diff --git a/src/cmd/go.mod b/src/cmd/go.mod
index e1e5b34e6ee..db9daa52427 100644
--- a/src/cmd/go.mod
+++ b/src/cmd/go.mod
@@ -5,7 +5,7 @@ go 1.14
 require (
 	github.com/google/pprof v0.0.0-20200229191704-1ebb73c60ed3
 	golang.org/x/arch v0.0.0-20191126211547-368ea8f32fff
-	golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6
+	golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992
 	golang.org/x/mod v0.2.0
 	golang.org/x/sys v0.0.0-20200219091948-cb0a6d8edb6c // indirect
 	golang.org/x/tools v0.0.0-20200309180859-aa4048aca1ca
diff --git a/src/cmd/go.sum b/src/cmd/go.sum
index 73eff83010b..69da57df4f4 100644
--- a/src/cmd/go.sum
+++ b/src/cmd/go.sum
@@ -11,8 +11,8 @@ golang.org/x/arch v0.0.0-20191126211547-368ea8f32fff/go.mod h1:flIaEI6LNU6xOCD5P
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
-golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6 h1:Sy5bstxEqwwbYs6n0/pBuxKENqOeZUgD45Gp3Q3pqLg=
-golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992 h1:B4Wjn2mWOWzjcWfyRYlf00lQ1/9h5vRKmQnhIKhMFR0=
+golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/mod v0.2.0 h1:KU7oHjnv3XNWfa5COkzUifxZmxp1TyI7ImMXqFxLwvQ=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
diff --git a/src/cmd/vendor/golang.org/x/crypto/ssh/terminal/terminal.go b/src/cmd/vendor/golang.org/x/crypto/ssh/terminal/terminal.go
index d1b4fca3a94..2ffb97bfb8a 100644
--- a/src/cmd/vendor/golang.org/x/crypto/ssh/terminal/terminal.go
+++ b/src/cmd/vendor/golang.org/x/crypto/ssh/terminal/terminal.go
@@ -113,6 +113,7 @@ func NewTerminal(c io.ReadWriter, prompt string) *Terminal {
 }
 
 const (
+	keyCtrlC     = 3
 	keyCtrlD     = 4
 	keyCtrlU     = 21
 	keyEnter     = '\r'
@@ -151,8 +152,12 @@ func bytesToKey(b []byte, pasteActive bool) (rune, []byte) {
 		switch b[0] {
 		case 1: // ^A
 			return keyHome, b[1:]
+		case 2: // ^B
+			return keyLeft, b[1:]
 		case 5: // ^E
 			return keyEnd, b[1:]
+		case 6: // ^F
+			return keyRight, b[1:]
 		case 8: // ^H
 			return keyBackspace, b[1:]
 		case 11: // ^K
@@ -738,6 +743,9 @@ func (t *Terminal) readLine() (line string, err error) {
 						return "", io.EOF
 					}
 				}
+				if key == keyCtrlC {
+					return "", io.EOF
+				}
 				if key == keyPasteStart {
 					t.pasteActive = true
 					if len(t.line) == 0 {
diff --git a/src/cmd/vendor/modules.txt b/src/cmd/vendor/modules.txt
index 9f4c9985c6c..3b2e6485e60 100644
--- a/src/cmd/vendor/modules.txt
+++ b/src/cmd/vendor/modules.txt
@@ -23,7 +23,7 @@ golang.org/x/arch/arm/armasm
 golang.org/x/arch/arm64/arm64asm
 golang.org/x/arch/ppc64/ppc64asm
 golang.org/x/arch/x86/x86asm
-# golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6
+# golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992
 ## explicit
 golang.org/x/crypto/ed25519
 golang.org/x/crypto/ed25519/internal/edwards25519
diff --git a/src/go.mod b/src/go.mod
index ab791642788..7ec8941743c 100644
--- a/src/go.mod
+++ b/src/go.mod
@@ -3,7 +3,7 @@ module std
 go 1.14
 
 require (
-	golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6
+	golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992
 	golang.org/x/net v0.0.0-20200301022130-244492dfa37a
 	golang.org/x/sys v0.0.0-20200219091948-cb0a6d8edb6c // indirect
 	golang.org/x/text v0.3.3-0.20191031172631-4b67af870c6f // indirect
diff --git a/src/go.sum b/src/go.sum
index 3f8e5d40b9f..0e256193f5d 100644
--- a/src/go.sum
+++ b/src/go.sum
@@ -1,6 +1,6 @@
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6 h1:Sy5bstxEqwwbYs6n0/pBuxKENqOeZUgD45Gp3Q3pqLg=
-golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992 h1:B4Wjn2mWOWzjcWfyRYlf00lQ1/9h5vRKmQnhIKhMFR0=
+golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a h1:GuSPYbZzB5/dcLNCwLQLsg3obCJtX9IJhpXkvY7kzk0=
 golang.org/x/net v0.0.0-20200301022130-244492dfa37a/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.go b/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.go
index 87f1e369cc2..b799e440b4a 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.go
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.go
@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build go1.11
-// +build !gccgo,!appengine
+// +build go1.11,!gccgo,!purego
 
 package chacha20
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.s b/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.s
index b3a16ef751a..891481539a1 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.s
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_arm64.s
@@ -2,8 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build go1.11
-// +build !gccgo,!appengine
+// +build go1.11,!gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_generic.go b/src/vendor/golang.org/x/crypto/chacha20/chacha_generic.go
index 098ec9f6be0..7c498e90d93 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_generic.go
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_generic.go
@@ -136,6 +136,33 @@ func quarterRound(a, b, c, d uint32) (uint32, uint32, uint32, uint32) {
 	return a, b, c, d
 }
 
+// SetCounter sets the Cipher counter. The next invocation of XORKeyStream will
+// behave as if (64 * counter) bytes had been encrypted so far.
+//
+// To prevent accidental counter reuse, SetCounter panics if counter is
+// less than the current value.
+func (s *Cipher) SetCounter(counter uint32) {
+	// Internally, s may buffer multiple blocks, which complicates this
+	// implementation slightly. When checking whether the counter has rolled
+	// back, we must use both s.counter and s.len to determine how many blocks
+	// we have already output.
+	outputCounter := s.counter - uint32(s.len)/blockSize
+	if counter < outputCounter {
+		panic("chacha20: SetCounter attempted to rollback counter")
+	}
+
+	// In the general case, we set the new counter value and reset s.len to 0,
+	// causing the next call to XORKeyStream to refill the buffer. However, if
+	// we're advancing within the existing buffer, we can save work by simply
+	// setting s.len.
+	if counter < s.counter {
+		s.len = int(s.counter-counter) * blockSize
+	} else {
+		s.counter = counter
+		s.len = 0
+	}
+}
+
 // XORKeyStream XORs each byte in the given slice with a byte from the
 // cipher's key stream. Dst and src must overlap entirely or not at all.
 //
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_noasm.go b/src/vendor/golang.org/x/crypto/chacha20/chacha_noasm.go
index ec609ed868b..4635307b8f2 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_noasm.go
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_noasm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !arm64,!s390x,!ppc64le arm64,!go1.11 gccgo appengine
+// +build !arm64,!s390x,!ppc64le arm64,!go1.11 gccgo purego
 
 package chacha20
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.go b/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.go
index d0ec61f08d9..b7993303415 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.go
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !gccgo,!appengine
+// +build !gccgo,!purego
 
 package chacha20
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.s b/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.s
index 533014ea3e8..23c60216430 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.s
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_ppc64le.s
@@ -19,7 +19,7 @@
 // The differences in this and the original implementation are
 // due to the calling conventions and initialization of constants.
 
-// +build !gccgo,!appengine
+// +build !gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.go b/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.go
index cd55f45a333..a9244bdf4db 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.go
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !gccgo,!appengine
+// +build !gccgo,!purego
 
 package chacha20
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.s b/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.s
index de52a2ea8d1..89c658c410b 100644
--- a/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.s
+++ b/src/vendor/golang.org/x/crypto/chacha20/chacha_s390x.s
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !gccgo,!appengine
+// +build !gccgo,!purego
 
 #include "go_asm.h"
 #include "textflag.h"
diff --git a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
index 737e46aa5a4..cda77819b84 100644
--- a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
+++ b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build go1.7,amd64,!gccgo,!appengine
+// +build !gccgo,!purego
 
 package chacha20poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
index 9dd5d7a979a..3469c87288e 100644
--- a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
+++ b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_amd64.s
@@ -4,7 +4,7 @@
 
 // This file was originally from https://golang.org/cl/24717 by Vlad Krasnov of CloudFlare.
 
-// +build go1.7,amd64,!gccgo,!appengine
+// +build !gccgo,!purego
 
 #include "textflag.h"
 // General register allocation
diff --git a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_noasm.go b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_noasm.go
index 4c2eb703c32..9ce4aa9fe65 100644
--- a/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_noasm.go
+++ b/src/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_noasm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64 !go1.7 gccgo appengine
+// +build !amd64 gccgo purego
 
 package chacha20poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/mac_noasm.go b/src/vendor/golang.org/x/crypto/poly1305/mac_noasm.go
index a8dd589ae39..b0c2cd05614 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/mac_noasm.go
+++ b/src/vendor/golang.org/x/crypto/poly1305/mac_noasm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64,!ppc64le gccgo appengine
+// +build !amd64,!ppc64le gccgo purego
 
 package poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.go b/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.go
index df56a652ff0..35b9e38c903 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.go
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64,!gccgo,!appengine
+// +build !gccgo,!purego
 
 package poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.s b/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.s
index 8c0cefbb3cb..8d394a212ee 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.s
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_amd64.s
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64,!gccgo,!appengine
+// +build !gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_noasm.go b/src/vendor/golang.org/x/crypto/poly1305/sum_noasm.go
index 32a9cef6bbf..2e3ae34c7dc 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_noasm.go
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_noasm.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build s390x,!go1.11 !amd64,!s390x,!ppc64le gccgo appengine nacl
+// +build s390x,!go1.11 !amd64,!s390x,!ppc64le gccgo purego
 
 package poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.go b/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.go
index 3233616935b..92597bb8c26 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.go
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build ppc64le,!gccgo,!appengine
+// +build !gccgo,!purego
 
 package poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.s b/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.s
index 4e20bf299a5..4e028138796 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.s
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_ppc64le.s
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build ppc64le,!gccgo,!appengine
+// +build !gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.go b/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.go
index a8920ee9d21..5f91ff84a9e 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.go
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build s390x,go1.11,!gccgo,!appengine
+// +build go1.11,!gccgo,!purego
 
 package poly1305
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.s b/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.s
index ca5a309d867..806d1694b04 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.s
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_s390x.s
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build s390x,go1.11,!gccgo,!appengine
+// +build go1.11,!gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/golang.org/x/crypto/poly1305/sum_vmsl_s390x.s b/src/vendor/golang.org/x/crypto/poly1305/sum_vmsl_s390x.s
index e60bbc1d7f8..b439af93693 100644
--- a/src/vendor/golang.org/x/crypto/poly1305/sum_vmsl_s390x.s
+++ b/src/vendor/golang.org/x/crypto/poly1305/sum_vmsl_s390x.s
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build s390x,go1.11,!gccgo,!appengine
+// +build go1.11,!gccgo,!purego
 
 #include "textflag.h"
 
diff --git a/src/vendor/modules.txt b/src/vendor/modules.txt
index 6feb23d65d1..f2697872040 100644
--- a/src/vendor/modules.txt
+++ b/src/vendor/modules.txt
@@ -1,4 +1,4 @@
-# golang.org/x/crypto v0.0.0-20200214034016-1d94cc7ab1c6
+# golang.org/x/crypto v0.0.0-20200414155820-4f8f47aa7992
 ## explicit
 golang.org/x/crypto/chacha20
 golang.org/x/crypto/chacha20poly1305