[#339] Fix logging in authmate [pre]sign command

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/auth/center.go

@@ -142,10 +142,6 @@ func (c *Center) parseAuthHeader(authHeader string, headers http.Header) (*AuthH
 	default:
 		return nil, fmt.Errorf("%w: %s", apierr.GetAPIError(apierr.ErrAuthorizationHeaderMalformed), authHeader)
 	}
-	// AWS4-ECDSA-P256-SHA256
-	// Credential=2XGRML5EW3LMHdf64W2DkBy1Nkuu4y4wGhUj44QjbXBi05ZNvs8WVwy1XTmSEkcVkydPKzCgtmR7U3zyLYTj3Snxf/20240326/s3/aws4_request,
-	// SignedHeaders=amz-sdk-invocation-id;amz-sdk-request;host;x-amz-content-sha256;x-amz-date;x-amz-region-set,
-	// Signature=3044022006a2bc760140834101d0a79667d6aa75768c1a28e9cafc8963484d0752a6c6050220629dc06d7d6505e1b1e2a5d1f974b25ba32fdffc6f3f70dc4dda31b8a6f7ea2b
 
 	return &AuthHeader{
 		AccessKeyID:  submatches["access_key_id"],
@@ -487,20 +483,19 @@ func SignStr(secret, service, region string, t time.Time, strToSign string) stri
 	return hex.EncodeToString(signature)
 }
 
-func SignStrV4A(cred aws.Credentials, strToSign string) (string, error) {
-	hash := sha256.New()
-	hash.Write([]byte(strToSign))
-
+func SignStrV4A(ctx context.Context, cred aws.Credentials, strToSign string) (string, error) {
 	credAdapter := v4a.SymmetricCredentialAdaptor{
 		SymmetricProvider: credentials.NewStaticCredentialsProvider(cred.AccessKeyID, cred.SecretAccessKey, ""),
 	}
 
-	creds, err := credAdapter.RetrievePrivateKey(context.Background()) // because of using StaticCredentialsProvider
+	creds, err := credAdapter.RetrievePrivateKey(ctx)
 	if err != nil {
-		// no error is expected
-		panic(err)
+		return "", err
 	}
 
+	hash := sha256.New()
+	hash.Write([]byte(strToSign))
+
 	sig, err := creds.PrivateKey.Sign(rand.Reader, hash.Sum(nil), crypto.SHA256)
 	if err != nil {
 		return "", err