Some wallet refactorings

components/brave_wallet/browser/BUILD.gn

@@ -34,6 +34,8 @@ static_library("browser") {
     "asset_ratio_response_parser.h",
     "asset_ratio_service.cc",
     "asset_ratio_service.h",
+    "bip39.cc",
+    "bip39.h",
     "bitcoin/bitcoin_block_tracker.cc",
     "bitcoin/bitcoin_block_tracker.h",
     "bitcoin/bitcoin_discover_account_task.cc",
@@ -293,7 +295,6 @@ static_library("browser") {
     "//brave/components/services/brave_wallet/public/mojom",
     "//brave/components/services/brave_wallet/public/proto:zcash_proto",
     "//brave/net/base:utils",
-    "//brave/third_party/argon2",
     "//components/component_updater",
     "//components/content_settings/core/browser",
     "//components/country_codes",

components/brave_wallet/browser/DEPS

@@ -18,7 +18,7 @@ include_rules = [
 ]
 
 specific_include_rules = {
-  "brave_wallet_utils\.cc": [
+  "bip39\.cc": [
     "+brave/third_party/bip39wally-core-native/include",
   ]
 }

components/brave_wallet/browser/account_discovery_manager_unittest.cc

@@ -10,11 +10,11 @@
 
 #include "base/test/scoped_feature_list.h"
 #include "base/test/task_environment.h"
+#include "brave/components/brave_wallet/browser/bip39.h"
 #include "brave/components/brave_wallet/browser/bitcoin/bitcoin_hd_keyring.h"
 #include "brave/components/brave_wallet/browser/bitcoin/bitcoin_test_utils.h"
 #include "brave/components/brave_wallet/browser/bitcoin/bitcoin_wallet_service.h"
 #include "brave/components/brave_wallet/browser/brave_wallet_prefs.h"
-#include "brave/components/brave_wallet/browser/brave_wallet_utils.h"
 #include "brave/components/brave_wallet/browser/keyring_service.h"
 #include "brave/components/brave_wallet/browser/network_manager.h"
 #include "brave/components/brave_wallet/browser/test_utils.h"
@@ -60,7 +60,7 @@ class AccountDiscoveryManagerUnitTest : public testing::Test {
     bitcoin_test_rpc_server_->SetUpBitcoinRpc(std::nullopt, std::nullopt);
 
     keyring_ = std::make_unique<BitcoinHDKeyring>(
-        *MnemonicToSeed(kMnemonicDivideCruise), false);
+        *bip39::MnemonicToSeed(kMnemonicDivideCruise), false);
   }
 
   AccountUtils GetAccountUtils() {

components/brave_wallet/browser/bip39.cc

@@ -0,0 +1,98 @@
+/* Copyright (c) 2025 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "brave/components/brave_wallet/browser/bip39.h"
+
+#include "base/containers/span.h"
+#include "base/strings/strcat.h"
+#include "brave/third_party/bip39wally-core-native/include/wally_bip39.h"
+#include "third_party/boringssl/src/include/openssl/digest.h"
+#include "third_party/boringssl/src/include/openssl/evp.h"
+
+namespace brave_wallet::bip39 {
+
+namespace {
+
+// https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki#generating-the-mnemonic
+inline constexpr uint32_t kMaxSupportedEntropySize = 32;
+
+// https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki#from-mnemonic-to-seed
+inline constexpr uint32_t kPBKDF2Iterations = 2048;
+inline constexpr uint32_t kSeedSize = 64;
+
+std::optional<std::string> GenerateMnemonicInternal(
+    base::span<const uint8_t> entropy) {
+  char* words = nullptr;
+  if (bip39_mnemonic_from_bytes(nullptr, entropy.data(), entropy.size(),
+                                &words) != WALLY_OK) {
+    return std::nullopt;
+  }
+  std::string result(words);
+  wally_free_string(words);
+  return result;
+}
+
+bool IsValidEntropySize(size_t entropy_size) {
+  // entropy size should be 128, 160, 192, 224, 256 bits
+  if (entropy_size < 16 || entropy_size > 32 || entropy_size % 4 != 0) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+std::optional<std::string> GenerateMnemonic(base::span<const uint8_t> entropy) {
+  if (!IsValidEntropySize(entropy.size())) {
+    return std::nullopt;
+  }
+  return GenerateMnemonicInternal(entropy);
+}
+
+std::optional<std::vector<uint8_t>> MnemonicToSeed(
+    std::string_view mnemonic,
+    std::string_view passphrase) {
+  if (!IsValidMnemonic(mnemonic)) {
+    return std::nullopt;
+  }
+
+  std::vector<uint8_t> seed(kSeedSize, 0);
+  const std::string salt = base::StrCat({"mnemonic", passphrase});
+  if (PKCS5_PBKDF2_HMAC(mnemonic.data(), mnemonic.length(),
+                        base::as_byte_span(salt).data(), salt.length(),
+                        kPBKDF2Iterations, EVP_sha512(), seed.size(),
+                        seed.data())) {
+    return seed;
+  }
+
+  return std::nullopt;
+}
+
+std::optional<std::vector<uint8_t>> MnemonicToEntropy(
+    std::string_view mnemonic) {
+  if (!IsValidMnemonic(mnemonic)) {
+    return std::nullopt;
+  }
+
+  std::vector<uint8_t> entropy(kMaxSupportedEntropySize, 0);
+  size_t written = 0;
+  if (bip39_mnemonic_to_bytes(nullptr, std::string(mnemonic).c_str(),
+                              entropy.data(), entropy.size(),
+                              &written) != WALLY_OK) {
+    return std::nullopt;
+  }
+  entropy.resize(written);
+  return entropy;
+}
+
+bool IsValidMnemonic(std::string_view mnemonic) {
+  if (bip39_mnemonic_validate(nullptr, std::string(mnemonic).c_str()) !=
+      WALLY_OK) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace brave_wallet::bip39

components/brave_wallet/browser/bip39.h

@@ -0,0 +1,41 @@
+/* Copyright (c) 2025 The Brave Authors. All rights reserved.
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#ifndef BRAVE_COMPONENTS_BRAVE_WALLET_BROWSER_BIP39_H_
+#define BRAVE_COMPONENTS_BRAVE_WALLET_BROWSER_BIP39_H_
+
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#include "base/containers/span.h"
+
+// Utility functions for BIP39 mnemonics support.
+// https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
+namespace brave_wallet::bip39 {
+
+inline constexpr uint32_t kDefaultEntropySize = 16;
+inline constexpr uint32_t kLegacyEthEntropySize = 32;
+
+// Generate mnemonic from entropy bytes following BIP39.
+// If |entropy.size()| is not in 16, 20, 24, 28, 32 range or
+// allocation failure, the std::nullopt will be returned.
+std::optional<std::string> GenerateMnemonic(base::span<const uint8_t> entropy);
+
+// Generate 64 bytes seed from mnemonic following BIP39.
+std::optional<std::vector<uint8_t>> MnemonicToSeed(
+    std::string_view mnemonic,
+    std::string_view passphrase = "");
+
+// This is mainly used for restoring legacy brave crypto wallet
+std::optional<std::vector<uint8_t>> MnemonicToEntropy(
+    std::string_view mnemonic);
+
+bool IsValidMnemonic(std::string_view mnemonic);
+
+}  // namespace brave_wallet::bip39
+
+#endif  // BRAVE_COMPONENTS_BRAVE_WALLET_BROWSER_BIP39_H_