all: use crypto/ed25519 instead of golang.org/x/crypto/ed25519

This is a follow-up to CL 317169, which dropped go1.12 compatibility,
and made the golang.org/x/crypto/ed25519 package an alias / wrapper for
crypto/ed25519 in stdlib.

This patch updates uses within this repository to use stdlib instead of
depending on the wrapper. With this patch applied, the only remaining
use of the wrapper is in ed25519_test, which appears to be in place to
verify compatibility of the wrapper itself.

Change-Id: I0195396102a75ae20bdd82ca8ab59855c0eb5cea
GitHub-Last-Rev: 24dbec563cbd84bc47bdc7736b0245fc83dd3353
GitHub-Pull-Request: golang/crypto#238
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/448238
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Nicola Murino <nicola.murino@gmail.com>
Reviewed-by: Nicola Murino <nicola.murino@gmail.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Joedian Reid <joedian@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
diff --git a/internal/wycheproof/eddsa_test.go b/internal/wycheproof/eddsa_test.go
index 0a7fbb7..118dfc0 100644
--- a/internal/wycheproof/eddsa_test.go
+++ b/internal/wycheproof/eddsa_test.go
@@ -8,9 +8,8 @@
 package wycheproof
 
 import (
+	"crypto/ed25519"
 	"testing"
-
-	"golang.org/x/crypto/ed25519"
 )
 
 func TestEddsa(t *testing.T) {
diff --git a/nacl/sign/sign.go b/nacl/sign/sign.go
index 8a6acdc..109c08b 100644
--- a/nacl/sign/sign.go
+++ b/nacl/sign/sign.go
@@ -21,9 +21,9 @@
 package sign
 
 import (
+	"crypto/ed25519"
 	"io"
 
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/internal/alias"
 )
 
diff --git a/ssh/agent/client.go b/ssh/agent/client.go
index c3e112a..9f09aae 100644
--- a/ssh/agent/client.go
+++ b/ssh/agent/client.go
@@ -16,6 +16,7 @@
 	"bytes"
 	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rsa"
 	"encoding/base64"
@@ -26,7 +27,6 @@
 	"math/big"
 	"sync"
 
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/ssh"
 )
 
diff --git a/ssh/agent/server.go b/ssh/agent/server.go
index 9a769de..dd2e0a3 100644
--- a/ssh/agent/server.go
+++ b/ssh/agent/server.go
@@ -7,6 +7,7 @@
 import (
 	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rsa"
 	"encoding/binary"
@@ -16,7 +17,6 @@
 	"log"
 	"math/big"
 
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/ssh"
 )
 
diff --git a/ssh/keys.go b/ssh/keys.go
index bcaae50..ef1bad7 100644
--- a/ssh/keys.go
+++ b/ssh/keys.go
@@ -11,6 +11,7 @@
 	"crypto/cipher"
 	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/md5"
 	"crypto/rand"
@@ -28,7 +29,6 @@
 	"math/big"
 	"strings"
 
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/ssh/internal/bcrypt_pbkdf"
 )
 
diff --git a/ssh/keys_test.go b/ssh/keys_test.go
index 365d93d..76d2338 100644
--- a/ssh/keys_test.go
+++ b/ssh/keys_test.go
@@ -8,6 +8,7 @@
 	"bytes"
 	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rand"
 	"crypto/rsa"
@@ -21,7 +22,6 @@
 	"strings"
 	"testing"
 
-	"golang.org/x/crypto/ed25519"
 	"golang.org/x/crypto/ssh/testdata"
 )