base64

git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@3186 ec53bebd-3082-4978-b11e-865c3cabbd6b

lib/roken/base64.c

@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska H<>gskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *      This product includes software developed by the Kungliga Tekniska
+ *      H<>gskolan and its contributors.
+ * 
+ * 4. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+RCSID("$Id$");
+#endif
+#include <stdlib.h>
+#include <string.h>
+#include "base64.h"
+
+static char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+static int pos(char c)
+{
+  char *p;
+  for(p = base64; *p; p++)
+    if(*p == c)
+      return p - base64;
+  return -1;
+}
+
+int base64_encode(const void *data, int size, char **str)
+{
+  char *s, *p;
+  int i;
+  int c;
+  unsigned char *q;
+
+  p = s = (char*)malloc(size*4/3+4);
+  q = (unsigned char*)data;
+  i=0;
+  for(i = 0; i < size;){
+    c=q[i++];
+    c*=256;
+    if(i < size)
+      c+=q[i];
+    i++;
+    c*=256;
+    if(i < size)
+      c+=q[i];
+    i++;
+    p[0]=base64[(c&0x00fc0000) >> 18];
+    p[1]=base64[(c&0x0003f000) >> 12];
+    p[2]=base64[(c&0x00000fc0) >> 6];
+    p[3]=base64[(c&0x0000003f) >> 0];
+    if(i > size)
+      p[3]='=';
+    if(i > size+1)
+      p[2]='=';
+    p+=4;
+  }
+  *p=0;
+  *str = s;
+  return strlen(s);
+}
+
+int base64_decode(const char *str, void *data)
+{
+  const char *p;
+  unsigned char *q;
+  int c;
+  int x;
+  int done = 0;
+  q=(unsigned char*)data;
+  for(p=str; *p && !done; p+=4){
+    x = pos(p[0]);
+    if(x >= 0)
+      c = x;
+    else{
+      done = 3;
+      break;
+    }
+    c*=64;
+    
+    x = pos(p[1]);
+    if(x >= 0)
+      c += x;
+    else
+      return -1;
+    c*=64;
+    
+    if(p[2] == '=')
+      done++;
+    else{
+      x = pos(p[2]);
+      if(x >= 0)
+	c += x;
+      else
+	return -1;
+    }
+    c*=64;
+    
+    if(p[3] == '=')
+      done++;
+    else{
+      if(done)
+	return -1;
+      x = pos(p[3]);
+      if(x >= 0)
+	c += x;
+      else
+	return -1;
+    }
+    if(done < 3)
+      *q++=(c&0x00ff0000)>>16;
+      
+    if(done < 2)
+      *q++=(c&0x0000ff00)>>8;
+    if(done < 1)
+      *q++=(c&0x000000ff)>>0;
+  }
+  return q - (unsigned char*)data;
+}