Update from stable branch.
[openssl.git] / crypto / x509v3 / v3_purp.c
index 717e23d..181bd34 100644 (file)
@@ -1,9 +1,9 @@
 /* v3_purp.c */
-/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
+ * 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 <openssl/x509v3.h>
 #include <openssl/x509_vfy.h>
 
-
 static void x509v3_cache_extensions(X509 *x);
 
-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);
@@ -73,7 +71,9 @@ 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 check_purpose_timestamp_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);
@@ -87,6 +87,8 @@ 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},
+       {X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0, check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign", NULL},
 };
 
 #define X509_PURPOSE_COUNT (sizeof(xstandard)/sizeof(X509_PURPOSE))
@@ -120,6 +122,16 @@ 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;
@@ -129,7 +141,7 @@ int X509_PURPOSE_get_count(void)
 X509_PURPOSE * X509_PURPOSE_get0(int idx)
 {
        if(idx < 0) return NULL;
-       if(idx < X509_PURPOSE_COUNT) return xstandard + idx;
+       if(idx < (int)X509_PURPOSE_COUNT) return xstandard + idx;
        return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
 }
 
@@ -144,7 +156,6 @@ int X509_PURPOSE_get_by_sname(char *sname)
        return -1;
 }
 
-
 int X509_PURPOSE_get_by_id(int purpose)
 {
        X509_PURPOSE tmp;
@@ -230,7 +241,7 @@ static void xptable_free(X509_PURPOSE *p)
 
 void X509_PURPOSE_cleanup(void)
 {
-       int i;
+       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;
@@ -256,21 +267,110 @@ int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
        return xp->trust;
 }
 
+static int nid_cmp(const int *a, const int *b)
+       {
+       return *a - *b;
+       }
+
+DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
+IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
+
+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 const int supported_nids[] = {
+               NID_netscape_cert_type, /* 71 */
+               NID_key_usage,          /* 83 */
+               NID_subject_alt_name,   /* 85 */
+               NID_basic_constraints,  /* 87 */
+               NID_certificate_policies, /* 89 */
+               NID_ext_key_usage,      /* 126 */
+#ifndef OPENSSL_NO_RFC3779
+               NID_sbgp_ipAddrBlock,   /* 290 */
+               NID_sbgp_autonomousSysNum, /* 291 */
+#endif
+               NID_policy_constraints, /* 401 */
+               NID_proxyCertInfo,      /* 663 */
+               NID_name_constraints,   /* 666 */
+               NID_policy_mappings,    /* 747 */
+               NID_inhibit_any_policy  /* 748 */
+       };
+
+       int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
+
+       if (ex_nid == NID_undef) 
+               return 0;
+
+       if (OBJ_bsearch_nid(&ex_nid, supported_nids,
+                       sizeof(supported_nids)/sizeof(int)))
+               return 1;
+       return 0;
+       }
+
+static void setup_dp(X509 *x, DIST_POINT *dp)
+       {
+       X509_NAME *iname = NULL;
+       int i;
+       if (dp->reasons)
+               {
+               if (dp->reasons->length > 0)
+                       dp->dp_reasons = dp->reasons->data[0];
+               if (dp->reasons->length > 1)
+                       dp->dp_reasons |= (dp->reasons->data[1] << 8);
+               dp->dp_reasons &= CRLDP_ALL_REASONS;
+               }
+       else
+               dp->dp_reasons = CRLDP_ALL_REASONS;
+       if (!dp->distpoint || (dp->distpoint->type != 1))
+               return;
+       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)
+                       {
+                       iname = gen->d.directoryName;
+                       break;
+                       }
+               }
+       if (!iname)
+               iname = X509_get_issuer_name(x);
+
+       DIST_POINT_set_dpname(dp->distpoint, iname);
+
+       }
+
+static void setup_crldp(X509 *x)
+       {
+       int i;
+       x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
+       for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
+               setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
+       }
+
 static void x509v3_cache_extensions(X509 *x)
 {
        BASIC_CONSTRAINTS *bs;
+       PROXY_CERT_INFO_EXTENSION *pci;
        ASN1_BIT_STRING *usage;
        ASN1_BIT_STRING *ns;
        EXTENDED_KEY_USAGE *extusage;
+       X509_EXTENSION *ex;
        
        int i;
        if(x->ex_flags & EXFLAG_SET) return;
-#ifndef NO_SHA
+#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;
+                        x->ex_flags |= EXFLAG_SI;
        /* V1 should mean no extensions ... */
        if(!X509_get_version(x)) x->ex_flags |= EXFLAG_V1;
        /* Handle basic constraints */
@@ -286,6 +386,20 @@ static void x509v3_cache_extensions(X509 *x)
                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=X509_get_ext_d2i(x, NID_key_usage, NULL, NULL))) {
                if(usage->length > 0) {
@@ -320,6 +434,19 @@ 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;
+
+                               case NID_dvcs:
+                               x->ex_xkusage |= XKU_DVCS;
+                               break;
                        }
                }
                sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
@@ -333,6 +460,31 @@ static void x509v3_cache_extensions(X509 *x)
        }
        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->altname = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
+       x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
+       if (!x->nc && (i != -1))
+               x->ex_flags |= EXFLAG_INVALID;
+       setup_crldp(x);
+
+#ifndef OPENSSL_NO_RFC3779
+       x->rfc3779_addr =X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
+       x->rfc3779_asid =X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
+                                         NULL, NULL);
+#endif
+       for (i = 0; i < X509_get_ext_count(x); i++)
+               {
+               ex = X509_get_ext(x, i);
+               if (!X509_EXTENSION_get_critical(ex))
+                       continue;
+               if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
+                                       == NID_freshest_crl)
+                       x->ex_flags |= EXFLAG_FRESHEST;
+               if (!X509_supported_extension(ex))
+                       {
+                       x->ex_flags |= EXFLAG_CRITICAL;
+                       break;
+                       }
+               }
        x->ex_flags |= EXFLAG_SET;
 }
 
@@ -342,6 +494,7 @@ static void x509v3_cache_extensions(X509 *x)
  * 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)
@@ -352,7 +505,7 @@ 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(const 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;
@@ -361,26 +514,40 @@ static int ca_check(const X509 *x)
                /* 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);
 }
 
 /* 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);
+       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_SSL_CA) return ca_ret;
-               return 0;
-       }
-       if(ca_ret != 2) return ca_ret;
+       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)
 {
@@ -422,14 +589,10 @@ 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) {
@@ -446,7 +609,7 @@ static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x, int c
        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;
 }
 
@@ -463,13 +626,61 @@ 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 check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
+                                       int ca)
+{
+       int i_ext;
+
+       /* If ca is true we must return if this is a valid CA certificate. */
+       if (ca) return check_ca(x);
+
+       /* 
+        * Check the optional key usage field:
+        * if Key Usage is present, it must be one of digitalSignature 
+        * and/or nonRepudiation (other values are not consistent and shall
+        * be rejected).
+        */
+       if ((x->ex_flags & EXFLAG_KUSAGE)
+           && ((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
+               !(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE))))
+               return 0;
+
+       /* Only time stamp key usage is permitted and it's required. */
+       if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP)
+               return 0;
+
+       /* Extended Key Usage MUST be critical */
+       i_ext = X509_get_ext_by_NID((X509 *) x, NID_ext_key_usage, 0);
+       if (i_ext >= 0)
+               {
+               X509_EXTENSION *ext = X509_get_ext((X509 *) x, i_ext);
+               if (!X509_EXTENSION_get_critical(ext))
+                       return 0;
+               }
+
+       return 1;
+}
+
 static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca)
 {
        return 1;
@@ -494,40 +705,63 @@ int X509_check_issued(X509 *issuer, X509 *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) )
+
+       if(subject->akid)
+               {
+               int ret = X509_check_akid(issuer, subject->akid);
+               if (ret != X509_V_OK)
+                       return ret;
+               }
+
+       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;
+}
+
+int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid)
+       {
+
+       if(!akid)
+               return X509_V_OK;
+
+       /* Check key ids (if present) */
+       if(akid->keyid && issuer->skid &&
+                ASN1_OCTET_STRING_cmp(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))
+       /* Check serial number */
+       if(akid->serial &&
+               ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), 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;
+       /* Check issuer name */
+       if(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 = 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(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;
-}
+       }