[GNUnet-SVN] r4285 - GNUnet/src/applications/fs/ecrs

[grothoff]

Author: grothoff
Date: 2007-01-11 00:09:35 -0800 (Thu, 11 Jan 2007)
New Revision: 4285

Modified:
   GNUnet/src/applications/fs/ecrs/uri.c
Log:
implemented enc2bin, bin2enc

Modified: GNUnet/src/applications/fs/ecrs/uri.c
===================================================================
--- GNUnet/src/applications/fs/ecrs/uri.c       2007-01-11 07:48:15 UTC (rev 
4284)
+++ GNUnet/src/applications/fs/ecrs/uri.c       2007-01-11 08:09:35 UTC (rev 
4285)
@@ -79,7 +79,7 @@
  * <p>
  * 
  * TODO:
- * - bin2enc, enc2bin
+ * - test bin2enc, enc2bin
  * - test conversion of LOC URIs from and to strings!
  * - verify LOC signatures
  */
@@ -167,6 +167,11 @@
 }
 
 /**
+ * 64 characters for encoding, 6 bits per character
+ */
+static char * encTable__ = 
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_=";
+
+/**
  * Convert binary data to a string.
  *
  * @return converted data
@@ -174,10 +179,49 @@
 static char * 
 bin2enc(const void * data,
        size_t size) {
-  /* FIXME */
-  return STRDUP("");
+  size_t len;
+  size_t pos;
+  unsigned int bits;
+  unsigned int hbits;
+  char * ret;
+
+  GE_ASSERT(NULL, strlen(encTable__) == 64);
+  len = size * 8 / 6;
+  if (((size * 8) % 6) != 0)
+    len++;
+  ret = MALLOC(len+1);
+  ret[len] = '\0';
+  len = 0;
+  bits = 0;
+  hbits = 0;
+  for (pos=0;pos<size;pos++) {
+    bits |= ((((const unsigned char*)data)[pos]) << hbits);
+    hbits += 8;
+    while (hbits >= 6) {
+      ret[len++] = encTable__[bits & 63];
+      bits >>= 6;
+      hbits -= 6;
+    }
+  }
+  if (hbits > 0) 
+    ret[len++] = encTable__[bits & 63];
+  return ret;
 }
 
+static unsigned int getValue__(unsigned char a) {
+  if ( (a >= '0') && (a <= '9') )
+    return a - '0';
+  if ( (a >= 'A') && (a <= 'Z') )
+    return (a - 'A' + 10);
+  if ( (a >= 'a') && (a <= 'z') )
+    return (a - 'A' + 36);
+  if (a == '_')
+    return 60;
+  if (a == '=')
+    return 61;
+  return -1;
+}
+
 /**
  * Convert string back to binary data.
  *
@@ -191,8 +235,30 @@
 enc2bin(const char * input,
        void * data,
        size_t size) {
-  /* FIXME */
-  return -1;
+  size_t len;
+  size_t pos;
+  unsigned int bits;
+  unsigned int hbits;
+
+  len = size * 8 / 6;
+  if (((size * 8) % 6) != 0)
+    len++;
+  if (strlen(input) < len)
+    return -1; /* error! */
+  bits = 0;
+  hbits = 0;
+  len = 0;
+  pos = 0;
+  for (pos=0;pos<size;pos++) {
+    while (hbits < 8) {
+      bits |= (getValue__(input[len++]) << hbits);
+      hbits += 6;
+    }
+    (((unsigned char*)data)[pos]) = (unsigned char) bits;
+    bits >>= 8;
+    hbits -= 8;
+  }
+  return len;
 }
 
 /**