import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

security/nss/lib/ssl/sslgrp.c

@@ -0,0 +1,164 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file contains prototypes for the public SSL functions.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nss.h"
+#include "pk11func.h"
+#include "ssl.h"
+#include "sslimpl.h"
+
+struct {
+    sslEphemeralKeyPair *keyPair;
+    PRCallOnceType once;
+} gECDHEKeyPairs[SSL_NAMED_GROUP_COUNT];
+
+typedef struct sslSocketAndGroupArgStr {
+    const sslNamedGroupDef *group;
+    const sslSocket *ss;
+} sslSocketAndGroupArg;
+
+/* Function to clear out the ECDHE keys. */
+static SECStatus
+ssl_CleanupECDHEKeys(void *appData, void *nssData)
+{
+    unsigned int i;
+
+    for (i = 0; i < SSL_NAMED_GROUP_COUNT; i++) {
+        if (gECDHEKeyPairs[i].keyPair) {
+            ssl_FreeEphemeralKeyPair(gECDHEKeyPairs[i].keyPair);
+        }
+    }
+    memset(gECDHEKeyPairs, 0, sizeof(gECDHEKeyPairs));
+    return SECSuccess;
+}
+
+/* Only run the cleanup once. */
+static PRCallOnceType cleanupECDHEKeysOnce;
+static PRStatus
+ssl_SetupCleanupECDHEKeysOnce(void)
+{
+    SECStatus rv = NSS_RegisterShutdown(ssl_CleanupECDHEKeys, NULL);
+    return (rv != SECSuccess) ? PR_FAILURE : PR_SUCCESS;
+}
+
+/* This creates a key pair for each of the supported EC groups.  If that works,
+ * we assume that the token supports that group.  Since this is relatively
+ * expensive, this is only done for the first socket that is used.  That means
+ * that if tokens are added or removed, then this will not pick up any changes.
+ */
+static PRStatus
+ssl_CreateStaticECDHEKeyPair(void *arg)
+{
+    const sslSocketAndGroupArg *typed_arg = (sslSocketAndGroupArg *)arg;
+    const sslNamedGroupDef *group = typed_arg->group;
+    const sslSocket *ss = typed_arg->ss;
+    unsigned int i = group - ssl_named_groups;
+    SECStatus rv;
+
+    PORT_Assert(group->keaType == ssl_kea_ecdh);
+    PORT_Assert(i < SSL_NAMED_GROUP_COUNT);
+    rv = ssl_CreateECDHEphemeralKeyPair(ss, group,
+                                        &gECDHEKeyPairs[i].keyPair);
+    if (rv != SECSuccess) {
+        gECDHEKeyPairs[i].keyPair = NULL;
+        SSL_TRC(5, ("%d: SSL[-]: disabling group %d",
+                    SSL_GETPID(), group->name));
+    }
+
+    return PR_SUCCESS;
+}
+
+void
+ssl_FilterSupportedGroups(sslSocket *ss)
+{
+    unsigned int i;
+    PRStatus prv;
+    sslSocketAndGroupArg arg = { NULL, ss };
+
+    prv = PR_CallOnce(&cleanupECDHEKeysOnce, ssl_SetupCleanupECDHEKeysOnce);
+    PORT_Assert(prv == PR_SUCCESS);
+    if (prv != PR_SUCCESS) {
+        return;
+    }
+
+    for (i = 0; i < SSL_NAMED_GROUP_COUNT; ++i) {
+        PRUint32 policy;
+        SECStatus srv;
+        unsigned int index;
+        const sslNamedGroupDef *group = ss->namedGroupPreferences[i];
+        if (!group) {
+            continue;
+        }
+
+        srv = NSS_GetAlgorithmPolicy(group->oidTag, &policy);
+        if (srv == SECSuccess && !(policy & NSS_USE_ALG_IN_SSL_KX)) {
+            ss->namedGroupPreferences[i] = NULL;
+            continue;
+        }
+
+        if (group->assumeSupported) {
+            continue;
+        }
+
+        /* For EC groups, we have to test that a key pair can be created. This
+         * is gross, and expensive, so only do it once. */
+        index = group - ssl_named_groups;
+        PORT_Assert(index < SSL_NAMED_GROUP_COUNT);
+
+        arg.group = group;
+        prv = PR_CallOnceWithArg(&gECDHEKeyPairs[index].once,
+                                 ssl_CreateStaticECDHEKeyPair,
+                                 (void *)&arg);
+        PORT_Assert(prv == PR_SUCCESS);
+        if (prv != PR_SUCCESS) {
+            continue;
+        }
+
+        if (!gECDHEKeyPairs[index].keyPair) {
+            ss->namedGroupPreferences[i] = NULL;
+        }
+    }
+}
+
+/*
+ * Creates the static "ephemeral" public and private ECDH keys used by server in
+ * ECDHE_RSA and ECDHE_ECDSA handshakes when we reuse the same key.
+ */
+SECStatus
+ssl_CreateStaticECDHEKey(sslSocket *ss, const sslNamedGroupDef *ecGroup)
+{
+    sslEphemeralKeyPair *keyPair;
+    /* We index gECDHEKeyPairs by the named group.  Pointer arithmetic! */
+    unsigned int index = ecGroup - ssl_named_groups;
+    PRStatus prv;
+    sslSocketAndGroupArg arg = { ecGroup, ss };
+
+    prv = PR_CallOnceWithArg(&gECDHEKeyPairs[index].once,
+                             ssl_CreateStaticECDHEKeyPair,
+                             (void *)&arg);
+    PORT_Assert(prv == PR_SUCCESS);
+    if (prv != PR_SUCCESS) {
+        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
+        return SECFailure;
+    }
+
+    keyPair = gECDHEKeyPairs[index].keyPair;
+    if (!keyPair) {
+        /* Attempting to use a key pair for an unsupported group. */
+        PORT_Assert(keyPair);
+        PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
+        return SECFailure;
+    }
+
+    keyPair = ssl_CopyEphemeralKeyPair(keyPair);
+    if (!keyPair)
+        return SECFailure;
+
+    PORT_Assert(PR_CLIST_IS_EMPTY(&ss->ephemeralKeyPairs));
+    PR_APPEND_LINK(&keyPair->link, &ss->ephemeralKeyPairs);
+    return SECSuccess;
+}