crypto: add comment to FromECDSAPub (ethereum#31241)

MariusVanDerWijden · jakub-freebit · commit f48dfc49e043 · 2025-07-03T14:04:30.000+09:00
closes ethereum#26240
diff --git a/crypto/crypto.go b/crypto/crypto.go
@@ -184,6 +184,9 @@ func UnmarshalPubkey(pub []byte) (*ecdsa.PublicKey, error) {
 	return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}, nil
 }
 
+// FromECDSAPub converts a secp256k1 public key to bytes.
+// Note: it does not use the curve from pub, instead it always
+// encodes using secp256k1.
 func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
 	if pub == nil || pub.X == nil || pub.Y == nil {
 		return nil

Original file line number	Diff line number	Diff line change
`@@ -184,6 +184,9 @@ func UnmarshalPubkey(pub []byte) (*ecdsa.PublicKey, error) {`
`184`	`184`	`return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}, nil`
`185`	`185`	`}`
`186`	`186`
	`187`	`+// FromECDSAPub converts a secp256k1 public key to bytes.`
	`188`	`+// Note: it does not use the curve from pub, instead it always`
	`189`	`+// encodes using secp256k1.`
`187`	`190`	`func FromECDSAPub(pub *ecdsa.PublicKey) []byte {`
`188`	`191`	`if pub == nil \|\| pub.X == nil \|\| pub.Y == nil {`
`189`	`192`	`return nil`