Fix ECDH using v6 keys (#233)

twiss · web-flow · commit 77090fe8654c · 2024-09-26T10:10:57.000-07:00
When using ECDH with v6 keys, the fingerprint length is not 20 bytes,
so the KDF param is not 45 bytes.
diff --git a/openpgp/ecdh/ecdh.go b/openpgp/ecdh/ecdh.go
@@ -166,9 +166,6 @@ func buildKey(pub *PublicKey, zb []byte, curveOID, fingerprint []byte, stripLead
 	if _, err := param.Write(fingerprint[:]); err != nil {
 		return nil, err
 	}
-	if param.Len()-len(curveOID) != 45 {
-		return nil, errors.New("ecdh: malformed KDF Param")
-	}
 
 	// MB = Hash ( 00 || 00 || 00 || 01 || ZB || Param );
 	h := pub.KDF.Hash.New()

Original file line number	Diff line number	Diff line change
`@@ -166,9 +166,6 @@ func buildKey(pub *PublicKey, zb []byte, curveOID, fingerprint []byte, stripLead`
`166`	`166`	`if _, err := param.Write(fingerprint[:]); err != nil {`
`167`	`167`	`return nil, err`
`168`	`168`	`}`
`169`		`- if param.Len()-len(curveOID) != 45 {`
`170`		`- return nil, errors.New("ecdh: malformed KDF Param")`
`171`		`- }`
`172`	`169`
`173`	`170`	`// MB = Hash ( 00 \|\| 00 \|\| 00 \|\| 01 \|\| ZB \|\| Param );`
`174`	`171`	`h := pub.KDF.Hash.New()`