From ff05d62013906f3086b452bfeda3e0d5b9b7a541 Mon Sep 17 00:00:00 2001 From: tjpcc Date: Mon, 9 Jan 2023 16:40:24 -0700 Subject: Initial commit. some basics: - minimal README - some TODOs - server and request handler framework - contribs: file serving, request logging - server examples - CI setup --- examples/cowsay/main.go | 99 +++++++++++++++++++++++++++++++++++++++++++++ examples/fileserver/main.go | 60 +++++++++++++++++++++++++++ examples/inspectls/main.go | 95 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 254 insertions(+) create mode 100644 examples/cowsay/main.go create mode 100644 examples/fileserver/main.go create mode 100644 examples/inspectls/main.go (limited to 'examples') diff --git a/examples/cowsay/main.go b/examples/cowsay/main.go new file mode 100644 index 0000000..e724421 --- /dev/null +++ b/examples/cowsay/main.go @@ -0,0 +1,99 @@ +package main + +import ( + "bytes" + "context" + "io" + "log" + "net" + "os" + "os/exec" + + guslog "tildegit.org/tjp/gus/contrib/log" + "tildegit.org/tjp/gus/gemini" +) + +func main() { + // Get TLS files from the environment + certfile, keyfile := envConfig() + + // build a TLS configuration suitable for gemini + tlsconf, err := gemini.FileTLS(certfile, keyfile) + if err != nil { + log.Fatal(err) + } + + // set up the network listener + listener, err := net.Listen("tcp4", ":1965") + if err != nil { + log.Fatal(err) + } + + // add request logging to the request handler + handler := guslog.Requests(os.Stdout, nil)(cowsayHandler) + + // run the server + gemini.NewServer(context.Background(), tlsconf, listener, handler).Serve() +} + +func cowsayHandler(ctx context.Context, req *gemini.Request) *gemini.Response { + // prompt for a query if there is none already + if req.RawQuery == "" { + return gemini.Input("enter a phrase") + } + + // find the "cowsay" executable + binpath, err := exec.LookPath("cowsay") + if err != nil { + return gemini.Failure(err) + } + + // build the command and set the query to be passed to its stdin + cmd := exec.CommandContext(ctx, binpath) + cmd.Stdin = bytes.NewBufferString(req.UnescapedQuery()) + + // set up a pipe so we can read the command's stdout + rd, err := cmd.StdoutPipe() + if err != nil { + return gemini.Failure(err) + } + + // start the command + if err := cmd.Start(); err != nil { + return gemini.Failure(err) + } + + // read the complete stdout contents, clean up the process on error + buf, err := io.ReadAll(rd) + if err != nil { + cmd.Process.Kill() + cmd.Wait() + return gemini.Failure(err) + } + + // wait for the process to close + cmd.Wait() + + // pass the buffer to the response wrapped in ``` toggles, + // and include a link to start over + out := io.MultiReader( + bytes.NewBufferString("```\n"), + bytes.NewBuffer(buf), + bytes.NewBufferString("\n```\n=> . again"), + ) + return gemini.Success("text/gemini", out) +} + +func envConfig() (string, string) { + certfile, ok := os.LookupEnv("SERVER_CERTIFICATE") + if !ok { + log.Fatal("missing SERVER_CERTIFICATE environment variable") + } + + keyfile, ok := os.LookupEnv("SERVER_PRIVATEKEY") + if !ok { + log.Fatal("missing SERVER_PRIVATEKEY environment variable") + } + + return certfile, keyfile +} diff --git a/examples/fileserver/main.go b/examples/fileserver/main.go new file mode 100644 index 0000000..01d22ee --- /dev/null +++ b/examples/fileserver/main.go @@ -0,0 +1,60 @@ +package main + +import ( + "context" + "log" + "net" + "os" + + "tildegit.org/tjp/gus/contrib/fs" + guslog "tildegit.org/tjp/gus/contrib/log" + "tildegit.org/tjp/gus/gemini" +) + +func main() { + // Get TLS files from the environment + certfile, keyfile := envConfig() + + // build a TLS configuration suitable for gemini + tlsconf, err := gemini.FileTLS(certfile, keyfile) + if err != nil { + log.Fatal(err) + } + + // set up the network listen + listener, err := net.Listen("tcp4", ":1965") + if err != nil { + log.Fatal(err) + } + + // build the request handler + fileSystem := os.DirFS(".") + // Fallthrough tries each handler in succession until it gets something other than "51 Not Found" + handler := gemini.Fallthrough( + // first see if they're fetching a directory and we have /index.gmi + fs.DirectoryDefault(fileSystem, "index.gmi"), + // next (still if they requested a directory) build a directory listing response + fs.DirectoryListing(fileSystem, nil), + // finally, try to find a file at the request path and respond with that + fs.FileHandler(fileSystem), + ) + // add request logging to stdout + handler = guslog.Requests(os.Stdout, nil)(handler) + + // run the server + gemini.NewServer(context.Background(), tlsconf, listener, handler).Serve() +} + +func envConfig() (string, string) { + certfile, ok := os.LookupEnv("SERVER_CERTIFICATE") + if !ok { + log.Fatal("missing SERVER_CERTIFICATE environment variable") + } + + keyfile, ok := os.LookupEnv("SERVER_PRIVATEKEY") + if !ok { + log.Fatal("missing SERVER_PRIVATEKEY environment variable") + } + + return certfile, keyfile +} diff --git a/examples/inspectls/main.go b/examples/inspectls/main.go new file mode 100644 index 0000000..a315e40 --- /dev/null +++ b/examples/inspectls/main.go @@ -0,0 +1,95 @@ +package main + +import ( + "bytes" + "context" + "crypto/md5" + "crypto/tls" + "crypto/x509" + "encoding/hex" + "fmt" + "log" + "net" + "os" + "strings" + + "tildegit.org/tjp/gus/gemini" + guslog "tildegit.org/tjp/gus/contrib/log" +) + +func main() { + // Get TLS files from the environment + certfile, keyfile := envConfig() + + // build a TLS configuration suitable for gemini + tlsconf, err := gemini.FileTLS(certfile, keyfile) + if err != nil { + log.Fatal(err) + } + + // set up the network listener + listener, err := net.Listen("tcp4", ":1965") + if err != nil { + log.Fatal(err) + } + + // add stdout logging to the request handler + handler := guslog.Requests(os.Stdout, nil)(inspectHandler) + + // run the server + gemini.NewServer(context.Background(), tlsconf, listener, handler).Serve() +} + +func envConfig() (string, string) { + certfile, ok := os.LookupEnv("SERVER_CERTIFICATE") + if !ok { + log.Fatal("missing SERVER_CERTIFICATE environment variable") + } + + keyfile, ok := os.LookupEnv("SERVER_PRIVATEKEY") + if !ok { + log.Fatal("missing SERVER_PRIVATEKEY environment variable") + } + + return certfile, keyfile +} + +func inspectHandler(ctx context.Context, req *gemini.Request) *gemini.Response { + // build and return a ```-wrapped description of the connection TLS state + body := "```\n" + displayTLSState(req.TLSState) + "\n```" + return gemini.Success("text/gemini", bytes.NewBufferString(body)) +} + +func displayTLSState(state *tls.ConnectionState) string { + builder := &strings.Builder{} + + builder.WriteString("Version: ") + builder.WriteString(map[uint16]string{ + tls.VersionTLS10: "TLSv1.0", + tls.VersionTLS11: "TLSv1.1", + tls.VersionTLS12: "TLSv1.2", + tls.VersionTLS13: "TLSv1.3", + tls.VersionSSL30: "SSLv3", + }[state.Version]) + builder.WriteString("\n") + + builder.WriteString(fmt.Sprintf("Handshake complete: %t\n", state.HandshakeComplete)) + builder.WriteString(fmt.Sprintf("Did resume: %t\n", state.DidResume)) + builder.WriteString(fmt.Sprintf("Cipher suite: %x\n", state.CipherSuite)) + builder.WriteString(fmt.Sprintf("Negotiated protocol: %q\n", state.NegotiatedProtocol)) + builder.WriteString(fmt.Sprintf("Server name: %s\n", state.ServerName)) + + builder.WriteString(fmt.Sprintf("Certificates (%d)\n", len(state.PeerCertificates))) + for i, cert := range state.PeerCertificates { + builder.WriteString(fmt.Sprintf(" #%d: %s\n", i+1, fingerprint(cert))) + } + + return builder.String() +} + +func fingerprint(cert *x509.Certificate) []byte { + raw := md5.Sum(cert.Raw) + dst := make([]byte, hex.EncodedLen(len(raw))) + hex.Encode(dst, raw[:]) + return dst +} -- cgit v1.2.3