diff options
author | James M Snell <jasnell@gmail.com> | 2015-04-02 16:10:15 -0700 |
---|---|---|
committer | James M Snell <jasnell@gmail.com> | 2015-04-08 12:10:49 -0700 |
commit | f9291a94498c6f9d70a74a1e402f333383286120 (patch) | |
tree | eb385c54eb4c5b03e72b943b30bd57b7f6f11ae6 | |
parent | 66b243dd87509a7e259bf9bfec1ab31e01620b3e (diff) | |
download | node-new-f9291a94498c6f9d70a74a1e402f333383286120.tar.gz |
disable RC4, add --cipher-list command line switch
Disable RC4 in the default cipher list
Add the `--cipher-list` command line switch and `NODE_CIPHER_LIST`
environment variable to completely override the default cipher list.
Add the `--enable-legacy-cipher-list` and `NODE_LEGACY_CIPHER_LIST`
environment variable to selectively enable the default cipher list from
previous node.js releases.
Reviewed-By: James M Snell <jasnell@gmail.com>
PR-URL: https://github.com/joyent/node/pull/14414
-rw-r--r-- | doc/api/tls.markdown | 82 | ||||
-rw-r--r-- | lib/tls.js | 12 | ||||
-rw-r--r-- | src/node.cc | 46 | ||||
-rw-r--r-- | src/node.h | 13 | ||||
-rw-r--r-- | src/node_crypto.cc | 23 | ||||
-rw-r--r-- | src/node_crypto.h | 31 | ||||
-rw-r--r-- | test/simple/test-tls-cipher-list.js | 69 | ||||
-rw-r--r-- | test/simple/test-tls-getcipher.js | 2 |
8 files changed, 266 insertions, 12 deletions
diff --git a/doc/api/tls.markdown b/doc/api/tls.markdown index 410d88300c..fba9a67623 100644 --- a/doc/api/tls.markdown +++ b/doc/api/tls.markdown @@ -134,6 +134,75 @@ the character "E" appended to the traditional abbreviations): Ephemeral methods may have some performance drawbacks, because key generation is expensive. +## Modifying the Default Cipher Suite + +Node.js is built with a default suite of enabled and disabled ciphers. +Currently, the default cipher suite is: + + ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:HIGH: + !RC4:!MD5:!aNULL + +This default can be overridden entirely using the `--cipher-list` command line +switch or `NODE_CIPHER_LIST` environment variable. For instance: + + node --cipher-list=ECDHE-RSA-AES256-SHA384:DHE-RSA-AES256-SHA384 + +Setting the environment variable would have the same effect: + + NODE_CIPHER_LIST=ECDHE-RSA-AES256-SHA384:DHE-RSA-AES256-SHA384 + +CAUTION: The default cipher suite has been carefully selected to reflect current +security best practices and risk mitigation. Changing the default cipher suite +can have a significant impact on the security of an application. The +`--cipher-list` and `NODE_CIPHER_LIST` options should only be used if +absolutely necessary. + +### Using Legacy Default Cipher Suite ### + +It is possible for the built-in default cipher suite to change from one release +of Node.js to another. For instance, v0.10.38 uses a different default than +v0.12.2. Such changes can cause issues with applications written to assume +certain specific defaults. To help buffer applications against such changes, +the `--enable-legacy-cipher-list` command line switch or `NODE_LEGACY_CIPHER_LIST` +environment variable can be set to specify a specific preset default: + + # Use the v0.10.38 defaults + node --enable-legacy-cipher-list=v0.10.38 + // or + NODE_LEGACY_CIPHER_LIST=v0.10.38 + + # Use the v0.12.2 defaults + node --enable-legacy-cipher-list=v0.12.2 + // or + NODE_LEGACY_CIPHER_LIST=v0.12.2 + +Currently, the values supported for the `enable-legacy-cipher-list` switch and +`NODE_LEGACY_CIPHER_LIST` environment variable include: + + v0.10.38 - To enable the default cipher suite used in v0.10.38 + + ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH + + v0.10.39 - To enable the default cipher suite used in v0.10.39 + + ECDHE-RSA-AES128-SHA256:AES128-GCM-SHA256:HIGH:!RC4:!MD5:!aNULL:!EDH + + v0.12.2 - To enable the default cipher suite used in v0.12.2 + + ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4: + HIGH:!MD5:!aNULL + +These legacy cipher suites are also made available for use via the +`getLegacyCiphers()` method: + + var tls = require('tls'); + console.log(tls.getLegacyCiphers('v0.10.38')); + +CAUTION: Changes to the default cipher suite are typically made in order to +strengthen the default security for applications running within Node.js. +Reverting back to the defaults used by older releases can weaken the security +of your applications. The legacy cipher suites should only be used if absolutely +necessary. ## tls.getCiphers() @@ -144,6 +213,12 @@ Example: var ciphers = tls.getCiphers(); console.log(ciphers); // ['AES128-SHA', 'AES256-SHA', ...] +## tls.getLegacyCiphers(version) + +Returns the legacy default cipher suite for the specified Node.js release. + +Example: + var cipher_suite = tls.getLegacyCiphers('v0.10.38'); ## tls.createServer(options[, secureConnectionListener]) @@ -177,7 +252,7 @@ automatically set as a listener for the [secureConnection][] event. The prioritize the non-CBC cipher. Defaults to - `ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL`. + `ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:HIGH:!RC4:!MD5:!aNULL`. Consult the [OpenSSL cipher list format documentation] for details on the format. @@ -187,10 +262,7 @@ automatically set as a listener for the [secureConnection][] event. The of OpenSSL. Note that it is still possible for a TLS v1.2 client to negotiate a weaker cipher unless `honorCipherOrder` is enabled. - `RC4` is used as a fallback for clients that speak on older version of - the TLS protocol. `RC4` has in recent years come under suspicion and - should be considered compromised for anything that is truly sensitive. - It is speculated that state-level actors possess the ability to break it. + `RC4` is explicitly switched off by default due to known vulnerabilities. **NOTE**: Previous revisions of this section suggested `AES256-SHA` as an acceptable cipher. Unfortunately, `AES256-SHA` is a CBC cipher and therefore diff --git a/lib/tls.js b/lib/tls.js index a00fbb9d72..04a41e8e2b 100644 --- a/lib/tls.js +++ b/lib/tls.js @@ -19,6 +19,8 @@ // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE // USE OR OTHER DEALINGS IN THE SOFTWARE. +var _crypto = process.binding('crypto'); + var net = require('net'); var url = require('url'); var util = require('util'); @@ -33,16 +35,14 @@ exports.CLIENT_RENEG_WINDOW = 600; exports.SLAB_BUFFER_SIZE = 10 * 1024 * 1024; -exports.DEFAULT_CIPHERS = - // TLS 1.2 - 'ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:' + - // TLS 1.0 - 'RC4:HIGH:!MD5:!aNULL'; +exports.DEFAULT_CIPHERS = _crypto.DEFAULT_CIPHER_LIST; + +exports.getLegacyCiphers = _crypto.getLegacyCiphers; exports.DEFAULT_ECDH_CURVE = 'prime256v1'; exports.getCiphers = function() { - var names = process.binding('crypto').getSSLCiphers(); + var names = _crypto.getSSLCiphers(); // Drop all-caps names in favor of their lowercase aliases, var ctx = {}; names.forEach(function(name) { diff --git a/src/node.cc b/src/node.cc index f0590d5a72..303a09196c 100644 --- a/src/node.cc +++ b/src/node.cc @@ -2936,6 +2936,11 @@ static void PrintHelp() { #endif " --enable-ssl2 enable ssl2\n" " --enable-ssl3 enable ssl3\n" + " --cipher-list=val specify the default TLS cipher list\n" + " --enable-legacy-cipher-list=val \n" + " set to v0.10.38 to use the v0.10.38 list,\n" + " set to v0.10.39 to use the v0.10.39 list.\n" + " set to v0.12.2 to use the v0.12.2 list.\n" "\n" "Environment variables:\n" #ifdef _WIN32 @@ -2953,6 +2958,11 @@ static void PrintHelp() { " (will extend linked-in data)\n" #endif #endif + "NODE_CIPHER_LIST Override the default TLS cipher list\n" + "NODE_LEGACY_CIPHER_LIST\n" + " Set to v0.10.38 to use the v0.10.38 list.\n" + " Set to v0.10.39 to use the v0.10.39 list.\n" + " Set to v0.12.2 to use the v0.12.2 list.\n" "\n" "Documentation can be found at http://nodejs.org/\n"); } @@ -2992,6 +3002,7 @@ static void ParseArgs(int* argc, unsigned int new_argc = 1; new_v8_argv[0] = argv[0]; new_argv[0] = argv[0]; + bool using_legacy_cipher_list = false; unsigned int index = 1; while (index < nargs && argv[index][0] == '-') { @@ -3047,6 +3058,20 @@ static void ParseArgs(int* argc, } else if (strcmp(arg, "--v8-options") == 0) { new_v8_argv[new_v8_argc] = "--help"; new_v8_argc += 1; + } else if (strncmp(arg, "--cipher-list=", 14) == 0) { + if (!using_legacy_cipher_list) { + DEFAULT_CIPHER_LIST = arg + 14; + } + } else if (strncmp(arg, "--enable-legacy-cipher-list=", 28) == 0) { + // use the original v0.10.x/v0.12.x cipher lists + const char * legacy_list = legacy_cipher_list(arg+28); + if (legacy_list != NULL) { + using_legacy_cipher_list = true; + DEFAULT_CIPHER_LIST = legacy_list; + } else { + fprintf(stderr, "Error: An unknown legacy cipher list was specified\n"); + exit(9); + } #if defined(NODE_HAVE_I18N_SUPPORT) } else if (strncmp(arg, "--icu-data-dir=", 15) == 0) { icu_data_dir = arg + 15; @@ -3414,6 +3439,27 @@ void Init(int* argc, } } + const char * cipher_list = getenv("NODE_CIPHER_LIST"); + if (cipher_list != NULL) { + DEFAULT_CIPHER_LIST = cipher_list; + } + // Allow the NODE_LEGACY_CIPHER_LIST envar to override the other + // cipher list options. NODE_LEGACY_CIPHER_LIST=v0.10.38 will use + // the cipher list from v0.10.38, NODE_LEGACY_CIPHER_LIST=v0.12.2 will + // use the cipher list from v0.12.2 + const char * leg_cipher_id = getenv("NODE_LEGACY_CIPHER_LIST"); + if (leg_cipher_id != NULL) { + const char * leg_cipher_list = + legacy_cipher_list(leg_cipher_id); + if (leg_cipher_list != NULL) { + DEFAULT_CIPHER_LIST = leg_cipher_list; + } else { + fprintf(stderr, "Error: An unknown legacy cipher list was specified\n"); + exit(9); + } + } + + #if defined(NODE_HAVE_I18N_SUPPORT) if (icu_data_dir == NULL) { // if the parameter isn't given, use the env variable. diff --git a/src/node.h b/src/node.h index 38356ac44f..c930928deb 100644 --- a/src/node.h +++ b/src/node.h @@ -223,6 +223,19 @@ NODE_EXTERN void RunAtExit(Environment* env); } \ while (0) +#define NODE_DEFINE_STRING_CONSTANT(target, constant) \ + do { \ + v8::Isolate* isolate = v8::Isolate::GetCurrent(); \ + v8::Local<v8::String> constant_name = \ + v8::String::NewFromUtf8(isolate, #constant); \ + v8::Local<v8::String> constant_value = \ + v8::String::NewFromUtf8(isolate, constant); \ + v8::PropertyAttribute constant_attributes = \ + static_cast<v8::PropertyAttribute>(v8::ReadOnly | v8::DontDelete); \ + (target)->ForceSet(constant_name, constant_value, constant_attributes); \ + } while (0) + + // Used to be a macro, hence the uppercase name. template <typename TypeName> inline void NODE_SET_METHOD(const TypeName& recv, diff --git a/src/node_crypto.cc b/src/node_crypto.cc index 03650a98c6..327bfce131 100644 --- a/src/node_crypto.cc +++ b/src/node_crypto.cc @@ -77,6 +77,7 @@ namespace node { bool SSL2_ENABLE = false; bool SSL3_ENABLE = false; +const char * DEFAULT_CIPHER_LIST = DEFAULT_CIPHER_LIST_HEAD; namespace crypto { @@ -4851,6 +4852,26 @@ static void array_push_back(const TypeName* md, ctx->arr->Set(ctx->arr->Length(), OneByteString(ctx->env()->isolate(), from)); } +// borrowed from v8 +// (see http://v8.googlecode.com/svn/trunk/samples/shell.cc) +const char* ToCString(const String::Utf8Value& value) { + return *value ? *value : "<string conversion failed>"; +} + +void DefaultCiphers(const v8::FunctionCallbackInfo<v8::Value>& args) { + Environment* env = Environment::GetCurrent(args.GetIsolate()); + HandleScope scope(env->isolate()); + v8::String::Utf8Value key(args[0]); + const char * list = legacy_cipher_list(ToCString(key)); + if (list != NULL) { + args.GetReturnValue().Set( + v8::String::NewFromUtf8(args.GetIsolate(), list)); + } else { + args.GetReturnValue().Set( + v8::String::NewFromUtf8(args.GetIsolate(), + DEFAULT_CIPHER_LIST_HEAD)); + } +} void GetCiphers(const FunctionCallbackInfo<Value>& args) { Environment* env = Environment::GetCurrent(args.GetIsolate()); @@ -5171,6 +5192,8 @@ void InitCrypto(Handle<Object> target, NODE_DEFINE_CONSTANT(target, SSL3_ENABLE); NODE_DEFINE_CONSTANT(target, SSL2_ENABLE); + NODE_DEFINE_STRING_CONSTANT(target, DEFAULT_CIPHER_LIST); + NODE_SET_METHOD(target, "getLegacyCiphers", DefaultCiphers); } } // namespace crypto diff --git a/src/node_crypto.h b/src/node_crypto.h index 0a4c34a1f3..d6cf9aa218 100644 --- a/src/node_crypto.h +++ b/src/node_crypto.h @@ -38,6 +38,7 @@ #include "v8.h" +#include <string.h> #include <openssl/ssl.h> #include <openssl/ec.h> #include <openssl/ecdh.h> @@ -59,10 +60,40 @@ # define NODE__HAVE_TLSEXT_STATUS_CB #endif // !defined(OPENSSL_NO_TLSEXT) && defined(SSL_CTX_set_tlsext_status_cb) +#define DEFAULT_CIPHER_LIST_V10_38 "ECDHE-RSA-AES128-SHA256:" \ + "AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL:!EDH" + +#define DEFAULT_CIPHER_LIST_V10_39 "ECDHE-RSA-AES128-SHA256:" \ + "AES128-GCM-SHA256:HIGH:!RC4:!MD5:!aNULL:!EDH" + +#define DEFAULT_CIPHER_LIST_V12_2 "ECDHE-RSA-AES128-SHA256:" \ + "DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:" \ + "HIGH:!MD5:!aNULL" + +#define DEFAULT_CIPHER_LIST_HEAD "ECDHE-RSA-AES128-SHA256:" \ + "DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:HIGH:"\ + "!RC4:!MD5:!aNULL" + +static inline const char * legacy_cipher_list(const char * ver) { + if (ver == NULL) { + return NULL; + } + if (strncmp(ver, "v0.10.38", 8) == 0) { + return DEFAULT_CIPHER_LIST_V10_38; + } else if (strncmp(ver, "v0.10.39", 8) == 0) { + return DEFAULT_CIPHER_LIST_V10_39; + } else if (strncmp(ver, "v0.12.2", 7) == 0) { + return DEFAULT_CIPHER_LIST_V12_2; + } else { + return NULL; + } +} + namespace node { extern bool SSL2_ENABLE; extern bool SSL3_ENABLE; +extern const char * DEFAULT_CIPHER_LIST; namespace crypto { diff --git a/test/simple/test-tls-cipher-list.js b/test/simple/test-tls-cipher-list.js new file mode 100644 index 0000000000..84e76eb5b5 --- /dev/null +++ b/test/simple/test-tls-cipher-list.js @@ -0,0 +1,69 @@ +// Copyright Joyent, Inc. and other Node contributors. +// +// Permission is hereby granted, free of charge, to any person obtaining a +// copy of this software and associated documentation files (the +// "Software"), to deal in the Software without restriction, including +// without limitation the rights to use, copy, modify, merge, publish, +// distribute, sublicense, and/or sell copies of the Software, and to permit +// persons to whom the Software is furnished to do so, subject to the +// following conditions: +// +// The above copyright notice and this permission notice shall be included +// in all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN +// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, +// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR +// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE +// USE OR OTHER DEALINGS IN THE SOFTWARE. + +var spawn = require('child_process').spawn; +var assert = require('assert'); +var tls = require('tls'); + +function doTest(checklist, env, useswitch) { + var options; + if (env && useswitch === 1) { + options = {env:env}; + } + var args = ['-e', 'console.log(require(\'tls\').DEFAULT_CIPHERS)']; + + switch(useswitch) { + case 1: + // Test --cipher-test + args.unshift('--cipher-list=' + env); + break; + case 2: + // Test --enable-legacy-cipher-list + args.unshift('--enable-legacy-cipher-list=' + env); + break; + case 3: + // Test NODE_LEGACY_CIPHER_LIST + if (env) options = {env:{"NODE_LEGACY_CIPHER_LIST": env}}; + break; + default: + // Test NODE_CIPHER_LIST + if (env) options = {env:env}; + } + + var out = ''; + spawn(process.execPath, args, options). + stdout. + on('data', function(data) { + out += data; + }). + on('end', function() { + assert.equal(out.trim(), checklist); + }); +} + +doTest(tls.DEFAULT_CIPHERS); // test the default +doTest('ABC', {'NODE_CIPHER_LIST':'ABC'}); // test the envar +doTest('ABC', 'ABC', 1); // test the --cipher-list switch + +['v0.10.38', 'v0.10.39', 'v0.12.2'].forEach(function(ver) { + doTest(tls.getLegacyCiphers(ver), ver, 2); + doTest(tls.getLegacyCiphers(ver), ver, 3); +}); diff --git a/test/simple/test-tls-getcipher.js b/test/simple/test-tls-getcipher.js index 22a280e587..8fb9d52873 100644 --- a/test/simple/test-tls-getcipher.js +++ b/test/simple/test-tls-getcipher.js @@ -49,7 +49,7 @@ server.listen(common.PORT, '127.0.0.1', function() { rejectUnauthorized: false }, function() { var cipher = client.getCipher(); - assert.equal(cipher.name, cipher_list[0]); + assert.equal(cipher.name, cipher_list[1]); assert(cipher_version_pattern.test(cipher.version)); client.end(); server.close(); |