Initial indirect CRL support.
authorDr. Stephen Henson <steve@openssl.org>
Wed, 20 Aug 2008 16:42:19 +0000 (16:42 +0000)
committerDr. Stephen Henson <steve@openssl.org>
Wed, 20 Aug 2008 16:42:19 +0000 (16:42 +0000)
CHANGES
crypto/asn1/asn1_locl.h
crypto/asn1/x_crl.c
crypto/x509/x509.h
crypto/x509/x509_vfy.c

diff --git a/CHANGES b/CHANGES
index 966a900..15ad439 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,14 @@
 
  Changes between 0.9.8i and 0.9.9  [xx XXX xxxx]
 
+  *) Initial indirect CRL support. Currently only supported in the CRLs
+     passed directly and not via lookup. Process certificate issuer
+     CRL entry extension and lookup CRL entries by bother issuer name
+     and serial number. Check and proces CRL issuer entry in IDP extension.
+
+     This work was sponsored by Google.
+     [Steve Henson]
+
   *) Add support for distinct certificate and CRL paths. The CRL issuer
      certificate is validated separately in this case. Only enabled if
      an extended CRL support flag is set: this flag will enable additional
index 3cead31..7d10700 100644 (file)
@@ -128,6 +128,7 @@ struct x509_crl_method_st
        int flags;
        int (*crl_init)(X509_CRL *crl);
        int (*crl_free)(X509_CRL *crl);
-       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser);
+       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+                               ASN1_INTEGER *ser, X509_NAME *issuer);
        int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk);
        };
index 6edc6f2..e634637 100644 (file)
@@ -75,7 +75,7 @@ ASN1_SEQUENCE(X509_REVOKED) = {
 
 static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r);
 static int def_crl_lookup(X509_CRL *crl,
-               X509_REVOKED **ret, ASN1_INTEGER *serial);
+               X509_REVOKED **ret, ASN1_INTEGER *serial, X509_NAME *issuer);
 
 static X509_CRL_METHOD int_crl_meth =
        {
@@ -119,6 +119,72 @@ ASN1_SEQUENCE_enc(X509_CRL_INFO, enc, crl_inf_cb) = {
        ASN1_EXP_SEQUENCE_OF_OPT(X509_CRL_INFO, extensions, X509_EXTENSION, 0)
 } ASN1_SEQUENCE_END_enc(X509_CRL_INFO, X509_CRL_INFO)
 
+/* Set CRL entry issuer according to CRL certificate issuer extension.
+ * Check for unhandled critical CRL entry extensions.
+ */
+
+static int crl_set_issuers(X509_CRL *crl)
+       {
+
+       int i, j;
+       GENERAL_NAMES *gens, *gtmp;
+       STACK_OF(X509_REVOKED) *revoked;
+
+       revoked = X509_CRL_get_REVOKED(crl);
+
+       gens = NULL;
+       for (i = 0; i < sk_X509_REVOKED_num(revoked); i++)
+               {
+               X509_REVOKED *rev = sk_X509_REVOKED_value(revoked, i);
+               STACK_OF(X509_EXTENSION) *exts;
+               X509_EXTENSION *ext;
+               gtmp = X509_REVOKED_get_ext_d2i(rev, 
+                                               NID_certificate_issuer,
+                                               &j, NULL);
+               if (!gtmp && (j != -1))
+                       {
+                       crl->flags |= EXFLAG_INVALID;
+                       return 1;
+                       }
+
+               if (gtmp)
+                       {
+                       gens = gtmp;
+                       if (!crl->issuers)
+                               {
+                               crl->issuers = sk_GENERAL_NAMES_new_null();
+                               if (!crl->issuers)
+                                       return 0;
+                               }
+                       if (!sk_GENERAL_NAMES_push(crl->issuers, gtmp))
+                               return 0;
+                       }
+               rev->issuer = gens;
+
+               /* Check for critical CRL entry extensions */
+
+               exts = rev->extensions;
+
+               for (j = 0; j < sk_X509_EXTENSION_num(exts); j++)
+                       {
+                       ext = sk_X509_EXTENSION_value(exts, j);
+                       if (ext->critical > 0)
+                               {
+                               if (OBJ_obj2nid(ext->object) ==
+                                       NID_certificate_issuer)
+                                       continue;
+                               crl->flags |= EXFLAG_CRITICAL;
+                               break;
+                               }
+                       }
+
+
+               }
+
+       return 1;
+
+       }
+
 /* The X509_CRL structure needs a bit of customisation. Cache some extensions
  * and hash of the whole CRL.
  */
@@ -139,6 +205,7 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                crl->idp_flags = 0;
                crl->meth = default_crl_method;
                crl->meth_data = NULL;
+               crl->issuers = NULL;
                break;
 
                case ASN1_OP_D2I_POST:
@@ -176,6 +243,11 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                                break;
                                }
                        }
+
+
+               if (!crl_set_issuers(crl))
+                       return 0;
+
                if (crl->meth->crl_init)
                        {
                        if (crl->meth->crl_init(crl) == 0)
@@ -193,6 +265,7 @@ static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
                        AUTHORITY_KEYID_free(crl->akid);
                if (crl->idp)
                        ISSUING_DIST_POINT_free(crl->idp);
+               sk_GENERAL_NAMES_pop_free(crl->issuers, GENERAL_NAMES_free);
                break;
                }
        return 1;
@@ -284,7 +357,16 @@ int X509_CRL_get0_by_serial(X509_CRL *crl,
                X509_REVOKED **ret, ASN1_INTEGER *serial)
        {
        if (crl->meth->crl_lookup)
-               return crl->meth->crl_lookup(crl, ret, serial);
+               return crl->meth->crl_lookup(crl, ret, serial, NULL);
+       return 0;
+       }
+
+int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x)
+       {
+       if (crl->meth->crl_lookup)
+               return crl->meth->crl_lookup(crl, ret,
+                                               X509_get_serialNumber(x),
+                                               X509_get_issuer_name(x));
        return 0;
        }
 
@@ -294,10 +376,39 @@ static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r)
                crl->sig_alg, crl->signature,crl->crl,r));
        }
 
+static int crl_revoked_issuer_match(X509_CRL *crl, X509_NAME *nm,
+                                               X509_REVOKED *rev)
+       {
+       int i;
+
+       if (!rev->issuer)
+               {
+               if (!nm)
+                       return 1;
+               if (!X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
+                       return 1;
+               return 0;
+               }
+
+       if (!nm)
+               nm = X509_CRL_get_issuer(crl);
+
+       for (i = 0; i < sk_GENERAL_NAME_num(rev->issuer); i++)
+               {
+               GENERAL_NAME *gen = sk_GENERAL_NAME_value(rev->issuer, i);
+               if (gen->type != GEN_DIRNAME)
+                       continue;
+               if (!X509_NAME_cmp(nm, gen->d.directoryName))
+                       return 1;
+               }
+       return 0;
+
+       }
+
 static int def_crl_lookup(X509_CRL *crl,
-               X509_REVOKED **ret, ASN1_INTEGER *serial)
+               X509_REVOKED **ret, ASN1_INTEGER *serial, X509_NAME *issuer)
        {
-       X509_REVOKED rtmp;
+       X509_REVOKED rtmp, *rev;
        int idx;
        rtmp.serialNumber = serial;
        /* Sort revoked into serial number order if not already sorted.
@@ -310,14 +421,20 @@ static int def_crl_lookup(X509_CRL *crl,
                CRYPTO_w_unlock(CRYPTO_LOCK_X509_CRL);
                }
        idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
-       /* If found assume revoked: want something cleverer than
-        * this to handle entry extensions in V2 CRLs.
-        */
-       if(idx >= 0)
+       if(idx < 0)
+               return 0;
+       /* Need to look for matching name */
+       for(;idx < sk_X509_REVOKED_num(crl->crl->revoked); idx++)
                {
-               if (ret)
-                       *ret = sk_X509_REVOKED_value(crl->crl->revoked, idx);
-               return 1;
+               rev = sk_X509_REVOKED_value(crl->crl->revoked, idx);
+               if (ASN1_INTEGER_cmp(rev->serialNumber, serial))
+                       return 0;
+               if (crl_revoked_issuer_match(crl, issuer, rev))
+                       {
+                       if (ret)
+                               *ret = rev;
+                       return 1;
+                       }
                }
        return 0;
        }
@@ -333,7 +450,8 @@ void X509_CRL_set_default_method(const X509_CRL_METHOD *meth)
 X509_CRL_METHOD *X509_CRL_METHOD_new(
        int (*crl_init)(X509_CRL *crl),
        int (*crl_free)(X509_CRL *crl),
-       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser),
+       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+                               ASN1_INTEGER *ser, X509_NAME *issuer),
        int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk))
        {
        X509_CRL_METHOD *m;
index adbdc65..a1ac619 100644 (file)
@@ -434,6 +434,8 @@ struct x509_revoked_st
        ASN1_INTEGER *serialNumber;
        ASN1_TIME *revocationDate;
        STACK_OF(X509_EXTENSION) /* optional */ *extensions;
+       /* Set up if indirect CRL */
+       STACK_OF(GENERAL_NAME) *issuer;
        int sequence; /* load sequence */
        };
 
@@ -469,6 +471,7 @@ struct X509_crl_st
 #ifndef OPENSSL_NO_SHA
        unsigned char sha1_hash[SHA_DIGEST_LENGTH];
 #endif
+       STACK_OF(GENERAL_NAMES) *issuers;
        const X509_CRL_METHOD *meth;
        void *meth_data;
        } /* X509_CRL */;
@@ -617,7 +620,8 @@ void X509_CRL_set_default_method(const X509_CRL_METHOD *meth);
 X509_CRL_METHOD *X509_CRL_METHOD_new(
        int (*crl_init)(X509_CRL *crl),
        int (*crl_free)(X509_CRL *crl),
-       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret, ASN1_INTEGER *ser),
+       int (*crl_lookup)(X509_CRL *crl, X509_REVOKED **ret,
+                               ASN1_INTEGER *ser, X509_NAME *issuer),
        int (*crl_verify)(X509_CRL *crl, EVP_PKEY *pk));
 void X509_CRL_METHOD_free(X509_CRL_METHOD *m);
 
@@ -847,6 +851,7 @@ DECLARE_ASN1_FUNCTIONS(X509_CRL)
 int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev);
 int X509_CRL_get0_by_serial(X509_CRL *crl,
                X509_REVOKED **ret, ASN1_INTEGER *serial);
+int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x);
 
 X509_PKEY *    X509_PKEY_new(void );
 void           X509_PKEY_free(X509_PKEY *a);
index 7435781..e92a9c3 100644 (file)
@@ -80,7 +80,7 @@ static int check_revocation(X509_STORE_CTX *ctx);
 static int check_cert(X509_STORE_CTX *ctx);
 static int check_policy(X509_STORE_CTX *ctx);
 static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer);
-static int idp_check_scope(X509 *x, X509_CRL *crl);
+static int idp_check_scope(X509 *x, X509_CRL *crl, int *pimatch);
 static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
 static int check_crl_chain(X509_STORE_CTX *ctx,
                        STACK_OF(X509) *cert_path,
@@ -751,7 +751,7 @@ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
 
 /* IDP flags which cause a CRL to be rejected */
 
-#define IDP_REJECT     (IDP_INVALID|IDP_INDIRECT|IDP_REASONS)
+#define IDP_REJECT     (IDP_INVALID|IDP_REASONS)
 
 static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
                        X509_NAME *nm, STACK_OF(X509_CRL) *crls)
@@ -761,11 +761,19 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
        X509 *crl_issuer, *best_crl_issuer = NULL;
        for (i = 0; i < sk_X509_CRL_num(crls); i++)
                {
+               int imatch = 1;
                crl_score = 0;
                crl_issuer = NULL;
                crl = sk_X509_CRL_value(crls, i);
                if (nm && X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))
-                       continue;
+                       {
+                       /* Issuer name does not match: could be indirect */
+                       if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
+                               continue;
+                       if (!(crl->idp_flags & IDP_INDIRECT))
+                               continue;
+                       imatch = 0;
+                       }
                if (check_crl_time(ctx, crl, 0))
                        crl_score |= CRL_SCORE_TIME;
 
@@ -773,12 +781,16 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
                        {
                        if (crl->idp_flags & IDP_REJECT)
                                continue;
-                       if (idp_check_scope(ctx->current_cert, crl))
+                       if (idp_check_scope(ctx->current_cert, crl, &imatch))
                                crl_score |= CRL_SCORE_SCOPE;
                        }
                else
                        crl_score |= CRL_SCORE_SCOPE;
 
+               /* If no issuer match at this point try next CRL */
+               if (!imatch)
+                       continue;
+
                if (crl_akid_check(ctx, crl, &crl_issuer))
                        crl_score |= CRL_SCORE_AKID;
                /* If CRL matches criteria and issuer is not different use it */
@@ -809,6 +821,7 @@ static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl,
 static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
        {
        X509 *crl_issuer;
+       X509_NAME *cnm = X509_CRL_get_issuer(crl);
        int cidx = ctx->error_depth;
        int i;
        if (!crl->akid)
@@ -818,25 +831,18 @@ static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
        crl_issuer = sk_X509_value(ctx->chain, cidx);
        if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
                return 1;
-       /* If crl_issuer is self issued we may get a match further along the
-        * chain.
-        */
-       if (crl_issuer->ex_flags & EXFLAG_SI)
+       for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++)
                {
-               for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++)
+               crl_issuer = sk_X509_value(ctx->chain, cidx);
+               if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm))
+                       continue;
+               if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
                        {
-                       crl_issuer = sk_X509_value(ctx->chain, cidx);
-                       if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK)
-                               {
-                               *pissuer = crl_issuer;
-                               return 1;
-                               }
-                       if (!(crl_issuer->ex_flags & EXFLAG_SI))
-                               break;
+                       *pissuer = crl_issuer;
+                       return 1;
                        }
                }
 
-
        /* Anything else needs extended CRL support */
 
        if (!(ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT))
@@ -845,7 +851,6 @@ static int crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer)
        /* Otherwise the CRL issuer is not on the path. Look for it in the
         * set of untrusted certificates.
         */
-
        for (i = 0; i < sk_X509_num(ctx->untrusted); i++)
                {
                crl_issuer = sk_X509_value(ctx->untrusted, i);
@@ -928,6 +933,7 @@ static int check_crl_chain(X509_STORE_CTX *ctx,
  * 1. Both are relative names and compare X509_NAME types.
  * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES.
  * 3. Both are full names and compare two GENERAL_NAMES.
+ * 4. One is NULL: automatic match.
  */
 
 
@@ -937,6 +943,8 @@ static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
        GENERAL_NAMES *gens = NULL;
        GENERAL_NAME *gena, *genb;
        int i, j;
+       if (!a || !b)
+               return 1;
        if (a->type == 1)
                {
                if (!a->dpname)
@@ -995,9 +1003,30 @@ static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b)
 
        }
 
+static int idp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int *pimatch)
+       {
+       int i;
+       X509_NAME *nm = X509_CRL_get_issuer(crl);
+       /* If no CRLissuer return is successful iff don't need a match */
+       if (!dp->CRLissuer)
+               return *pimatch;
+       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)
+                       continue;
+               if (!X509_NAME_cmp(gen->d.directoryName, nm))
+                       {
+                       *pimatch = 1;
+                       return 1;
+                       }
+               }
+       return 0;
+       }
+
 /* Check IDP name matches at least one CRLDP name */
 
-static int idp_check_scope(X509 *x, X509_CRL *crl)
+static int idp_check_scope(X509 *x, X509_CRL *crl, int *pimatch)
        {
        int i;
        if (crl->idp_flags & IDP_ONLYATTR)
@@ -1012,18 +1041,19 @@ static int idp_check_scope(X509 *x, X509_CRL *crl)
                if (crl->idp_flags & IDP_ONLYCA)
                        return 0;
                }
-       if (!crl->idp->distpoint)
+       if (!crl->idp->distpoint && *pimatch)
                return 1;
-       if (!x->crldp)
-               return 0;
        for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
                {
                DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i);
                /* We don't handle these at present */
-               if (dp->reasons || dp->CRLissuer)
+               if (dp->reasons)
                        continue;
                if (idp_check_dp(dp->distpoint, crl->idp->distpoint))
-                       return 1;
+                       {
+                       if (idp_check_crlissuer(dp, crl, pimatch))
+                               return 1;
+                       }
                }
        return 0;
        }
@@ -1117,19 +1147,20 @@ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
 
                if (crl->idp_flags & IDP_PRESENT)
                        {
+                       int dmy = 1;
                        if (crl->idp_flags & IDP_INVALID)
                                {
                                ctx->error = X509_V_ERR_INVALID_EXTENSION;
                                ok = ctx->verify_cb(0, ctx);
                                if(!ok) goto err;
                                }
-                       if (crl->idp_flags & (IDP_REASONS|IDP_INDIRECT))
+                       if (crl->idp_flags & IDP_REASONS)
                                {
                                ctx->error = X509_V_ERR_UNSUPPORTED_EXTENSION_FEATURE;
                                ok = ctx->verify_cb(0, ctx);
                                if(!ok) goto err;
                                }
-                       if (!idp_check_scope(ctx->current_cert, crl))
+                       if (!idp_check_scope(ctx->current_cert, crl, &dmy))
                                {
                                ctx->error = X509_V_ERR_DIFFERENT_CRL_SCOPE;
                                ok = ctx->verify_cb(0, ctx);
@@ -1177,7 +1208,7 @@ static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
         * If found assume revoked: want something cleverer than
         * this to handle entry extensions in V2 CRLs.
         */
-       if (X509_CRL_get0_by_serial(crl, NULL, X509_get_serialNumber(x)) > 0)
+       if (X509_CRL_get0_by_cert(crl, NULL, x) > 0)
                {
                ctx->error = X509_V_ERR_CERT_REVOKED;
                ok = ctx->verify_cb(0, ctx);