From 01672528cbe013f5ab35a11570acfafdeade0a05 Mon Sep 17 00:00:00 2001
From: Kenneth Jenkins <51246568+kenjenkins@users.noreply.github.com>
Date: Thu, 14 Sep 2023 11:25:19 -0700
Subject: [PATCH] cryptutil: remove unused functions (#4541)

Remove the unused functions Sign() and Verify().
---
 pkg/cryptutil/sign.go      | 36 -----------------------
 pkg/cryptutil/sign_test.go | 60 --------------------------------------
 2 files changed, 96 deletions(-)
 delete mode 100644 pkg/cryptutil/sign_test.go

diff --git a/pkg/cryptutil/sign.go b/pkg/cryptutil/sign.go
index 4d1a51f71..dad16c942 100644
--- a/pkg/cryptutil/sign.go
+++ b/pkg/cryptutil/sign.go
@@ -4,8 +4,6 @@ import (
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
-	"crypto/sha256"
-	"math/big"
 )
 
 // NewSigningKey generates a random P-256 ECDSA private key.
@@ -14,37 +12,3 @@ import (
 func NewSigningKey() (*ecdsa.PrivateKey, error) {
 	return ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 }
-
-// Sign signs arbitrary data using ECDSA.
-func Sign(data []byte, privkey *ecdsa.PrivateKey) ([]byte, error) {
-	// hash message
-	digest := sha256.Sum256(data)
-
-	// sign the hash
-	r, s, err := ecdsa.Sign(rand.Reader, privkey, digest[:])
-	if err != nil {
-		return nil, err
-	}
-
-	// encode the signature {R, S}
-	// big.Int.Bytes() will need padding in the case of leading zero bytes
-	params := privkey.Curve.Params()
-	curveOrderByteSize := params.P.BitLen() / 8
-	rBytes, sBytes := r.Bytes(), s.Bytes()
-	signature := make([]byte, curveOrderByteSize*2)
-	copy(signature[curveOrderByteSize-len(rBytes):], rBytes)
-	copy(signature[curveOrderByteSize*2-len(sBytes):], sBytes)
-	return signature, nil
-}
-
-// Verify checks a raw ECDSA signature.
-// Returns true if it's valid and false if not.
-func Verify(data, signature []byte, pubkey *ecdsa.PublicKey) bool {
-	// hash message
-	digest := sha256.Sum256(data)
-	curveOrderByteSize := pubkey.Curve.Params().P.BitLen() / 8
-	r, s := new(big.Int), new(big.Int)
-	r.SetBytes(signature[:curveOrderByteSize])
-	s.SetBytes(signature[curveOrderByteSize:])
-	return ecdsa.Verify(pubkey, digest[:], r, s)
-}
diff --git a/pkg/cryptutil/sign_test.go b/pkg/cryptutil/sign_test.go
deleted file mode 100644
index 7d68c10ca..000000000
--- a/pkg/cryptutil/sign_test.go
+++ /dev/null
@@ -1,60 +0,0 @@
-package cryptutil
-
-import (
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rand"
-	"testing"
-)
-
-func TestSign(t *testing.T) {
-	message := []byte("Hello, world!")
-
-	key, err := NewSigningKey()
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	signature, err := Sign(message, key)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	if !Verify(message, signature, &key.PublicKey) {
-		t.Error("signature was not correct")
-		return
-	}
-
-	message[0] ^= 0xff
-	if Verify(message, signature, &key.PublicKey) {
-		t.Error("signature was good for altered message")
-	}
-}
-
-func TestSignWithP384(t *testing.T) {
-	message := []byte("Hello, world!")
-
-	key, err := ecdsa.GenerateKey(elliptic.P384(), rand.Reader)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	signature, err := Sign(message, key)
-	if err != nil {
-		t.Error(err)
-		return
-	}
-
-	if !Verify(message, signature, &key.PublicKey) {
-		t.Error("signature was not correct")
-		return
-	}
-
-	message[0] ^= 0xff
-	if Verify(message, signature, &key.PublicKey) {
-		t.Error("signature was good for altered message")
-	}
-}