Undo previous change, X509_check_issued() was correct.
[openssl.git] / crypto / x509v3 / v3_purp.c
index 5594a1d64f9b257479e11bc4d941910eff37294c..b739e4fd837cf41093298c1116bfbf7e2afdd87b 100644 (file)
@@ -1,9 +1,9 @@
 /* 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) 1999-2001 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 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 no_check(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[] = {
@@ -84,6 +87,7 @@ static X509_PURPOSE xstandard[] = {
        {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))
@@ -92,15 +96,19 @@ 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 - (*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);
@@ -113,6 +121,16 @@ int X509_check_purpose(X509 *x, int id, int ca)
        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;
@@ -137,7 +155,6 @@ int X509_PURPOSE_get_by_sname(char *sname)
        return -1;
 }
 
-
 int X509_PURPOSE_get_by_id(int purpose)
 {
        X509_PURPOSE tmp;
@@ -152,7 +169,7 @@ int X509_PURPOSE_get_by_id(int purpose)
 }
 
 int X509_PURPOSE_add(int id, int trust, int flags,
-                       int (*ck)(X509_PURPOSE *, X509 *, int),
+                       int (*ck)(const X509_PURPOSE *, const X509 *, int),
                                        char *name, char *sname, void *arg)
 {
        int idx;
@@ -165,17 +182,17 @@ int X509_PURPOSE_add(int id, int trust, int flags,
        idx = X509_PURPOSE_get_by_id(id);
        /* Need a new entry */
        if(idx == -1) {
-               if(!(ptmp = Malloc(sizeof(X509_PURPOSE)))) {
+               if(!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
                        X509V3err(X509V3_F_X509_PURPOSE_ADD,ERR_R_MALLOC_FAILURE);
                        return 0;
                }
                ptmp->flags = X509_PURPOSE_DYNAMIC;
        } else ptmp = X509_PURPOSE_get0(idx);
 
-       /* Free existing name if dynamic */
+       /* OPENSSL_free existing name if dynamic */
        if(ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
-               Free(ptmp->name);
-               Free(ptmp->sname);
+               OPENSSL_free(ptmp->name);
+               OPENSSL_free(ptmp->sname);
        }
        /* dup supplied name */
        ptmp->name = BUF_strdup(name);
@@ -214,10 +231,10 @@ static void xptable_free(X509_PURPOSE *p)
        if (p->flags & X509_PURPOSE_DYNAMIC) 
                {
                if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
-                       Free(p->name);
-                       Free(p->sname);
+                       OPENSSL_free(p->name);
+                       OPENSSL_free(p->sname);
                }
-               Free(p);
+               OPENSSL_free(p);
                }
        }
 
@@ -249,16 +266,57 @@ int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
        return xp->trust;
 }
 
-#ifndef NO_SHA
+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 */
+       };
+
+       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;
        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)))
                         x->ex_flags |= EXFLAG_SS;
@@ -311,6 +369,15 @@ 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);
@@ -322,9 +389,21 @@ static void x509v3_cache_extensions(X509 *x)
                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;
 }
-#endif
 
 /* CA checks common to all purposes
  * return codes:
@@ -342,7 +421,7 @@ 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;
@@ -352,26 +431,32 @@ 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 */ 
@@ -379,11 +464,10 @@ 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 */
@@ -393,7 +477,7 @@ 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);
@@ -404,7 +488,7 @@ 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) {
@@ -428,16 +512,16 @@ 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);
@@ -446,7 +530,7 @@ 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;
@@ -457,7 +541,85 @@ static int check_purpose_crl_sign(X509_PURPOSE *xp, X509 *x, int ca)
        return 1;
 }
 
-static int no_check(X509_PURPOSE *xp, X509 *x, int ca)
+/* 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;
+}
+