Tolerate some "variations" used in some
[openssl.git] / crypto / x509v3 / v3_purp.c
index 6ec5f95..9fa0e50 100644 (file)
 #include <stdio.h>
 #include "cryptlib.h"
 #include <openssl/x509v3.h>
+#include <openssl/x509_vfy.h>
 
-
-static int x509_purpose_get_idx(int id);
 static void x509v3_cache_extensions(X509 *x);
 
-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 ca_check(const 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 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);
        }
        if(id == -1) return 1;
-       idx = x509_purpose_get_idx(id);
+       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_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 < X509_PURPOSE_COUNT) return xstandard + idx;
+       return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
+}
 
+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;
+}
 
-static int x509_purpose_get_idx(int id)
+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)
 {
+       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;
 }
 
 static void x509v3_cache_extensions(X509 *x)
@@ -197,17 +261,20 @@ static void x509v3_cache_extensions(X509 *x)
        BASIC_CONSTRAINTS *bs;
        ASN1_BIT_STRING *usage;
        ASN1_BIT_STRING *ns;
-       STACK_OF(ASN1_OBJECT) *extusage;
+       EXTENDED_KEY_USAGE *extusage;
+       
        int i;
        if(x->ex_flags & EXFLAG_SET) return;
+#ifndef 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)
@@ -220,7 +287,7 @@ static void x509v3_cache_extensions(X509 *x)
                x->ex_flags |= EXFLAG_BCONS;
        }
        /* 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) 
@@ -230,7 +297,7 @@ static void x509v3_cache_extensions(X509 *x)
                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))) {
@@ -253,17 +320,28 @@ static void x509v3_cache_extensions(X509 *x)
                                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;
                        }
                }
                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);
        x->ex_flags |= EXFLAG_SET;
 }
 
@@ -283,7 +361,7 @@ static void x509v3_cache_extensions(X509 *x)
 #define ns_reject(x, usage) \
        (((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
 
-static int ca_check(X509 *x)
+static int ca_check(const X509 *x)
 {
        /* keyUsage if present should allow cert signing */
        if(ku_reject(x, KU_KEY_CERT_SIGN)) return 0;
@@ -293,26 +371,32 @@ static int ca_check(X509 *x)
                else return 0;
        } else {
                if((x->ex_flags & V1_ROOT) == V1_ROOT) return 3;
+               /* If key usage present it must have certSign so tolerate it */
+               else if (x->ex_flags & EXFLAG_KUSAGE) return 3;
                else return 2;
        }
 }
 
+/* Check SSL CA: common checks for SSL client and server */
+static int check_ssl_ca(const X509 *x)
+{
+       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;
+}
+
 
-static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
+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 */ 
@@ -320,11 +404,10 @@ static int check_purpose_ssl_client(X509_PURPOSE *xp, X509 *x, int ca)
        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 */
@@ -334,7 +417,7 @@ 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 check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x, int ca)
 {
        int ret;
        ret = check_purpose_ssl_server(xp, x, ca);
@@ -345,7 +428,7 @@ static int check_purpose_ns_ssl_server(X509_PURPOSE *xp, X509 *x, int 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) {
@@ -369,16 +452,16 @@ static int purpose_smime(X509 *x, int ca)
        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);
@@ -387,7 +470,7 @@ static int check_purpose_smime_encrypt(X509_PURPOSE *xp, X509 *x, int 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;
@@ -397,3 +480,86 @@ static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
        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 */
+       if(ca) {
+               int ca_ret;
+               ca_ret = ca_check(x);
+               if(ca_ret != 2) return ca_ret;
+               if(x->ex_flags & EXFLAG_NSCERT) {
+                       if(x->ex_nscert & NS_ANY_CA) return ca_ret;
+                       return 0;
+               }
+               return 0;
+       }
+       /* 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(ku_reject(issuer, KU_KEY_CERT_SIGN)) return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
+       return X509_V_OK;
+}
+