Create new fuzzer build mode

1 files changed, 82 insertions, 0 deletions

diff --git a/src/fuzzer/pkcs1.cpp b/src/fuzzer/pkcs1.cpp
new file mode 100644
index 000000000..a0323d2b2
--- /dev/null
+++ b/src/fuzzer/pkcs1.cpp
@@ -0,0 +1,82 @@
+/*
+* (C) 2015,2016 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+#include "fuzzers.h"
+
+#include <botan/eme_pkcs.h>
+#include <botan/hex.h>
+
+namespace {
+
+std::vector<uint8_t> simple_pkcs1_unpad(const uint8_t in[], size_t len)
+   {
+   if(len < 10)
+      throw Botan::Decoding_Error("bad len");
+
+   if(in[0] != 0 || in[1] != 2)
+      throw Botan::Decoding_Error("bad header field");
+
+   for(size_t i = 2; i < len; ++i)
+      {
+      if(in[i] == 0)
+         {
+         if(i < 10) // at least 8 padding bytes required
+            throw Botan::Decoding_Error("insufficient padding bytes");
+         return std::vector<uint8_t>(in + i + 1, in + len);
+         }
+      }
+
+   throw Botan::Decoding_Error("delim not found");
+   }
+
+}
+
+void fuzz(const uint8_t in[], size_t len)
+   {
+   static Botan::EME_PKCS1v15 pkcs1;
+
+   Botan::secure_vector<uint8_t> lib_result;
+   std::vector<uint8_t> ref_result;
+   bool lib_rejected = false, ref_rejected = false;
+
+   try
+      {
+      uint8_t valid_mask = 0;
+      Botan::secure_vector<uint8_t> decoded = (static_cast<Botan::EME*>(&pkcs1))->unpad(valid_mask, in, len);
+
+      if(valid_mask == 0)
+         lib_rejected = true;
+      else if(valid_mask == 0xFF)
+         lib_rejected = false;
+      else
+         abort();
+      }
+   catch(Botan::Decoding_Error&) { lib_rejected = true; }
+
+   try
+      {
+      ref_result = simple_pkcs1_unpad(in, len);
+      }
+   catch(Botan::Decoding_Error& e) { ref_rejected = true; }
+
+   if(lib_rejected == ref_rejected)
+      {
+      return; // ok, they agree
+      }
+
+   // otherwise: incorrect result, log info and crash
+   if(lib_rejected == true && ref_rejected == false)
+      {
+      std::cerr << "Library rejected input accepted by ref\n";
+      std::cerr << "Ref decoded " << Botan::hex_encode(ref_result) << "\n";
+      }
+   else if(ref_rejected == true && lib_rejected == false)
+      {
+      std::cerr << "Library accepted input reject by ref\n";
+      std::cerr << "Lib decoded " << Botan::hex_encode(lib_result) << "\n";
+      }
+
+   abort();
+   }