Code modifications to integrate Ledger HW device into monero-wallet-cli.

The basic approach it to delegate all sensitive data (master key, secret
ephemeral key, key derivation, ....) and related operations to the device.
As device has low memory, it does not keep itself the values
(except for view/spend keys) but once computed there are encrypted (with AES
are equivalent) and return back to monero-wallet-cli. When they need to be
manipulated by the device, they are decrypted on receive.

Moreover, using the client for storing the value in encrypted form limits
the modification in the client code. Those values are transfered from one
C-structure to another one as previously.

The code modification has been done with the wishes to be open to any
other hardware wallet. To achieve that a C++ class hw::Device has been
introduced. Two initial implementations are provided: the "default", which
remaps all calls to initial Monero code, and  the "Ledger", which delegates
all calls to Ledger device.

7 files changed, 115 insertions, 6 deletions

diff --git a/src/crypto/CMakeLists.txt b/src/crypto/CMakeLists.txt
index 71dcedcab..35c099697 100644
--- a/src/crypto/CMakeLists.txt
+++ b/src/crypto/CMakeLists.txt
@@ -33,6 +33,7 @@ set(crypto_sources
   crypto-ops-data.c
   crypto-ops.c
   crypto.cpp
+  crypto_device.cpp
   groestl.c
   hash-extra-blake.c
   hash-extra-groestl.c
@@ -77,6 +78,7 @@ monero_add_library(cncrypto
 target_link_libraries(cncrypto
   PUBLIC
     epee
+    device
     ${Boost_SYSTEM_LIBRARY}
   PRIVATE
     ${EXTRA_LIBRARIES})
diff --git a/src/crypto/chacha.h b/src/crypto/chacha.h
index f74d0c352..b45c3d7c7 100644
--- a/src/crypto/chacha.h
+++ b/src/crypto/chacha.h
@@ -69,10 +69,10 @@ namespace crypto {
     chacha20(data, length, key.data(), reinterpret_cast<const uint8_t*>(&iv), cipher);
   }
 
-  inline void generate_chacha_key(const void *data, size_t size, chacha_key& key) {
+  inline void generate_chacha_key(const void *data, size_t size, chacha_key& key, bool prehashed=false) {
     static_assert(sizeof(chacha_key) <= sizeof(hash), "Size of hash must be at least that of chacha_key");
     tools::scrubbed_arr<char, HASH_SIZE> pwd_hash;
-    crypto::cn_slow_hash(data, size, pwd_hash.data());
+    crypto::cn_slow_hash_pre(data, size, pwd_hash.data(), prehashed);
     memcpy(&key, pwd_hash.data(), sizeof(key));
   }
 
diff --git a/src/crypto/crypto.cpp b/src/crypto/crypto.cpp
index d9b8b6787..afac105e4 100644
--- a/src/crypto/crypto.cpp
+++ b/src/crypto/crypto.cpp
@@ -436,7 +436,7 @@ namespace crypto {
     return sc_isnonzero(&c2) == 0;
   }
 
-  static void hash_to_ec(const public_key &key, ge_p3 &res) {
+  void crypto_ops::hash_to_ec(const public_key &key, ge_p3 &res) {
     hash h;
     ge_p2 point;
     ge_p1p1 point2;
diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h
index 81ebfb9e2..75b333473 100644
--- a/src/crypto/crypto.h
+++ b/src/crypto/crypto.h
@@ -46,6 +46,10 @@
 #include "hex.h"
 #include "span.h"
 #include "hash.h"
+#include "device/device_declare.hpp"
+extern "C" {
+  #include "crypto-ops.h"
+}
 
 namespace crypto {
 
@@ -113,6 +117,9 @@ namespace crypto {
     void operator=(const crypto_ops &);
     ~crypto_ops();
 
+    static void hash_to_ec(const public_key &key, ge_p3 &res) ;
+    friend void hash_to_ec(const public_key &key, ge_p3 &res) ;
+
     static secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key = secret_key(), bool recover = false);
     friend secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover);
     static bool check_key(const public_key &);
@@ -149,6 +156,17 @@ namespace crypto {
       const public_key *const *, std::size_t, const signature *);
   };
 
+  secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover, hw::device &hwdev);
+  secret_key generate_keys(public_key &pub, secret_key &sec, hw::device &hwdev);
+  bool secret_key_to_public_key(const secret_key &sec, public_key &pub, hw::device &hwdev);
+  bool generate_key_derivation(const public_key &key1, const secret_key &key2, key_derivation &derivation, hw::device &hwdev);
+  void derivation_to_scalar(const key_derivation &derivation, size_t output_index, ec_scalar &res, hw::device &hwdev) ;
+  bool derive_public_key(const key_derivation &derivation, size_t output_index, const public_key &base, public_key &derived_key, hw::device &hwdev);
+  void derive_secret_key(const key_derivation &derivation, size_t output_index, const secret_key &base, secret_key &derived_key, hw::device &hwdev);
+  bool derive_subaddress_public_key(const public_key &out_key, const key_derivation &derivation, std::size_t output_index, public_key &derived_key, hw::device &hwdev);
+  void generate_key_image(const public_key &pub, const secret_key &sec, key_image &image, hw::device &hwdev);
+
+
   /* Generate N random bytes
    */
   inline void rand(size_t N, uint8_t *bytes) {
@@ -166,6 +184,9 @@ namespace crypto {
     return res;
   }
 
+  inline void hash_to_ec(const public_key &key, ge_p3 &res) {
+    crypto_ops::hash_to_ec(key,res);
+  }
   /* Generate a new key pair
    */
   inline secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key = secret_key(), bool recover = false) {
diff --git a/src/crypto/crypto_device.cpp b/src/crypto/crypto_device.cpp
new file mode 100644
index 000000000..5536857c8
--- /dev/null
+++ b/src/crypto/crypto_device.cpp
@@ -0,0 +1,79 @@
+// Copyright (c) 2014-2018, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+// 
+
+
+#include "crypto.h"
+#include "device/device.hpp"
+#include "device/log.hpp"
+
+namespace crypto {
+
+    secret_key generate_keys(public_key &pub, secret_key &sec, const secret_key& recovery_key, bool recover, hw::device &hwdev) {
+        secret_key rng;
+        hwdev.generate_keys(pub, sec, recovery_key, recover, rng);
+        return rng;
+    }
+
+    secret_key generate_keys(public_key &pub, secret_key &sec, hw::device &hwdev) {
+        secret_key rng;
+        hwdev.generate_keys(pub, sec,  secret_key(), false, rng);
+        return rng;
+    }
+
+
+    bool secret_key_to_public_key(const secret_key &sec, public_key &pub, hw::device &hwdev) {
+       return hwdev.secret_key_to_public_key(sec, pub);
+    }
+
+    bool generate_key_derivation(const public_key &key1, const secret_key &key2, key_derivation &derivation, hw::device &hwdev) {
+        return hwdev.generate_key_derivation(key1, key2, derivation);
+    }
+
+    void derivation_to_scalar(const key_derivation &derivation, size_t output_index, ec_scalar &res, hw::device &hwdev) {
+        hwdev.derivation_to_scalar(derivation, output_index, res);
+    }
+
+    bool derive_public_key(const key_derivation &derivation, size_t output_index,
+                           const public_key &base, public_key &derived_key, hw::device &hwdev) {
+        return hwdev.derive_public_key(derivation, output_index, base, derived_key);
+    }
+
+    void derive_secret_key(const key_derivation &derivation, size_t output_index,
+                           const secret_key &base, secret_key &derived_key, hw::device &hwdev) {
+        hwdev.derive_secret_key(derivation, output_index, base, derived_key);
+    }
+
+    bool derive_subaddress_public_key(const public_key &out_key, const key_derivation &derivation, std::size_t output_index, public_key &derived_key, hw::device &hwdev) {
+        return hwdev.derive_subaddress_public_key(out_key, derivation, output_index, derived_key);
+    }
+
+    void generate_key_image(const public_key &pub, const secret_key &sec, key_image &image, hw::device &hwdev) {
+        hwdev.generate_key_image(pub,sec,image);
+    }
+}
\ No newline at end of file
diff --git a/src/crypto/hash-ops.h b/src/crypto/hash-ops.h
index 47c6f6425..130bf02db 100644
--- a/src/crypto/hash-ops.h
+++ b/src/crypto/hash-ops.h
@@ -80,6 +80,7 @@ enum {
 
 void cn_fast_hash(const void *data, size_t length, char *hash);
 void cn_slow_hash(const void *data, size_t length, char *hash);
+void cn_slow_hash_pre(const void *data, size_t length, char *hash, bool pre);
 
 void hash_extra_blake(const void *data, size_t length, char *hash);
 void hash_extra_groestl(const void *data, size_t length, char *hash);
diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index f921b2455..36bfba9fd 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -515,8 +515,11 @@ void slow_hash_free_state(void)
  * @param length the length in bytes of the data
  * @param hash a pointer to a buffer in which the final 256 bit hash will be stored
  */
+void cn_slow_hash(const void *data, size_t length, char *hash) {
+    cn_slow_hash_pre(data,length,hash,false);
+}
 
-void cn_slow_hash(const void *data, size_t length, char *hash)
+void cn_slow_hash_pre(const void *data, size_t length, char *hash, bool prehashed)
 {
     RDATA_ALIGN16 uint8_t expandedKey[240];  /* These buffers are aligned to use later with SSE functions */
 
@@ -543,8 +546,11 @@ void cn_slow_hash(const void *data, size_t length, char *hash)
         slow_hash_allocate_state();
 
     /* CryptoNight Step 1:  Use Keccak1600 to initialize the 'state' (and 'text') buffers from the data. */
-
-    hash_process(&state.hs, data, length);
+    if (prehashed) {
+        memcpy(&state.hs, data, length);
+    } else {
+        hash_process(&state.hs, data, length);
+    }
     memcpy(text, state.init, INIT_SIZE_BYTE);
 
     /* CryptoNight Step 2:  Iteratively encrypt the results from Keccak to fill