go-gemini/client.go
2020-09-21 22:09:50 -04:00

108 lines
2.0 KiB
Go

package gemini
import (
"bytes"
"crypto/tls"
"io/ioutil"
"strconv"
"strings"
)
// Client is a Gemini client.
type Client struct{}
// Request makes a request for the provided URL. The host is inferred from the URL.
func (c *Client) Request(url string) (*Response, error) {
if len(url) > 1024 {
return nil, ErrInvalidURL
}
req, err := NewRequest(url)
if err != nil {
return nil, err
}
return c.Do(req)
}
// ProxyRequest requests the provided URL from the provided host.
func (c *Client) ProxyRequest(host, url string) (*Response, error) {
if len(url) > 1024 {
return nil, ErrInvalidURL
}
req, err := NewProxyRequest(host, url)
if err != nil {
return nil, err
}
return c.Do(req)
}
// Do sends a Gemini request and returns a Gemini response.
func (c *Client) Do(req *Request) (*Response, error) {
host := req.Host
if strings.LastIndex(host, ":") == -1 {
// The default port is 1965
host += ":1965"
}
// Allow self signed certificates
config := tls.Config{}
config.InsecureSkipVerify = true
config.Certificates = req.Certificates
conn, err := tls.Dial("tcp", host, &config)
if err != nil {
return nil, err
}
defer conn.Close()
// Write the request
if err := req.Write(conn); err != nil {
return nil, err
}
// Read the response
b, err := ioutil.ReadAll(conn)
if err != nil {
return nil, err
}
// Ensure that the response is long enough
// The minimum response: <STATUS><SPACE><CR><LF> (5 bytes)
if len(b) < 5 {
return nil, ErrProtocol
}
// Parse the response header
status, err := strconv.Atoi(string(b[:2]))
if err != nil {
return nil, err
}
// Read one space
if b[2] != ' ' {
return nil, ErrProtocol
}
// Find the first <CR><LF>
i := bytes.Index(b, []byte("\r\n"))
if i < 3 {
return nil, ErrProtocol
}
// Read the meta
meta := string(b[3:i])
if len(meta) > 1024 {
return nil, ErrProtocol
}
// Read the response body
body := b[i+2:]
return &Response{
Status: status,
Meta: meta,
Body: body,
}, nil
}