1 files changed, 153 insertions, 0 deletions

diff --git a/libgemini.go b/libgemini.go
new file mode 100644
index 0000000..05321ef
--- /dev/null
+++ b/libgemini.go
@@ -0,0 +1,153 @@
+package gopherproxy
+
+import (
+        "bufio"
+        "crypto/tls"
+        "errors"
+        "io"
+        "net/url"
+        "regexp"
+        "strconv"
+        "strings"
+)
+
+const (
+        CRLF = "\r\n"
+)
+
+const (
+        STATUS_INPUT                  = 10
+        STATUS_SUCCESS                = 20
+        STATUS_SUCCESS_CERT           = 21
+        STATUS_REDIRECT_TEMP          = 30
+        STATUS_REDIRECT_PERM          = 31
+        STATUS_TEMP_FAILURE           = 40
+        STATUS_SERVER_UNAVAILABLE     = 41
+        STATUS_CGI_ERROR              = 42
+        STATUS_PROXY_ERROR            = 43
+        STATUS_SLOW_DOWN              = 44
+        STATUS_PERM_FAILURE           = 50
+        STATUS_NOT_FOUND              = 51
+        STATUS_GONE                   = 52
+        STATUS_PROXY_REFUSED          = 53
+        STATUS_BAD_REQUEST            = 59
+        STATUS_CLIENT_CERT_EXPIRED    = 60
+        STATUS_TRANSIENT_CERT_REQUEST = 61
+        STATUS_AUTH_CERT_REQUIRED     = 62
+        STATUS_CERT_REJECTED          = 63
+        STATUS_FUTURE_CERT_REJECTED   = 64
+        STATUS_EXPIRED_CERT_REJECTED  = 65
+)
+
+const (
+        MIME_GEMINI     = "text/gemini"
+        DEFAULT_MIME    = MIME_GEMINI
+        DEFAULT_CHARSET = "utf-8"
+)
+
+var (
+        HeaderPattern      = regexp.MustCompile("^(\\d\\d)[ \\t]+(.*)$")
+        MimeTypePattern    = regexp.MustCompile("^[-\\w.]+/[-\\w.]+")
+        MimeCharsetPattern = regexp.MustCompile("charset=([^ ;]+)")
+        GeminiLinkPattern  = regexp.MustCompile("^=>[ \\t]*([^ ]+)(?:[ \\t]+(.*))?$")
+)
+
+type GeminiHeader struct {
+        Status int
+        Meta   string
+}
+
+type GeminiResponse struct {
+        Header *GeminiHeader
+        Body   io.Reader
+}
+
+func GeminiGet(uri string) (*GeminiResponse, error) {
+        u, err := url.Parse(uri)
+        if err != nil {
+                return nil, err
+        }
+
+        if u.Scheme != "gemini" {
+                return nil, errors.New("invalid scheme for uri")
+        }
+
+        var (
+                host string
+                port int
+        )
+
+        hostport := strings.Split(u.Host, ":")
+        if len(hostport) == 2 {
+                host = hostport[0]
+                n, err := strconv.ParseInt(hostport[1], 10, 32)
+                if err != nil {
+                        return nil, err
+                }
+                port = int(n)
+        } else {
+                host, port = hostport[0], 1965
+        }
+
+        conn, err := tls.Dial("tcp", host+":"+strconv.Itoa(port), &tls.Config{
+                MinVersion:         tls.VersionTLS12,
+                InsecureSkipVerify: true,
+        })
+        if err != nil {
+                return nil, err
+        }
+
+        _, err = conn.Write([]byte(u.String() + CRLF))
+        if err != nil {
+                conn.Close()
+                return nil, err
+        }
+
+        reader := bufio.NewReader(conn)
+
+        line, _, err := reader.ReadLine()
+        if err != nil {
+                conn.Close()
+                return nil, err
+        }
+
+        header, err := ParseGeminiHeader(string(line))
+        if err != nil {
+                conn.Close()
+                return nil, err
+        }
+
+        return &GeminiResponse{
+                Header: header,
+                Body:   reader,
+        }, nil
+}
+
+func ParseGeminiHeader(line string) (header *GeminiHeader, err error) {
+        matches := HeaderPattern.FindStringSubmatch(line)
+
+        status, err := strconv.Atoi(matches[1])
+        if err != nil {
+                return nil, err
+        }
+
+        meta := matches[2]
+
+        if int(status/10) == 2 {
+                if meta == "" {
+                        meta = DEFAULT_MIME + ";charset=" + DEFAULT_CHARSET
+                }
+
+                mimeType := MimeTypePattern.FindString(meta)
+                if strings.HasPrefix(mimeType, "text/") && MimeCharsetPattern.FindString(meta) == "" {
+                        meta += ";charset=" + DEFAULT_CHARSET
+                }
+        }
+
+        header = &GeminiHeader{
+                Status: status,
+                Meta:   meta,
+        }
+
+        return
+}