From 63a5edfcc5ed1e8f0e352e8811b4ef9218e0cec7 Mon Sep 17 00:00:00 2001
From: Thom Wiggers <thom@thomwiggers.nl>
Date: Tue, 10 Jul 2018 10:18:09 +0200
Subject: [PATCH 1/3] Support different keymaps via attempting to decode

---
 NEWS             |  1 +
 modhex.c         |  8 ++++++--
 tests/selftest.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 ykhex.c          | 28 ++++++++++++++++++++++++----
 yubikey.h        | 16 ++++++++++++++--
 5 files changed, 87 insertions(+), 8 deletions(-)

diff --git a/NEWS b/NEWS
index f4d778f..4c0cd3a 100644
--- a/NEWS
+++ b/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".
diff --git a/modhex.c b/modhex.c
index 57c3927..ed23435 100644
--- a/modhex.c
+++ b/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)
diff --git a/tests/selftest.c b/tests/selftest.c
index 3f6c3cf..95e6a98 100644
--- a/tests/selftest.c
+++ b/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 ();
diff --git a/ykhex.c b/ykhex.c
index 3987ba7..91cd11b 100644
--- a/ykhex.c
+++ b/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 +113,37 @@ 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);
+  for (size_t 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);
+  for (size_t i = 0; i < N_MODHEX_MAPS; i++) {
+    if (_yubikey_p(str, YUBIKEY_MODHEX_MAPS[i])) {
+      return 1;
+    }
+  }
+  return 0;
 }
diff --git a/yubikey.h b/yubikey.h
index 39f75c0..64fb8d6 100644
--- a/yubikey.h
+++ b/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);
 
 /*

From 5c67be40534e0ca35fe8ecd29329fc1a5a975e0c Mon Sep 17 00:00:00 2001
From: Thom Wiggers <thom@thomwiggers.nl>
Date: Tue, 10 Jul 2018 10:22:44 +0200
Subject: [PATCH 2/3] C89

---
 ykhex.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/ykhex.c b/ykhex.c
index 91cd11b..3cc4a29 100644
--- a/ykhex.c
+++ b/ykhex.c
@@ -119,7 +119,8 @@ yubikey_modhex_encode (char *dst, const char *src, size_t srcSize)
 void
 yubikey_modhex_decode (char *dst, const char *src, size_t dstSize)
 {
-  for (size_t i = 0; i < N_MODHEX_MAPS; i++) {
+  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]);
     }
@@ -140,7 +141,8 @@ int yubikey_modhex_map_p(const char *str, const char *map) {
 int
 yubikey_modhex_p (const char *str)
 {
-  for (size_t i = 0; i < N_MODHEX_MAPS; i++) {
+  size_t i;
+  for (i = 0; i < N_MODHEX_MAPS; i++) {
     if (_yubikey_p(str, YUBIKEY_MODHEX_MAPS[i])) {
       return 1;
     }

From 1159fcc5417712528d58421e1322f76f0c865b5b Mon Sep 17 00:00:00 2001
From: Thom Wiggers <thom@thomwiggers.nl>
Date: Tue, 10 Jul 2018 10:25:34 +0200
Subject: [PATCH 3/3] Add note to docs

---
 modhex.1.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/modhex.1.txt b/modhex.1.txt
index ac0ef76..bc93255 100644
--- a/modhex.1.txt
+++ b/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/