Update ChangePassword.razor (#1404)

apps/server/AliasVault.Client/Main/Pages/Settings/Security/ChangePassword.razor

@@ -180,7 +180,10 @@ else
             CurrentSalt,
             srpIdentity);
 
-        // Generate salt and verifier for new password using Rust WASM.
+        // Generate salt for new password using Rust WASM.
+        // IMPORTANT: We must use the same salt for both key derivation AND SRP verifier generation.
+        // Otherwise login will fail because the server returns this salt, but the password hash
+        // was derived with a different salt.
         var newSalt = await SrpService.GenerateSaltAsync();
 
         byte[] newPasswordHash = await Encryption.DeriveKeyFromPasswordAsync(PasswordChangeFormModel.NewPassword, newSalt);
@@ -193,8 +196,9 @@ else
         // it is encrypted with the new password hash.
         await AuthService.StoreEncryptionKeyAsync(newPasswordHash);
 
-        // Use srpIdentity for generating the new verifier to maintain consistency.
-        var (srpSalt, srpVerifier) = await SrpService.PreparePasswordChangeAsync(srpIdentity, newPasswordHashString);
+        // Derive the SRP verifier using the same salt that was used for key derivation.
+        var newPrivateKey = await SrpService.DerivePrivateKeyAsync(newSalt, srpIdentity, newPasswordHashString);
+        var newVerifier = await SrpService.DeriveVerifierAsync(newPrivateKey);
 
         // Prepare new vault model to update to.
         var encryptedBase64String = await DbService.GetEncryptedDatabaseBase64String();
@@ -216,8 +220,8 @@ else
             UpdatedAt = vault.UpdatedAt,
             CurrentClientPublicEphemeral = ClientEphemeral.Public,
             CurrentClientSessionProof = ClientSession.Proof,
-            NewPasswordSalt = srpSalt,
-            NewPasswordVerifier = srpVerifier
+            NewPasswordSalt = newSalt,
+            NewPasswordVerifier = newVerifier
         };
 
         // Clear form.