Bring back pbkdf2

10 files changed, 204 insertions, 55 deletions

diff --git a/go.mod b/go.mod
index 4e975bb..5e702ba 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,7 @@
 module gitlab.com/rhogenson/roseh.moe
 
 go 1.24.0
+
+require golang.org/x/term v0.35.0
+
+require golang.org/x/sys v0.36.0 // indirect
diff --git a/go.sum b/go.sum
index e69de29..a7fae6a 100644
--- a/go.sum
+++ b/go.sum
@@ -0,0 +1,4 @@
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/term v0.35.0 h1:bZBVKBudEyhRcajGcNc3jIfWPqV4y/Kt2XcoigOWtDQ=
+golang.org/x/term v0.35.0/go.mod h1:TPGtkTLesOwf2DE8CgVYiZinHAOuy5AYUYT1lENIZnA=
diff --git a/internal/hole/hole.go b/internal/hole/hole.go
new file mode 100644
index 0000000..4824459
--- /dev/null
+++ b/internal/hole/hole.go
@@ -0,0 +1,25 @@
+package hole
+
+import (
+	"crypto/rand"
+	_ "embed"
+	"encoding/binary"
+	"strings"
+)
+
+var (
+	//go:embed wordlist.txt
+	wordListString string
+	wordList       = strings.Split(strings.TrimSuffix(wordListString, "\n"), "\n")
+)
+
+func New() string {
+	const nWords = 10
+	buf := make([]byte, 2*nWords)
+	rand.Read(buf)
+	words := make([]string, nWords)
+	for i := range words {
+		words[i] = wordList[binary.NativeEndian.Uint16(buf[2*i:])&0x1fff]
+	}
+	return strings.Join(words, "-")
+}
diff --git a/internal/wordlist/wordlist.txt b/internal/hole/wordlist.txt
index 5e304ce..5e304ce 100644
--- a/internal/wordlist/wordlist.txt
+++ b/internal/hole/wordlist.txt
diff --git a/internal/pwhash/pwhash.go b/internal/pwhash/pwhash.go
new file mode 100644
index 0000000..576d052
--- /dev/null
+++ b/internal/pwhash/pwhash.go
@@ -0,0 +1,18 @@
+package pwhash
+
+import (
+	"crypto/pbkdf2"
+	"crypto/sha512"
+)
+
+const SaltSize = 8
+
+const defaultIter = 12059332 // from tools/finditer
+
+func HashIter(password string, salt []byte, iter int) ([]byte, error) {
+	return pbkdf2.Key(sha512.New, password, salt, iter, 32)
+}
+
+func Hash(password string, salt []byte) ([]byte, error) {
+	return HashIter(password, salt, defaultIter)
+}
diff --git a/internal/wordlist/wordlist.go b/internal/wordlist/wordlist.go
deleted file mode 100644
index de929bc..0000000
--- a/internal/wordlist/wordlist.go
+++ /dev/null
@@ -1,11 +0,0 @@
-package wordlist
-
-import (
-	_ "embed"
-	"strings"
-)
-
-//go:embed wordlist.txt
-var wordList string
-
-var Words = strings.Split(strings.TrimSuffix(wordList, "\n"), "\n")
diff --git a/roseh.moe.go b/roseh.moe.go
index 140b1de..d3e96bf 100644
--- a/roseh.moe.go
+++ b/roseh.moe.go
@@ -8,7 +8,6 @@ import (
 	"crypto/subtle"
 	"embed"
 	"encoding/base64"
-	"encoding/binary"
 	"encoding/hex"
 	"flag"
 	"fmt"
@@ -21,7 +20,8 @@ import (
 	"sync"
 	"time"
 
-	"gitlab.com/rhogenson/roseh.moe/internal/wordlist"
+	"gitlab.com/rhogenson/roseh.moe/internal/hole"
+	"gitlab.com/rhogenson/roseh.moe/internal/pwhash"
 )
 
 var (
@@ -131,19 +131,8 @@ type wormholeTemplateArgs struct {
 	Hole string
 }
 
-func makeHole() string {
-	const nWords = 10
-	buf := make([]byte, 2*nWords)
-	rand.Read(buf)
-	words := make([]string, nWords)
-	for i := range words {
-		words[i] = wordlist.Words[binary.NativeEndian.Uint16(buf[2*i:])&0x1fff]
-	}
-	return strings.Join(words, "-")
-}
-
 func wormhole(w http.ResponseWriter, r *http.Request) {
-	if err := wormholeTemplate.Execute(w, wormholeTemplateArgs{Self: *selfURL, Hole: makeHole()}); err != nil {
+	if err := wormholeTemplate.Execute(w, wormholeTemplateArgs{Self: *selfURL, Hole: hole.New()}); err != nil {
 		log.Printf("Warning: wormhole: %s", err)
 	}
 }
@@ -358,6 +347,12 @@ func checkCSRFToken(r *http.Request) error {
 	return nil
 }
 
+func checkPassword(password string) bool {
+	expectedHash, salt := notepadPassword[:len(notepadPassword)-pwhash.SaltSize], notepadPassword[len(notepadPassword)-pwhash.SaltSize:]
+	hash, err := pwhash.Hash(password, salt)
+	return err == nil && subtle.ConstantTimeCompare(hash, expectedHash) != 0
+}
+
 var (
 	//go:embed templates/login.html.template
 	loginTemplateString string
@@ -380,8 +375,7 @@ func login(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "bad CSRF token", http.StatusBadRequest)
 		return
 	}
-	hash := sha256.Sum256([]byte(r.FormValue("password")))
-	if subtle.ConstantTimeCompare(notepadPassword, hash[:]) == 0 {
+	if !checkPassword(r.FormValue("password")) {
 		if err := loginTemplate.Execute(w, loginTemplateArgs{
 			Error:     true,
 			CSRFToken: r.FormValue("csrf-token"),
diff --git a/tools/finditer/finditer.go b/tools/finditer/finditer.go
new file mode 100644
index 0000000..fbd0363
--- /dev/null
+++ b/tools/finditer/finditer.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"encoding/hex"
+	"fmt"
+	"sort"
+	"testing"
+	"time"
+
+	"gitlab.com/rhogenson/roseh.moe/internal/pwhash"
+)
+
+func mustHex(s string) []byte {
+	b, err := hex.DecodeString(s)
+	if err != nil {
+		panic(err)
+	}
+	return b
+}
+
+const password = "emcee polio cardiac disclose superglue clapper cruelness stonework tingly unarmored"
+
+var salt = mustHex("a0aa6971f38827e5")
+
+var iterations int
+
+func BenchmarkHashIter(b *testing.B) {
+	for b.Loop() {
+		pwhash.HashIter(password, salt, iterations)
+	}
+}
+
+func main() {
+	const targetDuration = 5 * time.Second
+	for iterations = 8192; time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) < targetDuration; iterations *= 2 {
+	}
+	lo := iterations / 2
+	hi := iterations
+	fmt.Println(lo + sort.Search(hi-lo, func(i int) bool {
+		iterations = lo + i
+		return time.Duration(testing.Benchmark(BenchmarkHashIter).NsPerOp()) > targetDuration
+	}))
+}
diff --git a/tools/hashpw/hashpw.go b/tools/hashpw/hashpw.go
new file mode 100644
index 0000000..c75fa2e
--- /dev/null
+++ b/tools/hashpw/hashpw.go
@@ -0,0 +1,34 @@
+package main
+
+import (
+	"crypto/rand"
+	"fmt"
+	"os"
+
+	"gitlab.com/rhogenson/roseh.moe/internal/pwhash"
+	"golang.org/x/term"
+)
+
+func hashpw() error {
+	fmt.Fprint(os.Stderr, "Enter password: ")
+	password, err := term.ReadPassword(int(os.Stdin.Fd()))
+	fmt.Fprintln(os.Stderr)
+	if err != nil {
+		return err
+	}
+	salt := make([]byte, pwhash.SaltSize)
+	rand.Read(salt)
+	hash, err := pwhash.Hash(string(password), salt)
+	if err != nil {
+		return err
+	}
+	fmt.Printf("%x%x\n", hash, salt)
+	return nil
+}
+
+func main() {
+	if err := hashpw(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}
diff --git a/tools/hole/hole.go b/tools/hole/hole.go
index d701c40..c6946f0 100644
--- a/tools/hole/hole.go
+++ b/tools/hole/hole.go
@@ -1,36 +1,54 @@
+// The hole command is a CLI uploader tool for the roseh.moe wormhole.
+//
+// # Magic wormhole
+//
+// The name is inspired by the original "magic wormhole" library. The goal is to
+// get a file from one computer to another without a USB stick, Including cases
+// where scp might not be available. This includes transferring files to your
+// phone, for example, although a USB cord might still be more convenient when
+// moving many files. It should also work over restrictive firewalls. You should
+// be able to use the wormhole as long as you can access http://roseh.moe in
+// a browser.
+//
+// # Usage example
+//
+// The following shows a typical interaction with the tool
+//
+//	$ hole file.pdf
+//	https://roseh.moe/wormhole/dv-32-ethos-aztec-shako-spoils-2y-dwarf-sand-any
+//	Waiting for upload...
+//	<tool hangs, waiting to upload the file>
+//
+// Then, on another machine:
+//
+//	$ curl https://roseh.moe/wormhole/dv-32-ethos-aztec-shako-spoils-2y-dwarf-sand-any > file.pdf
+//
+// # Web interface
+//
+// There's also a web interface available for the wormhole, available at
+// https://roseh.moe/wormhole.
 package main
 
 import (
-	"crypto/rand"
-	"encoding/binary"
 	"flag"
 	"fmt"
 	"io"
 	"mime/multipart"
 	"net/http"
 	"os"
-	"strings"
 
-	"gitlab.com/rhogenson/roseh.moe/internal/wordlist"
+	"gitlab.com/rhogenson/roseh.moe/internal/hole"
 )
 
 var url = flag.String("url", "https://roseh.moe", "server URL")
 
-func makeHole() string {
-	const nWords = 10
-	buf := make([]byte, 2*nWords)
-	rand.Read(buf)
-	words := make([]string, nWords)
-	for i := range words {
-		words[i] = wordlist.Words[binary.NativeEndian.Uint16(buf[2*i:])&0x1fff]
-	}
-	return strings.Join(words, "-")
-}
-
-func hole() error {
+func upload() error {
 	args := flag.Args()
-	if len(args) != 1 {
-		return fmt.Errorf("usage error")
+	if len(args) == 0 {
+		return fmt.Errorf("usage error: missing filename")
+	}
+	if len(args) > 1 {
+		return fmt.Errorf("usage error: too many positional arguments")
 	}
 	fileName := args[0]
 	f, err := os.Open(fileName)
@@ -38,18 +56,19 @@ func hole() error {
 		return err
 	}
 	defer f.Close()
-	hole := makeHole()
+	hole := hole.New()
 	fmt.Println(*url + "/wormhole/" + hole)
+	fmt.Fprintln(os.Stderr, "Waiting for upload...")
 	resp, err := http.Get(*url + "/wormhole/" + hole + "/ready")
 	if err != nil {
-		return err
+		return fmt.Errorf("check wormhole ready: %s", err)
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("%s", resp.Status)
+		return fmt.Errorf("check wormhole ready: status: %s", resp.Status)
 	}
 	if _, err := io.Copy(io.Discard, resp.Body); err != nil {
-		return err
+		return fmt.Errorf("check wormhole ready: read response: %s", err)
 	}
 	pipeReader, pipeWriter := io.Pipe()
 	multipartWriter := multipart.NewWriter(pipeWriter)
@@ -57,15 +76,15 @@ func hole() error {
 		defer pipeWriter.Close()
 		part, err := multipartWriter.CreateFormFile("file", fileName)
 		if err != nil {
-			fmt.Fprintln(os.Stderr, err)
+			pipeWriter.CloseWithError(fmt.Errorf("create multipart reader: %s", err))
 			return
 		}
 		if _, err := io.Copy(part, f); err != nil {
-			fmt.Fprintln(os.Stderr, err)
+			pipeWriter.CloseWithError(fmt.Errorf("write body: %s", err))
 			return
 		}
 		if err := multipartWriter.Close(); err != nil {
-			fmt.Fprintln(os.Stderr, err)
+			pipeWriter.CloseWithError(fmt.Errorf("write trailer: %s", err))
 			return
 		}
 	}()
@@ -75,7 +94,7 @@ func hole() error {
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
-		return fmt.Errorf("%s", resp.Status)
+		return fmt.Errorf("upload: status: %s", resp.Status)
 	}
 	io.Copy(os.Stderr, resp.Body)
 	fmt.Fprintln(os.Stderr)
@@ -83,9 +102,28 @@ func hole() error {
 }
 
 func main() {
+	flag.Usage = func() {
+		fmt.Fprint(os.Stderr, `Usage: hole FILE
+Create a one-time wormhole that allows a specific client to download a
+file. Prints the URL to download the file and then hangs until the file
+is downloaded.
+
+Example:
+  $ hole file.pdf
+  https://roseh.moe/wormhole/dv-32-ethos-aztec-shako-spoils-2y-dwarf-sand-any
+  Waiting for upload...
+  <tool hangs, waiting to upload the file>
+
+Then, on another machine:
+  $ curl https://roseh.moe/wormhole/dv-32-ethos-aztec-shako-spoils-2y-dwarf-sand-any > file.pdf
+
+Flags:
+`)
+		flag.PrintDefaults()
+	}
 	flag.Parse()
-	if err := hole(); err != nil {
-		fmt.Fprintln(os.Stderr, err)
+	if err := upload(); err != nil {
+		fmt.Fprintf(os.Stderr, "hole: %s\n", err)
 		os.Exit(1)
 	}
 }