device: untangle cyclic depenency

When #3303 was merged, a cyclic dependency chain was generated:

    libdevice <- libcncrypto <- libringct <- libdevice

This was because libdevice needs access to a set of basic crypto operations
implemented in libringct such as scalarmultBase(), while libringct also needs
access to abstracted crypto operations implemented in libdevice such as
ecdhEncode(). To untangle this cyclic dependency chain, this patch splits libringct
into libringct_basic and libringct, where the basic crypto ops previously in
libringct are moved into libringct_basic. The cyclic dependency is now resolved
thanks to this separation:

    libcncrypto <- libringct_basic <- libdevice <- libcryptonote_basic <- libringct

This eliminates the need for crypto_device.cpp and rctOps_device.cpp.

Also, many abstracted interfaces of hw::device such as encrypt_payment_id() and
get_subaddress_secret_key() were previously implemented in libcryptonote_basic
(cryptonote_format_utils.cpp) and were then called from hw::core::device_default,
which is odd because libdevice is supposed to be independent of libcryptonote_basic.
Therefore, those functions were moved to device_default.cpp.

1 files changed, 100 insertions, 9 deletions

diff --git a/src/device/device_default.cpp b/src/device/device_default.cpp
index f93e7db15..6d60c8cc1 100644
--- a/src/device/device_default.cpp
+++ b/src/device/device_default.cpp
@@ -31,10 +31,13 @@
 
 
 #include "device_default.hpp"
-
-#include "cryptonote_basic/cryptonote_format_utils.h"
+#include "cryptonote_basic/account.h"
+#include "cryptonote_basic/subaddress_index.h"
 #include "ringct/rctOps.h"
 
+#define ENCRYPTED_PAYMENT_ID_TAIL 0x8d
+#define CHACHA8_KEY_TAIL 0x8c
+
 namespace hw {
 
     namespace core {
@@ -83,7 +86,14 @@ namespace hw {
         /* ======================================================================= */
 
         bool  device_default::generate_chacha_key(const cryptonote::account_keys &keys, crypto::chacha_key &key) {
-            return cryptonote::generate_chacha_key_from_secret_keys(keys, key);
+            const crypto::secret_key &view_key = keys.m_view_secret_key;
+            const crypto::secret_key &spend_key = keys.m_spend_secret_key;
+            tools::scrubbed_arr<char, sizeof(view_key) + sizeof(spend_key) + 1> data;
+            memcpy(data.data(), &view_key, sizeof(view_key));
+            memcpy(data.data() + sizeof(view_key), &spend_key, sizeof(spend_key));
+            data[sizeof(data) - 1] = CHACHA8_KEY_TAIL;
+            crypto::generate_chacha_key(data.data(), sizeof(data), key);
+            return true;
         }
         bool  device_default::get_public_address(cryptonote::account_public_address &pubkey) {
              dfns();
@@ -100,19 +110,84 @@ namespace hw {
         }
 
         crypto::public_key device_default::get_subaddress_spend_public_key(const cryptonote::account_keys& keys, const cryptonote::subaddress_index &index) {
-            return cryptonote::get_subaddress_spend_public_key(keys,index);
+            if (index.is_zero())
+              return keys.m_account_address.m_spend_public_key;
+
+            // m = Hs(a || index_major || index_minor)
+            crypto::secret_key m = get_subaddress_secret_key(keys.m_view_secret_key, index);
+
+            // M = m*G
+            crypto::public_key M;
+            crypto::secret_key_to_public_key(m, M);
+
+            // D = B + M
+            crypto::public_key D = rct::rct2pk(rct::addKeys(rct::pk2rct(keys.m_account_address.m_spend_public_key), rct::pk2rct(M)));
+            return D;
         }
 
         std::vector<crypto::public_key>  device_default::get_subaddress_spend_public_keys(const cryptonote::account_keys &keys, uint32_t account, uint32_t begin, uint32_t end) {
-            return cryptonote::get_subaddress_spend_public_keys(keys, account, begin, end);
+            CHECK_AND_ASSERT_THROW_MES(begin <= end, "begin > end");
+
+            std::vector<crypto::public_key> pkeys;
+            pkeys.reserve(end - begin);
+            cryptonote::subaddress_index index = {account, begin};
+
+            ge_p3 p3;
+            ge_cached cached;
+            CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&p3, (const unsigned char*)keys.m_account_address.m_spend_public_key.data) == 0,
+                "ge_frombytes_vartime failed to convert spend public key");
+            ge_p3_to_cached(&cached, &p3);
+
+            for (uint32_t idx = begin; idx < end; ++idx)
+            {
+                index.minor = idx;
+                if (index.is_zero())
+                {
+                    pkeys.push_back(keys.m_account_address.m_spend_public_key);
+                    continue;
+                }
+                crypto::secret_key m = get_subaddress_secret_key(keys.m_view_secret_key, index);
+
+                // M = m*G
+                ge_scalarmult_base(&p3, (const unsigned char*)m.data);
+
+                // D = B + M
+                crypto::public_key D;
+                ge_p1p1 p1p1;
+                ge_add(&p1p1, &p3, &cached);
+                ge_p1p1_to_p3(&p3, &p1p1);
+                ge_p3_tobytes((unsigned char*)D.data, &p3);
+
+                pkeys.push_back(D);
+            }
+            return pkeys;
         }
 
         cryptonote::account_public_address device_default::get_subaddress(const cryptonote::account_keys& keys, const cryptonote::subaddress_index &index) {
-            return cryptonote::get_subaddress(keys,index);
+            if (index.is_zero())
+              return keys.m_account_address;
+
+            crypto::public_key D = get_subaddress_spend_public_key(keys, index);
+
+            // C = a*D
+            crypto::public_key C = rct::rct2pk(rct::scalarmultKey(rct::pk2rct(D), rct::sk2rct(keys.m_view_secret_key)));
+
+            // result: (C, D)
+            cryptonote::account_public_address address;
+            address.m_view_public_key  = C;
+            address.m_spend_public_key = D;
+            return address;
         }
 
         crypto::secret_key  device_default::get_subaddress_secret_key(const crypto::secret_key &a, const cryptonote::subaddress_index &index) {
-            return cryptonote::get_subaddress_secret_key(a,index);
+            const char prefix[] = "SubAddr";
+            char data[sizeof(prefix) + sizeof(crypto::secret_key) + sizeof(cryptonote::subaddress_index)];
+            memcpy(data, prefix, sizeof(prefix));
+            memcpy(data + sizeof(prefix), &a, sizeof(crypto::secret_key));
+            memcpy(data + sizeof(prefix) + sizeof(crypto::secret_key), &index, sizeof(cryptonote::subaddress_index));
+            crypto::secret_key m;
+            crypto::hash_to_scalar(data, sizeof(data), m);
+            return m;
         }
 
         /* ======================================================================= */
@@ -120,7 +195,9 @@ namespace hw {
         /* ======================================================================= */
 
         bool  device_default::verify_keys(const crypto::secret_key &secret_key, const crypto::public_key &public_key) {
-            return cryptonote::verify_keys(secret_key, public_key);
+            crypto::public_key calculated_pub;
+            bool r = crypto::secret_key_to_public_key(secret_key, calculated_pub);
+            return r && public_key == calculated_pub;
         }
 
         bool device_default::scalarmultKey(rct::key & aP, const rct::key &P, const rct::key &a) {
@@ -190,7 +267,21 @@ namespace hw {
         }
 
         bool  device_default::encrypt_payment_id(crypto::hash8 &payment_id, const crypto::public_key &public_key, const crypto::secret_key &secret_key) {
-            return cryptonote::encrypt_payment_id(payment_id, public_key, secret_key);
+            crypto::key_derivation derivation;
+            crypto::hash hash;
+            char data[33]; /* A hash, and an extra byte */
+
+            if (!generate_key_derivation(public_key, secret_key, derivation))
+                return false;
+
+            memcpy(data, &derivation, 32);
+            data[32] = ENCRYPTED_PAYMENT_ID_TAIL;
+            cn_fast_hash(data, 33, hash);
+
+            for (size_t b = 0; b < 8; ++b)
+                payment_id.data[b] ^= hash.data[b];
+
+            return true;
         }
 
         bool  device_default::ecdhEncode(rct::ecdhTuple & unmasked, const rct::key & sharedSec) {