openssl/crypto/x509/x_x509.c
Pauli 66ddc0759a x509: fix a dangling pointer
If object was pointer was passed and an error occured the object was freed & the
pointer returned.  Fix this to NULL out the caller's pointer before returning.

Fixes #15115

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15238)
2021-05-13 18:00:36 +10:00

326 lines
9.1 KiB
C

/*
* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include <openssl/asn1t.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include "crypto/x509.h"
ASN1_SEQUENCE_enc(X509_CINF, enc, 0) = {
ASN1_EXP_OPT(X509_CINF, version, ASN1_INTEGER, 0),
ASN1_EMBED(X509_CINF, serialNumber, ASN1_INTEGER),
ASN1_EMBED(X509_CINF, signature, X509_ALGOR),
ASN1_SIMPLE(X509_CINF, issuer, X509_NAME),
ASN1_EMBED(X509_CINF, validity, X509_VAL),
ASN1_SIMPLE(X509_CINF, subject, X509_NAME),
ASN1_SIMPLE(X509_CINF, key, X509_PUBKEY),
ASN1_IMP_OPT(X509_CINF, issuerUID, ASN1_BIT_STRING, 1),
ASN1_IMP_OPT(X509_CINF, subjectUID, ASN1_BIT_STRING, 2),
ASN1_EXP_SEQUENCE_OF_OPT(X509_CINF, extensions, X509_EXTENSION, 3)
} ASN1_SEQUENCE_END_enc(X509_CINF, X509_CINF)
IMPLEMENT_ASN1_FUNCTIONS(X509_CINF)
/* X509 top level structure needs a bit of customisation */
extern void ossl_policy_cache_free(X509_POLICY_CACHE *cache);
static int x509_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
void *exarg)
{
X509 *ret = (X509 *)*pval;
switch (operation) {
case ASN1_OP_D2I_PRE:
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509, ret, &ret->ex_data);
X509_CERT_AUX_free(ret->aux);
ASN1_OCTET_STRING_free(ret->skid);
AUTHORITY_KEYID_free(ret->akid);
CRL_DIST_POINTS_free(ret->crldp);
ossl_policy_cache_free(ret->policy_cache);
GENERAL_NAMES_free(ret->altname);
NAME_CONSTRAINTS_free(ret->nc);
#ifndef OPENSSL_NO_RFC3779
sk_IPAddressFamily_pop_free(ret->rfc3779_addr, IPAddressFamily_free);
ASIdentifiers_free(ret->rfc3779_asid);
#endif
ASN1_OCTET_STRING_free(ret->distinguishing_id);
/* fall thru */
case ASN1_OP_NEW_POST:
ret->ex_cached = 0;
ret->ex_kusage = 0;
ret->ex_xkusage = 0;
ret->ex_nscert = 0;
ret->ex_flags = 0;
ret->ex_pathlen = -1;
ret->ex_pcpathlen = -1;
ret->skid = NULL;
ret->akid = NULL;
ret->policy_cache = NULL;
ret->altname = NULL;
ret->nc = NULL;
#ifndef OPENSSL_NO_RFC3779
ret->rfc3779_addr = NULL;
ret->rfc3779_asid = NULL;
#endif
ret->distinguishing_id = NULL;
ret->aux = NULL;
ret->crldp = NULL;
if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509, ret, &ret->ex_data))
return 0;
break;
case ASN1_OP_FREE_POST:
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509, ret, &ret->ex_data);
X509_CERT_AUX_free(ret->aux);
ASN1_OCTET_STRING_free(ret->skid);
AUTHORITY_KEYID_free(ret->akid);
CRL_DIST_POINTS_free(ret->crldp);
ossl_policy_cache_free(ret->policy_cache);
GENERAL_NAMES_free(ret->altname);
NAME_CONSTRAINTS_free(ret->nc);
#ifndef OPENSSL_NO_RFC3779
sk_IPAddressFamily_pop_free(ret->rfc3779_addr, IPAddressFamily_free);
ASIdentifiers_free(ret->rfc3779_asid);
#endif
ASN1_OCTET_STRING_free(ret->distinguishing_id);
OPENSSL_free(ret->propq);
break;
case ASN1_OP_DUP_POST:
{
X509 *old = exarg;
if (!ossl_x509_set0_libctx(ret, old->libctx, old->propq))
return 0;
}
break;
default:
break;
}
return 1;
}
ASN1_SEQUENCE_ref(X509, x509_cb) = {
ASN1_EMBED(X509, cert_info, X509_CINF),
ASN1_EMBED(X509, sig_alg, X509_ALGOR),
ASN1_EMBED(X509, signature, ASN1_BIT_STRING)
} ASN1_SEQUENCE_END_ref(X509, X509)
IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(X509, X509, X509)
IMPLEMENT_ASN1_DUP_FUNCTION(X509)
X509 *d2i_X509(X509 **a, const unsigned char **in, long len)
{
X509 *cert = NULL;
int free_on_error = a != NULL && *a == NULL;
cert = (X509 *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, (X509_it()));
/* Only cache the extensions if the cert object was passed in */
if (cert != NULL && a != NULL) { /* then cert == *a */
if (!ossl_x509v3_cache_extensions(cert)) {
if (free_on_error) {
*a = NULL;
X509_free(cert);
}
cert = NULL;
}
}
return cert;
}
int i2d_X509(const X509 *a, unsigned char **out)
{
return ASN1_item_i2d((const ASN1_VALUE *)a, out, (X509_it()));
}
/*
* This should only be used if the X509 object was embedded inside another
* asn1 object and it needs a libctx to operate.
* Use X509_new_ex() instead if possible.
*/
int ossl_x509_set0_libctx(X509 *x, OSSL_LIB_CTX *libctx, const char *propq)
{
if (x != NULL) {
x->libctx = libctx;
OPENSSL_free(x->propq);
x->propq = NULL;
if (propq != NULL) {
x->propq = OPENSSL_strdup(propq);
if (x->propq == NULL)
return 0;
}
}
return 1;
}
X509 *X509_new_ex(OSSL_LIB_CTX *libctx, const char *propq)
{
X509 *cert = NULL;
cert = (X509 *)ASN1_item_new((X509_it()));
if (!ossl_x509_set0_libctx(cert, libctx, propq)) {
X509_free(cert);
cert = NULL;
}
return cert;
}
int X509_set_ex_data(X509 *r, int idx, void *arg)
{
return CRYPTO_set_ex_data(&r->ex_data, idx, arg);
}
void *X509_get_ex_data(const X509 *r, int idx)
{
return CRYPTO_get_ex_data(&r->ex_data, idx);
}
/*
* X509_AUX ASN1 routines. X509_AUX is the name given to a certificate with
* extra info tagged on the end. Since these functions set how a certificate
* is trusted they should only be used when the certificate comes from a
* reliable source such as local storage.
*/
X509 *d2i_X509_AUX(X509 **a, const unsigned char **pp, long length)
{
const unsigned char *q;
X509 *ret;
int freeret = 0;
/* Save start position */
q = *pp;
if (a == NULL || *a == NULL)
freeret = 1;
ret = d2i_X509(a, &q, length);
/* If certificate unreadable then forget it */
if (ret == NULL)
return NULL;
/* update length */
length -= q - *pp;
if (length > 0 && !d2i_X509_CERT_AUX(&ret->aux, &q, length))
goto err;
*pp = q;
return ret;
err:
if (freeret) {
X509_free(ret);
if (a)
*a = NULL;
}
return NULL;
}
/*
* Serialize trusted certificate to *pp or just return the required buffer
* length if pp == NULL. We ultimately want to avoid modifying *pp in the
* error path, but that depends on similar hygiene in lower-level functions.
* Here we avoid compounding the problem.
*/
static int i2d_x509_aux_internal(const X509 *a, unsigned char **pp)
{
int length, tmplen;
unsigned char *start = pp != NULL ? *pp : NULL;
/*
* This might perturb *pp on error, but fixing that belongs in i2d_X509()
* not here. It should be that if a == NULL length is zero, but we check
* both just in case.
*/
length = i2d_X509(a, pp);
if (length <= 0 || a == NULL)
return length;
tmplen = i2d_X509_CERT_AUX(a->aux, pp);
if (tmplen < 0) {
if (start != NULL)
*pp = start;
return tmplen;
}
length += tmplen;
return length;
}
/*
* Serialize trusted certificate to *pp, or just return the required buffer
* length if pp == NULL.
*
* When pp is not NULL, but *pp == NULL, we allocate the buffer, but since
* we're writing two ASN.1 objects back to back, we can't have i2d_X509() do
* the allocation, nor can we allow i2d_X509_CERT_AUX() to increment the
* allocated buffer.
*/
int i2d_X509_AUX(const X509 *a, unsigned char **pp)
{
int length;
unsigned char *tmp;
/* Buffer provided by caller */
if (pp == NULL || *pp != NULL)
return i2d_x509_aux_internal(a, pp);
/* Obtain the combined length */
if ((length = i2d_x509_aux_internal(a, NULL)) <= 0)
return length;
/* Allocate requisite combined storage */
*pp = tmp = OPENSSL_malloc(length);
if (tmp == NULL) {
ERR_raise(ERR_LIB_X509, ERR_R_MALLOC_FAILURE);
return -1;
}
/* Encode, but keep *pp at the originally malloced pointer */
length = i2d_x509_aux_internal(a, &tmp);
if (length <= 0) {
OPENSSL_free(*pp);
*pp = NULL;
}
return length;
}
int i2d_re_X509_tbs(X509 *x, unsigned char **pp)
{
x->cert_info.enc.modified = 1;
return i2d_X509_CINF(&x->cert_info, pp);
}
void X509_get0_signature(const ASN1_BIT_STRING **psig,
const X509_ALGOR **palg, const X509 *x)
{
if (psig)
*psig = &x->signature;
if (palg)
*palg = &x->sig_alg;
}
int X509_get_signature_nid(const X509 *x)
{
return OBJ_obj2nid(x->sig_alg.algorithm);
}
void X509_set0_distinguishing_id(X509 *x, ASN1_OCTET_STRING *d_id)
{
ASN1_OCTET_STRING_free(x->distinguishing_id);
x->distinguishing_id = d_id;
}
ASN1_OCTET_STRING *X509_get0_distinguishing_id(X509 *x)
{
return x->distinguishing_id;
}