go-openssl/dhparam.go
2017-06-05 18:07:03 -06:00

65 lines
1.7 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
// #include "shim.h"
import "C"
import (
"errors"
"runtime"
"unsafe"
)
type DH struct {
dh *C.struct_dh_st
}
// LoadDHParametersFromPEM loads the Diffie-Hellman parameters from
// a PEM-encoded block.
func LoadDHParametersFromPEM(pem_block []byte) (*DH, error) {
if len(pem_block) == 0 {
return nil, errors.New("empty pem block")
}
bio := C.BIO_new_mem_buf(unsafe.Pointer(&pem_block[0]),
C.int(len(pem_block)))
if bio == nil {
return nil, errors.New("failed creating bio")
}
defer C.BIO_free(bio)
params := C.PEM_read_bio_DHparams(bio, nil, nil, nil)
if params == nil {
return nil, errors.New("failed reading dh parameters")
}
dhparams := &DH{dh: params}
runtime.SetFinalizer(dhparams, func(dhparams *DH) {
C.DH_free(dhparams.dh)
})
return dhparams, nil
}
// SetDHParameters sets the DH group (DH parameters) used to
// negotiate an emphemeral DH key during handshaking.
func (c *Ctx) SetDHParameters(dh *DH) error {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if int(C.X_SSL_CTX_set_tmp_dh(c.ctx, dh.dh)) != 1 {
return errorFromErrorQueue()
}
return nil
}