Support different keymaps via attempting to decode

NEWS

@@ -6,6 +6,7 @@ Libyubikey NEWS -- History of user-visible changes.             -*- outline -*-
  ** Better self tests.
  ** Fix memory leak.
  ** Document modhex alphabet.
+ ** Add different ModHex alphabets
 
 * Version 1.13 (released 2015-03-05)
  ** Correct hex decode with uneven characters, for example "abc".

modhex.1.txt

@@ -52,6 +52,9 @@ The modhex alphabet is a base16 alphabet just as hex, they map as follows:
  0 1 2 3 4 5 6 7 8 9 a b c d e f
  c b d e f g h i j k l n r t u v
 
+When using yubikey devices on non-QWERTY keyboard layouts, these keys may map
+to different letters.
+
 SEE ALSO
 ---------
 YubiKeys can be obtained from Yubico: http://www.yubico.com/

modhex.c

@@ -157,9 +157,13 @@ main (int argc, char *argv[])
 	return 1;
       }
 
-    if (decode_p)
+    if (decode_p) {
+      if (!yubikey_modhex_p(data)) {
+        printf("Invalid modhex string\n");
+        return 0;
+      }
       yubikey_modhex_decode (buf, data, inlen / 2);
-    else
+    } else
       yubikey_modhex_encode (buf, data, inlen);
 
     if (decode_p && hex_p)

tests/selftest.c

@@ -78,6 +78,45 @@ modhex_test3 (void)
   printf ("Modhex-3 success\n");
 }
 
+static void
+modhex_test4 (void)
+{
+  char buf[1024];
+  int rc;
+
+  strcpy (buf, "jxe.uidchtnbpygk");
+  rc = yubikey_modhex_p (buf);
+  printf ("modhex-p(\"%s\") = %d\n", buf, rc);
+  assert (rc == 1);
+  printf ("Modhex-4 success\n");
+}
+
+static void
+modhex_test5 (void)
+{
+  char buf[1024];
+  int rc;
+
+  strcpy (buf, "cbsftdhuneikpglv");
+  rc = yubikey_modhex_p (buf);
+  printf ("modhex-p(\"%s\") = %d\n", buf, rc);
+  assert (rc == 1);
+  printf ("Modhex-5 success\n");
+}
+
+static void
+modhex_test6 (void)
+{
+  char buf[1024];
+  char buf2[1024];
+
+  strcpy (buf, "vvnhvuuvihlstuhpkgvfthfpeifbnbbuscbhhphffisc");
+  yubikey_modhex_decode(buf2, buf, sizeof (buf2));
+  assert (memcmp (buf2, "\xff\xb6\xfe\xef\x76\xa0\xde\x60\x95\xf4\xd6\x40\x37\x41\xb1\x1e\x00\x16\x60\x64\x47\x00", 22) == 0);
+
+  printf ("Modhex-6 success\n");
+}
+
 static void
 hex_test1 (void)
 {
@@ -315,6 +354,9 @@ main (void)
   modhex_test1 ();
   modhex_test2 ();
   modhex_test3 ();
+  modhex_test4 ();
+  modhex_test5 ();
+  modhex_test6 ();
   hex_test1 ();
   hex_test2 ();
   hex_test3 ();

ykhex.c

@@ -33,7 +33,7 @@
 #include "yubikey.h"
 
 static const char hex_trans[] = "0123456789abcdef";
-static const char modhex_trans[] = YUBIKEY_MODHEX_MAP;
+//static const char modhex_trans[] = YUBIKEY_MODHEX_MAPS[0];
 
 static void
 _yubikey_encode (char *dst, const char *src, size_t srcSize,
@@ -113,17 +113,39 @@ yubikey_hex_p (const char *str)
 void
 yubikey_modhex_encode (char *dst, const char *src, size_t srcSize)
 {
-  _yubikey_encode (dst, src, srcSize, modhex_trans);
+  _yubikey_encode (dst, src, srcSize, YUBIKEY_MODHEX_MAPS[0]);
 }
 
 void
 yubikey_modhex_decode (char *dst, const char *src, size_t dstSize)
 {
-  _yubikey_decode (dst, src, dstSize, modhex_trans);
+  size_t i;
+  for (i = 0; i < N_MODHEX_MAPS; i++) {
+    if (_yubikey_p(src, YUBIKEY_MODHEX_MAPS[i])) {
+      _yubikey_decode (dst, src, dstSize, YUBIKEY_MODHEX_MAPS[0]);
+    }
+  }
+  _yubikey_decode (dst, src, dstSize, YUBIKEY_MODHEX_MAPS[0]);
+}
+
+void
+yubikey_modhex_decode_map(char *dst, const char *src, size_t dstSize, const char *map)
+{
+  _yubikey_decode(dst, src, dstSize, map);
+}
+
+int yubikey_modhex_map_p(const char *str, const char *map) {
+  return _yubikey_p(str, map);
 }
 
 int
 yubikey_modhex_p (const char *str)
 {
-  return _yubikey_p (str, modhex_trans);
+  size_t i;
+  for (i = 0; i < N_MODHEX_MAPS; i++) {
+    if (_yubikey_p(str, YUBIKEY_MODHEX_MAPS[i])) {
+      return 1;
+    }
+  }
+  return 0;
 }

yubikey.h

@@ -91,7 +91,13 @@ extern "C"
  * Low-level functions; ModHex.
  */
 
-#define YUBIKEY_MODHEX_MAP "cbdefghijklnrtuv"
+#define N_MODHEX_MAPS (sizeof YUBIKEY_MODHEX_MAPS / sizeof YUBIKEY_MODHEX_MAPS[0])
+const static char* YUBIKEY_MODHEX_MAPS[] = {
+    "cbdefghijklnrtuv", /* default (QWERTY, AZERTY) */
+    "jxe.uidchtnbpygk", /* English Dvorak */
+    "cbsftdhuneikpglv", /* English Colemak */
+};
+
 
 /* ModHex encode input string SRC of length SRCSIZE and put the zero
    terminated output string in DST.  The size of the output string DST
@@ -102,9 +108,14 @@ extern "C"
 
 /* ModHex decode input string SRC of length DSTSIZE/2 into output
    string DST.  The output string DST is always DSTSIZE/2 large plus
-   the terminating zero.  */
+   the terminating zero.
+
+   Tries to guess the modhex map
+*/
   extern void yubikey_modhex_decode (char *dst,
 				     const char *src, size_t dstsize);
+  extern void yubikey_modhex_decode_map (char *dst, const char *src,
+                                         size_t dstsize, const char *map);
 
 /* Hex encode/decode data, same interface as modhex functions. */
   extern void yubikey_hex_encode (char *dst, const char *src, size_t srcsize);
@@ -113,6 +124,7 @@ extern "C"
 /* Return non-zero if zero-terminated input STR is a valid (mod)hex
    string, and zero if any non-alphabetic characters are found. */
   extern int yubikey_modhex_p (const char *str);
+  extern int yubikey_modhex_map_p (const char *str, const char *map);
   extern int yubikey_hex_p (const char *str);
 
 /*