blob: 3c90fe836720b03bfb3431ab60d9657cc727e451 [file] [log] [blame]
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <openssl/asn1.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/thread.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include "../internal.h"
#include "../x509v3/internal.h"
#include "internal.h"
static CRYPTO_EX_DATA_CLASS g_ex_data_class =
CRYPTO_EX_DATA_CLASS_INIT_WITH_APP_DATA;
// CRL score values
// No unhandled critical extensions
#define CRL_SCORE_NOCRITICAL 0x100
// certificate is within CRL scope
#define CRL_SCORE_SCOPE 0x080
// CRL times valid
#define CRL_SCORE_TIME 0x040
// Issuer name matches certificate
#define CRL_SCORE_ISSUER_NAME 0x020
// If this score or above CRL is probably valid
#define CRL_SCORE_VALID \
(CRL_SCORE_NOCRITICAL | CRL_SCORE_TIME | CRL_SCORE_SCOPE)
// CRL issuer is certificate issuer
#define CRL_SCORE_ISSUER_CERT 0x018
// CRL issuer is on certificate path
#define CRL_SCORE_SAME_PATH 0x008
// CRL issuer matches CRL AKID
#define CRL_SCORE_AKID 0x004
// Have a delta CRL with valid times
#define CRL_SCORE_TIME_DELTA 0x002
static int null_callback(int ok, X509_STORE_CTX *e);
static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
static int check_chain_extensions(X509_STORE_CTX *ctx);
static int check_name_constraints(X509_STORE_CTX *ctx);
static int check_id(X509_STORE_CTX *ctx);
static int check_trust(X509_STORE_CTX *ctx);
static int check_revocation(X509_STORE_CTX *ctx);
static int check_cert(X509_STORE_CTX *ctx);
static int check_policy(X509_STORE_CTX *ctx);
static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
unsigned int *preasons, X509_CRL *crl, X509 *x);
static int get_crl_delta(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
X509 *x);
static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pcrl_score,
X509_CRL *base, STACK_OF(X509_CRL) *crls);
static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
int *pcrl_score);
static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
unsigned int *preasons);
static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
static int check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path,
STACK_OF(X509) *crl_path);
static int internal_verify(X509_STORE_CTX *ctx);
static int null_callback(int ok, X509_STORE_CTX *e) { return ok; }
// cert_self_signed checks if |x| is self-signed. If |x| is valid, it returns
// one and sets |*out_is_self_signed| to the result. If |x| is invalid, it
// returns zero.
static int cert_self_signed(X509 *x, int *out_is_self_signed) {
if (!x509v3_cache_extensions(x)) {
return 0;
}
*out_is_self_signed = (x->ex_flags & EXFLAG_SS) != 0;
return 1;
}
// Given a certificate try and find an exact match in the store
static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x) {
STACK_OF(X509) *certs;
X509 *xtmp = NULL;
size_t i;
// Lookup all certs with matching subject name
certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
if (certs == NULL) {
return NULL;
}
// Look for exact match
for (i = 0; i < sk_X509_num(certs); i++) {
xtmp = sk_X509_value(certs, i);
if (!X509_cmp(xtmp, x)) {
break;
}
}
if (i < sk_X509_num(certs)) {
X509_up_ref(xtmp);
} else {
xtmp = NULL;
}
sk_X509_pop_free(certs, X509_free);
return xtmp;
}
int X509_verify_cert(X509_STORE_CTX *ctx) {
X509 *x, *xtmp, *xtmp2, *chain_ss = NULL;
int bad_chain = 0;
X509_VERIFY_PARAM *param = ctx->param;
int depth, i, ok = 0;
int num, j, retry, trust;
STACK_OF(X509) *sktmp = NULL;
if (ctx->cert == NULL) {
OPENSSL_PUT_ERROR(X509, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
ctx->error = X509_V_ERR_INVALID_CALL;
return -1;
}
if (ctx->chain != NULL) {
// This X509_STORE_CTX has already been used to verify a cert. We
// cannot do another one.
OPENSSL_PUT_ERROR(X509, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
ctx->error = X509_V_ERR_INVALID_CALL;
return -1;
}
// first we make sure the chain we are going to build is present and that
// the first entry is in place
ctx->chain = sk_X509_new_null();
if (ctx->chain == NULL || !sk_X509_push(ctx->chain, ctx->cert)) {
ctx->error = X509_V_ERR_OUT_OF_MEM;
goto end;
}
X509_up_ref(ctx->cert);
ctx->last_untrusted = 1;
// We use a temporary STACK so we can chop and hack at it.
if (ctx->untrusted != NULL && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
ctx->error = X509_V_ERR_OUT_OF_MEM;
goto end;
}
num = (int)sk_X509_num(ctx->chain);
x = sk_X509_value(ctx->chain, num - 1);
depth = param->depth;
for (;;) {
// If we have enough, we break
if (depth < num) {
break; // FIXME: If this happens, we should take
// note of it and, if appropriate, use the
// X509_V_ERR_CERT_CHAIN_TOO_LONG error code
// later.
}
int is_self_signed;
if (!cert_self_signed(x, &is_self_signed)) {
ctx->error = X509_V_ERR_INVALID_EXTENSION;
goto end;
}
// If we are self signed, we break
if (is_self_signed) {
break;
}
// If asked see if we can find issuer in trusted store first
if (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) {
ok = ctx->get_issuer(&xtmp, ctx, x);
if (ok < 0) {
ctx->error = X509_V_ERR_STORE_LOOKUP;
goto end;
}
// If successful for now free up cert so it will be picked up
// again later.
if (ok > 0) {
X509_free(xtmp);
break;
}
}
// If we were passed a cert chain, use it first
if (sktmp != NULL) {
xtmp = find_issuer(ctx, sktmp, x);
if (xtmp != NULL) {
if (!sk_X509_push(ctx->chain, xtmp)) {
ctx->error = X509_V_ERR_OUT_OF_MEM;
ok = 0;
goto end;
}
X509_up_ref(xtmp);
(void)sk_X509_delete_ptr(sktmp, xtmp);
ctx->last_untrusted++;
x = xtmp;
num++;
// reparse the full chain for the next one
continue;
}
}
break;
}
// Remember how many untrusted certs we have
j = num;
// at this point, chain should contain a list of untrusted certificates.
// We now need to add at least one trusted one, if possible, otherwise we
// complain.
do {
// Examine last certificate in chain and see if it is self signed.
i = (int)sk_X509_num(ctx->chain);
x = sk_X509_value(ctx->chain, i - 1);
int is_self_signed;
if (!cert_self_signed(x, &is_self_signed)) {
ctx->error = X509_V_ERR_INVALID_EXTENSION;
goto end;
}
if (is_self_signed) {
// we have a self signed certificate
if (sk_X509_num(ctx->chain) == 1) {
// We have a single self signed certificate: see if we can
// find it in the store. We must have an exact match to avoid
// possible impersonation.
ok = ctx->get_issuer(&xtmp, ctx, x);
if ((ok <= 0) || X509_cmp(x, xtmp)) {
ctx->error = X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
ctx->current_cert = x;
ctx->error_depth = i - 1;
if (ok == 1) {
X509_free(xtmp);
}
bad_chain = 1;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
} else {
// We have a match: replace certificate with store
// version so we get any trust settings.
X509_free(x);
x = xtmp;
(void)sk_X509_set(ctx->chain, i - 1, x);
ctx->last_untrusted = 0;
}
} else {
// extract and save self signed certificate for later use
chain_ss = sk_X509_pop(ctx->chain);
ctx->last_untrusted--;
num--;
j--;
x = sk_X509_value(ctx->chain, num - 1);
}
}
// We now lookup certs from the certificate store
for (;;) {
// If we have enough, we break
if (depth < num) {
break;
}
if (!cert_self_signed(x, &is_self_signed)) {
ctx->error = X509_V_ERR_INVALID_EXTENSION;
goto end;
}
// If we are self signed, we break
if (is_self_signed) {
break;
}
ok = ctx->get_issuer(&xtmp, ctx, x);
if (ok < 0) {
ctx->error = X509_V_ERR_STORE_LOOKUP;
goto end;
}
if (ok == 0) {
break;
}
x = xtmp;
if (!sk_X509_push(ctx->chain, x)) {
X509_free(xtmp);
ctx->error = X509_V_ERR_OUT_OF_MEM;
ok = 0;
goto end;
}
num++;
}
// we now have our chain, lets check it...
trust = check_trust(ctx);
// If explicitly rejected error
if (trust == X509_TRUST_REJECTED) {
ok = 0;
goto end;
}
// If it's not explicitly trusted then check if there is an alternative
// chain that could be used. We only do this if we haven't already
// checked via TRUSTED_FIRST and the user hasn't switched off alternate
// chain checking
retry = 0;
if (trust != X509_TRUST_TRUSTED &&
!(ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) &&
!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) {
while (j-- > 1) {
xtmp2 = sk_X509_value(ctx->chain, j - 1);
ok = ctx->get_issuer(&xtmp, ctx, xtmp2);
if (ok < 0) {
goto end;
}
// Check if we found an alternate chain
if (ok > 0) {
// Free up the found cert we'll add it again later
X509_free(xtmp);
// Dump all the certs above this point - we've found an
// alternate chain
while (num > j) {
xtmp = sk_X509_pop(ctx->chain);
X509_free(xtmp);
num--;
}
ctx->last_untrusted = (int)sk_X509_num(ctx->chain);
retry = 1;
break;
}
}
}
} while (retry);
// If not explicitly trusted then indicate error unless it's a single
// self signed certificate in which case we've indicated an error already
// and set bad_chain == 1
if (trust != X509_TRUST_TRUSTED && !bad_chain) {
if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss)) {
if (ctx->last_untrusted >= num) {
ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
} else {
ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
}
ctx->current_cert = x;
} else {
sk_X509_push(ctx->chain, chain_ss);
num++;
ctx->last_untrusted = num;
ctx->current_cert = chain_ss;
ctx->error = X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
chain_ss = NULL;
}
ctx->error_depth = num - 1;
bad_chain = 1;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
}
// We have the chain complete: now we need to check its purpose
ok = check_chain_extensions(ctx);
if (!ok) {
goto end;
}
ok = check_id(ctx);
if (!ok) {
goto end;
}
// Check revocation status: we do this after copying parameters because
// they may be needed for CRL signature verification.
ok = ctx->check_revocation(ctx);
if (!ok) {
goto end;
}
// At this point, we have a chain and need to verify it
if (ctx->verify != NULL) {
ok = ctx->verify(ctx);
} else {
ok = internal_verify(ctx);
}
if (!ok) {
goto end;
}
// Check name constraints
ok = check_name_constraints(ctx);
if (!ok) {
goto end;
}
// If we get this far, evaluate policies.
if (!bad_chain) {
ok = ctx->check_policy(ctx);
}
end:
if (sktmp != NULL) {
sk_X509_free(sktmp);
}
if (chain_ss != NULL) {
X509_free(chain_ss);
}
// Safety net, error returns must set ctx->error
if (ok <= 0 && ctx->error == X509_V_OK) {
ctx->error = X509_V_ERR_UNSPECIFIED;
}
return ok;
}
// Given a STACK_OF(X509) find the issuer of cert (if any)
static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) {
size_t i;
X509 *issuer;
for (i = 0; i < sk_X509_num(sk); i++) {
issuer = sk_X509_value(sk, i);
if (ctx->check_issued(ctx, x, issuer)) {
return issuer;
}
}
return NULL;
}
// Given a possible certificate and issuer check them
static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer) {
int ret;
ret = X509_check_issued(issuer, x);
if (ret == X509_V_OK) {
return 1;
}
// If we haven't asked for issuer errors don't set ctx
if (!(ctx->param->flags & X509_V_FLAG_CB_ISSUER_CHECK)) {
return 0;
}
ctx->error = ret;
ctx->current_cert = x;
ctx->current_issuer = issuer;
return ctx->verify_cb(0, ctx);
}
// Alternative lookup method: look from a STACK stored in other_ctx
static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) {
*issuer = find_issuer(ctx, ctx->other_ctx, x);
if (*issuer) {
X509_up_ref(*issuer);
return 1;
} else {
return 0;
}
}
// Check a certificate chains extensions for consistency with the supplied
// purpose
static int check_chain_extensions(X509_STORE_CTX *ctx) {
int ok = 0, plen = 0;
// If |ctx->parent| is set, this is CRL path validation.
int purpose =
ctx->parent == NULL ? ctx->param->purpose : X509_PURPOSE_CRL_SIGN;
// Check all untrusted certificates
for (int i = 0; i < ctx->last_untrusted; i++) {
X509 *x = sk_X509_value(ctx->chain, i);
if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) &&
(x->ex_flags & EXFLAG_CRITICAL)) {
ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION;
ctx->error_depth = i;
ctx->current_cert = x;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
}
int must_be_ca = i > 0;
if (must_be_ca && !X509_check_ca(x)) {
ctx->error = X509_V_ERR_INVALID_CA;
ctx->error_depth = i;
ctx->current_cert = x;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
}
if (ctx->param->purpose > 0 &&
X509_check_purpose(x, purpose, must_be_ca) != 1) {
ctx->error = X509_V_ERR_INVALID_PURPOSE;
ctx->error_depth = i;
ctx->current_cert = x;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
}
// Check pathlen if not self issued
if (i > 1 && !(x->ex_flags & EXFLAG_SI) && x->ex_pathlen != -1 &&
plen > x->ex_pathlen + 1) {
ctx->error = X509_V_ERR_PATH_LENGTH_EXCEEDED;
ctx->error_depth = i;
ctx->current_cert = x;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
}
// Increment path length if not self issued
if (!(x->ex_flags & EXFLAG_SI)) {
plen++;
}
}
ok = 1;
end:
return ok;
}
static int reject_dns_name_in_common_name(X509 *x509) {
const X509_NAME *name = X509_get_subject_name(x509);
int i = -1;
for (;;) {
i = X509_NAME_get_index_by_NID(name, NID_commonName, i);
if (i == -1) {
return X509_V_OK;
}
const X509_NAME_ENTRY *entry = X509_NAME_get_entry(name, i);
const ASN1_STRING *common_name = X509_NAME_ENTRY_get_data(entry);
unsigned char *idval;
int idlen = ASN1_STRING_to_UTF8(&idval, common_name);
if (idlen < 0) {
return X509_V_ERR_OUT_OF_MEM;
}
// Only process attributes that look like host names. Note it is
// important that this check be mirrored in |X509_check_host|.
int looks_like_dns = x509v3_looks_like_dns_name(idval, (size_t)idlen);
OPENSSL_free(idval);
if (looks_like_dns) {
return X509_V_ERR_NAME_CONSTRAINTS_WITHOUT_SANS;
}
}
}
static int check_name_constraints(X509_STORE_CTX *ctx) {
int i, j, rv;
int has_name_constraints = 0;
// Check name constraints for all certificates
for (i = (int)sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
X509 *x = sk_X509_value(ctx->chain, i);
// Ignore self issued certs unless last in chain
if (i && (x->ex_flags & EXFLAG_SI)) {
continue;
}
// Check against constraints for all certificates higher in chain
// including trust anchor. Trust anchor not strictly speaking needed
// but if it includes constraints it is to be assumed it expects them
// to be obeyed.
for (j = (int)sk_X509_num(ctx->chain) - 1; j > i; j--) {
NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
if (nc) {
has_name_constraints = 1;
rv = NAME_CONSTRAINTS_check(x, nc);
switch (rv) {
case X509_V_OK:
continue;
case X509_V_ERR_OUT_OF_MEM:
ctx->error = rv;
return 0;
default:
ctx->error = rv;
ctx->error_depth = i;
ctx->current_cert = x;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
break;
}
}
}
}
// Name constraints do not match against the common name, but
// |X509_check_host| still implements the legacy behavior where, on
// certificates lacking a SAN list, DNS-like names in the common name are
// checked instead.
//
// While we could apply the name constraints to the common name, name
// constraints are rare enough that can hold such certificates to a higher
// standard. Note this does not make "DNS-like" heuristic failures any
// worse. A decorative common-name misidentified as a DNS name would fail
// the name constraint anyway.
X509 *leaf = sk_X509_value(ctx->chain, 0);
if (has_name_constraints && leaf->altname == NULL) {
rv = reject_dns_name_in_common_name(leaf);
switch (rv) {
case X509_V_OK:
break;
case X509_V_ERR_OUT_OF_MEM:
ctx->error = rv;
return 0;
default:
ctx->error = rv;
ctx->error_depth = i;
ctx->current_cert = leaf;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
break;
}
}
return 1;
}
static int check_id_error(X509_STORE_CTX *ctx, int errcode) {
ctx->error = errcode;
ctx->current_cert = ctx->cert;
ctx->error_depth = 0;
return ctx->verify_cb(0, ctx);
}
static int check_hosts(X509 *x, X509_VERIFY_PARAM *param) {
size_t i;
size_t n = sk_OPENSSL_STRING_num(param->hosts);
char *name;
if (param->peername != NULL) {
OPENSSL_free(param->peername);
param->peername = NULL;
}
for (i = 0; i < n; ++i) {
name = sk_OPENSSL_STRING_value(param->hosts, i);
if (X509_check_host(x, name, strlen(name), param->hostflags,
&param->peername) > 0) {
return 1;
}
}
return n == 0;
}
static int check_id(X509_STORE_CTX *ctx) {
X509_VERIFY_PARAM *vpm = ctx->param;
X509 *x = ctx->cert;
if (vpm->poison) {
if (!check_id_error(ctx, X509_V_ERR_INVALID_CALL)) {
return 0;
}
}
if (vpm->hosts && check_hosts(x, vpm) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) {
return 0;
}
}
if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) {
return 0;
}
}
if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) {
return 0;
}
}
return 1;
}
static int check_trust(X509_STORE_CTX *ctx) {
int ok;
X509 *x = NULL;
// Check all trusted certificates in chain
for (size_t i = ctx->last_untrusted; i < sk_X509_num(ctx->chain); i++) {
x = sk_X509_value(ctx->chain, i);
ok = X509_check_trust(x, ctx->param->trust, 0);
// If explicitly trusted return trusted
if (ok == X509_TRUST_TRUSTED) {
return X509_TRUST_TRUSTED;
}
// If explicitly rejected notify callback and reject if not
// overridden.
if (ok == X509_TRUST_REJECTED) {
ctx->error_depth = (int)i;
ctx->current_cert = x;
ctx->error = X509_V_ERR_CERT_REJECTED;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
return X509_TRUST_REJECTED;
}
}
}
// If we accept partial chains and have at least one trusted certificate
// return success.
if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
X509 *mx;
if (ctx->last_untrusted < (int)sk_X509_num(ctx->chain)) {
return X509_TRUST_TRUSTED;
}
x = sk_X509_value(ctx->chain, 0);
mx = lookup_cert_match(ctx, x);
if (mx) {
(void)sk_X509_set(ctx->chain, 0, mx);
X509_free(x);
ctx->last_untrusted = 0;
return X509_TRUST_TRUSTED;
}
}
// If no trusted certs in chain at all return untrusted and allow
// standard (no issuer cert) etc errors to be indicated.
return X509_TRUST_UNTRUSTED;
}
static int check_revocation(X509_STORE_CTX *ctx) {
if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK)) {
return 1;
}
int last;
if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) {
last = (int)sk_X509_num(ctx->chain) - 1;
} else {
// If checking CRL paths this isn't the EE certificate
if (ctx->parent) {
return 1;
}
last = 0;
}
for (int i = 0; i <= last; i++) {
ctx->error_depth = i;
int ok = check_cert(ctx);
if (!ok) {
return ok;
}
}
return 1;
}
static int check_cert(X509_STORE_CTX *ctx) {
X509_CRL *crl = NULL, *dcrl = NULL;
X509 *x;
int ok = 0, cnum;
unsigned int last_reasons;
cnum = ctx->error_depth;
x = sk_X509_value(ctx->chain, cnum);
ctx->current_cert = x;
ctx->current_issuer = NULL;
ctx->current_crl_score = 0;
ctx->current_reasons = 0;
while (ctx->current_reasons != CRLDP_ALL_REASONS) {
last_reasons = ctx->current_reasons;
// Try to retrieve relevant CRL
if (ctx->get_crl) {
ok = ctx->get_crl(ctx, &crl, x);
} else {
ok = get_crl_delta(ctx, &crl, &dcrl, x);
}
// If error looking up CRL, nothing we can do except notify callback
if (!ok) {
ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
ok = ctx->verify_cb(0, ctx);
goto err;
}
ctx->current_crl = crl;
ok = ctx->check_crl(ctx, crl);
if (!ok) {
goto err;
}
if (dcrl) {
ok = ctx->check_crl(ctx, dcrl);
if (!ok) {
goto err;
}
ok = ctx->cert_crl(ctx, dcrl, x);
if (!ok) {
goto err;
}
} else {
ok = 1;
}
// Don't look in full CRL if delta reason is removefromCRL
if (ok != 2) {
ok = ctx->cert_crl(ctx, crl, x);
if (!ok) {
goto err;
}
}
X509_CRL_free(crl);
X509_CRL_free(dcrl);
crl = NULL;
dcrl = NULL;
// If reasons not updated we wont get anywhere by another iteration,
// so exit loop.
if (last_reasons == ctx->current_reasons) {
ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
ok = ctx->verify_cb(0, ctx);
goto err;
}
}
err:
X509_CRL_free(crl);
X509_CRL_free(dcrl);
ctx->current_crl = NULL;
return ok;
}
// Check CRL times against values in X509_STORE_CTX
static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) {
if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) {
return 1;
}
if (notify) {
ctx->current_crl = crl;
}
int64_t ptime;
if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) {
ptime = ctx->param->check_time;
} else {
ptime = time(NULL);
}
int i = X509_cmp_time_posix(X509_CRL_get0_lastUpdate(crl), ptime);
if (i == 0) {
if (!notify) {
return 0;
}
ctx->error = X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
if (i > 0) {
if (!notify) {
return 0;
}
ctx->error = X509_V_ERR_CRL_NOT_YET_VALID;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
if (X509_CRL_get0_nextUpdate(crl)) {
i = X509_cmp_time_posix(X509_CRL_get0_nextUpdate(crl), ptime);
if (i == 0) {
if (!notify) {
return 0;
}
ctx->error = X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
// Ignore expiry of base CRL is delta is valid
if ((i < 0) && !(ctx->current_crl_score & CRL_SCORE_TIME_DELTA)) {
if (!notify) {
return 0;
}
ctx->error = X509_V_ERR_CRL_HAS_EXPIRED;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
}
if (notify) {
ctx->current_crl = NULL;
}
return 1;
}
static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
X509 **pissuer, int *pscore, unsigned int *preasons,
STACK_OF(X509_CRL) *crls) {
int crl_score, best_score = *pscore;
size_t i;
unsigned int reasons, best_reasons = 0;
X509 *x = ctx->current_cert;
X509_CRL *crl, *best_crl = NULL;
X509 *crl_issuer = NULL, *best_crl_issuer = NULL;
for (i = 0; i < sk_X509_CRL_num(crls); i++) {
crl = sk_X509_CRL_value(crls, i);
reasons = *preasons;
crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);
if (crl_score < best_score || crl_score == 0) {
continue;
}
// If current CRL is equivalent use it if it is newer
if (crl_score == best_score && best_crl != NULL) {
int day, sec;
if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl),
X509_CRL_get0_lastUpdate(crl)) == 0) {
continue;
}
// ASN1_TIME_diff never returns inconsistent signs for |day|
// and |sec|.
if (day <= 0 && sec <= 0) {
continue;
}
}
best_crl = crl;
best_crl_issuer = crl_issuer;
best_score = crl_score;
best_reasons = reasons;
}
if (best_crl) {
if (*pcrl) {
X509_CRL_free(*pcrl);
}
*pcrl = best_crl;
*pissuer = best_crl_issuer;
*pscore = best_score;
*preasons = best_reasons;
X509_CRL_up_ref(best_crl);
if (*pdcrl) {
X509_CRL_free(*pdcrl);
*pdcrl = NULL;
}
get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
}
if (best_score >= CRL_SCORE_VALID) {
return 1;
}
return 0;
}
// Compare two CRL extensions for delta checking purposes. They should be
// both present or both absent. If both present all fields must be identical.
static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) {
const ASN1_OCTET_STRING *exta, *extb;
int i;
i = X509_CRL_get_ext_by_NID(a, nid, -1);
if (i >= 0) {
// Can't have multiple occurrences
if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) {
return 0;
}
exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i));
} else {
exta = NULL;
}
i = X509_CRL_get_ext_by_NID(b, nid, -1);
if (i >= 0) {
if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) {
return 0;
}
extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i));
} else {
extb = NULL;
}
if (!exta && !extb) {
return 1;
}
if (!exta || !extb) {
return 0;
}
if (ASN1_OCTET_STRING_cmp(exta, extb)) {
return 0;
}
return 1;
}
// See if a base and delta are compatible
static int check_delta_base(X509_CRL *delta, X509_CRL *base) {
// Delta CRL must be a delta
if (!delta->base_crl_number) {
return 0;
}
// Base must have a CRL number
if (!base->crl_number) {
return 0;
}
// Issuer names must match
if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta))) {
return 0;
}
// AKID and IDP must match
if (!crl_extension_match(delta, base, NID_authority_key_identifier)) {
return 0;
}
if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) {
return 0;
}
// Delta CRL base number must not exceed Full CRL number.
if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) {
return 0;
}
// Delta CRL number must exceed full CRL number
if (ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0) {
return 1;
}
return 0;
}
// For a given base CRL find a delta... maybe extend to delta scoring or
// retrieve a chain of deltas...
static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore,
X509_CRL *base, STACK_OF(X509_CRL) *crls) {
X509_CRL *delta;
size_t i;
if (!(ctx->param->flags & X509_V_FLAG_USE_DELTAS)) {
return;
}
if (!((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST)) {
return;
}
for (i = 0; i < sk_X509_CRL_num(crls); i++) {
delta = sk_X509_CRL_value(crls, i);
if (check_delta_base(delta, base)) {
if (check_crl_time(ctx, delta, 0)) {
*pscore |= CRL_SCORE_TIME_DELTA;
}
X509_CRL_up_ref(delta);
*dcrl = delta;
return;
}
}
*dcrl = NULL;
}
// For a given CRL return how suitable it is for the supplied certificate
// 'x'. The return value is a mask of several criteria. If the issuer is not
// the certificate issuer this is returned in *pissuer. The reasons mask is
// also used to determine if the CRL is suitable: if no new reasons the CRL
// is rejected, otherwise reasons is updated.
static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
unsigned int *preasons, X509_CRL *crl, X509 *x) {
int crl_score = 0;
unsigned int tmp_reasons = *preasons, crl_reasons;
// First see if we can reject CRL straight away
// Invalid IDP cannot be processed
if (crl->idp_flags & IDP_INVALID) {
return 0;
}
// Reason codes or indirect CRLs need extended CRL support
if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) {
return 0;
}
} else if (crl->idp_flags & IDP_REASONS) {
// If no new reasons reject
if (!(crl->idp_reasons & ~tmp_reasons)) {
return 0;
}
}
// Don't process deltas at this stage
else if (crl->base_crl_number) {
return 0;
}
// If issuer name doesn't match certificate need indirect CRL
if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl))) {
if (!(crl->idp_flags & IDP_INDIRECT)) {
return 0;
}
} else {
crl_score |= CRL_SCORE_ISSUER_NAME;
}
if (!(crl->flags & EXFLAG_CRITICAL)) {
crl_score |= CRL_SCORE_NOCRITICAL;
}
// Check expiry
if (check_crl_time(ctx, crl, 0)) {
crl_score |= CRL_SCORE_TIME;
}
// Check authority key ID and locate certificate issuer
crl_akid_check(ctx, crl, pissuer, &crl_score);
// If we can't locate certificate issuer at this point forget it
if (!(crl_score & CRL_SCORE_AKID)) {
return 0;
}
// Check cert for matching CRL distribution points
if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) {
// If no new reasons reject
if (!(crl_reasons & ~tmp_reasons)) {
return 0;
}
tmp_reasons |= crl_reasons;
crl_score |= CRL_SCORE_SCOPE;
}
*preasons = tmp_reasons;
return crl_score;
}
static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
int *pcrl_score) {
X509 *crl_issuer = NULL;
X509_NAME *cnm = X509_CRL_get_issuer(crl);
int cidx = ctx->error_depth;
size_t i;
if ((size_t)cidx != sk_X509_num(ctx->chain) - 1) {
cidx++;
}
crl_issuer = sk_X509_value(ctx->chain, cidx);
if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
if (*pcrl_score & CRL_SCORE_ISSUER_NAME) {
*pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT;
*pissuer = crl_issuer;
return;
}
}
for (cidx++; cidx < (int)sk_X509_num(ctx->chain); cidx++) {
crl_issuer = sk_X509_value(ctx->chain, cidx);
if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) {
continue;
}
if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
*pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH;
*pissuer = crl_issuer;
return;
}
}
// Anything else needs extended CRL support
if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT)) {
return;
}
// Otherwise the CRL issuer is not on the path. Look for it in the set of
// untrusted certificates.
for (i = 0; i < sk_X509_num(ctx->untrusted); i++) {
crl_issuer = sk_X509_value(ctx->untrusted, i);
if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) {
continue;
}
if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) {
*pissuer = crl_issuer;
*pcrl_score |= CRL_SCORE_AKID;
return;
}
}
}
// Check the path of a CRL issuer certificate. This creates a new
// X509_STORE_CTX and populates it with most of the parameters from the
// parent. This could be optimised somewhat since a lot of path checking will
// be duplicated by the parent, but this will rarely be used in practice.
static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) {
X509_STORE_CTX crl_ctx;
int ret;
// Don't allow recursive CRL path validation
if (ctx->parent) {
return 0;
}
if (!X509_STORE_CTX_init(&crl_ctx, ctx->ctx, x, ctx->untrusted)) {
return -1;
}
crl_ctx.crls = ctx->crls;
// Copy verify params across
X509_STORE_CTX_set0_param(&crl_ctx, ctx->param);
crl_ctx.parent = ctx;
crl_ctx.verify_cb = ctx->verify_cb;
// Verify CRL issuer
ret = X509_verify_cert(&crl_ctx);
if (ret <= 0) {
goto err;
}
// Check chain is acceptable
ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain);
err:
X509_STORE_CTX_cleanup(&crl_ctx);
return ret;
}
// RFC 3280 says nothing about the relationship between CRL path and
// certificate path, which could lead to situations where a certificate could
// be revoked or validated by a CA not authorised to do so. RFC 5280 is more
// strict and states that the two paths must end in the same trust anchor,
// though some discussions remain... until this is resolved we use the
// RFC 5280 version
static int check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path,
STACK_OF(X509) *crl_path) {
X509 *cert_ta, *crl_ta;
cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1);
crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1);
if (!X509_cmp(cert_ta, crl_ta)) {
return 1;
}
return 0;
}
// Check for match between two dist point names: three separate cases. 1.
// Both are relative names and compare X509_NAME types. 2. One full, one
// relative. Compare X509_NAME to GENERAL_NAMES. 3. Both are full names and
// compare two GENERAL_NAMES. 4. One is NULL: automatic match.
static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) {
X509_NAME *nm = NULL;
GENERAL_NAMES *gens = NULL;
GENERAL_NAME *gena, *genb;
size_t i, j;
if (!a || !b) {
return 1;
}
if (a->type == 1) {
if (!a->dpname) {
return 0;
}
// Case 1: two X509_NAME
if (b->type == 1) {
if (!b->dpname) {
return 0;
}
if (!X509_NAME_cmp(a->dpname, b->dpname)) {
return 1;
} else {
return 0;
}
}
// Case 2: set name and GENERAL_NAMES appropriately
nm = a->dpname;
gens = b->name.fullname;
} else if (b->type == 1) {
if (!b->dpname) {
return 0;
}
// Case 2: set name and GENERAL_NAMES appropriately
gens = a->name.fullname;
nm = b->dpname;
}
// Handle case 2 with one GENERAL_NAMES and one X509_NAME
if (nm) {
for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
gena = sk_GENERAL_NAME_value(gens, i);
if (gena->type != GEN_DIRNAME) {
continue;
}
if (!X509_NAME_cmp(nm, gena->d.directoryName)) {
return 1;
}
}
return 0;
}
// Else case 3: two GENERAL_NAMES
for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) {
gena = sk_GENERAL_NAME_value(a->name.fullname, i);
for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) {
genb = sk_GENERAL_NAME_value(b->name.fullname, j);
if (!GENERAL_NAME_cmp(gena, genb)) {
return 1;
}
}
}
return 0;
}
static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) {
size_t i;
X509_NAME *nm = X509_CRL_get_issuer(crl);
// If no CRLissuer return is successful iff don't need a match
if (!dp->CRLissuer) {
return !!(crl_score & CRL_SCORE_ISSUER_NAME);
}
for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
if (gen->type != GEN_DIRNAME) {
continue;
}
if (!X509_NAME_cmp(gen->d.directoryName, nm)) {
return 1;
}
}
return 0;
}
// Check CRLDP and IDP
static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
unsigned int *preasons) {
size_t i;
if (crl->idp_flags & IDP_ONLYATTR) {
return 0;
}
if (x->ex_flags & EXFLAG_CA) {
if (crl->idp_flags & IDP_ONLYUSER) {
return 0;
}
} else {
if (crl->idp_flags & IDP_ONLYCA) {
return 0;
}
}
*preasons = crl->idp_reasons;
for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
if (crldp_check_crlissuer(dp, crl, crl_score)) {
if (!crl->idp || idp_check_dp(dp->distpoint, crl->idp->distpoint)) {
*preasons &= dp->dp_reasons;
return 1;
}
}
}
if ((!crl->idp || !crl->idp->distpoint) &&
(crl_score & CRL_SCORE_ISSUER_NAME)) {
return 1;
}
return 0;
}
// Retrieve CRL corresponding to current certificate. If deltas enabled try
// to find a delta CRL too
static int get_crl_delta(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
X509 *x) {
int ok;
X509 *issuer = NULL;
int crl_score = 0;
unsigned int reasons;
X509_CRL *crl = NULL, *dcrl = NULL;
STACK_OF(X509_CRL) *skcrl;
X509_NAME *nm = X509_get_issuer_name(x);
reasons = ctx->current_reasons;
ok = get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, ctx->crls);
if (ok) {
goto done;
}
// Lookup CRLs from store
skcrl = ctx->lookup_crls(ctx, nm);
// If no CRLs found and a near match from get_crl_sk use that
if (!skcrl && crl) {
goto done;
}
get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl);
sk_X509_CRL_pop_free(skcrl, X509_CRL_free);
done:
// If we got any kind of CRL use it and return success
if (crl) {
ctx->current_issuer = issuer;
ctx->current_crl_score = crl_score;
ctx->current_reasons = reasons;
*pcrl = crl;
*pdcrl = dcrl;
return 1;
}
return 0;
}
// Check CRL validity
static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) {
X509 *issuer = NULL;
EVP_PKEY *ikey = NULL;
int ok = 0;
int cnum = ctx->error_depth;
int chnum = (int)sk_X509_num(ctx->chain) - 1;
// if we have an alternative CRL issuer cert use that
if (ctx->current_issuer) {
issuer = ctx->current_issuer;
}
// Else find CRL issuer: if not last certificate then issuer is next
// certificate in chain.
else if (cnum < chnum) {
issuer = sk_X509_value(ctx->chain, cnum + 1);
} else {
issuer = sk_X509_value(ctx->chain, chnum);
// If not self signed, can't check signature
if (!ctx->check_issued(ctx, issuer, issuer)) {
ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
}
if (issuer) {
// Skip most tests for deltas because they have already been done
if (!crl->base_crl_number) {
// Check for cRLSign bit if keyUsage present
if ((issuer->ex_flags & EXFLAG_KUSAGE) &&
!(issuer->ex_kusage & KU_CRL_SIGN)) {
ctx->error = X509_V_ERR_KEYUSAGE_NO_CRL_SIGN;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
if (!(ctx->current_crl_score & CRL_SCORE_SCOPE)) {
ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
if (!(ctx->current_crl_score & CRL_SCORE_SAME_PATH)) {
if (check_crl_path(ctx, ctx->current_issuer) <= 0) {
ctx->error = X509_V_ERR_CRL_PATH_VALIDATION_ERROR;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
}
if (crl->idp_flags & IDP_INVALID) {
ctx->error = X509_V_ERR_INVALID_EXTENSION;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
}
if (!(ctx->current_crl_score & CRL_SCORE_TIME)) {
ok = check_crl_time(ctx, crl, 1);
if (!ok) {
goto err;
}
}
// Attempt to get issuer certificate public key
ikey = X509_get_pubkey(issuer);
if (!ikey) {
ctx->error = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
} else {
// Verify CRL signature
if (X509_CRL_verify(crl, ikey) <= 0) {
ctx->error = X509_V_ERR_CRL_SIGNATURE_FAILURE;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto err;
}
}
}
}
ok = 1;
err:
EVP_PKEY_free(ikey);
return ok;
}
// Check certificate against CRL
static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) {
int ok;
X509_REVOKED *rev;
// The rules changed for this... previously if a CRL contained unhandled
// critical extensions it could still be used to indicate a certificate
// was revoked. This has since been changed since critical extension can
// change the meaning of CRL entries.
if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) &&
(crl->flags & EXFLAG_CRITICAL)) {
ctx->error = X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
return 0;
}
}
// Look for serial number of certificate in CRL If found make sure reason
// is not removeFromCRL.
if (X509_CRL_get0_by_cert(crl, &rev, x)) {
if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) {
return 2;
}
ctx->error = X509_V_ERR_CERT_REVOKED;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
return 0;
}
}
return 1;
}
static int check_policy(X509_STORE_CTX *ctx) {
// TODO(davidben): Why do we disable policy validation for CRL paths?
if (ctx->parent) {
return 1;
}
X509 *current_cert = NULL;
int ret = X509_policy_check(ctx->chain, ctx->param->policies,
ctx->param->flags, &current_cert);
if (ret != X509_V_OK) {
ctx->current_cert = current_cert;
ctx->error = ret;
if (ret == X509_V_ERR_OUT_OF_MEM) {
return 0;
}
return ctx->verify_cb(0, ctx);
}
if (ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) {
ctx->current_cert = NULL;
// Verification errors need to be "sticky", a callback may have allowed
// an SSL handshake to continue despite an error, and we must then
// remain in an error state. Therefore, we MUST NOT clear earlier
// verification errors by setting the error to X509_V_OK.
if (!ctx->verify_cb(2, ctx)) {
return 0;
}
}
return 1;
}
static int check_cert_time(X509_STORE_CTX *ctx, X509 *x) {
if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) {
return 1;
}
int64_t ptime;
if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) {
ptime = ctx->param->check_time;
} else {
ptime = time(NULL);
}
int i = X509_cmp_time_posix(X509_get_notBefore(x), ptime);
if (i == 0) {
ctx->error = X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD;
ctx->current_cert = x;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
if (i > 0) {
ctx->error = X509_V_ERR_CERT_NOT_YET_VALID;
ctx->current_cert = x;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
i = X509_cmp_time_posix(X509_get_notAfter(x), ptime);
if (i == 0) {
ctx->error = X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD;
ctx->current_cert = x;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
if (i < 0) {
ctx->error = X509_V_ERR_CERT_HAS_EXPIRED;
ctx->current_cert = x;
if (!ctx->verify_cb(0, ctx)) {
return 0;
}
}
return 1;
}
static int internal_verify(X509_STORE_CTX *ctx) {
int ok = 0;
X509 *xs, *xi;
EVP_PKEY *pkey = NULL;
int n = (int)sk_X509_num(ctx->chain);
ctx->error_depth = n - 1;
n--;
xi = sk_X509_value(ctx->chain, n);
if (ctx->check_issued(ctx, xi, xi)) {
xs = xi;
} else {
if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
xs = xi;
goto check_cert;
}
if (n <= 0) {
ctx->error = X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
ctx->current_cert = xi;
ok = ctx->verify_cb(0, ctx);
goto end;
} else {
n--;
ctx->error_depth = n;
xs = sk_X509_value(ctx->chain, n);
}
}
// ctx->error=0; not needed
while (n >= 0) {
ctx->error_depth = n;
// Skip signature check for self signed certificates unless
// explicitly asked for. It doesn't add any security and just wastes
// time.
if (xs != xi || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE)) {
if ((pkey = X509_get_pubkey(xi)) == NULL) {
ctx->error = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
ctx->current_cert = xi;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
goto end;
}
} else if (X509_verify(xs, pkey) <= 0) {
ctx->error = X509_V_ERR_CERT_SIGNATURE_FAILURE;
ctx->current_cert = xs;
ok = ctx->verify_cb(0, ctx);
if (!ok) {
EVP_PKEY_free(pkey);
goto end;
}
}
EVP_PKEY_free(pkey);
pkey = NULL;
}
check_cert:
ok = check_cert_time(ctx, xs);
if (!ok) {
goto end;
}
// The last error (if any) is still in the error value
ctx->current_issuer = xi;
ctx->current_cert = xs;
ok = ctx->verify_cb(1, ctx);
if (!ok) {
goto end;
}
n--;
if (n >= 0) {
xi = xs;
xs = sk_X509_value(ctx->chain, n);
}
}
ok = 1;
end:
return ok;
}
int X509_cmp_current_time(const ASN1_TIME *ctm) {
return X509_cmp_time_posix(ctm, time(NULL));
}
int X509_cmp_time(const ASN1_TIME *ctm, const time_t *cmp_time) {
int64_t compare_time = (cmp_time == NULL) ? time(NULL) : *cmp_time;
return X509_cmp_time_posix(ctm, compare_time);
}
int X509_cmp_time_posix(const ASN1_TIME *ctm, int64_t cmp_time) {
int64_t ctm_time;
if (!ASN1_TIME_to_posix(ctm, &ctm_time)) {
return 0;
}
// The return value 0 is reserved for errors.
return (ctm_time - cmp_time <= 0) ? -1 : 1;
}
ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long offset_sec) {
return X509_time_adj(s, offset_sec, NULL);
}
ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, const time_t *in_tm) {
return X509_time_adj_ex(s, 0, offset_sec, in_tm);
}
ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, int offset_day, long offset_sec,
const time_t *in_tm) {
int64_t t = 0;
if (in_tm) {
t = *in_tm;
} else {
t = time(NULL);
}
return ASN1_TIME_adj(s, t, offset_day, offset_sec);
}
// Make a delta CRL as the diff between two full CRLs
X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, EVP_PKEY *skey,
const EVP_MD *md, unsigned int flags) {
X509_CRL *crl = NULL;
int i;
size_t j;
STACK_OF(X509_REVOKED) *revs = NULL;
// CRLs can't be delta already
if (base->base_crl_number || newer->base_crl_number) {
OPENSSL_PUT_ERROR(X509, X509_R_CRL_ALREADY_DELTA);
return NULL;
}
// Base and new CRL must have a CRL number
if (!base->crl_number || !newer->crl_number) {
OPENSSL_PUT_ERROR(X509, X509_R_NO_CRL_NUMBER);
return NULL;
}
// Issuer names must match
if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
OPENSSL_PUT_ERROR(X509, X509_R_ISSUER_MISMATCH);
return NULL;
}
// AKID and IDP must match
if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
OPENSSL_PUT_ERROR(X509, X509_R_AKID_MISMATCH);
return NULL;
}
if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
OPENSSL_PUT_ERROR(X509, X509_R_IDP_MISMATCH);
return NULL;
}
// Newer CRL number must exceed full CRL number
if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
OPENSSL_PUT_ERROR(X509, X509_R_NEWER_CRL_NOT_NEWER);
return NULL;
}
// CRLs must verify
if (skey &&
(X509_CRL_verify(base, skey) <= 0 || X509_CRL_verify(newer, skey) <= 0)) {
OPENSSL_PUT_ERROR(X509, X509_R_CRL_VERIFY_FAILURE);
return NULL;
}
// Create new CRL
crl = X509_CRL_new();
if (!crl || !X509_CRL_set_version(crl, X509_CRL_VERSION_2)) {
goto memerr;
}
// Set issuer name
if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) {
goto memerr;
}
if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) {
goto memerr;
}
if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) {
goto memerr;
}
// Set base CRL number: must be critical
if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) {
goto memerr;
}
// Copy extensions across from newest CRL to delta: this will set CRL
// number to correct value too.
for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
const X509_EXTENSION *ext = X509_CRL_get_ext(newer, i);
if (!X509_CRL_add_ext(crl, ext, -1)) {
goto memerr;
}
}
// Go through revoked entries, copying as needed
revs = X509_CRL_get_REVOKED(newer);
for (j = 0; j < sk_X509_REVOKED_num(revs); j++) {
X509_REVOKED *rvn, *rvtmp;
rvn = sk_X509_REVOKED_value(revs, j);
// Add only if not also in base. TODO: need something cleverer here
// for some more complex CRLs covering multiple CAs.
if (!X509_CRL_get0_by_serial(base, &rvtmp, rvn->serialNumber)) {
rvtmp = X509_REVOKED_dup(rvn);
if (!rvtmp) {
goto memerr;
}
if (!X509_CRL_add0_revoked(crl, rvtmp)) {
X509_REVOKED_free(rvtmp);
goto memerr;
}
}
}
// TODO: optionally prune deleted entries
if (skey && md && !X509_CRL_sign(crl, skey, md)) {
goto memerr;
}
return crl;
memerr:
if (crl) {
X509_CRL_free(crl);
}
return NULL;
}
int X509_STORE_CTX_get_ex_new_index(long argl, void *argp,
CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_unused,
CRYPTO_EX_free *free_func) {
// This function is (usually) called only once, by
// SSL_get_ex_data_X509_STORE_CTX_idx (ssl/ssl_cert.c).
int index;
if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp,
free_func)) {
return -1;
}
return index;
}
int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) {
return CRYPTO_set_ex_data(&ctx->ex_data, idx, data);
}
void *X509_STORE_CTX_get_ex_data(X509_STORE_CTX *ctx, int idx) {
return CRYPTO_get_ex_data(&ctx->ex_data, idx);
}
int X509_STORE_CTX_get_error(X509_STORE_CTX *ctx) { return ctx->error; }
void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) {
ctx->error = err;
}
int X509_STORE_CTX_get_error_depth(X509_STORE_CTX *ctx) {
return ctx->error_depth;
}
X509 *X509_STORE_CTX_get_current_cert(X509_STORE_CTX *ctx) {
return ctx->current_cert;
}
STACK_OF(X509) *X509_STORE_CTX_get_chain(X509_STORE_CTX *ctx) {
return ctx->chain;
}
STACK_OF(X509) *X509_STORE_CTX_get0_chain(X509_STORE_CTX *ctx) {
return ctx->chain;
}
STACK_OF(X509) *X509_STORE_CTX_get1_chain(X509_STORE_CTX *ctx) {
if (!ctx->chain) {
return NULL;
}
return X509_chain_up_ref(ctx->chain);
}
X509 *X509_STORE_CTX_get0_current_issuer(X509_STORE_CTX *ctx) {
return ctx->current_issuer;
}
X509_CRL *X509_STORE_CTX_get0_current_crl(X509_STORE_CTX *ctx) {
return ctx->current_crl;
}
X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(X509_STORE_CTX *ctx) {
return ctx->parent;
}
void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) { ctx->cert = x; }
void X509_STORE_CTX_set_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) {
ctx->untrusted = sk;
}
STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(X509_STORE_CTX *ctx) {
return ctx->untrusted;
}
void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) {
ctx->crls = sk;
}
int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) {
return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0);
}
int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) {
return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust);
}
// This function is used to set the X509_STORE_CTX purpose and trust values.
// This is intended to be used when another structure has its own trust and
// purpose values which (if set) will be inherited by the ctx. If they aren't
// set then we will usually have a default purpose in mind which should then
// be used to set the trust value. An example of this is SSL use: an SSL
// structure will have its own purpose and trust settings which the
// application can set: if they aren't set then we use the default of SSL
// client/server.
int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose,
int purpose, int trust) {
int idx;
// If purpose not set use default
if (!purpose) {
purpose = def_purpose;
}
// If we have a purpose then check it is valid
if (purpose) {
X509_PURPOSE *ptmp;
idx = X509_PURPOSE_get_by_id(purpose);
if (idx == -1) {
OPENSSL_PUT_ERROR(X509, X509_R_UNKNOWN_PURPOSE_ID);
return 0;
}
ptmp = X509_PURPOSE_get0(idx);
if (ptmp->trust == X509_TRUST_DEFAULT) {
idx = X509_PURPOSE_get_by_id(def_purpose);
if (idx == -1) {
OPENSSL_PUT_ERROR(X509, X509_R_UNKNOWN_PURPOSE_ID);
return 0;
}
ptmp = X509_PURPOSE_get0(idx);
}
// If trust not set then get from purpose default
if (!trust) {
trust = ptmp->trust;
}
}
if (trust) {
idx = X509_TRUST_get_by_id(trust);
if (idx == -1) {
OPENSSL_PUT_ERROR(X509, X509_R_UNKNOWN_TRUST_ID);
return 0;
}
}
if (purpose && !ctx->param->purpose) {
ctx->param->purpose = purpose;
}
if (trust && !ctx->param->trust) {
ctx->param->trust = trust;
}
return 1;
}
X509_STORE_CTX *X509_STORE_CTX_new(void) {
X509_STORE_CTX *ctx;
ctx = (X509_STORE_CTX *)OPENSSL_malloc(sizeof(X509_STORE_CTX));
if (!ctx) {
return NULL;
}
X509_STORE_CTX_zero(ctx);
return ctx;
}
void X509_STORE_CTX_zero(X509_STORE_CTX *ctx) {
OPENSSL_memset(ctx, 0, sizeof(X509_STORE_CTX));
}
void X509_STORE_CTX_free(X509_STORE_CTX *ctx) {
if (ctx == NULL) {
return;
}
X509_STORE_CTX_cleanup(ctx);
OPENSSL_free(ctx);
}
int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
STACK_OF(X509) *chain) {
X509_STORE_CTX_zero(ctx);
ctx->ctx = store;
ctx->cert = x509;
ctx->untrusted = chain;
CRYPTO_new_ex_data(&ctx->ex_data);
if (store == NULL) {
OPENSSL_PUT_ERROR(X509, ERR_R_PASSED_NULL_PARAMETER);
goto err;
}
ctx->param = X509_VERIFY_PARAM_new();
if (!ctx->param) {
goto err;
}
// Inherit callbacks and flags from X509_STORE.
ctx->verify_cb = store->verify_cb;
ctx->cleanup = store->cleanup;
if (!X509_VERIFY_PARAM_inherit(ctx->param, store->param) ||
!X509_VERIFY_PARAM_inherit(ctx->param,
X509_VERIFY_PARAM_lookup("default"))) {
goto err;
}
if (store->check_issued) {
ctx->check_issued = store->check_issued;
} else {
ctx->check_issued = check_issued;
}
if (store->get_issuer) {
ctx->get_issuer = store->get_issuer;
} else {
ctx->get_issuer = X509_STORE_CTX_get1_issuer;
}
if (store->verify_cb) {
ctx->verify_cb = store->verify_cb;
} else {
ctx->verify_cb = null_callback;
}
if (store->verify) {
ctx->verify = store->verify;
} else {
ctx->verify = internal_verify;
}
if (store->check_revocation) {
ctx->check_revocation = store->check_revocation;
} else {
ctx->check_revocation = check_revocation;
}
if (store->get_crl) {
ctx->get_crl = store->get_crl;
} else {
ctx->get_crl = NULL;
}
if (store->check_crl) {
ctx->check_crl = store->check_crl;
} else {
ctx->check_crl = check_crl;
}
if (store->cert_crl) {
ctx->cert_crl = store->cert_crl;
} else {
ctx->cert_crl = cert_crl;
}
if (store->lookup_certs) {
ctx->lookup_certs = store->lookup_certs;
} else {
ctx->lookup_certs = X509_STORE_get1_certs;
}
if (store->lookup_crls) {
ctx->lookup_crls = store->lookup_crls;
} else {
ctx->lookup_crls = X509_STORE_get1_crls;
}
ctx->check_policy = check_policy;
return 1;
err:
CRYPTO_free_ex_data(&g_ex_data_class, ctx, &ctx->ex_data);
if (ctx->param != NULL) {
X509_VERIFY_PARAM_free(ctx->param);
}
OPENSSL_memset(ctx, 0, sizeof(X509_STORE_CTX));
return 0;
}
// Set alternative lookup method: just a STACK of trusted certificates. This
// avoids X509_STORE nastiness where it isn't needed.
void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx,
STACK_OF(X509) *sk) {
ctx->other_ctx = sk;
ctx->get_issuer = get_issuer_sk;
}
void X509_STORE_CTX_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) {
X509_STORE_CTX_set0_trusted_stack(ctx, sk);
}
void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) {
// We need to be idempotent because, unfortunately, |X509_STORE_CTX_free|
// also calls this function.
if (ctx->cleanup != NULL) {
ctx->cleanup(ctx);
ctx->cleanup = NULL;
}
if (ctx->param != NULL) {
if (ctx->parent == NULL) {
X509_VERIFY_PARAM_free(ctx->param);
}
ctx->param = NULL;
}
if (ctx->chain != NULL) {
sk_X509_pop_free(ctx->chain, X509_free);
ctx->chain = NULL;
}
CRYPTO_free_ex_data(&g_ex_data_class, ctx, &(ctx->ex_data));
OPENSSL_memset(&ctx->ex_data, 0, sizeof(CRYPTO_EX_DATA));
}
void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) {
X509_VERIFY_PARAM_set_depth(ctx->param, depth);
}
void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) {
X509_VERIFY_PARAM_set_flags(ctx->param, flags);
}
void X509_STORE_CTX_set_time_posix(X509_STORE_CTX *ctx, unsigned long flags,
int64_t t) {
X509_VERIFY_PARAM_set_time_posix(ctx->param, t);
}
void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags,
time_t t) {
X509_STORE_CTX_set_time_posix(ctx, flags, t);
}
X509 *X509_STORE_CTX_get0_cert(X509_STORE_CTX *ctx) {
return ctx->cert;
}
void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx,
int (*verify_cb)(int, X509_STORE_CTX *)) {
ctx->verify_cb = verify_cb;
}
int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) {
const X509_VERIFY_PARAM *param;
param = X509_VERIFY_PARAM_lookup(name);
if (!param) {
return 0;
}
return X509_VERIFY_PARAM_inherit(ctx->param, param);
}
X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(X509_STORE_CTX *ctx) {
return ctx->param;
}
void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) {
if (ctx->param) {
X509_VERIFY_PARAM_free(ctx->param);
}
ctx->param = param;
}