From 56c62e4eef0cd3084e52e5f6e4e38e3a233716ee Mon Sep 17 00:00:00 2001
From: Bohdan Kuchma <bogdan.kuchma2@gmail.com>
Date: Tue, 10 Dec 2024 20:56:25 +0200
Subject: [PATCH] Refactor ECDSA signature verification

---
 internal/algorithms/ecdsa.go              | 28 -----------------------
 internal/service/api/requests/register.go |  3 +--
 internal/types/signature_algorithm.go     | 11 +++++++--
 3 files changed, 10 insertions(+), 32 deletions(-)
 delete mode 100644 internal/algorithms/ecdsa.go

diff --git a/internal/algorithms/ecdsa.go b/internal/algorithms/ecdsa.go
deleted file mode 100644
index bba11ae..0000000
--- a/internal/algorithms/ecdsa.go
+++ /dev/null
@@ -1,28 +0,0 @@
-package algorithms
-
-import (
-	"crypto/ecdsa"
-	"crypto/sha256"
-	"encoding/asn1"
-	"math/big"
-
-	"gitlab.com/distributed_lab/logan/v3/errors"
-)
-
-type ECDSASignature struct {
-	R, S *big.Int
-}
-
-func VerifyECDSA(data, sig []byte, publicKey *ecdsa.PublicKey) error {
-	var esig ECDSASignature
-	_, err := asn1.Unmarshal(sig, &esig)
-	if err != nil {
-		return errors.New("failed to unmarshal ASN.1 ECDSA signature")
-	}
-	hash := sha256.Sum256(data)
-	if ok := ecdsa.Verify(publicKey, hash[:], esig.R, esig.S); !ok {
-		return err
-	}
-
-	return nil
-}
diff --git a/internal/service/api/requests/register.go b/internal/service/api/requests/register.go
index 4b39b3b..d4353b5 100644
--- a/internal/service/api/requests/register.go
+++ b/internal/service/api/requests/register.go
@@ -45,8 +45,7 @@ func validateRegister(r resources.RegisterResponse) error {
 			})),
 		"/data/attributes/document_sod/dg15": validation.Validate(
 			r.Data.Attributes.DocumentSod.Dg15,
-			validation.Required,
-			validation.Length(1, 512),
+			validation.Length(0, 512),
 		),
 		"/data/attributes/document_sod/signed_attributes": validation.Validate(
 			r.Data.Attributes.DocumentSod.SignedAttributes,
diff --git a/internal/types/signature_algorithm.go b/internal/types/signature_algorithm.go
index d85ce4c..973adc8 100644
--- a/internal/types/signature_algorithm.go
+++ b/internal/types/signature_algorithm.go
@@ -6,7 +6,6 @@ import (
 	"crypto/rsa"
 	"hash"
 
-	"github.com/rarimo/passport-identity-provider/internal/algorithms"
 	"gitlab.com/distributed_lab/logan/v3/errors"
 )
 
@@ -43,12 +42,20 @@ func GeneralVerify(publicKey interface{}, hash []byte, signature []byte, algo Al
 		if !ok {
 			return ErrInvalidPublicKey{Expected: algo.SignatureAlgorithm}
 		}
-		return algorithms.VerifyECDSA(hash, signature, ecdsaKey)
+		return verifyECDSA(hash, signature, ecdsaKey)
 	default:
 		return errors.New("unsupported signature algorithm")
 	}
 }
 
+func verifyECDSA(data, sig []byte, publicKey *ecdsa.PublicKey) error {
+	if ok := ecdsa.VerifyASN1(publicKey, data, sig); !ok {
+		return errors.New("failed to verify ECDSA signature")
+	}
+
+	return nil
+}
+
 func GeneralHash(algorithm HashAlgorithm) hash.Hash {
 	switch algorithm {
 	case SHA1: