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tls,crypto: revert recent cipher lists changes

Revert "disable RC4, add --cipher-list command line switch" and
"tls: make --enable-legacy-cipher-list=val less verbose"

This reverts commit f9291a9449 and
b5737bb977.

There is still some work to be done to guarantee secure defaults and a
smooth upgrade path for v0.12.x users. Before this work is finished, we
want to be able to release new versions of v0.12.x. So instead of
waiting for these changes to be ready to ship, revert them and integrate
them when they're ready to be shipped.

Conflicts:
	src/node.cc

Reviewed-By: James M Snell <jasnell@gmail.com>
PR-URL: https://github.com/joyent/node/pull/25296
v0.12.3-release
Julien Gilli 10 years ago
parent
commit
72188d87d0
  1. 82
      doc/api/tls.markdown
  2. 12
      lib/tls.js
  3. 42
      src/node.cc
  4. 13
      src/node.h
  5. 23
      src/node_crypto.cc
  6. 31
      src/node_crypto.h
  7. 69
      test/simple/test-tls-cipher-list.js
  8. 2
      test/simple/test-tls-getcipher.js

82
doc/api/tls.markdown

@ -134,75 +134,6 @@ 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()
@ -213,12 +144,6 @@ 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])
@ -252,7 +177,7 @@ 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:HIGH:!RC4:!MD5:!aNULL`.
`ECDHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA256:AES128-GCM-SHA256:RC4:HIGH:!MD5:!aNULL`.
Consult the [OpenSSL cipher list format documentation] for details
on the format.
@ -262,7 +187,10 @@ 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 explicitly switched off by default due to known vulnerabilities.
`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.
**NOTE**: Previous revisions of this section suggested `AES256-SHA` as an
acceptable cipher. Unfortunately, `AES256-SHA` is a CBC cipher and therefore

12
lib/tls.js

@ -19,8 +19,6 @@
// 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');
@ -35,14 +33,16 @@ exports.CLIENT_RENEG_WINDOW = 600;
exports.SLAB_BUFFER_SIZE = 10 * 1024 * 1024;
exports.DEFAULT_CIPHERS = _crypto.DEFAULT_CIPHER_LIST;
exports.getLegacyCiphers = _crypto.getLegacyCiphers;
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_ECDH_CURVE = 'prime256v1';
exports.getCiphers = function() {
var names = _crypto.getSSLCiphers();
var names = process.binding('crypto').getSSLCiphers();
// Drop all-caps names in favor of their lowercase aliases,
var ctx = {};
names.forEach(function(name) {

42
src/node.cc

@ -2936,9 +2936,6 @@ 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"
" val = v0.10.38, v0.10.39, or v0.12.2\n"
"\n"
"Environment variables:\n"
#ifdef _WIN32
@ -2956,9 +2953,6 @@ 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=val\n"
" val = v0.10.38, v0.10.39, or v0.12.2\n"
"\n"
"Documentation can be found at http://nodejs.org/\n");
}
@ -2998,7 +2992,6 @@ 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] == '-') {
@ -3054,20 +3047,6 @@ 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;
@ -3435,27 +3414,6 @@ 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.

13
src/node.h

@ -223,19 +223,6 @@ 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,

23
src/node_crypto.cc

@ -77,7 +77,6 @@ namespace node {
bool SSL2_ENABLE = false;
bool SSL3_ENABLE = false;
const char * DEFAULT_CIPHER_LIST = DEFAULT_CIPHER_LIST_HEAD;
namespace crypto {
@ -4852,26 +4851,6 @@ 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());
@ -5192,8 +5171,6 @@ 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

31
src/node_crypto.h

@ -38,7 +38,6 @@
#include "v8.h"
#include <string.h>
#include <openssl/ssl.h>
#include <openssl/ec.h>
#include <openssl/ecdh.h>
@ -60,40 +59,10 @@
# 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 {

69
test/simple/test-tls-cipher-list.js

@ -1,69 +0,0 @@
// 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);
});

2
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[1]);
assert.equal(cipher.name, cipher_list[0]);
assert(cipher_version_pattern.test(cipher.version));
client.end();
server.close();

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