Initial CRL based revocation checking.
[openssl.git] / crypto / x509 / x509_vfy.c
index 298016b..c8fa53d 100644 (file)
@@ -75,6 +75,8 @@ static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
 static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
 static int check_chain_purpose(X509_STORE_CTX *ctx);
 static int check_trust(X509_STORE_CTX *ctx);
+static int check_revocation(X509_STORE_CTX *ctx);
+static int check_cert(X509_STORE_CTX *ctx);
 static int internal_verify(X509_STORE_CTX *ctx);
 const char *X509_version="X.509" OPENSSL_VERSION_PTEXT;
 
@@ -296,6 +298,13 @@ int X509_verify_cert(X509_STORE_CTX *ctx)
        /* We may as well copy down any DSA parameters that are required */
        X509_get_pubkey_parameters(NULL,ctx->chain);
 
+       /* Check revocation status: we do this after copying parameters
+        * because they may be needed for CRL signature verification.
+        */
+
+       ok = ctx->check_revocation(ctx);
+       if(!ok) goto end;
+
        /* At this point, we have a chain and just need to verify it */
        if (ctx->verify != NULL)
                ok=ctx->verify(ctx);
@@ -425,7 +434,7 @@ static int check_trust(X509_STORE_CTX *ctx)
        ok = X509_check_trust(x, ctx->trust, 0);
        if (ok == X509_TRUST_TRUSTED)
                return 1;
-       ctx->error_depth = sk_X509_num(ctx->chain) - 1;
+       ctx->error_depth = i;
        ctx->current_cert = x;
        if (ok == X509_TRUST_REJECTED)
                ctx->error = X509_V_ERR_CERT_REJECTED;
@@ -436,6 +445,196 @@ static int check_trust(X509_STORE_CTX *ctx)
 #endif
 }
 
+static int check_revocation(X509_STORE_CTX *ctx)
+       {
+       int i, last, ok;
+       if (!(ctx->flags & X509_V_FLAG_CRL_CHECK))
+               return 1;
+       if (ctx->flags & X509_V_FLAG_CRL_CHECK_ALL)
+               last = 0;
+       else
+               last = sk_X509_num(ctx->chain) - 1;
+       for(i = 0; i <= last; i++)
+               {
+               ctx->error_depth = i;
+               ok = check_cert(ctx);
+               if (!ok) return ok;
+               }
+       return 1;
+       }
+
+static int check_cert(X509_STORE_CTX *ctx)
+       {
+       X509_CRL *crl = NULL;
+       X509 *x;
+       int ok, cnum;
+       cnum = ctx->error_depth;
+       x = sk_X509_value(ctx->chain, cnum);
+       ctx->current_cert = x;
+       /* Try to retrieve relevant CRL */
+       ok = ctx->get_crl(ctx, &crl, x);
+       /* If error looking up CRL, nothing we can do except
+        * notify callback
+        */
+       if(!ok)
+               {
+               ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
+               if (ctx->verify_cb)
+                       ok = ctx->verify_cb(0, ctx);
+               goto err;
+               }
+       ctx->current_crl = crl;
+       ok = ctx->check_crl(ctx, crl);
+       if (!ok) goto err;
+       ok = ctx->cert_crl(ctx, crl, x);
+       err:
+       ctx->current_crl = NULL;
+       X509_CRL_free(crl);
+       return ok;
+
+       }
+
+/* Retrieve CRL corresponding to certificate: currently just a
+ * subject lookup: maybe use AKID later...
+ * Also might look up any included CRLs too (e.g PKCS#7 signedData).
+ */
+static int get_crl(X509_STORE_CTX *ctx, X509_CRL **crl, X509 *x)
+       {
+       int ok;
+       X509_OBJECT xobj;
+       ok = X509_STORE_get_by_subject(ctx, X509_LU_CRL, X509_get_issuer_name(x), &xobj);
+       if (!ok) return 0;
+       *crl = xobj.data.crl;
+       return 1;
+       }
+
+/* Check CRL validity */
+static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl)
+       {
+       X509 *issuer = NULL;
+       EVP_PKEY *ikey = NULL;
+       int ok = 0, chnum, cnum, i;
+       time_t *ptime;
+       cnum = ctx->error_depth;
+       chnum = sk_X509_num(ctx->chain) - 1;
+       /* Find CRL issuer: if not last certificate then issuer
+        * is next certificate in chain.
+        */
+       if(cnum < chnum)
+               issuer = sk_X509_value(ctx->chain, cnum + 1);
+       else
+               {
+               issuer = sk_X509_value(ctx->chain, chnum);
+               /* If not self signed, can't check signature */
+               if(!ctx->check_issued(ctx, issuer, issuer))
+                       {
+                       ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER;
+                       if(ctx->verify_cb)
+                               ok = ctx->verify_cb(0, ctx);
+                       if(!ok) goto err;
+                       }
+               }
+
+       if(issuer)
+               {
+
+               /* Attempt to get issuer certificate public key */
+               ikey = X509_get_pubkey(issuer);
+
+               if(!ikey)
+                       {
+                       ctx->error=X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
+                       if(ctx->verify_cb)
+                               ok = ctx->verify_cb(0, ctx);
+                       if (!ok) goto err;
+                       }
+               else
+                       {
+                       /* Verify CRL signature */
+                       if(X509_CRL_verify(crl, ikey) <= 0)
+                               {
+                               ctx->error=X509_V_ERR_CRL_SIGNATURE_FAILURE;
+                               if(ctx->verify_cb)
+                                       ok = ctx->verify_cb(0, ctx);
+                               if (!ok) goto err;
+                               }
+                       }
+               }
+
+       /* OK, CRL signature valid check times */
+       if (ctx->flags & X509_V_FLAG_USE_CHECK_TIME)
+               ptime = &ctx->check_time;
+       else
+               ptime = NULL;
+
+       i=X509_cmp_time(X509_CRL_get_lastUpdate(crl), ptime);
+       if (i == 0)
+               {
+               ctx->error=X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD;
+               ok= 0;
+               if(ctx->verify_cb)
+                       ok = ctx->verify_cb(0, ctx);
+               if (!ok) goto err;
+               }
+
+       if (i > 0)
+               {
+               ctx->error=X509_V_ERR_CRL_NOT_YET_VALID;
+               ok= 0;
+               if(ctx->verify_cb)
+                       ok = ctx->verify_cb(0, ctx);
+               if (!ok) goto err;
+               }
+
+       if(X509_CRL_get_nextUpdate(crl))
+               {
+               i=X509_cmp_time(X509_CRL_get_nextUpdate(crl), ptime);
+
+               if (i == 0)
+                       {
+                       ctx->error=X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD;
+                       ok= 0;
+                       if(ctx->verify_cb)
+                               ok = ctx->verify_cb(0, ctx);
+                       if (!ok) goto err;
+                       }
+
+               if (i < 0)
+                       {
+                       ctx->error=X509_V_ERR_CRL_HAS_EXPIRED;
+                       ok= 0;
+                       if(ctx->verify_cb)
+                               ok = ctx->verify_cb(0, ctx);
+                       if (!ok) goto err;
+                       }
+               }
+
+       ok = 1;
+
+       err:
+       EVP_PKEY_free(ikey);
+       return ok;
+       }
+
+/* Check certificate against CRL */
+static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x)
+       {
+       int idx, ok;
+       X509_REVOKED rtmp;
+       /* Look for serial number of certificate in CRL */
+       rtmp.serialNumber = X509_get_serialNumber(x);
+       idx = sk_X509_REVOKED_find(crl->crl->revoked, &rtmp);
+       /* Not found: OK */
+       if(idx == -1) return 1;
+       /* Otherwise revoked: want something cleverer than
+        * this to handle entry extensions in V2 CRLs.
+        */
+       ctx->error = X509_V_ERR_CERT_REVOKED;
+       if (ctx->verify_cb)
+               ok = ctx->verify_cb(0, ctx);
+       return ok;
+       }
+
 static int internal_verify(X509_STORE_CTX *ctx)
        {
        int i,ok=0,n;
@@ -885,6 +1084,10 @@ void X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
        ctx->get_issuer = X509_STORE_CTX_get1_issuer;
        ctx->verify_cb = store->verify_cb;
        ctx->verify = store->verify;
+       ctx->check_revocation = check_revocation;
+       ctx->get_crl = get_crl;
+       ctx->check_crl = check_crl;
+       ctx->cert_crl = cert_crl;
        ctx->cleanup = 0;
        memset(&(ctx->ex_data),0,sizeof(CRYPTO_EX_DATA));
        }