I'm trying to connect to a server through a socket using an ssl certificate. I have the private key and the certificate needed to connect to the server, i have looked around for something to help me write this code in Go but i have not found anything helpful. Here is the code i write so far, but it does not seem to get me anywhere, it seems to be sending data(tls.dial) before getting to the actual data, which forces the server to reply with some encrypted data which i am unable to check.
func main() {
cert, err := tls.LoadX509KeyPair("cert.pem", "key.pem")
if err != nil {
log.Fatalf("server: loadkeys: %s", err)
}
config := tls.Config{Certificates: []tls.Certificate{cert}, InsecureSkipVerify: true}
conn, err := tls.Dial("tcp", "1.2.3.4:1234", &config)
if err != nil {
log.Fatalf("client: dial: %s", err)
}
defer conn.Close()
log.Println("client: connected to: ", conn.RemoteAddr())
state := conn.ConnectionState()
for _, v := range state.PeerCertificates {
fmt.Println(x509.MarshalPKIXPublicKey(v.PublicKey))
fmt.Println(v.Subject)
}
log.Println("client: handshake: ", state.HandshakeComplete)
log.Println("client: mutual: ", state.NegotiatedProtocolIsMutual)
message := "data"
n, err := io.WriteString(conn, message)
if err != nil {
log.Fatalf("client: write: %s", err)
}
log.Printf("client: wrote %q (%d bytes)", message, n)
reply := make([]byte, 256)
n, err = conn.Read(reply)
log.Printf("client: read %q (%d bytes)", string(reply[:n]), n)
log.Print("client: exiting")
}
Related
I'm trying to connect to my mongo db atlas database, but I'm getting an error that I can't solve it within mongo+go forums.
The code:
package main
import (
"context"
"log"
"time"
"fmt"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"go.mongodb.org/mongo-driver/mongo/readpref"
"go.mongodb.org/mongo-driver/bson"
)
func main(){
client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://my-user:<my-pass>#datalake0-lesz0.a.query.mongodb.net/my-db?ssl=true&authSource=admin"))
if err != nil {
log.Fatal(err)
}
ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
err = client.Connect(ctx)
if err != nil {
log.Fatal(err)
}
defer client.Disconnect(ctx)
err = client.Ping(ctx, readpref.Primary())
if err != nil {
log.Fatal(err)
}
databases, err := client.ListDatabaseNames(ctx, bson.M{})
if err != nil {
log.Fatal(err)
}
fmt.Println(databases)
}
The error:
connection() error occured during connection handshake: auth error: sasl conversation error: unable to authenticate using mechanism "SCRAM-SHA-1": (AuthenticationFailed) authentication failed, correlationID = 167bc5ba18415510a4144b7a
exit status 1
If the URI in the connect string is verbatim, then this is your problem:
mongodb://my-user:<my-pass> is incorrect, <my-pass> should be substituted with your password
You've probably cut and pasted the provided URI on completion of DB setup but this connect string does not include items like your password, also you gave my-user which, unless you set up the username my-user that also needs changing.
I am trying to connect MongoDB by the native MongoDB driver with go language
(ref).
Here is my snapcode.
package main
import (
"context"
"fmt"
"log"
"time"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
)
const (
account = "rootAdmin"
password = "12345678"
iP = "127.0.0.1"
port = 27017
tlsCertificateKeyFile = "D:/cert/wa.pem"
)
type mongoStuff struct {
ctx context.Context
client *mongo.Client
cancel context.CancelFunc
}
func connectToMongoDB() *mongoStuff {
uri := fmt.Sprintf("mongodb://%v:%v#%v:%v/?authSource=admin&tlsCertificateKeyFile=%v&tls=true",
account,
password,
iP,
port,
tlsCertificateKeyFile)
credential := options.Credential{
AuthMechanism: "MONGODB-X509",
Username: account,
Password: password,
}
log.Println(uri)
clientOpts := options.Client().ApplyURI(uri).SetAuth(credential)
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
client, err := mongo.Connect(ctx, clientOpts)
if err != nil {
log.Println("Dead connect")
log.Fatal(err)
}
return &mongoStuff{ctx, client, cancel}
}
func disconnectMongoDB(mongodb *mongoStuff) {
cancel := mongodb.cancel
client := mongodb.client
ctx := mongodb.ctx
defer cancel()
defer func() {
if err := client.Disconnect(ctx); err != nil {
log.Println("Dead disconnect")
panic(err)
}
}()
}
func insertExamples(mongodb *mongoStuff) {
ctx := mongodb.ctx
var db *mongo.Database = mongodb.client.Database("documentation_examples")
coll := db.Collection("inventory_insert")
err := coll.Drop(ctx)
if err != nil {
log.Println("Dead drop")
log.Fatal(err)
}
{
result, err := coll.InsertOne(
ctx,
bson.D{
{"item", "canvas"},
{"qty", 100},
{"tags", bson.A{"cotton"}},
{
"size", bson.D{
{"h", 28},
{"w", 35.5},
{"uom", "cm"},
}},
})
if err != nil {
log.Println("Dead insertone")
log.Fatal(err)
}
log.Printf("insertone success. id=%v", result.InsertedID)
}
}
func main() {
mongodb := connectToMongoDB()
defer disconnectMongoDB(mongodb)
insertExamples(mongodb)
}
Whenever I run the code, it just comes up with the below error.
connection() error occured during connection handshake: auth error: round trip error: (AuthenticationFailed) No user name provided
I can't figure out what's going on.
To authenticate with x.509, the username should be either the common name of the certificate or empty. You seem to be attempting some mix of password and x.509 authentication.
All required options can be provided in the URI. See How can I connect with X509 by putting all options in the connection string in node.js driver for mongodb?.
If you insist on specifying credentials not in a URI, reference driver documentation that describes how to do that for x509 credentials.
in GO net/http Response Body annotation says:
It is the caller's responsibility to close Body. The default HTTP client's Transport does not attempt to reuse HTTP/1.0 or HTTP/1.1 TCP connections ("keep-alive") unless the Body is read to completion and is
closed.
It's mean: if I use http.Get and don't call resp.Body.Close() then it will not resue HTTP/1.0 or HTTP/1.1 TCP connections ("keep-alive") yeah?
so I write some code:
package main
import (
"time"
"fmt"
"io/ioutil"
"net/http"
)
func main() {
resp, err := http.Get("http://127.0.0.1:8588")
if err != nil {
panic(err)
}
_, err = ioutil.ReadAll(resp.Body)
if err != nil {
panic(err)
}
resp2, err := http.Get("http://127.0.0.1:8588")
if err != nil {
panic(err)
}
_, err = ioutil.ReadAll(resp2.Body)
if err != nil {
panic(err)
}
fmt.Println("before time sleep")
time.Sleep(time.Second * 35)
}
and I only see ONE tcp connection build in wireshark, why?
I don't close res.Body so the http client should't be reuse the tcp connection.
this problem has been solved in
https://github.com/golang/go/issues/22954.
You have read it till the end in first occurence of line:
_, err = ioutil.ReadAll(resp.Body)
So the connection is ready to be resused. Try not to read and run again.
I'm having trouble with socket programming.
I have a program that reads from localhost:7777 and writes to localhost:8000.
I use netcat from the command line to write and read to 7777 and 8000 respectively.
This is the reader:
netcat -l -p 8000
And this is the writer:
printf "asti||" | netcat localhost 7777
But my program gets network errors when it tries to write to port 8000 for the second
time. The error is Fatal error: dial tcp 127.0.0.1:8000: getsockopt: connection refused.
What's happening? Why on the second write the error appears?
Furthermore, I noticed that if I kill the netcat reader and restart it then there's no network errors. So to reiterate, the program writes once to 8000 and netcat reads it. Then I kill netcat reader and restart it. At this point the program can write again to 8000. But if the program tries to write two successive times to 8000 without me restarting netcat, then the error appears.
Here is the entire program (it's short). If you like, you experience this mystical behaviour yourself:
package main
import (
"fmt"
"net"
"os"
"strings"
// "io/ioutil"
)
func main() {
end_of_message_terminator := "||"
beginning_of_next_message := ""
request := make([]byte, 512)
service_port := ":7777"
tcpAddr, err := net.ResolveTCPAddr("tcp4", service_port)
checkError(err)
listener, err := net.ListenTCP("tcp", tcpAddr)
checkError(err)
for {
conn, err := listener.Accept()
if err != nil {
continue
}
read_len, err := conn.Read(request)
if read_len == 0 {
continue
}
request_string := string(request[:read_len])
fmt.Printf("Request String %s\\END", request_string)
messages := strings.Split(request_string, end_of_message_terminator)
fmt.Printf("%q\n", messages)
messages[0] = beginning_of_next_message + messages[0]
if messages[len(messages) - 1] != "" {
beginning_of_next_message = messages[len(messages) - 1]
messages[len(messages) - 1] = ""
fmt.Printf("was here 00\n")
}
if len(messages) == 1 {
continue
}
for i := range messages {
go func(){
fmt.Printf("was here 04\n")
respond_to_message(messages[i])
}()
fmt.Printf("was here 01\n")
}
conn.Close()
}
}
func respond_to_message(message string){
message_parameters := strings.Split(message, "|")
response_port := "localhost:8000"
tcpAddr_res, err := net.ResolveTCPAddr("tcp4", response_port)
checkError(err)
response_writer, err := net.DialTCP("tcp", nil, tcpAddr_res)
for i := range message_parameters {
fmt.Printf("was here03\n")
param_parts := strings.Split(message_parameters[i], "=")
fmt.Printf("message: %s\n", message)
fmt.Printf("message_parameters%q\n", message_parameters)
fmt.Printf("params_parts: %q\n", param_parts)
//param_name := param_parts[0]
//param_value := param_parts[1]
checkError(err)
response_writer.Write([]byte("asti de crhis"))
checkError(err)
//result, err := ioutil.ReadAll(response_writer)
//checkError(err)
//fmt.Println(string(result))
}
//response_writer.Close()
}
func checkError(err error) {
if err != nil {
fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
os.Exit(1)
}
}
I'm trying to learn the go language, and I'm writing a simple echo server. I'm having difficulty making it work, though.
func listen(server string) {
var buf []byte
listener, ok := net.Listen("tcp", server)
if ok != nil {
fmt.Fprintf(os.Stderr, "Could not listen on socket: %s\n", ok.String())
return
}
conn, ok := listener.Accept()
if ok != nil {
fmt.Fprintf(os.Stderr, "Could not accept connection on socket: %s\n", ok.String())
return
}
writelen, ok := conn.Write(strings.Bytes("Ready to receive\n"))
if ok != nil {
fmt.Fprintf(os.Stderr, "Could not write to socket: %s\n", ok.String())
} else {
fmt.Printf("Wrote %d bytes to socket\n", writelen)
}
for ;; {
readlen, ok := conn.Read(buf)
if ok != nil {
fmt.Fprintf(os.Stderr, "Error when reading from socket: %s\n", ok.String())
return
}
if readlen == 0 {
fmt.Printf("Connection closed by remote host\n")
return
}
fmt.Printf("Client at %s says '%s'\n", conn.RemoteAddr().String(), buf)
}
}
I get the following output from this function:
[nathan#ebisu ~/src/go/echo_server] ./6.out 1234
Using port 1234
Wrote 17 bytes to socket
Error when reading from socket: EOF
This is what I see on the client:
[nathan#ebisu ~] telnet 127.0.0.1 1234
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
Ready to receive
Connection closed by foreign host.
Any help would be appreciated (or pointers to resources; the go documentation on the sockets API leaves a little to be desired).
Thanks,
Nathan
In your example, buf needs to have a definite size. You've declared it as a 0-length slice.
Declare it as:
var buf = make([]byte, 1024)
Of course, if you want to learn, it is better to write it yourself but, if it helps, here is my own echo server in Go.
package main
import (
"net";
"os";
"fmt";
)
func handle(conn *net.TCPConn) {
fmt.Printf("Connection from %s\n", conn.RemoteAddr());
message := make([]byte, 1024);
// TODO: loop the read, we can have >1024 bytes
n1, error := conn.Read(message);
if error != nil {
fmt.Printf("Cannot read: %s\n", error);
os.Exit(1);
}
n2, error := conn.Write(message[0:n1]);
if error != nil || n2 != n1 {
fmt.Printf("Cannot write: %s\n", error);
os.Exit(1);
}
fmt.Printf("Echoed %d bytes\n", n2);
conn.Close(); // TODO: wait to see if more data? It would be better with telnet...
}
func main() {
listen := ":7";
addr, error := net.ResolveTCPAddr(listen);
if error != nil {
fmt.Printf("Cannot parse \"%s\": %s\n", listen, error);
os.Exit(1);
}
listener, error := net.ListenTCP("tcp", addr);
if error != nil {
fmt.Printf("Cannot listen: %s\n", error);
os.Exit(1);
}
for { // ever...
conn, error := listener.AcceptTCP();
if error != nil {
fmt.Printf("Cannot accept: %s\n", error);
os.Exit(1);
}
go handle(conn);
}
}