replace base64encode in src/futils.cpp

src/futils.cpp

@@ -212,51 +212,70 @@ namespace Exiv2 {
         result[resultIndex] = 0;
         return 1;   /* indicate success */
     } // base64encode
-
-    long base64decode(const char *in, char *out, size_t out_size) {
-        static const char decode[] = "|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW"
-                         "$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
-        long len;
-        long i;
-        long done = 0;
-        unsigned char v;
-        unsigned char quad[4];
-
-        while (*in) {
-            len = 0;
-            for (i = 0; i < 4 && *in; i++) {
-                v = 0;
-                while (*in && !v) {
-                    v = *in++;
-                    v = (v < 43 || v > 122) ? 0 : decode[v - 43];
-                    if (v)
-                        v = (v == '$') ? 0 : v - 61;
-                    if (*in) {
-                        len++;
-                        if (v)
-                            quad[i] = v - 1;
-                    } else
-                        quad[i] = 0;
-                }
-            }
-            if (!len)
-                continue;
-            if (out_size < (size_t) (done + len - 1))
-                /* out buffer is too small */
-                return -1;
-            if (len >= 2)
-                *out++ = quad[0] << 2 | quad[1] >> 4;
-            if (len >= 3)
-                *out++ = quad[1] << 4 | quad[2] >> 2;
-            if (len >= 4)
-                *out++ = ((quad[2] << 6) & 0xc0) | quad[3];
-            done += len - 1;
-        }
-        if ((size_t)(done + 1) >= out_size)
-            return -1;
-        *out++ = '\0';
-        return done;
-    } // base64decode
+    
+    // https://stackoverflow.com/questions/342409/how-do-i-base64-encode-decode-in-c
+	static const std::string base64_chars = 
+				 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+				 "abcdefghijklmnopqrstuvwxyz"
+				 "0123456789+/";
+
+
+	static inline bool is_base64(unsigned char c) {
+	  return (isalnum(c) || (c == '+') || (c == '/'));
+	}
+
+	static std::string base64_decode(std::string const& encoded_string) {
+	  int in_len = encoded_string.size();
+	  int i = 0;
+	  int j = 0;
+	  int in_ = 0;
+	  unsigned char char_array_4[4], char_array_3[3];
+	  std::string ret;
+
+	  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
+		char_array_4[i++] = encoded_string[in_]; in_++;
+		if (i ==4) {
+		  for (i = 0; i <4; i++)
+			char_array_4[i] = base64_chars.find(char_array_4[i]);
+
+		  char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+		  char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+		  char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+		  for (i = 0; (i < 3); i++)
+			ret += char_array_3[i];
+		  i = 0;
+		}
+	  }
+
+	  if (i) {
+		for (j = i; j <4; j++)
+		  char_array_4[j] = 0;
+
+		for (j = 0; j <4; j++)
+		  char_array_4[j] = base64_chars.find(char_array_4[j]);
+
+		char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+		char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+		char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
+
+		for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
+	  }
+
+	  return ret;
+	}
+
+    long base64decode(const char *in, char *out, size_t out_size)
+    {
+       std::string in_string(in);
+       std::string out_string = base64_decode(in_string);
+       long result = (long) out_string.size();
+       if ( (long) out_size > result ) {
+           memcpy(out,out_string.c_str(),result);
+           out[result] = 0;
+       } else result = -1 ;
+       return result;
+    }
 
     Protocol fileProtocol(const std::string& path) {
         Protocol result = pFile ;