Issue #6: implement api key hashing and verification

2026-04-26 16:40:36 -04:00
parent 4094e64ee0
commit 696be17139
17 changed files with 524 additions and 0 deletions
@@ -0,0 +1,57 @@
+using System.Security.Cryptography;
+
+namespace MxGateway.Server.Security.Authentication;
+
+public sealed class ApiKeyVerifier(
+    IApiKeyParser parser,
+    IApiKeySecretHasher hasher,
+    IApiKeyStore keyStore) : IApiKeyVerifier
+{
+    public async Task<ApiKeyVerificationResult> VerifyAsync(
+        string? authorizationHeader,
+        CancellationToken cancellationToken)
+    {
+        if (!parser.TryParseAuthorizationHeader(authorizationHeader, out ParsedApiKey? parsedKey)
+            || parsedKey is null)
+        {
+            return ApiKeyVerificationResult.Fail(ApiKeyVerificationFailure.MissingOrMalformedCredentials);
+        }
+
+        ApiKeyRecord? storedKey = await keyStore.FindByKeyIdAsync(parsedKey.KeyId, cancellationToken)
+            .ConfigureAwait(false);
+
+        if (storedKey is null)
+        {
+            return ApiKeyVerificationResult.Fail(ApiKeyVerificationFailure.KeyNotFound);
+        }
+
+        if (storedKey.RevokedUtc is not null)
+        {
+            return ApiKeyVerificationResult.Fail(ApiKeyVerificationFailure.KeyRevoked);
+        }
+
+        byte[] presentedHash;
+        try
+        {
+            presentedHash = hasher.HashSecret(parsedKey.Secret);
+        }
+        catch (ApiKeyPepperUnavailableException)
+        {
+            return ApiKeyVerificationResult.Fail(ApiKeyVerificationFailure.PepperUnavailable);
+        }
+
+        if (!CryptographicOperations.FixedTimeEquals(presentedHash, storedKey.SecretHash))
+        {
+            return ApiKeyVerificationResult.Fail(ApiKeyVerificationFailure.SecretMismatch);
+        }
+
+        await keyStore.MarkKeyUsedAsync(storedKey.KeyId, DateTimeOffset.UtcNow, cancellationToken)
+            .ConfigureAwait(false);
+
+        return ApiKeyVerificationResult.Success(new ApiKeyIdentity(
+            KeyId: storedKey.KeyId,
+            KeyPrefix: storedKey.KeyPrefix,
+            DisplayName: storedKey.DisplayName,
+            Scopes: storedKey.Scopes));
+    }
+}