Port crypt package

0.go

@@ -1,12 +1,10 @@
 package main
 
-/*
+// #include <string.h>
-typedef struct {
+// #include <stdlib.h>
-    char* data;
+// #include "types.h"
-    int len;
-} PascalString;
-*/
 import "C"
+import "unsafe"
 
 // getPascalString returns a pascal
 // string struct for the input Go string.
@@ -28,3 +26,24 @@ func getPascalStringFromBytes(goBytes []byte) C.PascalString {
 		len:  C.int(len(goBytes)),
 	}
 }
+
+// GetPascalStringFromCString is a helper meant to be used from C.
+//
+//export GetPascalStringFromCString
+func GetPascalStringFromCString(cString *C.char) C.PascalString {
+	return C.PascalString{
+		data: cString,
+		len:  C.int(C.strlen(cString)),
+	}
+}
+
+// FreeArray frees the memory allocated by a C-allocated array.
+//
+//export FreeArray
+func FreeArray(items *C.PascalString, count C.int) {
+	linesSlice := (*[1 << 30]C.PascalString)(unsafe.Pointer(items))[:count:count]
+	for i := 0; i < int(count); i++ {
+		C.free(unsafe.Pointer(linesSlice[i].data))
+	}
+	C.free(unsafe.Pointer(items))
+}

README.md

@@ -12,23 +12,40 @@ to export to C.
 All relevant exported libmutton functions have C functions of the same name.
 Functions with multiple return values all have CGO-generated structs to store the return values.
 These structs are named `<FunctionName>_return`, as per CGO.
-All functions continue to perform the same basic operations, with a couple caveats:
+All functions perform similar basic operations, with a couple caveats:
 - Anything that would normally return a Go error now returns a null-terminated *C.char containing the error string.
 These are safe to null-terminate because their values are much more predictable than other strings.
 Errors are always the *first* return value, so they can always be referenced with `<result>.r0`.
-- Anything that would normally return a Go string or byte slice now returns a C.PascalString struct.
+- Many things that would normally require/return a Go string or byte slice now require/return a C.PascalString struct.
 This is to avoid bugs with null-terminated strings.
 
 Additionally, since comments tend to fall out of date, please rely on the [Go documentation for libmutton](https://pkg.go.dev/github.com/rwinkhart/libmutton). Documentation for the CGO bindings present in this repo only specify return values.
-### Example (libmutton's global.DirInit)
+### Example (decrypting and printing lines of a libmutton entry)
 Build the following example with `gcc <filename> ./cmutton.a`.
 ```c
 #include <stdio.h>
+#include <string.h>
 #include "cmutton.h" // import cmutton
 
+static void read_input(const char *prompt, char *buffer, size_t size) {
+    printf("%s", prompt);
+    fflush(stdout);
+    if (fgets(buffer, size, stdin) == NULL) {
+        fprintf(stderr, "Error reading user input\n");
+        exit(1);
+    }
+    // remove trailing newline
+    buffer[strlen(buffer)-1] = '\0';
+}
+
 int main() {
+    char vanityPath[256];
+    char password[256];
+    read_input("Enter vanity path: ", vanityPath, sizeof(vanityPath));
+    read_input("Enter password: ", password, sizeof(password));
+
     // use CGO-generated struct to get multiple return values
-    struct DirInit_return result = DirInit(1);
+    struct DecryptFileToSlice_return result = DecryptFileToSlice(GetRealPath(vanityPath), GetPascalStringFromCString(password));
 
     // familiar error handling pattern
     if (result.r0 != NULL) {
@@ -36,17 +53,19 @@ int main() {
         exit(1); // result.r0 not freed since program exits
     }
 
+    for (int i = 0; i < result.r2; i++) {
         // print Pascal string using "%.*s" with printf and supplying both length and data
-    printf("Old device ID: %.*s\n", result.r1.len, result.r1.data);
+        printf("%.*s\n", result.r1[i].len, result.r1[i].data);
+    }
 
     // be sure to free the data!
-    free(result.r1.data);
+    FreeArray(result.r1, result.r2);
 }
 ```
 
 # Progress
 - [ ] age
-    - [ ] AllPasswordEntries(forceReage bool) error
+    - [ ] AllPasswordEntries(forceReage bool, rcwPassword []byte) error
     - [ ] Entry(vanityPath string, timestamp int64) error
     - [ ] TranslateAgeTimestamp(timestamp *int64) uint8
 - [ ] clip
@@ -65,25 +84,26 @@ int main() {
     - [ ] EntryIsNotEmpty(entryData []string) bool
     - [ ] EntryRefresh(oldRCWPassword, newRCWPassword []byte, removeOldDir bool) error
     - [ ] GenTOTP(secret string, time time.Time) (string, error)
-    - [ ] GetOldEntryData(realPath string, field int) ([]string, error)
+    - [ ] GetOldEntryData(realPath string, field int, rcwPassword []byte) ([]string, error)
     - [ ] LibmuttonInit(inputCB func(prompt string) string, rcwPassword []byte, ...) error
     - [ ] RCWSanityCheckGen(password []byte) error
-    - [ ] WriteEntry(realPath string, decSlice []string, passwordIsNew bool) error
+    - [ ] WriteEntry(realPath string, decSlice []string, passwordIsNew bool, rcwPassword []byte) error
 - [ ] crypt
-    - [ ] DecryptFileToSlice(realPath string) ([]string, error)
+    - [ ] Address TODOs
-    - [ ] EncryptBytes(decBytes []byte) []byte
+    - [X] ~~VAR: RetryPassword bool~~ (RCWD not supported)
-    - [ ] RCWDArgument()
+    - [X] DecryptFileToSlice(realPath string) ([]string, error)
-    - [ ] VAR: Daemonize bool
+    - [X] EncryptBytes(decBytes []byte) []byte
-    - [ ] VAR: RetryPassword bool
+    - [X] ~~RCWDArgument()~~ (RCWD not supported)
 - [ ] global
+    - [ ] Address TODOs
+    - [X] ~~VAR (CB func): GetPassword~~ (RCWD not supported)
     - [X] DirInit(preserveOldCfgDir bool) (string, error)
-    - [ ] ~~GenDeviceIDList() ([]fs.DirEntry, error)~~ (not for use outside of libmutton)
+    - [X] ~~GenDeviceIDList() ([]fs.DirEntry, error)~~ (not for use outside of libmutton)
     - [X] GetCurrentDeviceID() (string, error)
     - [X] GetRealAgePath(vanityPath string) string
     - [X] GetRealPath(vanityPath string) string
-    - [ ] ~~GetSysProcAttr() *syscall.SysProcAttr~~ (not for use outside of libmutton)
+    - [X] ~~GetSysProcAttr() *syscall.SysProcAttr~~ (not for use outside of libmutton)
     - [X] GetVanityPath(realPath string) string
-    - [ ] VAR (CB func): GetPassword
 - [ ] syncclient
     - [ ] AddFolderRemote(vanityPath string) error
     - [ ] GenDeviceID(oldDeviceID, prefix string) (string, string, bool, error)

crypt.go

@@ -0,0 +1,53 @@
+package main
+
+// #include <stdlib.h>
+// #include "types.h"
+import "C"
+import (
+	"unsafe"
+
+	"github.com/rwinkhart/libmutton/crypt"
+	"github.com/rwinkhart/rcw/wrappers"
+)
+
+// TODO investigate username+password only entries still having blank lines at the end when decrypted
+
+// DecryptFileToSlice returns:
+// r0: err
+//
+// r1: decLines (pointer to C-allocated array)
+//
+// r2: length decLines array
+//
+//export DecryptFileToSlice
+func DecryptFileToSlice(realPath, rcwPassword C.PascalString) (*C.char, *C.PascalString, C.int) {
+	lines, err := crypt.DecryptFileToSlice(C.GoStringN(realPath.data, realPath.len), []byte(C.GoStringN(rcwPassword.data, rcwPassword.len)))
+	if err != nil {
+		return C.CString(err.Error()), nil, 0
+	}
+
+	if len(lines) == 0 {
+		return nil, nil, 0
+	}
+
+	// allocate C array for PascalStrings
+	cLinesPtr := (*C.PascalString)(C.malloc(C.size_t(len(lines)) * C.size_t(C.sizeof_PascalString)))
+
+	// populate the array with the decrypted lines
+	cLinesSlice := (*[1 << 30]C.PascalString)(unsafe.Pointer(cLinesPtr))[:len(lines):len(lines)]
+	for i, line := range lines {
+		cLinesSlice[i] = getPascalString(line)
+	}
+
+	return nil, cLinesPtr, C.int(len(lines))
+}
+
+// EncryptBytes returns:
+// encBytes
+//
+//export EncryptBytes
+func EncryptBytes(decBytes, rcwPassword C.PascalString) C.PascalString {
+	// use wrappers.Encrypt directly since C bindings do no support the RCWD daemon
+	encBytes := wrappers.Encrypt([]byte(C.GoStringN(decBytes.data, decBytes.len)), []byte(C.GoStringN(rcwPassword.data, rcwPassword.len)))
+	return getPascalStringFromBytes(encBytes)
+}

global.go

@@ -1,12 +1,7 @@
 package main
 
-/*
+// #include <stdlib.h>
-#include <stdlib.h>
+// #include "types.h"
-typedef struct {
-    char* data;
-    int len;
-} PascalString;
-*/
 import "C"
 import (
 	"github.com/rwinkhart/libmutton/global"

go.mod

@@ -2,9 +2,17 @@ module cmutton
 
 go 1.25.6
 
-require github.com/rwinkhart/libmutton v0.4.3-0.20260111043639-f82b35bc4398
+require (
+	github.com/rwinkhart/libmutton v0.4.3-0.20260111043639-f82b35bc4398
+	github.com/rwinkhart/rcw v0.2.4
+)
 
 require (
+	github.com/Microsoft/go-winio v0.6.2 // indirect
 	github.com/rwinkhart/go-boilerplate v0.1.1 // indirect
+	github.com/rwinkhart/peercred-mini v0.1.2 // indirect
+	golang.org/x/crypto v0.46.0 // indirect
 	golang.org/x/sys v0.40.0 // indirect
 )
+
+replace github.com/rwinkhart/libmutton => ../libmutton

go.sum

@@ -1,6 +1,12 @@
+github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
+github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/rwinkhart/go-boilerplate v0.1.1 h1:C+yyscGWeqvNpR91iw0i91zqX0LcxnCr1VOyT7iM4JY=
 github.com/rwinkhart/go-boilerplate v0.1.1/go.mod h1:/NVRKGslU20E5xU5YOgXzWxA6aa94BMtv5MtHRTb5Ek=
-github.com/rwinkhart/libmutton v0.4.3-0.20260111043639-f82b35bc4398 h1:QufX3nG3H1N986Xh7NZWsVELxmGms1yhNP7/fejBeHY=
+github.com/rwinkhart/peercred-mini v0.1.2 h1:4cGWDbv0whvLeVvbUdx84V/9p+2fS+DEXgrA1KxlRFo=
-github.com/rwinkhart/libmutton v0.4.3-0.20260111043639-f82b35bc4398/go.mod h1:qInUv19lzX1adFNI6Ih/IEVy+pktSTh/yA7cRTdVPH8=
+github.com/rwinkhart/peercred-mini v0.1.2/go.mod h1:LLHG7YshHEpbpJJP+Il9nx2dnGj5O3VGE32rWmflj0c=
+github.com/rwinkhart/rcw v0.2.4 h1:FrRSsl+ui1WLmDwqjLSROtFPKqSeGLEfF2SPENt4qP0=
+github.com/rwinkhart/rcw v0.2.4/go.mod h1:nhW4RAHvEjW2QcOlqEdWqRQOFJLjoOGSPkSRZlMjU3s=
+golang.org/x/crypto v0.46.0 h1:cKRW/pmt1pKAfetfu+RCEvjvZkA9RimPbh7bhFjGVBU=
+golang.org/x/crypto v0.46.0/go.mod h1:Evb/oLKmMraqjZ2iQTwDwvCtJkczlDuTmdJXoZVzqU0=
 golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
 golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=

types.h

@@ -0,0 +1,9 @@
+#ifndef TYPES_H
+#define TYPES_H
+
+typedef struct {
+    char* data;
+    int len;
+} PascalString;
+
+#endif