all: remove a few unused parameters

I recently modified tabwriter to reduce the number of defers due to
flush calls. However, I forgot to notice that the new function
flushNoDefers can no longer return an error, due to the lack of the
defer.

In crypto/tls, hashForServerKeyExchange never returned a non-nil error,
so simplify the code.

Finally, in go/types and net we can find a few trivially unused
parameters, so remove them.

Change-Id: I54c8de83fbc944df432453b55c93008d7e810e61
Reviewed-on: https://go-review.googlesource.com/c/go/+/174131
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>

1 files changed, 6 insertions, 12 deletions

diff --git a/src/crypto/tls/key_agreement.go b/src/crypto/tls/key_agreement.go
index 628e578e48..488401d038 100644
--- a/src/crypto/tls/key_agreement.go
+++ b/src/crypto/tls/key_agreement.go
@@ -106,19 +106,19 @@ func md5SHA1Hash(slices [][]byte) []byte {
 // hashForServerKeyExchange hashes the given slices and returns their digest
 // using the given hash function (for >= TLS 1.2) or using a default based on
 // the sigType (for earlier TLS versions).
-func hashForServerKeyExchange(sigType uint8, hashFunc crypto.Hash, version uint16, slices ...[]byte) ([]byte, error) {
+func hashForServerKeyExchange(sigType uint8, hashFunc crypto.Hash, version uint16, slices ...[]byte) []byte {
 	if version >= VersionTLS12 {
 		h := hashFunc.New()
 		for _, slice := range slices {
 			h.Write(slice)
 		}
 		digest := h.Sum(nil)
-		return digest, nil
+		return digest
 	}
 	if sigType == signatureECDSA {
-		return sha1Hash(slices), nil
+		return sha1Hash(slices)
 	}
-	return md5SHA1Hash(slices), nil
+	return md5SHA1Hash(slices)
 }
 
 // ecdheKeyAgreement implements a TLS key agreement where the server
@@ -185,10 +185,7 @@ NextCandidate:
 		return nil, errors.New("tls: certificate cannot be used with the selected cipher suite")
 	}
 
-	digest, err := hashForServerKeyExchange(sigType, hashFunc, ka.version, clientHello.random, hello.random, serverECDHParams)
-	if err != nil {
-		return nil, err
-	}
+	digest := hashForServerKeyExchange(sigType, hashFunc, ka.version, clientHello.random, hello.random, serverECDHParams)
 
 	signOpts := crypto.SignerOpts(hashFunc)
 	if sigType == signatureRSAPSS {
@@ -297,10 +294,7 @@ func (ka *ecdheKeyAgreement) processServerKeyExchange(config *Config, clientHell
 	}
 	sig = sig[2:]
 
-	digest, err := hashForServerKeyExchange(sigType, hashFunc, ka.version, clientHello.random, serverHello.random, serverECDHParams)
-	if err != nil {
-		return err
-	}
+	digest := hashForServerKeyExchange(sigType, hashFunc, ka.version, clientHello.random, serverHello.random, serverECDHParams)
 	return verifyHandshakeSignature(sigType, cert.PublicKey, hashFunc, digest, sig)
 }