Merge pull request #2895

5ad312a1 wallet2: switch to chacha20 instead of chacha8 (moneromooo-monero)
1e5491e9 Add a chacha20 variant to go with chacha8 (moneromooo-monero)

9 files changed, 101 insertions, 69 deletions

diff --git a/src/crypto/CMakeLists.txt b/src/crypto/CMakeLists.txt
index 1e06a0dfd..fd71a87e7 100644
--- a/src/crypto/CMakeLists.txt
+++ b/src/crypto/CMakeLists.txt
@@ -29,7 +29,7 @@
 set(crypto_sources
   aesb.c
   blake256.c
-  chacha8.c
+  chacha.c
   crypto-ops-data.c
   crypto-ops.c
   crypto.cpp
@@ -51,7 +51,7 @@ set(crypto_headers)
 
 set(crypto_private_headers
   blake256.h
-  chacha8.h
+  chacha.h
   crypto-ops.h
   crypto.h
   generic-ops.h
diff --git a/src/crypto/chacha8.c b/src/crypto/chacha.c
index df135af59..f573083be 100644
--- a/src/crypto/chacha8.c
+++ b/src/crypto/chacha.c
@@ -8,7 +8,7 @@ Public domain.
 #include <stdio.h>
 #include <sys/param.h>
 
-#include "chacha8.h"
+#include "chacha.h"
 #include "common/int-util.h"
 #include "warnings.h"
 
@@ -40,7 +40,7 @@ static const char sigma[] = "expand 32-byte k";
 
 DISABLE_GCC_AND_CLANG_WARNING(strict-aliasing)
 
-void chacha8(const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher) {
+static void chacha(unsigned rounds, const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher) {
   uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
   uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
   char* ctarget = 0;
@@ -89,7 +89,7 @@ void chacha8(const void* data, size_t length, const uint8_t* key, const uint8_t*
     x13 = j13;
     x14 = j14;
     x15 = j15;
-    for (i = 8;i > 0;i -= 2) {
+    for (i = rounds;i > 0;i -= 2) {
       QUARTERROUND( x0, x4, x8,x12)
       QUARTERROUND( x1, x5, x9,x13)
       QUARTERROUND( x2, x6,x10,x14)
@@ -168,3 +168,13 @@ void chacha8(const void* data, size_t length, const uint8_t* key, const uint8_t*
     data = (uint8_t*)data + 64;
   }
 }
+
+void chacha8(const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher)
+{
+  chacha(8, data, length, key, iv, cipher);
+}
+
+void chacha20(const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher)
+{
+  chacha(20, data, length, key, iv, cipher);
+}
diff --git a/src/crypto/chacha8.h b/src/crypto/chacha.h
index dcbe6a933..a9665030d 100644
--- a/src/crypto/chacha8.h
+++ b/src/crypto/chacha.h
@@ -33,8 +33,8 @@
 #include <stdint.h>
 #include <stddef.h>
 
-#define CHACHA8_KEY_SIZE 32
-#define CHACHA8_IV_SIZE 8
+#define CHACHA_KEY_SIZE 32
+#define CHACHA_IV_SIZE 8
 
 #if defined(__cplusplus)
 #include <memory.h>
@@ -46,33 +46,38 @@ namespace crypto {
   extern "C" {
 #endif
     void chacha8(const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher);
+    void chacha20(const void* data, size_t length, const uint8_t* key, const uint8_t* iv, char* cipher);
 #if defined(__cplusplus)
   }
 
-  using chacha8_key = tools::scrubbed_arr<uint8_t, CHACHA8_KEY_SIZE>;
+  using chacha_key = tools::scrubbed_arr<uint8_t, CHACHA_KEY_SIZE>;
 
 #pragma pack(push, 1)
-  // MS VC 2012 doesn't interpret `class chacha8_iv` as POD in spite of [9.0.10], so it is a struct
-  struct chacha8_iv {
-    uint8_t data[CHACHA8_IV_SIZE];
+  // MS VC 2012 doesn't interpret `class chacha_iv` as POD in spite of [9.0.10], so it is a struct
+  struct chacha_iv {
+    uint8_t data[CHACHA_IV_SIZE];
   };
 #pragma pack(pop)
 
-  static_assert(sizeof(chacha8_key) == CHACHA8_KEY_SIZE && sizeof(chacha8_iv) == CHACHA8_IV_SIZE, "Invalid structure size");
+  static_assert(sizeof(chacha_key) == CHACHA_KEY_SIZE && sizeof(chacha_iv) == CHACHA_IV_SIZE, "Invalid structure size");
 
-  inline void chacha8(const void* data, std::size_t length, const chacha8_key& key, const chacha8_iv& iv, char* cipher) {
+  inline void chacha8(const void* data, std::size_t length, const chacha_key& key, const chacha_iv& iv, char* cipher) {
     chacha8(data, length, key.data(), reinterpret_cast<const uint8_t*>(&iv), cipher);
   }
 
-  inline void generate_chacha8_key(const void *data, size_t size, chacha8_key& key) {
-    static_assert(sizeof(chacha8_key) <= sizeof(hash), "Size of hash must be at least that of chacha8_key");
+  inline void chacha20(const void* data, std::size_t length, const chacha_key& key, const chacha_iv& iv, char* cipher) {
+    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) {
+    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());
     memcpy(&key, pwd_hash.data(), sizeof(key));
   }
 
-  inline void generate_chacha8_key(std::string password, chacha8_key& key) {
-    return generate_chacha8_key(password.data(), password.size(), key);
+  inline void generate_chacha_key(std::string password, chacha_key& key) {
+    return generate_chacha_key(password.data(), password.size(), key);
   }
 }
 
diff --git a/src/serialization/crypto.h b/src/serialization/crypto.h
index 4213f2e58..8083bdeb1 100644
--- a/src/serialization/crypto.h
+++ b/src/serialization/crypto.h
@@ -34,7 +34,7 @@
 
 #include "serialization.h"
 #include "debug_archive.h"
-#include "crypto/chacha8.h"
+#include "crypto/chacha.h"
 #include "crypto/crypto.h"
 #include "crypto/hash.h"
 
@@ -77,7 +77,7 @@ bool do_serialize(Archive<true> &ar, std::vector<crypto::signature> &v)
   return true;
 }
 
-BLOB_SERIALIZER(crypto::chacha8_iv);
+BLOB_SERIALIZER(crypto::chacha_iv);
 BLOB_SERIALIZER(crypto::hash);
 BLOB_SERIALIZER(crypto::hash8);
 BLOB_SERIALIZER(crypto::public_key);
diff --git a/src/wallet/wallet2.cpp b/src/wallet/wallet2.cpp
index cf24689da..90977b20a 100644
--- a/src/wallet/wallet2.cpp
+++ b/src/wallet/wallet2.cpp
@@ -2373,12 +2373,12 @@ bool wallet2::store_keys(const std::string& keys_file_name, const epee::wipeable
   account_data = buffer.GetString();
 
   // Encrypt the entire JSON object.
-  crypto::chacha8_key key;
-  crypto::generate_chacha8_key(password.data(), password.size(), key);
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key);
   std::string cipher;
   cipher.resize(account_data.size());
-  keys_file_data.iv = crypto::rand<crypto::chacha8_iv>();
-  crypto::chacha8(account_data.data(), account_data.size(), key, keys_file_data.iv, &cipher[0]);
+  keys_file_data.iv = crypto::rand<crypto::chacha_iv>();
+  crypto::chacha20(account_data.data(), account_data.size(), key, keys_file_data.iv, &cipher[0]);
   keys_file_data.account_data = cipher;
 
   std::string buf;
@@ -2406,6 +2406,7 @@ namespace
  */
 bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_string& password)
 {
+  rapidjson::Document json;
   wallet2::keys_file_data keys_file_data;
   std::string buf;
   bool r = epee::file_io_utils::load_file_to_string(keys_file_name, buf);
@@ -2414,14 +2415,15 @@ bool wallet2::load_keys(const std::string& keys_file_name, const epee::wipeable_
   // Decrypt the contents
   r = ::serialization::parse_binary(buf, keys_file_data);
   THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "internal error: failed to deserialize \"" + keys_file_name + '\"');
-  crypto::chacha8_key key;
-  crypto::generate_chacha8_key(password.data(), password.size(), key);
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key);
   std::string account_data;
   account_data.resize(keys_file_data.account_data.size());
-  crypto::chacha8(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
+  crypto::chacha20(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
+  if (json.Parse(account_data.c_str()).HasParseError() || !json.IsObject())
+    crypto::chacha8(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
 
   // The contents should be JSON if the wallet follows the new format.
-  rapidjson::Document json;
   if (json.Parse(account_data.c_str()).HasParseError())
   {
     is_old_file_format = true;
@@ -2591,6 +2593,7 @@ bool wallet2::verify_password(const epee::wipeable_string& password) const
  */
 bool wallet2::verify_password(const std::string& keys_file_name, const epee::wipeable_string& password, bool no_spend_key)
 {
+  rapidjson::Document json;
   wallet2::keys_file_data keys_file_data;
   std::string buf;
   bool r = epee::file_io_utils::load_file_to_string(keys_file_name, buf);
@@ -2599,14 +2602,15 @@ bool wallet2::verify_password(const std::string& keys_file_name, const epee::wip
   // Decrypt the contents
   r = ::serialization::parse_binary(buf, keys_file_data);
   THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "internal error: failed to deserialize \"" + keys_file_name + '\"');
-  crypto::chacha8_key key;
-  crypto::generate_chacha8_key(password.data(), password.size(), key);
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(password.data(), password.size(), key);
   std::string account_data;
   account_data.resize(keys_file_data.account_data.size());
-  crypto::chacha8(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
+  crypto::chacha20(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
+  if (json.Parse(account_data.c_str()).HasParseError() || !json.IsObject())
+    crypto::chacha8(keys_file_data.account_data.data(), keys_file_data.account_data.size(), key, keys_file_data.iv, &account_data[0]);
 
   // The contents should be JSON if the wallet follows the new format.
-  rapidjson::Document json;
   if (json.Parse(account_data.c_str()).HasParseError())
   {
     // old format before JSON wallet key file format
@@ -3292,7 +3296,7 @@ bool wallet2::check_connection(uint32_t *version, uint32_t timeout)
   return true;
 }
 //----------------------------------------------------------------------------------------------------
-bool wallet2::generate_chacha8_key_from_secret_keys(crypto::chacha8_key &key) const
+bool wallet2::generate_chacha_key_from_secret_keys(crypto::chacha_key &key) const
 {
   const account_keys &keys = m_account.get_keys();
   const crypto::secret_key &view_key = keys.m_view_secret_key;
@@ -3301,7 +3305,7 @@ bool wallet2::generate_chacha8_key_from_secret_keys(crypto::chacha8_key &key) co
   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_chacha8_key(data.data(), sizeof(data), key);
+  crypto::generate_chacha_key(data.data(), sizeof(data), key);
   return true;
 }
 //----------------------------------------------------------------------------------------------------
@@ -3341,34 +3345,46 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
 
       r = ::serialization::parse_binary(buf, cache_file_data);
       THROW_WALLET_EXCEPTION_IF(!r, error::wallet_internal_error, "internal error: failed to deserialize \"" + m_wallet_file + '\"');
-      crypto::chacha8_key key;
-      generate_chacha8_key_from_secret_keys(key);
+      crypto::chacha_key key;
+      generate_chacha_key_from_secret_keys(key);
       std::string cache_data;
       cache_data.resize(cache_file_data.cache_data.size());
-      crypto::chacha8(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
+      crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
 
-      std::stringstream iss;
-      iss << cache_data;
       try {
+        std::stringstream iss;
+        iss << cache_data;
         boost::archive::portable_binary_iarchive ar(iss);
         ar >> *this;
       }
       catch (...)
       {
-        LOG_PRINT_L0("Failed to open portable binary, trying unportable");
-        boost::filesystem::copy_file(m_wallet_file, m_wallet_file + ".unportable", boost::filesystem::copy_option::overwrite_if_exists);
-        iss.str("");
-        iss << cache_data;
-        boost::archive::binary_iarchive ar(iss);
-        ar >> *this;
+        crypto::chacha8(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cache_data[0]);
+        try
+        {
+          std::stringstream iss;
+          iss << cache_data;
+          boost::archive::portable_binary_iarchive ar(iss);
+          ar >> *this;
+        }
+        catch (...)
+        {
+          LOG_PRINT_L0("Failed to open portable binary, trying unportable");
+          boost::filesystem::copy_file(m_wallet_file, m_wallet_file + ".unportable", boost::filesystem::copy_option::overwrite_if_exists);
+          std::stringstream iss;
+          iss.str("");
+          iss << cache_data;
+          boost::archive::binary_iarchive ar(iss);
+          ar >> *this;
+        }
       }
     }
     catch (...)
     {
       LOG_PRINT_L1("Failed to load encrypted cache, trying unencrypted");
-      std::stringstream iss;
-      iss << buf;
       try {
+        std::stringstream iss;
+        iss << buf;
         boost::archive::portable_binary_iarchive ar(iss);
         ar >> *this;
       }
@@ -3376,6 +3392,7 @@ void wallet2::load(const std::string& wallet_, const epee::wipeable_string& pass
       {
         LOG_PRINT_L0("Failed to open portable binary, trying unportable");
         boost::filesystem::copy_file(m_wallet_file, m_wallet_file + ".unportable", boost::filesystem::copy_option::overwrite_if_exists);
+        std::stringstream iss;
         iss.str("");
         iss << buf;
         boost::archive::binary_iarchive ar(iss);
@@ -3500,12 +3517,12 @@ void wallet2::store_to(const std::string &path, const epee::wipeable_string &pas
 
   wallet2::cache_file_data cache_file_data = boost::value_initialized<wallet2::cache_file_data>();
   cache_file_data.cache_data = oss.str();
-  crypto::chacha8_key key;
-  generate_chacha8_key_from_secret_keys(key);
+  crypto::chacha_key key;
+  generate_chacha_key_from_secret_keys(key);
   std::string cipher;
   cipher.resize(cache_file_data.cache_data.size());
-  cache_file_data.iv = crypto::rand<crypto::chacha8_iv>();
-  crypto::chacha8(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cipher[0]);
+  cache_file_data.iv = crypto::rand<crypto::chacha_iv>();
+  crypto::chacha20(cache_file_data.cache_data.data(), cache_file_data.cache_data.size(), key, cache_file_data.iv, &cipher[0]);
   cache_file_data.cache_data = cipher;
 
   const std::string new_file = same_file ? m_wallet_file + ".new" : path;
@@ -8732,12 +8749,12 @@ size_t wallet2::import_multisig(std::vector<cryptonote::blobdata> blobs)
 //----------------------------------------------------------------------------------------------------
 std::string wallet2::encrypt(const std::string &plaintext, const crypto::secret_key &skey, bool authenticated) const
 {
-  crypto::chacha8_key key;
-  crypto::generate_chacha8_key(&skey, sizeof(skey), key);
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(&skey, sizeof(skey), key);
   std::string ciphertext;
-  crypto::chacha8_iv iv = crypto::rand<crypto::chacha8_iv>();
+  crypto::chacha_iv iv = crypto::rand<crypto::chacha_iv>();
   ciphertext.resize(plaintext.size() + sizeof(iv) + (authenticated ? sizeof(crypto::signature) : 0));
-  crypto::chacha8(plaintext.data(), plaintext.size(), key, iv, &ciphertext[sizeof(iv)]);
+  crypto::chacha20(plaintext.data(), plaintext.size(), key, iv, &ciphertext[sizeof(iv)]);
   memcpy(&ciphertext[0], &iv, sizeof(iv));
   if (authenticated)
   {
@@ -8758,13 +8775,13 @@ std::string wallet2::encrypt_with_view_secret_key(const std::string &plaintext,
 //----------------------------------------------------------------------------------------------------
 std::string wallet2::decrypt(const std::string &ciphertext, const crypto::secret_key &skey, bool authenticated) const
 {
-  const size_t prefix_size = sizeof(chacha8_iv) + (authenticated ? sizeof(crypto::signature) : 0);
+  const size_t prefix_size = sizeof(chacha_iv) + (authenticated ? sizeof(crypto::signature) : 0);
   THROW_WALLET_EXCEPTION_IF(ciphertext.size() < prefix_size,
     error::wallet_internal_error, "Unexpected ciphertext size");
 
-  crypto::chacha8_key key;
-  crypto::generate_chacha8_key(&skey, sizeof(skey), key);
-  const crypto::chacha8_iv &iv = *(const crypto::chacha8_iv*)&ciphertext[0];
+  crypto::chacha_key key;
+  crypto::generate_chacha_key(&skey, sizeof(skey), key);
+  const crypto::chacha_iv &iv = *(const crypto::chacha_iv*)&ciphertext[0];
   std::string plaintext;
   plaintext.resize(ciphertext.size() - prefix_size);
   if (authenticated)
@@ -8777,7 +8794,7 @@ std::string wallet2::decrypt(const std::string &ciphertext, const crypto::secret
     THROW_WALLET_EXCEPTION_IF(!crypto::check_signature(hash, pkey, signature),
       error::wallet_internal_error, "Failed to authenticate ciphertext");
   }
-  crypto::chacha8(ciphertext.data() + sizeof(iv), ciphertext.size() - prefix_size, key, iv, &plaintext[0]);
+  crypto::chacha20(ciphertext.data() + sizeof(iv), ciphertext.size() - prefix_size, key, iv, &plaintext[0]);
   return plaintext;
 }
 //----------------------------------------------------------------------------------------------------
diff --git a/src/wallet/wallet2.h b/src/wallet/wallet2.h
index 2b46359bf..b1115f67b 100644
--- a/src/wallet/wallet2.h
+++ b/src/wallet/wallet2.h
@@ -49,7 +49,7 @@
 #include "cryptonote_basic/cryptonote_format_utils.h"
 #include "cryptonote_core/cryptonote_tx_utils.h"
 #include "common/unordered_containers_boost_serialization.h"
-#include "crypto/chacha8.h"
+#include "crypto/chacha.h"
 #include "crypto/hash.h"
 #include "ringct/rctTypes.h"
 #include "ringct/rctOps.h"
@@ -404,7 +404,7 @@ namespace tools
 
     struct keys_file_data
     {
-      crypto::chacha8_iv iv;
+      crypto::chacha_iv iv;
       std::string account_data;
 
       BEGIN_SERIALIZE_OBJECT()
@@ -415,7 +415,7 @@ namespace tools
 
     struct cache_file_data
     {
-      crypto::chacha8_iv iv;
+      crypto::chacha_iv iv;
       std::string cache_data;
 
       BEGIN_SERIALIZE_OBJECT()
@@ -996,7 +996,7 @@ namespace tools
     void add_unconfirmed_tx(const cryptonote::transaction& tx, uint64_t amount_in, const std::vector<cryptonote::tx_destination_entry> &dests, const crypto::hash &payment_id, uint64_t change_amount, uint32_t subaddr_account, const std::set<uint32_t>& subaddr_indices);
     void generate_genesis(cryptonote::block& b);
     void check_genesis(const crypto::hash& genesis_hash) const; //throws
-    bool generate_chacha8_key_from_secret_keys(crypto::chacha8_key &key) const;
+    bool generate_chacha_key_from_secret_keys(crypto::chacha_key &key) const;
     crypto::hash get_payment_id(const pending_tx &ptx) const;
     void check_acc_out_precomp(const cryptonote::tx_out &o, const crypto::key_derivation &derivation, const std::vector<crypto::key_derivation> &additional_derivations, size_t i, tx_scan_info_t &tx_scan_info) const;
     void parse_block_round(const cryptonote::blobdata &blob, cryptonote::block &bl, crypto::hash &bl_id, bool &error) const;
diff --git a/tests/unit_tests/CMakeLists.txt b/tests/unit_tests/CMakeLists.txt
index cfacd5688..ba3acef0c 100644
--- a/tests/unit_tests/CMakeLists.txt
+++ b/tests/unit_tests/CMakeLists.txt
@@ -36,7 +36,7 @@ set(unit_tests_sources
   block_reward.cpp
   bulletproofs.cpp
   canonical_amounts.cpp
-  chacha8.cpp
+  chacha.cpp
   checkpoints.cpp
   command_line.cpp
   crypto.cpp
diff --git a/tests/unit_tests/chacha8.cpp b/tests/unit_tests/chacha.cpp
index bf0699eba..eadebf9d8 100644
--- a/tests/unit_tests/chacha8.cpp
+++ b/tests/unit_tests/chacha.cpp
@@ -32,7 +32,7 @@
 
 #include "gtest/gtest.h"
 
-#include "crypto/chacha8.h"
+#include "crypto/chacha.h"
 
 namespace
 {
diff --git a/tests/unit_tests/serialization.cpp b/tests/unit_tests/serialization.cpp
index 9e76efadf..2ef1097da 100644
--- a/tests/unit_tests/serialization.cpp
+++ b/tests/unit_tests/serialization.cpp
@@ -802,12 +802,12 @@ TEST(Serialization, portability_outputs)
   // decrypt (copied from wallet2::decrypt)
   auto decrypt = [] (const std::string &ciphertext, const crypto::secret_key &skey, bool authenticated) -> string
   {
-    const size_t prefix_size = sizeof(chacha8_iv) + (authenticated ? sizeof(crypto::signature) : 0);
+    const size_t prefix_size = sizeof(chacha_iv) + (authenticated ? sizeof(crypto::signature) : 0);
     if(ciphertext.size() < prefix_size)
       return {};
-    crypto::chacha8_key key;
-    crypto::generate_chacha8_key(&skey, sizeof(skey), key);
-    const crypto::chacha8_iv &iv = *(const crypto::chacha8_iv*)&ciphertext[0];
+    crypto::chacha_key key;
+    crypto::generate_chacha_key(&skey, sizeof(skey), key);
+    const crypto::chacha_iv &iv = *(const crypto::chacha_iv*)&ciphertext[0];
     std::string plaintext;
     plaintext.resize(ciphertext.size() - prefix_size);
     if (authenticated)