x509v3/v3_purp.c: re-implement lock-free check for extensions cache validity.

[oweals/openssl.git] / crypto / x509v3 / v3_purp.c

diff --git a/crypto/x509v3/v3_purp.c b/crypto/x509v3/v3_purp.c
index ab3fd7e6b04e965cf4de8fbe2b52ea3875a0eb45..5a535e2adeb6f39f9202f2770bc9a4b15a09bece 100644 (file)
--- a/crypto/x509v3/v3_purp.c
+++ b/crypto/x509v3/v3_purp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -13,6 +13,7 @@
 #include <openssl/x509v3.h>
 #include <openssl/x509_vfy.h>
 #include "internal/x509_int.h"
+#include "internal/tsan_assist.h"
 
 static void x509v3_cache_extensions(X509 *x);
 
@@ -78,11 +79,9 @@ int X509_check_purpose(X509 *x, int id, int ca)
 {
     int idx;
     const X509_PURPOSE *pt;
-    if (!(x->ex_flags & EXFLAG_SET)) {
-        CRYPTO_THREAD_write_lock(x->lock);
-        x509v3_cache_extensions(x);
-        CRYPTO_THREAD_unlock(x->lock);
-    }
+
+    x509v3_cache_extensions(x);
+
     /* Return if side-effect only call */
     if (id == -1)
         return 1;
@@ -135,13 +134,14 @@ int X509_PURPOSE_get_by_id(int purpose)
 {
     X509_PURPOSE tmp;
     int idx;
+
     if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
         return purpose - X509_PURPOSE_MIN;
-    tmp.purpose = purpose;
-    if (!xptable)
+    if (xptable == NULL)
         return -1;
+    tmp.purpose = purpose;
     idx = sk_X509_PURPOSE_find(xptable, &tmp);
-    if (idx == -1)
+    if (idx < 0)
         return -1;
     return idx + X509_PURPOSE_COUNT;
 }
@@ -229,10 +229,7 @@ static void xptable_free(X509_PURPOSE *p)
 
 void X509_PURPOSE_cleanup(void)
 {
-    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;
 }
 
@@ -280,6 +277,7 @@ int X509_supported_extension(X509_EXTENSION *ex)
         NID_subject_alt_name,   /* 85 */
         NID_basic_constraints,  /* 87 */
         NID_certificate_policies, /* 89 */
+        NID_crl_distribution_points, /* 103 */
         NID_ext_key_usage,      /* 126 */
 #ifndef OPENSSL_NO_RFC3779
         NID_sbgp_ipAddrBlock,   /* 290 */
@@ -354,10 +352,18 @@ static void x509v3_cache_extensions(X509 *x)
     ASN1_BIT_STRING *ns;
     EXTENDED_KEY_USAGE *extusage;
     X509_EXTENSION *ex;
-
     int i;
-    if (x->ex_flags & EXFLAG_SET)
+
+    /* fast lock-free check, see end of the function for details. */
+    if (tsan_load((TSAN_QUALIFIER int *)&x->ex_cached))
+        return;
+
+    CRYPTO_THREAD_write_lock(x->lock);
+    if (x->ex_flags & EXFLAG_SET) {
+        CRYPTO_THREAD_unlock(x->lock);
         return;
+    }
+
     X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
     /* V1 should mean no extensions ... */
     if (!X509_get_version(x))
@@ -490,7 +496,15 @@ static void x509v3_cache_extensions(X509 *x)
             break;
         }
     }
+    x509_init_sig_info(x);
     x->ex_flags |= EXFLAG_SET;
+    CRYPTO_THREAD_unlock(x->lock);
+    /*
+     * It has to be placed after memory barrier, which is implied by unlock.
+     * Worst thing that can happen is that another thread proceeds to lock
+     * and checks x->ex_flags & EXFLAGS_SET. See beginning of the function.
+     */
+    tsan_store((TSAN_QUALIFIER int *)&x->ex_cached, 1);
 }
 
 /*-
@@ -531,13 +545,19 @@ static int check_ca(const X509 *x)
     }
 }
 
+void X509_set_proxy_flag(X509 *x)
+{
+    x->ex_flags |= EXFLAG_PROXY;
+}
+
+void X509_set_proxy_pathlen(X509 *x, long l)
+{
+    x->ex_pcpathlen = l;
+}
+
 int X509_check_ca(X509 *x)
 {
-    if (!(x->ex_flags & EXFLAG_SET)) {
-        CRYPTO_THREAD_write_lock(x->lock);
-        x509v3_cache_extensions(x);
-        CRYPTO_THREAD_unlock(x->lock);
-    }
+    x509v3_cache_extensions(x);
 
     return check_ca(x);
 }
@@ -718,7 +738,7 @@ static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
         return 0;
 
     /* Extended Key Usage MUST be critical */
-    i_ext = X509_get_ext_by_NID((X509 *)x, NID_ext_key_usage, -1);
+    i_ext = X509_get_ext_by_NID(x, NID_ext_key_usage, -1);
     if (i_ext >= 0) {
         X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
         if (!X509_EXTENSION_get_critical(ext))
@@ -751,6 +771,7 @@ 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);
 
@@ -839,6 +860,13 @@ const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
     return x->skid;
 }
 
+const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x)
+{
+    /* Call for side-effect of computing hash and caching extensions */
+    X509_check_purpose(x, -1, -1);
+    return (x->akid != NULL ? x->akid->keyid : NULL);
+}
+
 long X509_get_pathlen(X509 *x)
 {
     /* Called for side effect of caching extensions */
@@ -847,3 +875,12 @@ long X509_get_pathlen(X509 *x)
         return -1;
     return x->ex_pathlen;
 }
+
+long X509_get_proxy_pathlen(X509 *x)
+{
+    /* Called for side effect of caching extensions */
+    if (X509_check_purpose(x, -1, -1) != 1
+            || (x->ex_flags & EXFLAG_PROXY) == 0)
+        return -1;
+    return x->ex_pcpathlen;
+}