/* v3_purp.c */
/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+ * project 2001.
*/
/* ====================================================================
- * Copyright (c) 1999 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
#include <stdio.h>
#include "cryptlib.h"
#include <openssl/x509v3.h>
+#include <openssl/x509_vfy.h>
+static void x509v3_cache_extensions(X509 *x);
-static int x509_purpose_get_idx(int id);
-void x509v3_cache_extensions(X509 *x);
+static int check_ssl_ca(const X509 *x);
+static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int purpose_smime(const X509 *x, int ca);
+static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
+static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
-static int ca_check(X509 *x);
-static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca);
-static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
-static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca);
-static int purpose_smime(X509 *x, int ca);
-static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca);
-static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca);
-static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca);
-
-static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b);
+static int xp_cmp(const X509_PURPOSE * const *a,
+ const X509_PURPOSE * const *b);
+static void xptable_free(X509_PURPOSE *p);
static X509_PURPOSE xstandard[] = {
- {1, 0, check_purpose_ssl_client, "SSL client", /* NULL */},
- {2, 0, check_purpose_ssl_server, "SSL server", /* NULL */},
- {3, 0, check_purpose_ns_ssl_server, "Netscape SSL server", /* NULL */},
- {4, 0, check_purpose_smime_sign, "S/MIME signing", /* NULL */},
- {5, 0, check_purpose_smime_encrypt, "S/MIME encryption", /* NULL */},
- {6, 0, check_purpose_crl_sign, "CRL signing", /* NULL */},
- {-1, 0, NULL, NULL, /* NULL */}
+ {X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0, check_purpose_ssl_client, "SSL client", "sslclient", NULL},
+ {X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ssl_server, "SSL server", "sslserver", NULL},
+ {X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0, check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
+ {X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign, "S/MIME signing", "smimesign", NULL},
+ {X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0, check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
+ {X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign, "CRL signing", "crlsign", NULL},
+ {X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any", NULL},
+ {X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper, "OCSP helper", "ocsphelper", NULL},
};
+#define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
+
IMPLEMENT_STACK_OF(X509_PURPOSE)
static STACK_OF(X509_PURPOSE) *xptable = NULL;
-static int xp_cmp(X509_PURPOSE **a, X509_PURPOSE **b)
+static int xp_cmp(const X509_PURPOSE * const *a,
+ const X509_PURPOSE * const *b)
{
- return (*a)->purpose_id - (*b)->purpose_id;
+ return (*a)->purpose - (*b)->purpose;
}
+/* As much as I'd like to make X509_check_purpose use a "const" X509*
+ * I really can't because it does recalculate hashes and do other non-const
+ * things. */
int X509_check_purpose(X509 *x, int id, int ca)
{
int idx;
- X509_PURPOSE *pt;
+ const X509_PURPOSE *pt;
if(!(x->ex_flags & EXFLAG_SET)) {
CRYPTO_w_lock(CRYPTO_LOCK_X509);
x509v3_cache_extensions(x);
CRYPTO_w_unlock(CRYPTO_LOCK_X509);
}
- idx = x509_purpose_get_idx(id);
+ if(id == -1) return 1;
+ idx = X509_PURPOSE_get_by_id(id);
if(idx == -1) return -1;
- pt = sk_X509_PURPOSE_value(xptable, idx);
- return pt->check_purpose(pt, x,ca);
+ pt = X509_PURPOSE_get0(idx);
+ return pt->check_purpose(pt, x, ca);
+}
+
+int X509_PURPOSE_set(int *p, int purpose)
+{
+ if(X509_PURPOSE_get_by_id(purpose) == -1) {
+ X509V3err(X509V3_F_X509_PURPOSE_SET, X509V3_R_INVALID_PURPOSE);
+ return 0;
+ }
+ *p = purpose;
+ return 1;
}
-
-
+int X509_PURPOSE_get_count(void)
+{
+ if(!xptable) return X509_PURPOSE_COUNT;
+ return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
+}
+
+X509_PURPOSE * X509_PURPOSE_get0(int idx)
+{
+ if(idx < 0) return NULL;
+ if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
+ return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
+}
-static int x509_purpose_get_idx(int id)
+int X509_PURPOSE_get_by_sname(char *sname)
+{
+ int i;
+ X509_PURPOSE *xptmp;
+ for(i = 0; i < X509_PURPOSE_get_count(); i++) {
+ xptmp = X509_PURPOSE_get0(i);
+ if(!strcmp(xptmp->sname, sname)) return i;
+ }
+ return -1;
+}
+
+int X509_PURPOSE_get_by_id(int purpose)
{
X509_PURPOSE tmp;
- tmp.purpose_id = id;
+ int idx;
+ if((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
+ return purpose - X509_PURPOSE_MIN;
+ tmp.purpose = purpose;
if(!xptable) return -1;
- return sk_X509_PURPOSE_find(xptable, &tmp);
+ idx = sk_X509_PURPOSE_find(xptable, &tmp);
+ if(idx == -1) return -1;
+ return idx + X509_PURPOSE_COUNT;
}
-int X509_PURPOSE_add(X509_PURPOSE *xp)
+int X509_PURPOSE_add(int id, int trust, int flags,
+ int (*ck)(const X509_PURPOSE *, const X509 *, int),
+ char *name, char *sname, void *arg)
{
int idx;
- if(!xptable)
- {
- xptable = sk_X509_PURPOSE_new(xp_cmp);
- if (!xptable)
- {
+ X509_PURPOSE *ptmp;
+ /* This is set according to what we change: application can't set it */
+ flags &= ~X509_PURPOSE_DYNAMIC;
+ /* This will always be set for application modified trust entries */
+ flags |= X509_PURPOSE_DYNAMIC_NAME;
+ /* Get existing entry if any */
+ idx = X509_PURPOSE_get_by_id(id);
+ /* Need a new entry */
+ if(idx == -1) {
+ if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
return 0;
- }
}
-
- idx = x509_purpose_get_idx(xp->purpose_id);
- if(idx != -1)
- sk_X509_PURPOSE_set(xptable, idx, xp);
- else
- if (!sk_X509_PURPOSE_push(xptable, xp))
- {
+ ptmp->flags = X509_PURPOSE_DYNAMIC;
+ } else ptmp = X509_PURPOSE_get0(idx);
+
+ /* OPENSSL_free existing name if dynamic */
+ if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
+ OPENSSL_free(ptmp->name);
+ OPENSSL_free(ptmp->sname);
+ }
+ /* dup supplied name */
+ ptmp->name = BUF_strdup(name);
+ ptmp->sname = BUF_strdup(sname);
+ if(!ptmp->name || !ptmp->sname) {
+ X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ /* Keep the dynamic flag of existing entry */
+ ptmp->flags &= X509_PURPOSE_DYNAMIC;
+ /* Set all other flags */
+ ptmp->flags |= flags;
+
+ ptmp->purpose = id;
+ ptmp->trust = trust;
+ ptmp->check_purpose = ck;
+ ptmp->usr_data = arg;
+
+ /* If its a new entry manage the dynamic table */
+ if(idx == -1) {
+ if(!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
return 0;
- }
+ }
+ if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
+ X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+ }
return 1;
}
static void xptable_free(X509_PURPOSE *p)
{
- if (p->purpose_flags & X509_PURPOSE_DYNAMIC)
+ if(!p) return;
+ if (p->flags & X509_PURPOSE_DYNAMIC)
{
- if (p->purpose_flags & X509_PURPOSE_DYNAMIC_NAME)
- Free(p->purpose_name);
- Free(p);
+ if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
+ OPENSSL_free(p->name);
+ OPENSSL_free(p->sname);
+ }
+ OPENSSL_free(p);
}
}
void X509_PURPOSE_cleanup(void)
{
+ unsigned int i;
sk_X509_PURPOSE_pop_free(xptable, xptable_free);
+ for(i = 0; i < X509_PURPOSE_COUNT; i++) xptable_free(xstandard + i);
xptable = NULL;
}
-void X509_PURPOSE_add_standard(void)
+int X509_PURPOSE_get_id(X509_PURPOSE *xp)
{
- X509_PURPOSE *xp;
- for(xp = xstandard; xp->purpose_name; xp++)
- X509_PURPOSE_add(xp);
+ return xp->purpose;
}
-int X509_PURPOSE_enum(int (*efunc)(X509_PURPOSE *, void *), void *usr)
+char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
{
- int i;
- X509_PURPOSE *xp;
- if(!xptable) return 0;
- for(i = 0; i < sk_X509_PURPOSE_num(xptable); i++) {
- xp = sk_X509_PURPOSE_value(xptable, i);
- if(!efunc(xp, usr)) return i;
- }
- return i;
+ return xp->name;
}
-
-int X509_PURPOSE_get_id(X509_PURPOSE *xp)
+char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
{
- return xp->purpose_id;
+ return xp->sname;
}
-char *X509_PURPOSE_get_name(X509_PURPOSE *xp)
+int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
{
- return xp->purpose_name;
+ return xp->trust;
}
-void x509v3_cache_extensions(X509 *x)
+static int nid_cmp(int *a, int *b)
+ {
+ return *a - *b;
+ }
+
+int X509_supported_extension(X509_EXTENSION *ex)
+ {
+ /* This table is a list of the NIDs of supported extensions:
+ * that is those which are used by the verify process. If
+ * an extension is critical and doesn't appear in this list
+ * then the verify process will normally reject the certificate.
+ * The list must be kept in numerical order because it will be
+ * searched using bsearch.
+ */
+
+ static int supported_nids[] = {
+ NID_netscape_cert_type, /* 71 */
+ NID_key_usage, /* 83 */
+ NID_subject_alt_name, /* 85 */
+ NID_basic_constraints, /* 87 */
+ NID_ext_key_usage, /* 126 */
+ NID_proxyCertInfo /* 661 */
+ };
+
+ int ex_nid;
+
+ ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
+
+ if (ex_nid == NID_undef)
+ return 0;
+
+ if (OBJ_bsearch((char *)&ex_nid, (char *)supported_nids,
+ sizeof(supported_nids)/sizeof(int), sizeof(int),
+ (int (*)(const void *, const void *))nid_cmp))
+ return 1;
+ return 0;
+ }
+
+
+static void x509v3_cache_extensions(X509 *x)
{
BASIC_CONSTRAINTS *bs;
+ PROXY_CERT_INFO_EXTENSION *pci;
ASN1_BIT_STRING *usage;
ASN1_BIT_STRING *ns;
- STACK_OF(ASN1_OBJECT) *extusage;
+ EXTENDED_KEY_USAGE *extusage;
+ X509_EXTENSION *ex;
+
int i;
if(x->ex_flags & EXFLAG_SET) return;
+#ifndef OPENSSL_NO_SHA
+ X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
+#endif
/* Does subject name match issuer ? */
- if(X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
+ if(!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x)))
x->ex_flags |= EXFLAG_SS;
/* V1 should mean no extensions ... */
if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
/* Handle basic constraints */
- if((bs=X509V3_X509_get_d2i(x, NID_basic_constraints, NULL, NULL))) {
+ if((bs=X509_get_ext_d2i(x, NID_basic_constraints, NULL, NULL))) {
if(bs->ca) x->ex_flags |= EXFLAG_CA;
if(bs->pathlen) {
if((bs->pathlen->type == V_ASN1_NEG_INTEGER)
BASIC_CONSTRAINTS_free(bs);
x->ex_flags |= EXFLAG_BCONS;
}
+ /* Handle proxy certificates */
+ if((pci=X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
+ if (x->ex_flags & EXFLAG_CA
+ || X509_get_ext_by_NID(x, NID_subject_alt_name, 0) >= 0
+ || X509_get_ext_by_NID(x, NID_issuer_alt_name, 0) >= 0) {
+ x->ex_flags |= EXFLAG_INVALID;
+ }
+ if (pci->pcPathLengthConstraint) {
+ x->ex_pcpathlen =
+ ASN1_INTEGER_get(pci->pcPathLengthConstraint);
+ } else x->ex_pcpathlen = -1;
+ PROXY_CERT_INFO_EXTENSION_free(pci);
+ x->ex_flags |= EXFLAG_PROXY;
+ }
/* Handle key usage */
- if((usage=X509V3_X509_get_d2i(x, NID_key_usage, NULL, NULL))) {
+ if((usage=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
if(usage->length > 0) {
x->ex_kusage = usage->data[0];
if(usage->length > 1)
ASN1_BIT_STRING_free(usage);
}
x->ex_xkusage = 0;
- if((extusage=X509V3_X509_get_d2i(x, NID_ext_key_usage, NULL, NULL))) {
+ if((extusage=X509_get_ext_d2i(x, NID_ext_key_usage, NULL, NULL))) {
x->ex_flags |= EXFLAG_XKUSAGE;
for(i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
switch(OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage,i))) {
case NID_ms_sgc:
case NID_ns_sgc:
x->ex_xkusage |= XKU_SGC;
+ break;
+
+ case NID_OCSP_sign:
+ x->ex_xkusage |= XKU_OCSP_SIGN;
+ break;
+
+ case NID_time_stamp:
+ x->ex_xkusage |= XKU_TIMESTAMP;
+ break;
+
+ case NID_dvcs:
+ x->ex_xkusage |= XKU_DVCS;
+ break;
}
}
sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
}
- if((ns=X509V3_X509_get_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
+ if((ns=X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, NULL))) {
if(ns->length > 0) x->ex_nscert = ns->data[0];
else x->ex_nscert = 0;
x->ex_flags |= EXFLAG_NSCERT;
ASN1_BIT_STRING_free(ns);
}
+ x->skid =X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
+ x->akid =X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
+ for (i = 0; i < X509_get_ext_count(x); i++)
+ {
+ ex = X509_get_ext(x, i);
+ if (!X509_EXTENSION_get_critical(ex))
+ continue;
+ if (!X509_supported_extension(ex))
+ {
+ x->ex_flags |= EXFLAG_CRITICAL;
+ break;
+ }
+ }
x->ex_flags |= EXFLAG_SET;
}
* 1 is a CA
* 2 basicConstraints absent so "maybe" a CA
* 3 basicConstraints absent but self signed V1.
+ * 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
*/
#define V1_ROOT (EXFLAG_V1|EXFLAG_SS)
#define ns_reject(x, usage) \
(((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
-static int ca_check(X509 *x)
+static int check_ca(const X509 *x)
{
/* keyUsage if present should allow cert signing */
if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
/* If basicConstraints says not a CA then say so */
else return 0;
} else {
+ /* we support V1 roots for... uh, I don't really know why. */
if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
- else return 2;
+ /* If key usage present it must have certSign so tolerate it */
+ else if (x->ex_flags & EXFLAG_KUSAGE) return 4;
+ /* Older certificates could have Netscape-specific CA types */
+ else if (x->ex_flags & EXFLAG_NSCERT
+ && x->ex_nscert & NS_ANY_CA) return 5;
+ /* can this still be regarded a CA certificate? I doubt it */
+ return 0;
}
}
+int X509_check_ca(X509 *x)
+{
+ if(!(x->ex_flags & EXFLAG_SET)) {
+ CRYPTO_w_lock(CRYPTO_LOCK_X509);
+ x509v3_cache_extensions(x);
+ CRYPTO_w_unlock(CRYPTO_LOCK_X509);
+ }
+
+ return check_ca(x);
+}
-static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
+/* Check SSL CA: common checks for SSL client and server */
+static int check_ssl_ca(const X509 *x)
+{
+ int ca_ret;
+ ca_ret = check_ca(x);
+ if(!ca_ret) return 0;
+ /* check nsCertType if present */
+ if(ca_ret != 5 || x->ex_nscert & NS_SSL_CA) return ca_ret;
+ else return 0;
+}
+
+
+static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x, int ca)
{
if(xku_reject(x,XKU_SSL_CLIENT)) return 0;
- if(ca) {
- int ca_ret;
- ca_ret = ca_check(x);
- if(!ca_ret) return 0;
- /* check nsCertType if present */
- if(x->ex_flags & EXFLAG_NSCERT) {
- if(x->ex_nscert & NS_SSL_CA) return ca_ret;
- return 0;
- }
- if(ca_ret != 2) return ca_ret;
- else return 0;
- }
+ if(ca) return check_ssl_ca(x);
/* We need to do digital signatures with it */
if(ku_reject(x,KU_DIGITAL_SIGNATURE)) return 0;
/* nsCertType if present should allow SSL client use */
return 1;
}
-static int check_purpose_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
+static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
{
if(xku_reject(x,XKU_SSL_SERVER|XKU_SGC)) return 0;
- /* Otherwise same as SSL client for a CA */
- if(ca) return check_purpose_ssl_client(xp, x, 1);
+ if(ca) return check_ssl_ca(x);
if(ns_reject(x, NS_SSL_SERVER)) return 0;
/* Now as for keyUsage: we'll at least need to sign OR encipher */
}
-static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int ca)
+static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
{
int ret;
ret = check_purpose_ssl_server(xp, x, ca);
}
/* common S/MIME checks */
-static int purpose_smime(X509 *x, int ca)
+static int purpose_smime(const X509 *x, int ca)
{
if(xku_reject(x,XKU_SMIME)) return 0;
if(ca) {
int ca_ret;
- ca_ret = ca_check(x);
+ ca_ret = check_ca(x);
if(!ca_ret) return 0;
/* check nsCertType if present */
- if(x->ex_flags & EXFLAG_NSCERT) {
- if(x->ex_nscert & NS_SMIME_CA) return ca_ret;
- return 0;
- }
- if(ca_ret != 2) return ca_ret;
+ if(ca_ret != 5 || x->ex_nscert & NS_SMIME_CA) return ca_ret;
else return 0;
}
if(x->ex_flags & EXFLAG_NSCERT) {
return 1;
}
-static int check_purpose_smime_sign(X509_PURPOSE *xp, X509 *x, int ca)
+static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
{
int ret;
ret = purpose_smime(x, ca);
if(!ret || ca) return ret;
- if(ku_reject(x, KU_DIGITAL_SIGNATURE)) return 0;
+ if(ku_reject(x, KU_DIGITAL_SIGNATURE|KU_NON_REPUDIATION)) return 0;
return ret;
}
-static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int ca)
+static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x, int ca)
{
int ret;
ret = purpose_smime(x, ca);
return ret;
}
-static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
+static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x, int ca)
{
if(ca) {
int ca_ret;
- if((ca_ret = ca_check(x)) != 2) return ca_ret;
+ if((ca_ret = check_ca(x)) != 2) return ca_ret;
else return 0;
}
if(ku_reject(x, KU_CRL_SIGN)) return 0;
return 1;
}
+
+/* OCSP helper: this is *not* a full OCSP check. It just checks that
+ * each CA is valid. Additional checks must be made on the chain.
+ */
+
+static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca)
+{
+ /* Must be a valid CA. Should we really support the "I don't know"
+ value (2)? */
+ if(ca) return check_ca(x);
+ /* leaf certificate is checked in OCSP_verify() */
+ return 1;
+}
+
+static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
+{
+ return 1;
+}
+
+/* Various checks to see if one certificate issued the second.
+ * This can be used to prune a set of possible issuer certificates
+ * which have been looked up using some simple method such as by
+ * subject name.
+ * These are:
+ * 1. Check issuer_name(subject) == subject_name(issuer)
+ * 2. If akid(subject) exists check it matches issuer
+ * 3. If key_usage(issuer) exists check it supports certificate signing
+ * returns 0 for OK, positive for reason for mismatch, reasons match
+ * codes for X509_verify_cert()
+ */
+
+int X509_check_issued(X509 *issuer, X509 *subject)
+{
+ if(X509_NAME_cmp(X509_get_subject_name(issuer),
+ X509_get_issuer_name(subject)))
+ return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
+ x509v3_cache_extensions(issuer);
+ x509v3_cache_extensions(subject);
+ if(subject->akid) {
+ /* Check key ids (if present) */
+ if(subject->akid->keyid && issuer->skid &&
+ ASN1_OCTET_STRING_cmp(subject->akid->keyid, issuer->skid) )
+ return X509_V_ERR_AKID_SKID_MISMATCH;
+ /* Check serial number */
+ if(subject->akid->serial &&
+ ASN1_INTEGER_cmp(X509_get_serialNumber(issuer),
+ subject->akid->serial))
+ return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
+ /* Check issuer name */
+ if(subject->akid->issuer) {
+ /* Ugh, for some peculiar reason AKID includes
+ * SEQUENCE OF GeneralName. So look for a DirName.
+ * There may be more than one but we only take any
+ * notice of the first.
+ */
+ GENERAL_NAMES *gens;
+ GENERAL_NAME *gen;
+ X509_NAME *nm = NULL;
+ int i;
+ gens = subject->akid->issuer;
+ for(i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
+ gen = sk_GENERAL_NAME_value(gens, i);
+ if(gen->type == GEN_DIRNAME) {
+ nm = gen->d.dirn;
+ break;
+ }
+ }
+ if(nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer)))
+ return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
+ }
+ }
+ if(subject->ex_flags & EXFLAG_PROXY)
+ {
+ if(ku_reject(issuer, KU_DIGITAL_SIGNATURE))
+ return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
+ }
+ else if(ku_reject(issuer, KU_KEY_CERT_SIGN))
+ return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
+ return X509_V_OK;
+}
+