Move ASN1 printer to the library

4 files changed, 415 insertions, 0 deletions

diff --git a/src/lib/asn1/asn1_obj.cpp b/src/lib/asn1/asn1_obj.cpp
index 2dc73738c..1f93a4b8b 100644
--- a/src/lib/asn1/asn1_obj.cpp
+++ b/src/lib/asn1/asn1_obj.cpp
@@ -12,6 +12,63 @@
 
 namespace Botan {
 
+std::string asn1_tag_to_string(ASN1_Tag type)
+   {
+   switch(type)
+      {
+      case Botan::PRINTABLE_STRING:
+         return "PRINTABLE STRING";
+
+      case Botan::NUMERIC_STRING:
+         return "NUMERIC STRING";
+
+      case Botan::IA5_STRING:
+         return "IA5 STRING";
+
+      case Botan::T61_STRING:
+         return "T61 STRING";
+
+      case Botan::UTF8_STRING:
+         return "UTF8 STRING";
+
+      case Botan::VISIBLE_STRING:
+         return "VISIBLE STRING";
+
+      case Botan::BMP_STRING:
+         return "BMP STRING";
+
+      case Botan::UTC_TIME:
+         return "UTC TIME";
+
+      case Botan::GENERALIZED_TIME:
+         return "GENERALIZED TIME";
+
+      case Botan::OCTET_STRING:
+         return "OCTET STRING";
+
+      case Botan::BIT_STRING:
+         return "BIT STRING";
+
+      case Botan::ENUMERATED:
+         return "ENUMERATED";
+
+      case Botan::INTEGER:
+         return "INTEGER";
+
+      case Botan::NULL_TAG:
+         return "NULL";
+
+      case Botan::OBJECT_ID:
+         return "OBJECT";
+
+      case Botan::BOOLEAN:
+         return "BOOLEAN";
+
+      default:
+         return "TAG(" + std::to_string(static_cast<size_t>(type)) + ")";
+      }
+   }
+
 /*
 * BER Decoding Exceptions
 */
diff --git a/src/lib/asn1/asn1_obj.h b/src/lib/asn1/asn1_obj.h
index da065ff6d..a785a5807 100644
--- a/src/lib/asn1/asn1_obj.h
+++ b/src/lib/asn1/asn1_obj.h
@@ -56,6 +56,8 @@ enum ASN1_Tag : uint32_t {
    DIRECTORY_STRING = 0xFF01
 };
 
+std::string BOTAN_DLL asn1_tag_to_string(ASN1_Tag type);
+
 /**
 * Basic ASN.1 Object Interface
 */
diff --git a/src/lib/asn1/asn1_print.cpp b/src/lib/asn1/asn1_print.cpp
new file mode 100644
index 000000000..e314b5c99
--- /dev/null
+++ b/src/lib/asn1/asn1_print.cpp
@@ -0,0 +1,279 @@
+/*
+* (C) 2014,2015,2017 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/asn1_print.h>
+#include <botan/bigint.h>
+#include <botan/hex.h>
+#include <botan/der_enc.h>
+#include <botan/ber_dec.h>
+#include <botan/asn1_time.h>
+#include <botan/asn1_str.h>
+#include <botan/oids.h>
+#include <iomanip>
+#include <sstream>
+#include <cctype>
+
+namespace Botan {
+
+std::string ASN1_Pretty_Printer::print(const uint8_t in[], size_t len) const
+   {
+   std::ostringstream output;
+   print_to_stream(output, in, len);
+   return output.str();
+   }
+
+void ASN1_Pretty_Printer::print_to_stream(std::ostream& output,
+                                          const uint8_t in[],
+                                          size_t len) const
+   {
+   BER_Decoder dec(in, len);
+   decode(output, dec, m_initial_level);
+   }
+
+std::string ASN1_Pretty_Printer::format_binary(const std::vector<uint8_t>& in) const
+   {
+   std::ostringstream out;
+
+   size_t unprintable = 0;
+
+   for(size_t i = 0; i != in.size(); ++i)
+      {
+      const int c = in[i];
+      if(std::isalnum(c))
+         {
+         out << static_cast<char>(c);
+         }
+      else
+         {
+         out << "%" << std::hex << static_cast<int>(c) << std::dec;
+         ++unprintable;
+         if(unprintable >= in.size() / 4)
+            {
+            return hex_encode(in);
+            }
+         }
+      }
+
+   return out.str();
+   }
+
+void ASN1_Pretty_Printer::emit(std::ostream& output,
+                               const std::string& type,
+                               size_t level, size_t length,
+                               const std::string& value) const
+   {
+   std::ostringstream oss;
+
+   oss << "  d=" << std::setw(2) << level
+       << ", l=" << std::setw(4) << length << ":"
+       << std::string(level + 1, ' ') << type;
+
+   bool should_skip = false;
+
+   if(value.length() > m_print_limit)
+      {
+      should_skip = true;
+      }
+
+   if((type == "OCTET STRING" || type == "BIT STRING") && value.length() > m_print_binary_limit)
+      {
+      should_skip = true;
+      }
+
+   const std::string s = oss.str();
+
+   output << s;
+
+   if(value != "" && !should_skip)
+      {
+      const size_t spaces_to_align =
+         (s.size() >= m_value_column) ? 1 : (m_value_column - s.size());
+
+      output << std::string(spaces_to_align, ' ') << value;
+      }
+
+   output << "\n";
+   }
+
+void ASN1_Pretty_Printer::decode(std::ostream& output,
+                                 BER_Decoder& decoder,
+                                 size_t level) const
+   {
+   BER_Object obj = decoder.get_next_object();
+
+   while(obj.type_tag != NO_OBJECT)
+      {
+      const ASN1_Tag type_tag = obj.type_tag;
+      const ASN1_Tag class_tag = obj.class_tag;
+      const size_t length = obj.value.size();
+
+      /* hack to insert the tag+length back in front of the stuff now
+         that we've gotten the type info */
+      DER_Encoder encoder;
+      encoder.add_object(type_tag, class_tag, obj.value);
+      std::vector<uint8_t> bits = encoder.get_contents_unlocked();
+
+      BER_Decoder data(bits);
+
+      if(class_tag & CONSTRUCTED)
+         {
+         BER_Decoder cons_info(obj.value);
+         if(type_tag == SEQUENCE)
+            {
+            emit(output, "SEQUENCE", level, length);
+            decode(output, cons_info, level + 1); // recurse
+            }
+         else if(type_tag == SET)
+            {
+            emit(output, "SET", level, length);
+            decode(output, cons_info, level + 1); // recurse
+            }
+         else
+            {
+            std::string name;
+
+            if((class_tag & APPLICATION) || (class_tag & CONTEXT_SPECIFIC))
+               {
+               name = "cons [" + std::to_string(type_tag) + "]";
+
+               if(class_tag & APPLICATION)
+                  {
+                  name += " appl";
+                  }
+               if(class_tag & CONTEXT_SPECIFIC)
+                  {
+                  name += " context";
+                  }
+               }
+            else
+               {
+               name = asn1_tag_to_string(type_tag) + " (cons)";
+               }
+
+            emit(output, name, level, length);
+            decode(output, cons_info, level + 1); // recurse
+            }
+         }
+      else if((class_tag & APPLICATION) || (class_tag & CONTEXT_SPECIFIC))
+         {
+         if(m_print_context_specific)
+            {
+            std::vector<uint8_t> bits;
+            data.decode(bits, type_tag);
+
+            try
+               {
+               BER_Decoder inner(bits);
+               decode(output, inner, level + 1); // recurse
+               }
+            catch(...)
+               {
+               emit(output, "[" + std::to_string(type_tag) + "]", level, length, format_binary(bits));
+               }
+            }
+         else
+            {
+            emit(output, "[" + std::to_string(type_tag) + "]", level, length, format_binary(bits));
+            }
+         }
+      else if(type_tag == OBJECT_ID)
+         {
+         OID oid;
+         data.decode(oid);
+
+         std::string out = OIDS::lookup(oid);
+         if(out.empty())
+            {
+            out = oid.as_string();
+            }
+         else
+            {
+            out += " [" + oid.as_string() + "]";
+            }
+
+         emit(output, asn1_tag_to_string(type_tag), level, length, out);
+         }
+      else if(type_tag == INTEGER || type_tag == ENUMERATED)
+         {
+         BigInt number;
+
+         if(type_tag == INTEGER)
+            {
+            data.decode(number);
+            }
+         else if(type_tag == ENUMERATED)
+            {
+            data.decode(number, ENUMERATED, class_tag);
+            }
+
+         std::vector<uint8_t> rep;
+
+         /* If it's small, it's probably a number, not a hash */
+         if(number.bits() <= 20)
+            {
+            rep = BigInt::encode(number, BigInt::Decimal);
+            }
+         else
+            {
+            rep = BigInt::encode(number, BigInt::Hexadecimal);
+            }
+
+         std::string str;
+         for(size_t i = 0; i != rep.size(); ++i)
+            {
+            str += static_cast<char>(rep[i]);
+            }
+
+         emit(output, asn1_tag_to_string(type_tag), level, length, str);
+         }
+      else if(type_tag == BOOLEAN)
+         {
+         bool boolean;
+         data.decode(boolean);
+         emit(output, asn1_tag_to_string(type_tag), level, length, (boolean ? "true" : "false"));
+         }
+      else if(type_tag == NULL_TAG)
+         {
+         emit(output, asn1_tag_to_string(type_tag), level, length);
+         }
+      else if(type_tag == OCTET_STRING || type_tag == BIT_STRING)
+         {
+         std::vector<uint8_t> decoded_bits;
+         data.decode(decoded_bits, type_tag);
+
+         try
+            {
+            BER_Decoder inner(decoded_bits);
+            decode(output, inner, level + 1);
+            }
+         catch(...)
+            {
+            emit(output, asn1_tag_to_string(type_tag), level, length, format_binary(decoded_bits));
+            }
+         }
+      else if(ASN1_String::is_string_type(type_tag))
+         {
+         ASN1_String str;
+         data.decode(str);
+         emit(output, asn1_tag_to_string(type_tag), level, length, str.value());
+         }
+      else if(type_tag == UTC_TIME || type_tag == GENERALIZED_TIME)
+         {
+         X509_Time time;
+         data.decode(time);
+         emit(output, asn1_tag_to_string(type_tag), level, length, time.readable_string());
+         }
+      else
+         {
+         output << "Unknown ASN.1 tag class=" << static_cast<int>(class_tag)
+                << " type=" << static_cast<int>(type_tag) << "\n";;
+         }
+
+      obj = decoder.get_next_object();
+      }
+   }
+
+}
diff --git a/src/lib/asn1/asn1_print.h b/src/lib/asn1/asn1_print.h
new file mode 100644
index 000000000..0fd760e89
--- /dev/null
+++ b/src/lib/asn1/asn1_print.h
@@ -0,0 +1,77 @@
+/*
+* (C) 2014,2015,2017 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_ASN1_PRINT_H_
+#define BOTAN_ASN1_PRINT_H_
+
+#include <botan/types.h>
+#include <string>
+#include <vector>
+#include <iosfwd>
+
+namespace Botan {
+
+class BER_Decoder;
+
+/**
+* Format ASN.1 data into human readable strings
+*/
+class BOTAN_DLL ASN1_Pretty_Printer
+   {
+   public:
+      /**
+      * @param print_limit strings larger than this are not printed
+      * @param print_binary_limit binary strings larger than this are not printed
+      * @param print_context_specific if true, try to parse nested context specific data.
+      * @param initial_level the initial depth (0 or 1 are the only reasonable values)
+      * @param value_column ASN.1 values are lined up at this column in output
+      */
+      ASN1_Pretty_Printer(size_t print_limit = 256,
+                          size_t print_binary_limit = 256,
+                          bool print_context_specific = true,
+                          size_t initial_level = 0,
+                          size_t value_column = 60) :
+         m_print_limit(print_limit),
+         m_print_binary_limit(print_binary_limit),
+         m_initial_level(initial_level),
+         m_value_column(value_column),
+         m_print_context_specific(print_context_specific)
+         {}
+
+      void print_to_stream(std::ostream& out,
+                           const uint8_t in[],
+                           size_t len) const;
+
+      std::string print(const uint8_t in[], size_t len) const;
+
+      template<typename Alloc>
+      std::string print(const std::vector<uint8_t, Alloc>& vec) const
+         {
+         return print(vec.data(), vec.size());
+         }
+
+   private:
+      void emit(std::ostream& out,
+                const std::string& type,
+                size_t level, size_t length,
+                const std::string& value = "") const;
+
+      void decode(std::ostream& output,
+                  BER_Decoder& decoder,
+                  size_t level) const;
+
+      std::string format_binary(const std::vector<uint8_t>& in) const;
+
+      const size_t m_print_limit;
+      const size_t m_print_binary_limit;
+      const size_t m_initial_level;
+      const size_t m_value_column;
+      const bool m_print_context_specific;
+   };
+
+}
+
+#endif