2020-09-21 19:48:42 +00:00
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package gemini
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import (
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2020-09-22 01:31:09 +00:00
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"bytes"
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2020-09-21 19:48:42 +00:00
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"crypto/tls"
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"errors"
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"io/ioutil"
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"net/url"
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"strconv"
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"strings"
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)
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var (
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ErrProtocol = errors.New("Protocol error")
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ErrInvalidURL = errors.New("Invalid URL")
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)
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// Client is a Gemini client.
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type Client struct{}
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// Request makes a request for the provided URL. The host is inferred from the URL.
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func (c *Client) Request(url string) (*Response, error) {
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if len(url) > 1024 {
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return nil, ErrInvalidURL
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}
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2020-09-21 19:48:42 +00:00
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req, err := NewRequest(url)
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if err != nil {
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return nil, err
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}
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return c.Do(req)
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}
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2020-09-21 21:23:51 +00:00
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// ProxyRequest requests the provided URL from the provided host.
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func (c *Client) ProxyRequest(host, url string) (*Response, error) {
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if len(url) > 1024 {
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return nil, ErrInvalidURL
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}
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2020-09-21 19:48:42 +00:00
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req, err := NewProxyRequest(host, url)
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if err != nil {
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return nil, err
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}
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return c.Do(req)
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}
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// Request is a Gemini request.
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//
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// A Request can optionally be configured with a client certificate. Example:
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//
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// req := NewRequest(url)
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// cert, err := tls.LoadX509KeyPair("client.crt", "client.key")
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// if err != nil {
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// panic(err)
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// }
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// req.Certificates = append(req.Certificates, cert)
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//
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type Request struct {
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Host string // host or host:port
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URL *url.URL // the requested URL
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Certificates []tls.Certificate // client certificates
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}
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// NewRequest returns a new request. The host is inferred from the provided url.
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func NewRequest(rawurl string) (*Request, error) {
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u, err := url.Parse(rawurl)
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if err != nil {
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return nil, err
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}
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// Ignore UserInfo if present
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u.User = nil
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return &Request{
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Host: u.Host,
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URL: u,
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}, nil
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}
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// NewProxyRequest makes a new request using the provided host.
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func NewProxyRequest(host, rawurl string) (*Request, error) {
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u, err := url.Parse(rawurl)
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if err != nil {
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return nil, err
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}
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// Ignore UserInfo if present
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u.User = nil
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return &Request{
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Host: host,
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URL: u,
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}, nil
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}
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2020-09-21 21:36:09 +00:00
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// Do sends a Gemini request and returns a Gemini response.
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func (c *Client) Do(req *Request) (*Response, error) {
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host := req.Host
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if strings.LastIndex(host, ":") == -1 {
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// The default port is 1965
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host += ":1965"
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}
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2020-09-21 22:21:42 +00:00
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// Allow self signed certificates
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config := tls.Config{}
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config.InsecureSkipVerify = true
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config.Certificates = req.Certificates
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conn, err := tls.Dial("tcp", host, &config)
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if err != nil {
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return nil, err
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}
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defer conn.Close()
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// Write the request
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request := req.URL.String() + "\r\n"
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if _, err := conn.Write([]byte(request)); err != nil {
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return nil, err
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}
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2020-09-22 01:31:09 +00:00
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// Read the response
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b, err := ioutil.ReadAll(conn)
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if err != nil {
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return nil, err
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}
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// Ensure that the response is long enough
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// The minimum response: <STATUS><SPACE><CR><LF> (5 bytes)
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if len(b) < 5 {
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return nil, ErrProtocol
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}
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// Parse the response header
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status, err := strconv.Atoi(string(b[:2]))
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if err != nil {
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return nil, err
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}
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// Read one space
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if b[2] != ' ' {
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return nil, ErrProtocol
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}
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// Find the first <CR><LF>
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i := bytes.Index(b, []byte("\r\n"))
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if i < 3 {
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return nil, ErrProtocol
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}
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// Read the meta
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meta := string(b[3:i])
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if len(meta) > 1024 {
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return nil, ErrProtocol
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}
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// Read the response body
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body := b[i+2:]
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return &Response{
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Status: status,
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Meta: meta,
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Body: body,
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}, nil
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}
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