Refactor ASN1_Pretty_Printer

Now the base class ASN1_Formatter parses the data and calls virtuals
to format. This allows custom formatting, or in the case of the fuzzer
skipping the overhead of formatting entirely.

1 files changed, 63 insertions, 23 deletions

diff --git a/src/lib/asn1/asn1_print.h b/src/lib/asn1/asn1_print.h
index 0fd760e89..4f9fa8f4d 100644
--- a/src/lib/asn1/asn1_print.h
+++ b/src/lib/asn1/asn1_print.h
@@ -7,7 +7,7 @@
 #ifndef BOTAN_ASN1_PRINT_H_
 #define BOTAN_ASN1_PRINT_H_
 
-#include <botan/types.h>
+#include <botan/asn1_obj.h>
 #include <string>
 #include <vector>
 #include <iosfwd>
@@ -17,27 +17,17 @@ namespace Botan {
 class BER_Decoder;
 
 /**
-* Format ASN.1 data into human readable strings
+* Format ASN.1 data and call a virtual to format
 */
-class BOTAN_DLL ASN1_Pretty_Printer
+class BOTAN_DLL ASN1_Formatter
    {
    public:
+      virtual ~ASN1_Formatter() = default;
+
       /**
-      * @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),
+      ASN1_Formatter(bool print_context_specific) :
          m_print_context_specific(print_context_specific)
          {}
 
@@ -53,23 +43,73 @@ class BOTAN_DLL ASN1_Pretty_Printer
          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;
+   protected:
+      /**
+      * This is called for each element
+      */
+      virtual std::string format(ASN1_Tag type_tag,
+                                 ASN1_Tag class_tag,
+                                 size_t level,
+                                 size_t length,
+                                 const std::string& value) const = 0;
+
+      /**
+      * This is called to format binary elements that we don't know how to
+      * convert to a string The result will be passed as value to format; the
+      * tags are included as a hint to aid decoding.
+      */
+      virtual std::string format_bin(ASN1_Tag type_tag,
+                                     ASN1_Tag class_tag,
+                                     const std::vector<uint8_t>& vec) const = 0;
 
+   private:
       void decode(std::ostream& output,
                   BER_Decoder& decoder,
                   size_t level) const;
 
-      std::string format_binary(const std::vector<uint8_t>& in) const;
+      const bool m_print_context_specific;
+   };
+
+/**
+* Format ASN.1 data into human readable strings
+*/
+class BOTAN_DLL ASN1_Pretty_Printer final : public ASN1_Formatter
+   {
+   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) :
+         ASN1_Formatter(print_context_specific),
+         m_print_limit(print_limit),
+         m_print_binary_limit(print_binary_limit),
+         m_initial_level(initial_level),
+         m_value_column(value_column)
+         {}
+
+   private:
+      std::string format(ASN1_Tag type_tag,
+                         ASN1_Tag class_tag,
+                         size_t level,
+                         size_t length,
+                         const std::string& value) const override;
+
+      std::string format_bin(ASN1_Tag type_tag,
+                             ASN1_Tag class_tag,
+                             const std::vector<uint8_t>& vec) const override;
 
       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;
    };
 
 }