate *cert)
{
if ((cert->extensions_present & X509_EXT_BASIC_CONSTRAINTS) &&
!cert->ca) {
wpa_printf(MSG_DEBUG, "X509: Non-CA certificate used as an "
"issuer");
return -1;
}
if ((cert->extensions_present & X509_EXT_KEY_USAGE) &&
!(cert->key_usage & X509_KEY_USAGE_KEY_CERT_SIGN)) {
wpa_printf(MSG_DEBUG, "X509: Issuer certificate did not have "
"keyCertSign bit in Key Usage");
return -1;
}
return 0;
}
/**
* x509_certificate_chain_validate - Validate X.509 certificate chain
* @trusted: List of trusted certificates
* @chain: Certificate chain to be validated (first chain must be issued by
* signed by the second certificate in the chain and so on)
* @reason: Buffer for returning failure reason (X509_VALIDATE_*)
* Returns: 0 if chain is valid, -1 if not
*/
int x509_certificate_chain_validate(struct x509_certificate *trusted,
struct x509_certificate *chain,
int *reason)
{
int idx, chain_trusted = 0;
struct x509_certificate *cert, *trust;
char buf[128];
struct os_time now;
*reason = X509_VALIDATE_OK;
wpa_printf(MSG_DEBUG, "X509: Validate certificate chain");
os_get_time(&now);
for (cert = chain, idx = 0; cert; cert = cert->next, idx++) {
x509_name_string(&cert->subject, buf, sizeof(buf));
wpa_printf(MSG_DEBUG, "X509: %d: %s", idx, buf);
if (chain_trusted)
continue;
if (now.sec < cert->not_before || now.sec > cert->not_after) {
wpa_printf(MSG_INFO, "X509: Certificate not valid "
"(now=%lu not_before=%lu not_after=%lu)",
now.sec, cert->not_before, cert->not_after);
*reason = X509_VALIDATE_CERTIFICATE_EXPIRED;
return -1;
}
if (cert->next) {
if (x509_name_compare(&cert->issuer,
&cert->next->subject) != 0) {
wpa_printf(MSG_DEBUG, "X509: Certificate "
"chain issuer name mismatch");
*reason = X509_VALIDATE_CERTIFICATE_UNKNOWN;
return -1;
}
if (x509_valid_issuer(cert->next) < 0) {
*reason = X509_VALIDATE_BAD_CERTIFICATE;
return -1;
}
/* TODO: validate pathLenConstraint */
if (x509_certificate_check_signature(cert->next, cert)
< 0) {
wpa_printf(MSG_DEBUG, "X509: Invalid "
"certificate signature within "
"chain");
*reason = X509_VALIDATE_BAD_CERTIFICATE;
return -1;
}
}
for (trust = trusted; trust; trust = trust->next) {
if (x509_name_compare(&cert->issuer, &trust->subject)
== 0)
break;
}
if (trust) {
wpa_printf(MSG_DEBUG, "X509: Found issuer from the "
"list of trusted certificates");
if (x509_valid_issuer(trust) < 0) {
*reason = X509_VALIDATE_BAD_CERTIFICATE;
return -1;
}
if (x509_certificate_check_signature(trust, cert) < 0)
{
wpa_printf(MSG_DEBUG, "X509: Invalid "
"certificate signature");
*reason = X509_VALIDATE_BAD_CERTIFICATE;
return -1;
}
wpa_printf(MSG_DEBUG, "X509: Trusted certificate "
"found to complete the chain");
chain_trusted = 1;
}
}
if (!chain_trusted) {
wpa_printf(MSG_DEBUG, "X509: Did not find any of the issuers "
"from the list of trusted certificates");
if (trusted) {
*reason = X509_VALIDATE_UNKNOWN_CA;
return -1;
}
wpa_printf(MSG_DEBUG, "X509: Certificate chain validation "
"disabled - ignore unknown CA issue");
}
wpa_printf(MSG_DEBUG, "X509: Certificate chain valid");
return 0;
}
/**
* x509_certificate_get_subject - Get a certificate based on Subject name
* @chain: Certificate chain to search through
* @name: Subject name to search for
* Returns: Pointer to the certificate with the given Subject name or
* %NULL on failure
*/
struct x509_certificate *
x509_certificate_get_subject(struct x509_certificate *chain,
struct x509_name *name)
{
struct x509_certificate *cert;
for (cert = chain; cert; cert = cert->next) {
if (x509_name_compare(&cert->subject, name) == 0)
return cert;
}
return NULL;
}
/**
* x509_certificate_self_signed - Is the certificate self-signed?
* @cert: Certificate
* Returns: 1 if certificate is self-signed, 0 if not
*/
int x509_certificate_self_signed(struct x509_certificate *cert)
{
return x509_name_compare(&cert->issuer, &cert->subject) == 0;
}
#endif /* CONFIG_INTERNAL_X509 */
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