exp/ssh: use ClientConfig.rand() for publickey authentication

Closes TODO from 5373055

R=agl
CC=golang-dev
https://golang.org/cl/5375081

diff --git a/src/pkg/exp/ssh/client_auth.go b/src/pkg/exp/ssh/client_auth.go
index bb43eafff517605da12a46e2b135d871d52a0819..25f9e21622530b40ef687fcf5133fc3066cd80ad 100644 (file)
--- a/src/pkg/exp/ssh/client_auth.go
+++ b/src/pkg/exp/ssh/client_auth.go
@@ -5,7 +5,6 @@
 package ssh
 
 import (
-       "crypto/rand"
        "errors"
        "io"
 )
@@ -28,7 +27,7 @@ func (c *ClientConn) authenticate(session []byte) error {
        // then any untried methods suggested by the server. 
        tried, remain := make(map[string]bool), make(map[string]bool)
        for auth := ClientAuth(new(noneAuth)); auth != nil; {
-               ok, methods, err := auth.auth(session, c.config.User, c.transport)
+               ok, methods, err := auth.auth(session, c.config.User, c.transport, c.config.rand())
                if err != nil {
                        return err
                }
@@ -62,7 +61,7 @@ type ClientAuth interface {
        // Returns true if authentication is successful.
        // If authentication is not successful, a []string of alternative 
        // method names is returned.
-       auth(session []byte, user string, t *transport) (bool, []string, error)
+       auth(session []byte, user string, t *transport, rand io.Reader) (bool, []string, error)
 
        // method returns the RFC 4252 method name.
        method() string
@@ -71,7 +70,7 @@ type ClientAuth interface {
 // "none" authentication, RFC 4252 section 5.2.
 type noneAuth int
 
-func (n *noneAuth) auth(session []byte, user string, t *transport) (bool, []string, error) {
+func (n *noneAuth) auth(session []byte, user string, t *transport, rand io.Reader) (bool, []string, error) {
        if err := t.writePacket(marshal(msgUserAuthRequest, userAuthRequestMsg{
                User:    user,
                Service: serviceSSH,
@@ -104,7 +103,7 @@ type passwordAuth struct {
        ClientPassword
 }
 
-func (p *passwordAuth) auth(session []byte, user string, t *transport) (bool, []string, error) {
+func (p *passwordAuth) auth(session []byte, user string, t *transport, rand io.Reader) (bool, []string, error) {
        type passwordAuthMsg struct {
                User     string
                Service  string
@@ -174,7 +173,7 @@ type publickeyAuth struct {
        ClientKeyring
 }
 
-func (p *publickeyAuth) auth(session []byte, user string, t *transport) (bool, []string, error) {
+func (p *publickeyAuth) auth(session []byte, user string, t *transport, rand io.Reader) (bool, []string, error) {
        type publickeyAuthMsg struct {
                User    string
                Service string
@@ -241,8 +240,7 @@ func (p *publickeyAuth) auth(session []byte, user string, t *transport) (bool, [
        for i, key := range validKeys {
                pubkey := serializePublickey(key)
                algoname := algoName(key)
-               // TODO(dfc) use random source from the ClientConfig
-               sign, err := p.Sign(i, rand.Reader, buildDataSignedForAuth(session, userAuthRequestMsg{
+               sign, err := p.Sign(i, rand, buildDataSignedForAuth(session, userAuthRequestMsg{
                        User:    user,
                        Service: serviceSSH,
                        Method:  p.method(),