added basic suisse id functions; refs #28

src/cryptaux.hxx

@@ -11,6 +11,8 @@
 #include <string>
 #include <sstream>
 #include <iomanip>
+#include <stdexcept>
+#include <algorithm>
 
 /*! @defgroup gcrypto Auxiliary Crypto-Functions */
 //@{
@@ -65,6 +67,44 @@ namespace crypto {
     else
       return "\""+data+"\"";
   }
+
+  //! Convert binary to readable hexadecimal
+  inline std::string binToHex(char c) {
+    std::stringstream ss;
+    ss<<std::hex<<std::setw(2)<<std::setfill('0')
+      <<(unsigned int)(unsigned char)(c);
+    return ss.str();
+  }
+
+  //! Convert binary to readable hexadecimal
+  inline std::string binToHex(const std::string& s) {
+    std::string result;
+    for (std::string::const_iterator c(s.begin()); c!=s.end(); ++c)
+      result += binToHex(*c);
+    return result;
+  }
+  
+  //! Convert readable lowercase hexadecimal to binary
+  inline std::string hexToBin(std::string s) {
+    const static std::string HEX("0123456789abcdef");
+    std::transform(s.begin(), s.end(), s.begin(), ::tolower);
+    if (s.size()%2)
+      throw std::runtime_error
+        ("input string \""+s
+         +"\" must have an even number of hexadecimal numbers");
+    if (s.find_first_not_of(HEX)!=std::string::npos)
+      throw std::runtime_error
+        ("input string \""+s+"\" has non hexadecimal value at position "
+         +((std::stringstream&)(std::stringstream()
+                                <<s.find_first_not_of(HEX))).str());
+    std::string res;
+    for (std::string::const_iterator it(s.begin()); it!=s.end(); ++it) {
+      unsigned char c(HEX.find(*it));
+      if (++it!=s.end()) (c <<= 4) += HEX.find(*it);
+      res += std::string(1, (char)c);
+    }
+    return res;
+  }
 }
 
 //@}