draft of PASSPHRASE_MOVE option implementation

Signed-off-by: Mattias Andrée <maandree@operamail.com>

2 files changed, 233 insertions, 26 deletions

diff --git a/Makefile b/Makefile
index b20e0a0..8ccea46 100644
--- a/Makefile
+++ b/Makefile
@@ -3,9 +3,17 @@ LIB = /lib
 INCLUDE = /include
 
 OPTIONS = 
-# PASSPHRASE_ECHO:    Do not hide the passphrase
-# PASSPHRASE_STAR:    Use '*' for each character instead of no echo
-# PASSPHRASE_REALLOC: Soften security by using `realloc`
+# PASSPHRASE_ECHO:      Do not hide the passphrase
+# PASSPHRASE_STAR:      Use '*' for each character instead of no echo
+# PASSPHRASE_REALLOC:   Soften security by using `realloc`
+# PASSPHRASE_MOVE:      Enable move of point
+# PASSPHRASE_INSERT:    Enable insert mode
+# PASSPHRASE_OVERRIDE:  Enable override mode
+# PASSPHRASE_DELETE:    Enable reversed erase command
+# PASSPHRASE_CONTROL:   Enable use of control key combinations
+# PASSPHRASE_DEDICATED: Enable use of dedicated keys
+# DEFAULT_INSERT:       Use insert mode as default
+# PASSPHRASE_INVALID:   Prevent duplication of non-initialised memory
 
 OPTIMISE = -Os
 CPPFLAGS = $(foreach D, $(OPTIONS), -D'$(D)=1')
diff --git a/src/passphrase.c b/src/passphrase.c
index 8ff4c56..751a77b 100644
--- a/src/passphrase.c
+++ b/src/passphrase.c
@@ -27,7 +27,7 @@
 #define START_PASSPHRASE_LIMIT  32
 
 
-#ifndef PASSPHRASE_ECHO
+#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
 /**
  * The original TTY settings
  */
@@ -36,28 +36,43 @@ static struct termios saved_stty;
 
 
 #ifndef PASSPHRASE_REALLOC
-static inline char* xrealloc(char* array, size_t size)
+static inline char* xrealloc(char* array, size_t cur_size, size_t new_size)
 {
-  char* rc = malloc(size);
-  int i;
+  char* rc = malloc(new_size * sizeof(char));
+  size_t i;
   if (rc)
-    for (i = 0; *(array + i); i++)
-      {
+    for (i = 0; i < cur_size; i++)
 	*(rc + i) = *(array + i);
-	*(array + i) = 0;
-      }
-  else
-    for (i = 0; *(array + i); i++)
-      *(array + i) = 0;
+  for (i = 0; i < cur_size; i++)
+    *(array + i) = 0;
   free(array);
   return rc;
 }
 #else
-#define  xrealloc  realloc
+#define xrealloc(array, _cur_size, new_size)  realloc(array, (new_size) * sizeof(char))
 #endif
 
 
-#define xprintf(...)  ({ printf(__VA_ARGS__); fflush(stdout); })
+#if defined(PASSPHRASE_MOVE) && !defined(PASSPHRASE_STAR) && !defined(PASSPHRASE_ECHO)
+#  define xprintf(...)  /* do nothing */
+#  define xflush()      /* do nothing */
+#elif defined(PASSPHRASE_MOVE) || defined(PASSPHRASE_STAR)
+#  define xprintf       printf
+#  define xflush()      fflush(stdout)
+#else
+#  define xflush()      fflush(stdout)
+#endif
+
+
+#ifdef PASSPHRASE_MOVE
+#  if defined(PASSPHRASE_STAR)
+#    define xputchar(C)  ({ if ((c & 0xC0) != 0x80)  putchar('*'); })
+#  elif defined(PASSPHRASE_ECHO)
+#    define xputchar(C)  putchar(C)
+#  else
+#    define xputchar(C)  /* be silent */
+#  endif
+#endif
 
 
 /**
@@ -69,7 +84,18 @@ char* passphrase_read(void)
 {
   char* rc = malloc(START_PASSPHRASE_LIMIT * sizeof(char));
   long size = START_PASSPHRASE_LIMIT;
-  long len = 0;
+  long len =  0;
+#ifdef PASSPHRASE_MOVE
+  long point = 0;
+  long i = 0;
+#  ifdef PASSPHRASE_OVERRIDE
+#    if defined(PASSPHRASE_INSERT) && defined(DEFAULT_INSERT)
+  char insert = 1;
+#    elif defined(PASSPHRASE_INSERT)
+  char insert = 0;
+#    endif
+#  endif
+#endif
   int c;
   
   if (rc == NULL)
@@ -85,28 +111,201 @@ char* passphrase_read(void)
 	break;
       if (c != 0)
         {
-#ifdef PASSPHRASE_STAR
+#if defined(PASSPHRASE_MOVE)
+	  /* \e[1~  \eOH  ^A  -1  home   */
+	  /* \e[2~            -2  insert */
+	  /* \e[3~  ^D        -3  delete */
+	  /* \e[4~  \eOF  ^E  -4  end    */
+	  /* \8     \127      -5  erase  */
+	  /* \e[C   ^F        -6  right  */
+	  /* \e[D   ^B        -7  left   */
+	  int cc = 0;
+#ifdef PASSPHRASE_DEDICATED
+	  if (c == '\033')
+	    {
+	      c = getchar();
+	      if (c == 'O')
+		{
+		  c = getchar();
+		  if      (c == 'H')  cc = -1;
+		  else if (c == 'F')  cc = -4;
+		}
+	      else if (c == '[')
+		{
+		  c = getchar();
+		  if      (c == 'C')  cc = -6;
+		  else if (c == 'D')  cc = -7;
+		  else if (('1' <= c) && (c <= '4') && (getchar() == '~'))
+		    cc = -(c - '0');
+		}
+	    }
+	  else
+#endif
+	    if ((c == 8) || (c == 127))
+	      cc = -5;
+	    else if ((c < 0) || (c >= ' '))
+	      cc = ((int)c) & 255;
+#ifdef PASSPHRASE_CONTROL
+	    else if (c == 'A' - '@')  cc = -1;
+	    else if (c == 'B' - '@')  cc = -7;
+	    else if (c == 'D' - '@')  cc = -3;
+	    else if (c == 'E' - '@')  cc = -4;
+	    else if (c == 'F' - '@')  cc = -6;
+#endif
+	  
+	  if (cc > 0)
+	    {
+	      c = (char)cc;
+	      if (point == len)
+		{
+		  xputchar(c);
+		  *(rc + len++) = c;
+		}
+#ifdef PASSPHRASE_INSERT
+	      else
+#ifdef PASSPHRASE_OVERRIDE
+		if (insert)
+#endif
+		  {
+		    if ((c & 0xC0) != 0x80)
+		      xprintf("\033[@");
+		    xputchar(c);
+		    for (i = point; i < len; i++)
+		      *(rc + i + 1) = *(rc + i);
+		    len++;
+		    *(rc + point++) = c;
+		  }
+#endif
+#ifdef PASSPHRASE_OVERRIDE
+		else
+		  {
+		    long n = 1;
+		    char cn = c;
+		    while (*(rc + point + n))
+		      n++;
+		    for (i = point; i < len; i++)
+		      *(rc + i) = *(rc + i + n);
+		    for (i = len - n; i < len; i++)
+		      *(rc + point + i) = 0;
+		    len -= n;
+		    n = 0;
+		    while (cn & 0x80)
+		      {
+			cn <<= 1;
+			n++;
+		      }
+		    n = n ?: 1;
+		    if (len + n > size)
+		      {
+			if ((rc = xrealloc(rc, size, size << 1L)) == NULL)
+			  return NULL;
+			size <<= 1L;
+		      }
+		    for (i = point; i < len; i++)
+		      *(rc + i + n) = *(rc + i);
+		    len += n;
+		    for (i = 0; i < n; i++)
+		      {
+			if (i)
+			  c = getchar();
+			xputchar(c);
+			*(rc + point++) = c;
+		      }
+		  }
+#endif
+	    }
+	  else if ((cc == -1) && point) /* home */
+	    {
+	      xprintf("\033[%liD", point);
+	      point = 0;
+	    }
+#if defined(PASSPHRASE_INSERT) && defined(PASSPHRASE_OVERRIDE)
+	  else if (cc == -2) /* insert */
+	    insert ^= 1;
+#endif
+#ifdef PASSPHRASE_DELETE
+	  else if ((cc == -3) && (len != point)) /* delete */
+	    {
+	      xprintf("\033[P");
+#ifdef PASSPHRASE_INVALID
+	      *(rc + len) = 0;
+#endif
+	      do
+		{
+		  for (i = point; i < len; i++)
+		    *(rc + i) = *(rc + i + 1);
+		  len--;
+		}
+	      while ((len != point) && ((*(rc + point) & 0xC0) == 0x80));
+	    }
+#endif
+	  else if ((cc == -4) && (len != point)) /* end */
+	    {
+	      xprintf("\033[%liC", len - point);
+	      point = len;
+	    }
+	  else if ((cc == -5) && point) /* erase */
+	    {
+	      char redo = 1;
+	      xprintf("\033[D\033[P");
+#ifdef PASSPHRASE_INVALID
+	      *(rc + len) = 0;
+#endif
+	      while (redo)
+		{
+		  redo = (*(rc + point) & 0xC0) == 0x80;
+		  for (i = point; i <= len; i++)
+		    *(rc + i - 1) = *(rc + i);
+		  point--;
+		  len--;
+		}
+	    }
+	  else if ((cc == -6) && (len != point)) /* right */
+	    {
+	      xprintf("\033[C");
+	      do
+		point++;
+	      while ((len != point) && ((*(rc + point) & 0xC0) == 0x80));
+	    }
+	  else if ((cc == -7) && point) /* left */
+	    {
+	      char redo = 1
+	      xprintf("\033[D");
+	      while (redo)
+		redo = (*(rc + point--) & 0xC0) == 0x80;
+	    }
+	  
+#elif defined(PASSPHRASE_STAR)
 	  if ((c == 8) || (c == 127))
 	    {
 	      if (len == 0)
 		continue;
 	      xprintf("\033[D \033[D");
+	      xflush();
 	      *(rc + --len) = 0;
 	      continue;
 	    }
-	  putchar('*');
-#endif
+	  if ((c & 0xC0) != 0x80)
+	    putchar('*');
 	  *(rc + len++) = c;
+#else
+	  *(rc + len++) = c;
+#endif
+	  
+	  xflush();
 	  if (len == size)
-	    if ((rc = xrealloc(rc, (size <<= 1L) * sizeof(char))) == NULL)
-	      return rc;
+	    {
+	      if ((rc = xrealloc(rc, size, size << 1L)) == NULL)
+		return NULL;
+	      size <<= 1L;
+	    }
 	}
     }
   
   /* NUL-terminate passphrase */
   *(rc + len) = 0;
   
-#ifndef PASSPHRASE_ECHO
+#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
   printf("\n");
 #endif
   return rc;
@@ -118,13 +317,13 @@ char* passphrase_read(void)
  */
 void passphrase_disable_echo(void)
 {
-#ifndef PASSPHRASE_ECHO
+#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
   struct termios stty;
   
   tcgetattr(STDIN_FILENO, &stty);
   saved_stty = stty;
   stty.c_lflag &= ~ECHO;
-#ifdef PASSPHRASE_STAR
+#if defined(PASSPHRASE_STAR) || defined(PASSPHRASE_MOVE)
   stty.c_lflag &= ~ICANON;
 #endif
   tcsetattr(STDIN_FILENO, TCSAFLUSH, &stty);
@@ -137,7 +336,7 @@ void passphrase_disable_echo(void)
  */
 void passphrase_reenable_echo(void)
 {
-#ifndef PASSPHRASE_ECHO
+#if !defined(PASSPHRASE_ECHO) || defined(PASSPHRASE_MOVE)
   tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_stty);
 #endif
 }