Add Bcrypt-PBKDF

4 files changed, 276 insertions, 0 deletions

diff --git a/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.cpp b/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.cpp
new file mode 100644
index 000000000..ecdac689a
--- /dev/null
+++ b/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.cpp
@@ -0,0 +1,182 @@
+/*
+* (C) 2018,2019 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/bcrypt_pbkdf.h>
+#include <botan/blowfish.h>
+#include <botan/hash.h>
+#include <botan/internal/timer.h>
+
+namespace Botan {
+
+void Bcrypt_PBKDF::derive_key(uint8_t output[], size_t output_len,
+                              const char* password, const size_t password_len,
+                              const uint8_t salt[], size_t salt_len) const
+   {
+   bcrypt_pbkdf(output, output_len,
+                password, password_len,
+                salt, salt_len,
+                m_iterations);
+   }
+
+std::string Bcrypt_PBKDF::to_string() const
+   {
+   return "Bcrypt-PBKDF(" + std::to_string(m_iterations) + ")";
+   }
+
+std::string Bcrypt_PBKDF_Family::name() const
+   {
+   return "Bcrypt-PBKDF";
+   }
+
+std::unique_ptr<PasswordHash> Bcrypt_PBKDF_Family::tune(size_t output_length,
+                                                        std::chrono::milliseconds msec,
+                                                        size_t /*max_memory*/) const
+   {
+   Timer timer("Bcrypt_PBKDF");
+   const auto tune_time = BOTAN_PBKDF_TUNING_TIME;
+
+   const size_t blocks = (output_length + 32 - 1) / 32;
+
+   if(blocks == 0)
+      return default_params();
+
+   const size_t starting_iter = 2;
+
+   timer.run_until_elapsed(tune_time, [&]() {
+      uint8_t output[32] = { 0 };
+      bcrypt_pbkdf(output, sizeof(output), "test", 4, nullptr, 0, starting_iter);
+      });
+
+   if(timer.events() < blocks || timer.value() == 0)
+      return default_params();
+
+   const uint64_t measured_time = timer.value() / (timer.events() / blocks);
+
+   const uint64_t target_nsec = msec.count() * static_cast<uint64_t>(1000000);
+
+   const size_t desired_increase = target_nsec / measured_time;
+
+   if(desired_increase == 0)
+      return this->from_iterations(starting_iter);
+
+   return this->from_iterations(desired_increase * starting_iter);
+   }
+
+std::unique_ptr<PasswordHash> Bcrypt_PBKDF_Family::default_params() const
+   {
+   return this->from_iterations(32); // About 100 ms on fast machine
+   }
+
+std::unique_ptr<PasswordHash> Bcrypt_PBKDF_Family::from_iterations(size_t iter) const
+   {
+   return std::unique_ptr<PasswordHash>(new Bcrypt_PBKDF(iter));
+   }
+
+std::unique_ptr<PasswordHash> Bcrypt_PBKDF_Family::from_params(size_t iter, size_t /*t*/, size_t /*p*/) const
+   {
+   return this->from_iterations(iter);
+   }
+
+namespace {
+
+void bcrypt_round(Blowfish& blowfish,
+                  const secure_vector<uint8_t>& pass_hash,
+                  const secure_vector<uint8_t>& salt_hash,
+                  secure_vector<uint8_t>& out,
+                  secure_vector<uint8_t>& tmp)
+   {
+   const size_t BCRYPT_PBKDF_OUTPUT = 32;
+
+   // "OxychromaticBlowfishSwatDynamite"
+   static const uint8_t BCRYPT_PBKDF_MAGIC[BCRYPT_PBKDF_OUTPUT] = {
+      0x4F, 0x78, 0x79, 0x63, 0x68, 0x72, 0x6F, 0x6D,
+      0x61, 0x74, 0x69, 0x63, 0x42, 0x6C, 0x6F, 0x77,
+      0x66, 0x69, 0x73, 0x68, 0x53, 0x77, 0x61, 0x74,
+      0x44, 0x79, 0x6E, 0x61, 0x6D, 0x69, 0x74, 0x65
+   };
+
+   const size_t BCRYPT_PBKDF_WORKFACTOR = 6;
+   const size_t BCRYPT_PBKDF_ROUNDS = 64;
+
+   blowfish.salted_set_key(pass_hash.data(), pass_hash.size(),
+                           salt_hash.data(), salt_hash.size(),
+                           BCRYPT_PBKDF_WORKFACTOR, true);
+
+   copy_mem(tmp.data(), BCRYPT_PBKDF_MAGIC, BCRYPT_PBKDF_OUTPUT);
+   for(size_t i = 0; i != BCRYPT_PBKDF_ROUNDS; ++i)
+      blowfish.encrypt(tmp);
+
+   /*
+   Bcrypt PBKDF loads the Blowfish output as big endian for no reason
+   in particular. We can't just swap everything once at the end
+   because the (big-endian) values are fed into SHA-512 to generate
+   the salt for the next round
+   */
+   for(size_t i = 0; i != 32/4; ++i)
+      {
+      const uint32_t w = load_le<uint32_t>(tmp.data(), i);
+      store_be(w, &tmp[sizeof(uint32_t)*i]);
+      }
+
+   xor_buf(out.data(), tmp.data(), BCRYPT_PBKDF_OUTPUT);
+   }
+
+}
+
+void bcrypt_pbkdf(uint8_t output[], size_t output_len,
+                  const char* pass, size_t pass_len,
+                  const uint8_t salt[], size_t salt_len,
+                  size_t rounds)
+   {
+   BOTAN_ARG_CHECK(rounds >= 1, "Invalid rounds for Bcrypt PBKDF");
+
+   // No output desired, so we are all done already...
+   if(output_len == 0)
+      return;
+
+   BOTAN_ARG_CHECK(output_len <= 10*1024*1024, "Too much output for Bcrypt PBKDF");
+
+   const size_t BCRYPT_BLOCK_SIZE = 32;
+   const size_t blocks = (output_len + BCRYPT_BLOCK_SIZE - 1) / BCRYPT_BLOCK_SIZE;
+
+   std::unique_ptr<HashFunction> sha512 = HashFunction::create_or_throw("SHA-512");
+   const secure_vector<uint8_t> pass_hash = sha512->process(reinterpret_cast<const uint8_t*>(pass), pass_len);
+
+   secure_vector<uint8_t> salt_hash(sha512->output_length());
+
+   Blowfish blowfish;
+   secure_vector<uint8_t> out(BCRYPT_BLOCK_SIZE);
+   secure_vector<uint8_t> tmp(BCRYPT_BLOCK_SIZE);
+
+   for(size_t block = 0; block != blocks; ++block)
+      {
+      clear_mem(out.data(), out.size());
+
+      sha512->update(salt, salt_len);
+      sha512->update_be(static_cast<uint32_t>(block + 1));
+      sha512->final(salt_hash.data());
+
+      bcrypt_round(blowfish, pass_hash, salt_hash, out, tmp);
+
+      for(size_t r = 1; r != rounds; ++r)
+         {
+         // Next salt is H(prev_output)
+         sha512->update(tmp);
+         sha512->final(salt_hash.data());
+
+         bcrypt_round(blowfish, pass_hash, salt_hash, out, tmp);
+         }
+
+      for(size_t i = 0; i != BCRYPT_BLOCK_SIZE; ++i)
+         {
+         const size_t dest = i * blocks + block;
+         if(dest < output_len)
+            output[dest] = out[i];
+         }
+      }
+   }
+
+}
diff --git a/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.h b/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.h
new file mode 100644
index 000000000..8984e6497
--- /dev/null
+++ b/src/lib/pbkdf/bcrypt_pbkdf/bcrypt_pbkdf.h
@@ -0,0 +1,75 @@
+/*
+* (C) 2018,2019 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#ifndef BOTAN_PBKDF_BCRYPT_H_
+#define BOTAN_PBKDF_BCRYPT_H_
+
+#include <botan/pwdhash.h>
+
+namespace Botan {
+
+/**
+* Bcrypt-PBKDF key derivation function
+*/
+class BOTAN_PUBLIC_API(2,11) Bcrypt_PBKDF final : public PasswordHash
+   {
+   public:
+      Bcrypt_PBKDF(size_t iterations) : m_iterations(iterations) {}
+
+      Bcrypt_PBKDF(const Bcrypt_PBKDF& other) = default;
+      Bcrypt_PBKDF& operator=(const Bcrypt_PBKDF&) = default;
+
+      /**
+      * Derive a new key under the current Bcrypt-PBKDF parameter set
+      */
+      void derive_key(uint8_t out[], size_t out_len,
+                      const char* password, const size_t password_len,
+                      const uint8_t salt[], size_t salt_len) const override;
+
+      std::string to_string() const override;
+
+      size_t iterations() const override { return m_iterations; }
+
+      size_t parallelism() const override { return 0; }
+
+      size_t memory_param() const override { return 0; }
+
+      size_t total_memory_usage() const override { return 4096; }
+
+   private:
+      size_t m_iterations;
+   };
+
+class BOTAN_PUBLIC_API(2,11) Bcrypt_PBKDF_Family final : public PasswordHashFamily
+   {
+   public:
+      Bcrypt_PBKDF_Family() {}
+
+      std::string name() const override;
+
+      std::unique_ptr<PasswordHash> tune(size_t output_length,
+                                         std::chrono::milliseconds msec,
+                                         size_t max_memory) const override;
+
+      std::unique_ptr<PasswordHash> default_params() const override;
+
+      std::unique_ptr<PasswordHash> from_iterations(size_t iter) const override;
+
+      std::unique_ptr<PasswordHash> from_params(
+         size_t i, size_t, size_t) const override;
+   };
+
+/**
+* Bcrypt PBKDF compatible with OpenBSD bcrypt_pbkdf
+*/
+void BOTAN_UNSTABLE_API bcrypt_pbkdf(uint8_t output[], size_t output_len,
+                                     const char* pass, size_t pass_len,
+                                     const uint8_t salt[], size_t salt_len,
+                                     size_t rounds);
+
+}
+
+#endif
diff --git a/src/lib/pbkdf/bcrypt_pbkdf/info.txt b/src/lib/pbkdf/bcrypt_pbkdf/info.txt
new file mode 100644
index 000000000..0e2b10178
--- /dev/null
+++ b/src/lib/pbkdf/bcrypt_pbkdf/info.txt
@@ -0,0 +1,8 @@
+<defines>
+PBKDF_BCRYPT -> 20190531
+</defines>
+
+<requires>
+blowfish
+sha2_64
+</requires>
diff --git a/src/lib/pbkdf/pwdhash.cpp b/src/lib/pbkdf/pwdhash.cpp
index f5ee26c6a..718024a22 100644
--- a/src/lib/pbkdf/pwdhash.cpp
+++ b/src/lib/pbkdf/pwdhash.cpp
@@ -24,6 +24,10 @@
    #include <botan/argon2.h>
 #endif
 
+#if defined(BOTAN_HAS_PBKDF_BCRYPT)
+   #include <botan/bcrypt_pbkdf.h>
+#endif
+
 namespace Botan {
 
 std::unique_ptr<PasswordHashFamily> PasswordHashFamily::create(const std::string& algo_spec,
@@ -71,6 +75,13 @@ std::unique_ptr<PasswordHashFamily> PasswordHashFamily::create(const std::string
       }
 #endif
 
+#if defined(BOTAN_HAS_PBKDF_BCRYPT)
+   if(req.algo_name() == "Bcrypt-PBKDF")
+      {
+      return std::unique_ptr<PasswordHashFamily>(new Bcrypt_PBKDF_Family);
+      }
+#endif
+
 #if defined(BOTAN_HAS_PGP_S2K)
    if(req.algo_name() == "OpenPGP-S2K" && req.arg_count() == 1)
       {