3 files changed, 153 insertions, 0 deletions
diff --git a/src/libstate/info.txt b/src/libstate/info.txt
index 6e200ee3f..7ca35c5a4 100644
--- a/src/libstate/info.txt
+++ b/src/libstate/info.txt
@@ -18,6 +18,8 @@ lookup.h
 pk_engine.cpp
 pk_engine.h
 policy.cpp
+scan_name.cpp
+scan_name.h
 </add>
 
 <requires>
diff --git a/src/libstate/scan_name.cpp b/src/libstate/scan_name.cpp
new file mode 100644
index 000000000..ef771871d
--- /dev/null
+++ b/src/libstate/scan_name.cpp
@@ -0,0 +1,74 @@
+/**
+SCAN Name Abstraction
+(C) 2008 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/scan_name.h>
+#include <botan/parsing.h>
+#include <botan/libstate.h>
+#include <stdexcept>
+
+namespace Botan {
+
+namespace {
+
+std::vector<std::string>
+parse_and_deref_aliases(const std::string& algo_spec)
+   {
+   std::vector<std::string> parts = parse_algorithm_name(algo_spec);
+   std::vector<std::string> out;
+
+   for(size_t i = 0; i != parts.size(); ++i)
+      {
+      std::string part_i = global_state().deref_alias(parts[i]);
+
+      if(i == 0 && part_i.find_first_of(",()") != std::string::npos)
+         {
+         std::vector<std::string> parts_i = parse_and_deref_aliases(part_i);
+
+         for(size_t j = 0; j != parts_i.size(); ++j)
+            out.push_back(parts_i[j]);
+         }
+      else
+         out.push_back(part_i);
+      }
+
+   return out;
+   }
+
+}
+
+SCAN_Name::SCAN_Name(const std::string& algo_spec)
+   {
+   orig_algo_spec = algo_spec;
+
+   name = parse_and_deref_aliases(algo_spec);
+
+   if(name.size() == 0)
+      throw Decoding_Error("Bad SCAN name " + algo_spec);
+   }
+
+std::string SCAN_Name::arg(u32bit i) const
+   {
+   if(i >= arg_count())
+      throw std::range_error("SCAN_Name::argument");
+   return name[i+1];
+   }
+
+std::string SCAN_Name::arg(u32bit i, const std::string& def_value) const
+   {
+   if(i >= arg_count())
+      return def_value;
+   return name[i+1];
+   }
+
+u32bit SCAN_Name::arg_as_u32bit(u32bit i, u32bit def_value) const
+   {
+   if(i >= arg_count())
+      return def_value;
+   return to_u32bit(name[i+1]);
+   }
+
+}
diff --git a/src/libstate/scan_name.h b/src/libstate/scan_name.h
new file mode 100644
index 000000000..9e7af40d6
--- /dev/null
+++ b/src/libstate/scan_name.h
@@ -0,0 +1,77 @@
+/**
+SCAN Name Abstraction
+(C) 2008 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#ifndef BOTAN_SCAN_NAME_H__
+#define BOTAN_SCAN_NAME_H__
+
+#include <botan/types.h>
+#include <string>
+#include <vector>
+#include <set>
+
+namespace Botan {
+
+/**
+A class encapsulating a SCAN name (similar to JCE conventions)
+http://www.users.zetnet.co.uk/hopwood/crypto/scan/
+*/
+class SCAN_Name
+   {
+   public:
+      /**
+      @param algo_spec A SCAN name
+      */
+      SCAN_Name(const std::string& algo_spec);
+
+      /**
+      @return the original input string
+      */
+      std::string as_string() const { return orig_algo_spec; }
+
+      /**
+      @return the algorithm name
+      */
+      std::string algo_name() const { return name[0]; }
+
+      /**
+      @return the number of arguments
+      */
+      u32bit arg_count() const { return name.size() - 1; }
+
+      /**
+      @return if the number of arguments is between lower and upper
+      */
+      bool arg_count_between(u32bit lower, u32bit upper) const
+         { return ((arg_count() >= lower) && (arg_count() <= upper)); }
+
+      /**
+      @param i which argument
+      @return the ith argument
+      */
+      std::string arg(u32bit i) const;
+
+      /**
+      @param i which argument
+      @param def_value the default value
+      @return the ith argument or the default value
+      */
+      std::string arg(u32bit i, const std::string& def_value) const;
+
+      /**
+      @param i which argument
+      @param def_value the default value
+      @return the ith argument as a u32bit, or the default value
+      */
+      u32bit arg_as_u32bit(u32bit i, u32bit def_value) const;
+   private:
+      std::string orig_algo_spec;
+      std::vector<std::string> name;
+   };
+
+}
+
+#endif