DeriveSigningKeysFromSeed now requires info so we can derive keys for…

… different purposes with same seed
brave · Jun 9, 2020 · 0a9b7e6 · 0a9b7e6 · diracdeltas · Jun 9, 2020
1 parent 4275aef
commit 0a9b7e6
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Showing 5 changed files with 14 additions and 9 deletions.
diff --git a/components/brave_sync/crypto/crypto.cc b/components/brave_sync/crypto/crypto.cc
@@ -39,13 +39,14 @@ std::vector<uint8_t> HKDFSha512(const std::vector<uint8_t>& ikm,
 
 void DeriveSigningKeysFromSeed(const std::vector<uint8_t>& seed,
                                const std::vector<uint8_t>* salt,
+                               const std::vector<uint8_t>* info,
                                std::vector<uint8_t>* public_key,
                                std::vector<uint8_t>* private_key) {
   DCHECK(public_key);
   DCHECK(private_key);
-  const std::vector<uint8_t> info = {0};
+  DCHECK(info);
   std::vector<uint8_t> output =
-      HKDFSha512(seed, salt, &info, DEFAULT_SEED_SIZE);
+      HKDFSha512(seed, salt, info, DEFAULT_SEED_SIZE);
   public_key->resize(ED25519_PUBLIC_KEY_LEN);
   private_key->resize(ED25519_PRIVATE_KEY_LEN);
   ED25519_keypair_from_seed(public_key->data(), private_key->data(),

diff --git a/components/brave_sync/crypto/crypto.h b/components/brave_sync/crypto/crypto.h
@@ -26,6 +26,7 @@ std::vector<uint8_t> HKDFSha512(const std::vector<uint8_t>& ikm,
 // Derives an Ed25519 keypair given a random seed and an optional HKDF salt
 void DeriveSigningKeysFromSeed(const std::vector<uint8_t>& seed,
                                const std::vector<uint8_t>* salt,
+                               const std::vector<uint8_t>* info,
                                std::vector<uint8_t>* public_key,
                                std::vector<uint8_t>* private_key);
 

diff --git a/components/brave_sync/crypto/crypto_unittest.cc b/components/brave_sync/crypto/crypto_unittest.cc
@@ -134,7 +134,8 @@ TEST(CryptoTest, Ed25519KeyDerivation) {
       &seed);
   std::vector<uint8_t> public_key = {};
   std::vector<uint8_t> private_key = {};
-  DeriveSigningKeysFromSeed(seed, &HKDF_SALT, &public_key, &private_key);
+  std::vector<uint8_t> info = {0};
+  DeriveSigningKeysFromSeed(seed, &HKDF_SALT, &info, &public_key, &private_key);
   EXPECT_EQ("f58ca446f0c33ee7e8e9874466da442b2e764afd77ad46034bdff9e01f9b87d4",
             base::ToLowerASCII(
                 base::HexEncode(public_key.data(), public_key.size())));

diff --git a/components/sync/driver/brave_sync_auth_manager.cc b/components/sync/driver/brave_sync_auth_manager.cc
@@ -34,7 +34,9 @@ void BraveSyncAuthManager::DeriveSigningKeys(const std::string& seed) {
       212, 239, 225, 52,  192, 219, 145, 40,  95,  19,  142, 98};
   std::vector<uint8_t> seed_bytes;
   brave_sync::crypto::PassphraseToBytes32(seed, &seed_bytes);
-  brave_sync::crypto::DeriveSigningKeysFromSeed(seed_bytes, &HKDF_SALT,
+  const std::string info_str = "sync-auth-key";
+  std::vector<uint8_t> info(info_str.begin(), info_str.end());
+  brave_sync::crypto::DeriveSigningKeysFromSeed(seed_bytes, &HKDF_SALT, &info,
                                                 &public_key_, &private_key_);
   if (registered_for_auth_notifications_)
     UpdateSyncAccountIfNecessary();

diff --git a/components/sync/driver/brave_sync_auth_manager_unittest.cc b/components/sync/driver/brave_sync_auth_manager_unittest.cc
@@ -27,13 +27,13 @@ const char kSyncCode[] =
     "proud cabbage fee slow economy wage final fox cancel";
 
 const char kAccessToken[] =
-    "MzEzMjMzMzQzNTM2Mzd8RDM0NDYyREVBNzAwQzg0QkVDNjEzMTlCRTk3QTMwOENGMzI2ODM2RD"
-    "UxM0Y1QjJCODU5RkM3RkU1REJGQjNDQTI2OTFCN0JCODA5NDM5NTgwQzQxNzlCQzYwQzk5Njk5"
-    "OTdEREMwRTIyRkU1NzQ2ODFFNUQ2QzIyNjkxM0M3MDJ8Rjk5NzNBNzdDQTlDRTRENzhGNDU2ND"
-    "kwMjUwMEM5NjY3NEQxOEU2QTM3QUU3NjJGODUzRUM5RkZGRDIyNzU1OQ==";
+    "MzEzMjMzMzQzNTM2Mzd8MDBGNkExNjgxODkxQzU5RDZGMEYwNkVDQ0VGQzBFMTQ3QjA2NDE2RD"
+    "EzNzE0QkQ3MzE3ODJGRjE1NUZFNjMxMTNBNTE2Qzk2NTFFM0ZGQTEyRDhDMzcyQTcyNUZEMzZG"
+    "RjE3QUIxMDRDNDVBNTcyMDVCRkIwNjUwRjgxQ0MyMDl8NTAyMDQyMjcwQzgxNDUyNDdFRDcwQT"
+    "E4Rjg3MDIyQTM5ODg2OTAwQUIzNkYyRkZGNjU1NjM1REJFNTE2NzY1RQ==";
 
 const char kAccountId[] =
-    "F9973A77CA9CE4D78F4564902500C96674D18E6A37AE762F853EC9FFFD227559";
+    "502042270C8145247ED70A18F87022A39886900AB36F2FFF655635DBE516765E";
 
 class BraveSyncAuthManagerTest : public testing::Test {
  protected: