Fix bugs and add comments (see description)

Fix bug where config destination directory is ignored
Switch to base91 (14%-23% size increase) from hex (100% size increase)
Add comments

files.go

@@ -19,7 +19,7 @@ package main
 import (
 	"bufio"
 	"bytes"
-	"encoding/hex"
+	"ekyu.moe/base91"
 	"errors"
 	"fmt"
 	"github.com/rs/zerolog"
@@ -29,10 +29,45 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 )
 
+// Encode byte slice to base91 encoded, escaped string for transmission
+func EncodeToSafeString(data []byte) string {
+	// Encode data to base91 string
+	base91Data := base91.EncodeToString(data)
+	// Create regex to match |, ;, and %
+	escapeRegex := regexp.MustCompile(`[|;%]`)
+	// Map each character to its escape code
+	escapeMap := map[string]string{"|": "%7C", ";": "%3B", "%": "%25"}
+	// Replace all matched characters in accordance with the function
+	escapedBase91Data := escapeRegex.ReplaceAllStringFunc(base91Data, func(in string) string {
+		// Return character mapping
+		return escapeMap[in]
+	})
+	// Return escaped base91 string
+	return escapedBase91Data
+}
+
+// Decode base91 encoded, escaped string to byte slice
+func DecodeSafeString(base91Str string) ([]byte, error) {
+	// Create regex to match %7C, %3B, %25
+	unescapeRegex := regexp.MustCompile(`%7C|%3B|%25`)
+	// Map each escape code to its character
+	escapeMap := map[string]string{"%7C": "|", "%3B": ";", "%25": "%"}
+	// Replace all matched characters in accordance with the function
+	base91Data := unescapeRegex.ReplaceAllStringFunc(base91Str, func(in string) string {
+		// Return escape code mapping
+		return escapeMap[in]
+	})
+	// Decode unescaped base91 string
+	data := base91.DecodeString(base91Data)
+	// Return byte slice
+	return data, nil
+}
+
 // Save encrypted key to file
 func SaveEncryptedKey(encryptedKey []byte, filePath string) {
 	// Use ConsoleWriter logger
@@ -100,7 +135,7 @@ connectionLoop:
 				log.Fatal().Err(err).Msg("Error reading key")
 			}
 			// Write saved key to ResponseWriter
-			_, err = fmt.Fprintln(connection, "OK;"+hex.EncodeToString(key)+";")
+			_, err = fmt.Fprintln(connection, "OK;"+EncodeToSafeString(key)+";")
 			if err != nil {
 				log.Fatal().Err(err).Msg("Error writing response")
 			}
@@ -152,8 +187,8 @@ connectionLoop:
 				// Inform user client has requested a file
 				log.Info().Str("file", file).Msg("File requested")
 			}
-			// Write file as hex to connection
-			_, err = fmt.Fprintln(connection, "OK;"+hex.EncodeToString(fileData)+";")
+			// Write file as base91 to connection
+			_, err = fmt.Fprintln(connection, "OK;"+EncodeToSafeString(fileData)+";")
 			if err != nil {
 				log.Fatal().Err(err).Msg("Error writing response")
 			}
@@ -243,8 +278,8 @@ func RecvFiles(connection net.Conn) {
 			if err != nil {
 				log.Fatal().Err(err).Msg("Error creating file")
 			}
-			// Decode file data from hex string
-			fileData, err := hex.DecodeString(strings.TrimSpace(procMessage[1]))
+			// Decode file data from base91 string
+			fileData, err := DecodeSafeString(strings.TrimSpace(procMessage[1]))
 			if err != nil {
 				log.Fatal().Err(err).Msg("Error decoding hex")
 			}

go.mod

@@ -3,6 +3,7 @@ module opensend
 go 1.15
 
 require (
+	ekyu.moe/base91 v0.2.3
 	github.com/grandcat/zeroconf v1.0.0
 	github.com/klauspost/compress v1.11.3
 	github.com/pelletier/go-toml v1.8.1

go.sum

@@ -1,3 +1,5 @@
+ekyu.moe/base91 v0.2.3 h1:1jCZrrpWjDSMMjjU9LANfQV+n7EHeW0OQ0MO9fpDRHg=
+ekyu.moe/base91 v0.2.3/go.mod h1:/qmmaFUj5d0p9xcpj8beZDj33yXrc54eGU+hO/V5vuo=
 github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=

keyCrypto.go

@@ -21,7 +21,6 @@ import (
 	"crypto/rand"
 	"crypto/rsa"
 	"crypto/sha256"
-	"encoding/hex"
 	"fmt"
 	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
@@ -63,8 +62,8 @@ func GetKey(connection net.Conn) []byte {
 	procMessage := strings.Split(strings.TrimSpace(message), ";")
 	// If ok code returned
 	if procMessage[0] == "OK" {
-		// Decode received hex string into key
-		key, err := hex.DecodeString(procMessage[1])
+		// Decode received safe base91 string into key
+		key, err := DecodeSafeString(procMessage[1])
 		if err != nil {
 			log.Fatal().Err(err).Msg("Error reading key")
 		}

main.go

@@ -34,6 +34,7 @@ import (
 )
 
 var workDir *string
+var destDir *string
 
 func main() {
 	// Use ConsoleWriter logger
@@ -42,8 +43,10 @@ func main() {
 	// Create --send-to flag to send to a specific IP
 	sendTo := flag.String("send-to", "", "Use IP address of receiver instead of mDNS")
 	// Create --dest-dir flag to save to a specified folder
-	destDir := flag.String("dest-dir", "", "Destination directory for files or dirs sent over opensend")
+	destDir = flag.String("dest-dir", "", "Destination directory for files or dirs sent over opensend")
+	// Create --work-dir flag to perform operations in a specified directory
 	workDir = flag.String("work-dir", "", "Working directory for opensend")
+	// Create --config to select config file to use
 	givenCfgPath := flag.String("config", "", "Opensend config to use")
 	// Create --skip-mdns to skip service registration
 	skipMdns := flag.Bool("skip-mdns", false, "Skip zeroconf service registration (use if mdns fails)")
@@ -84,6 +87,15 @@ func main() {
 		}
 	}
 
+	// If destination directory flag not provided
+	if *destDir == "" {
+		// If receiver flag provided
+		if *recvFlag {
+			// Set destination directory to receiver as defined in config
+			*destDir = ExpandPath(config.Receiver.DestDir)
+		}
+	}
+
 	// If target flag provided
 	if *targetFlag != "" {
 		// Set IP to target's IP