118 lines
3.9 KiB
Go
118 lines
3.9 KiB
Go
// Copyright (C) 2017. See AUTHORS.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
/*
|
|
Package openssl is a light wrapper around OpenSSL for Go.
|
|
|
|
It strives to provide a near-drop-in replacement for the Go standard library
|
|
tls package, while allowing for:
|
|
|
|
Performance
|
|
|
|
OpenSSL is battle-tested and optimized C. While Go's built-in library shows
|
|
great promise, it is still young and in some places, inefficient. This simple
|
|
OpenSSL wrapper can often do at least 2x with the same cipher and protocol.
|
|
|
|
On my lappytop, I get the following benchmarking speeds:
|
|
BenchmarkSHA1Large_openssl 1000 2611282 ns/op 401.56 MB/s
|
|
BenchmarkSHA1Large_stdlib 500 3963983 ns/op 264.53 MB/s
|
|
BenchmarkSHA1Small_openssl 1000000 3476 ns/op 0.29 MB/s
|
|
BenchmarkSHA1Small_stdlib 5000000 550 ns/op 1.82 MB/s
|
|
BenchmarkSHA256Large_openssl 200 8085314 ns/op 129.69 MB/s
|
|
BenchmarkSHA256Large_stdlib 100 18948189 ns/op 55.34 MB/s
|
|
BenchmarkSHA256Small_openssl 1000000 4262 ns/op 0.23 MB/s
|
|
BenchmarkSHA256Small_stdlib 1000000 1444 ns/op 0.69 MB/s
|
|
BenchmarkOpenSSLThroughput 100000 21634 ns/op 47.33 MB/s
|
|
BenchmarkStdlibThroughput 50000 58974 ns/op 17.36 MB/s
|
|
|
|
Interoperability
|
|
|
|
Many systems support OpenSSL with a variety of plugins and modules for things,
|
|
such as hardware acceleration in embedded devices.
|
|
|
|
Greater flexibility and configuration
|
|
|
|
OpenSSL allows for far greater configuration of corner cases and backwards
|
|
compatibility (such as support of SSLv2). You shouldn't be using SSLv2 if you
|
|
can help but, but sometimes you can't help it.
|
|
|
|
Security
|
|
|
|
Yeah yeah, Heartbleed. But according to the author of the standard library's
|
|
TLS implementation, Go's TLS library is vulnerable to timing attacks. And
|
|
whether or not OpenSSL received the appropriate amount of scrutiny
|
|
pre-Heartbleed, it sure is receiving it now.
|
|
|
|
Usage
|
|
|
|
Starting an HTTP server that uses OpenSSL is very easy. It's as simple as:
|
|
log.Fatal(openssl.ListenAndServeTLS(
|
|
":8443", "my_server.crt", "my_server.key", myHandler))
|
|
|
|
Getting a net.Listener that uses OpenSSL is also easy:
|
|
ctx, err := openssl.NewCtxFromFiles("my_server.crt", "my_server.key")
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
l, err := openssl.Listen("tcp", ":7777", ctx)
|
|
|
|
Making a client connection is straightforward too:
|
|
ctx, err := NewCtx()
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
err = ctx.LoadVerifyLocations("/etc/ssl/certs/ca-certificates.crt", "")
|
|
if err != nil {
|
|
log.Fatal(err)
|
|
}
|
|
conn, err := openssl.Dial("tcp", "localhost:7777", ctx, 0)
|
|
|
|
Help wanted: To get this library to work with net/http's client, we
|
|
had to fork net/http. It would be nice if an alternate http client library
|
|
supported the generality needed to use OpenSSL instead of crypto/tls.
|
|
*/
|
|
package openssl
|
|
|
|
// #include "shim.h"
|
|
import "C"
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"strings"
|
|
)
|
|
|
|
func init() {
|
|
if rc := C.X_shim_init(); rc != 0 {
|
|
panic(fmt.Errorf("X_shim_init failed with %d", rc))
|
|
}
|
|
}
|
|
|
|
// errorFromErrorQueue needs to run in the same OS thread as the operation
|
|
// that caused the possible error
|
|
func errorFromErrorQueue() error {
|
|
var errs []string
|
|
for {
|
|
err := C.ERR_get_error()
|
|
if err == 0 {
|
|
break
|
|
}
|
|
errs = append(errs, fmt.Sprintf("%s:%s:%s",
|
|
C.GoString(C.ERR_lib_error_string(err)),
|
|
C.GoString(C.ERR_func_error_string(err)),
|
|
C.GoString(C.ERR_reason_error_string(err))))
|
|
}
|
|
return errors.New(fmt.Sprintf("SSL errors: %s", strings.Join(errs, "\n")))
|
|
}
|