Reviewers: mp+217314_code.launchpad.net,

Message:
Please take a look.

Description:
utils/ssh: Override rsa.GenerateKey in tests

Make ssh tests faster by generating one, smaller,
RSA key and reusing it for all tests. This is
particularly helpful on arm where the math prime
functions are very slow.

https://code.launchpad.net/~gz/juju-core/generatekey_testoverride_1312850/+merge/217314

(do not edit description out of merge proposal)


Please review this at https://codereview.appspot.com/95780044/

Affected files (+31, -1 lines):
   A [revision details]
   M utils/ssh/clientkeys_test.go
   M utils/ssh/export_test.go
   M utils/ssh/generate.go
   M utils/ssh/generate_test.go
   M utils/ssh/ssh_gocrypto_test.go
   M utils/ssh/ssh_test.go


Index: [revision details]
=== added file '[revision details]'
--- [revision details]	2012-01-01 00:00:00 +0000
+++ [revision details]	2012-01-01 00:00:00 +0000
@@ -0,0 +1,2 @@
+Old revision: tarmac-20140423115706-1c02li5w6rmcg533
+New revision: <email address hidden>

Index: utils/ssh/clientkeys_test.go
=== modified file 'utils/ssh/clientkeys_test.go'
--- utils/ssh/clientkeys_test.go	2014-03-13 07:54:56 +0000
+++ utils/ssh/clientkeys_test.go	2014-04-25 23:47:12 +0000
@@ -27,6 +27,8 @@
  	fakeHome := testing.MakeEmptyFakeHome(c)
  	s.AddCleanup(func(*gc.C) { fakeHome.Restore() })
  	s.AddCleanup(func(*gc.C) { ssh.ClearClientKeys() })
+	generateKeyRestorer := overrideGenerateKey(c)
+	s.AddCleanup(func(*gc.C) { generateKeyRestorer.Restore() })
  }

  func checkFiles(c *gc.C, obtained, expected []string) {


Index: utils/ssh/export_test.go
=== modified file 'utils/ssh/export_test.go'
--- utils/ssh/export_test.go	2014-02-14 04:58:10 +0000
+++ utils/ssh/export_test.go	2014-04-25 23:47:12 +0000
@@ -9,4 +9,5 @@
  	InitDefaultClient   = initDefaultClient
  	DefaultIdentities   = &defaultIdentities
  	SSHDial             = &sshDial
+	RSAGenerateKey      = &rsaGenerateKey
  )


Index: utils/ssh/generate.go
=== modified file 'utils/ssh/generate.go'
--- utils/ssh/generate.go	2013-12-19 20:55:25 +0000
+++ utils/ssh/generate.go	2014-04-25 23:47:12 +0000
@@ -14,6 +14,8 @@
  	"code.google.com/p/go.crypto/ssh"
  )

+var rsaGenerateKey = rsa.GenerateKey
+
  // KeyBits is used to determine the number of bits to use for the RSA keys
  // created using the GenerateKey function.
  var KeyBits = 2048
@@ -24,7 +26,7 @@
  // be added into an authorized_keys file, and has the comment passed in as  
the
  // comment part of the key.
  func GenerateKey(comment string) (private, public string, err error) {
-	key, err := rsa.GenerateKey(rand.Reader, KeyBits)
+	key, err := rsaGenerateKey(rand.Reader, KeyBits)
  	if err != nil {
  		return "", "", err
  	}


Index: utils/ssh/generate_test.go
=== modified file 'utils/ssh/generate_test.go'
--- utils/ssh/generate_test.go	2014-03-13 07:54:56 +0000
+++ utils/ssh/generate_test.go	2014-04-25 23:47:12 +0000
@@ -4,6 +4,10 @@
  package ssh_test

  import (
+	"crypto/rsa"
+	"io"
+
+	"github.com/juju/testing"
  	jc "github.com/juju/testing/checkers"
  	gc "launchpad.net/gocheck"

@@ -17,7 +21,23 @@

  var _ = gc.Suite(&GenerateSuite{})

+var pregeneratedKey *rsa.PrivateKey
+
+func overrideGenerateKey(c *gc.C) testing.Restorer {
+	restorer := testing.PatchValue(ssh.RSAGenerateKey, func(random io.Reader,  
bits int) (*rsa.PrivateKey, error) {
+		if pregeneratedKey != nil {
+			return pregeneratedKey, nil
+		}
+		key, err := rsa.GenerateKey(random, 512)
+		key.Precompute()
+		pregeneratedKey = key
+		return key, err
+	})
+	return restorer
+}
+
  func (s *GenerateSuite) TestGenerate(c *gc.C) {
+	defer overrideGenerateKey(c).Restore()
  	private, public, err := ssh.GenerateKey("some-comment")

  	c.Check(err, gc.IsNil)


Index: utils/ssh/ssh_gocrypto_test.go
=== modified file 'utils/ssh/ssh_gocrypto_test.go'
--- utils/ssh/ssh_gocrypto_test.go	2014-04-12 05:53:58 +0000
+++ utils/ssh/ssh_gocrypto_test.go	2014-04-25 23:47:12 +0000
@@ -87,6 +87,8 @@

  func (s *SSHGoCryptoCommandSuite) SetUpTest(c *gc.C) {
  	s.LoggingSuite.SetUpTest(c)
+	generateKeyRestorer := overrideGenerateKey(c)
+	s.AddCleanup(func(*gc.C) { generateKeyRestorer.Restore() })
  	client, err := ssh.NewGoCryptoClient()
  	c.Assert(err, gc.IsNil)
  	s.client = client


Index: utils/ssh/ssh_test.go
=== modified file 'utils/ssh/ssh_test.go'
--- utils/ssh/ssh_test.go	2014-04-12 05:53:58 +0000
+++ utils/ssh/ssh_test.go	2014-04-25 23:47:12 +0000
@@ -152,6 +152,7 @@
  }

  func (s *SSHCommandSuite) TestCommandClientKeys(c *gc.C) {
+	defer overrideGenerateKey(c).Restore()
  	clientKeysDir := c.MkDir()
  	defer ssh.ClearClientKeys()
  	err := ssh.LoadClientKeys(clientKeysDir)