diff --git a/go.mod b/go.mod
index d1209e96d..c72162190 100644
--- a/go.mod
+++ b/go.mod
@@ -25,7 +25,7 @@ require (
 	github.com/ziutek/mymysql v1.5.4 // indirect
 	github.com/zmap/zcrypto v0.0.0-20190729165852-9051775e6a2e
 	github.com/zmap/zlint v0.0.0-20190806154020-fd021b4cfbeb
-	golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4
+	golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68
 	golang.org/x/lint v0.0.0-20190930215403-16217165b5de
 	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3
 	golang.org/x/text v0.3.2 // indirect
diff --git a/go.sum b/go.sum
index e94d4b226..837e2a07e 100644
--- a/go.sum
+++ b/go.sum
@@ -82,6 +82,8 @@ golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnf
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 h1:HuIa8hRrWRSrqYzx1qI49NNxhdi2PrY7gxVSq1JjLDc=
 golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68 h1:WPLCzSEbawp58wezcvLvLnvhiDJAai54ESbc41NdXS0=
+golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de h1:5hukYrvBGR8/eNkX5mdUezrA6JiaEZDtJb9Ei+1LlBs=
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
diff --git a/vendor/golang.org/x/crypto/cryptobyte/asn1.go b/vendor/golang.org/x/crypto/cryptobyte/asn1.go
index 528b9bff6..f930f7e52 100644
--- a/vendor/golang.org/x/crypto/cryptobyte/asn1.go
+++ b/vendor/golang.org/x/crypto/cryptobyte/asn1.go
@@ -470,7 +470,8 @@ func (s *String) ReadASN1GeneralizedTime(out *time.Time) bool {
 // It reports whether the read was successful.
 func (s *String) ReadASN1BitString(out *encoding_asn1.BitString) bool {
 	var bytes String
-	if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 {
+	if !s.ReadASN1(&bytes, asn1.BIT_STRING) || len(bytes) == 0 ||
+		len(bytes)*8/8 != len(bytes) {
 		return false
 	}
 
@@ -740,7 +741,7 @@ func (s *String) readASN1(out *String, outTag *asn1.Tag, skipHeader bool) bool {
 		length = headerLen + len32
 	}
 
-	if uint32(int(length)) != length || !s.ReadBytes((*[]byte)(out), int(length)) {
+	if int(length) < 0 || !s.ReadBytes((*[]byte)(out), int(length)) {
 		return false
 	}
 	if skipHeader && !out.Skip(int(headerLen)) {
diff --git a/vendor/golang.org/x/crypto/cryptobyte/string.go b/vendor/golang.org/x/crypto/cryptobyte/string.go
index 39bf98aee..589d297e6 100644
--- a/vendor/golang.org/x/crypto/cryptobyte/string.go
+++ b/vendor/golang.org/x/crypto/cryptobyte/string.go
@@ -24,7 +24,7 @@ type String []byte
 // read advances a String by n bytes and returns them. If less than n bytes
 // remain, it returns nil.
 func (s *String) read(n int) []byte {
-	if len(*s) < n {
+	if len(*s) < n || n < 0 {
 		return nil
 	}
 	v := (*s)[:n]
@@ -105,11 +105,6 @@ func (s *String) readLengthPrefixed(lenLen int, outChild *String) bool {
 		length = length << 8
 		length = length | uint32(b)
 	}
-	if int(length) < 0 {
-		// This currently cannot overflow because we read uint24 at most, but check
-		// anyway in case that changes in the future.
-		return false
-	}
 	v := s.read(int(length))
 	if v == nil {
 		return false
diff --git a/vendor/golang.org/x/crypto/ed25519/ed25519.go b/vendor/golang.org/x/crypto/ed25519/ed25519.go
index c7f8c7e64..d6f683ba3 100644
--- a/vendor/golang.org/x/crypto/ed25519/ed25519.go
+++ b/vendor/golang.org/x/crypto/ed25519/ed25519.go
@@ -2,11 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// In Go 1.13, the ed25519 package was promoted to the standard library as
-// crypto/ed25519, and this package became a wrapper for the standard library one.
-//
-// +build !go1.13
-
 // Package ed25519 implements the Ed25519 signature algorithm. See
 // https://ed25519.cr.yp.to/.
 //
diff --git a/vendor/golang.org/x/crypto/ed25519/ed25519_go113.go b/vendor/golang.org/x/crypto/ed25519/ed25519_go113.go
deleted file mode 100644
index d1448d8d2..000000000
--- a/vendor/golang.org/x/crypto/ed25519/ed25519_go113.go
+++ /dev/null
@@ -1,73 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build go1.13
-
-// Package ed25519 implements the Ed25519 signature algorithm. See
-// https://ed25519.cr.yp.to/.
-//
-// These functions are also compatible with the “Ed25519” function defined in
-// RFC 8032. However, unlike RFC 8032's formulation, this package's private key
-// representation includes a public key suffix to make multiple signing
-// operations with the same key more efficient. This package refers to the RFC
-// 8032 private key as the “seed”.
-//
-// Beginning with Go 1.13, the functionality of this package was moved to the
-// standard library as crypto/ed25519. This package only acts as a compatibility
-// wrapper.
-package ed25519
-
-import (
-	"crypto/ed25519"
-	"io"
-)
-
-const (
-	// PublicKeySize is the size, in bytes, of public keys as used in this package.
-	PublicKeySize = 32
-	// PrivateKeySize is the size, in bytes, of private keys as used in this package.
-	PrivateKeySize = 64
-	// SignatureSize is the size, in bytes, of signatures generated and verified by this package.
-	SignatureSize = 64
-	// SeedSize is the size, in bytes, of private key seeds. These are the private key representations used by RFC 8032.
-	SeedSize = 32
-)
-
-// PublicKey is the type of Ed25519 public keys.
-//
-// This type is an alias for crypto/ed25519's PublicKey type.
-// See the crypto/ed25519 package for the methods on this type.
-type PublicKey = ed25519.PublicKey
-
-// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
-//
-// This type is an alias for crypto/ed25519's PrivateKey type.
-// See the crypto/ed25519 package for the methods on this type.
-type PrivateKey = ed25519.PrivateKey
-
-// GenerateKey generates a public/private key pair using entropy from rand.
-// If rand is nil, crypto/rand.Reader will be used.
-func GenerateKey(rand io.Reader) (PublicKey, PrivateKey, error) {
-	return ed25519.GenerateKey(rand)
-}
-
-// NewKeyFromSeed calculates a private key from a seed. It will panic if
-// len(seed) is not SeedSize. This function is provided for interoperability
-// with RFC 8032. RFC 8032's private keys correspond to seeds in this
-// package.
-func NewKeyFromSeed(seed []byte) PrivateKey {
-	return ed25519.NewKeyFromSeed(seed)
-}
-
-// Sign signs the message with privateKey and returns a signature. It will
-// panic if len(privateKey) is not PrivateKeySize.
-func Sign(privateKey PrivateKey, message []byte) []byte {
-	return ed25519.Sign(privateKey, message)
-}
-
-// Verify reports whether sig is a valid signature of message by publicKey. It
-// will panic if len(publicKey) is not PublicKeySize.
-func Verify(publicKey PublicKey, message, sig []byte) bool {
-	return ed25519.Verify(publicKey, message, sig)
-}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index df696d0ba..6f0739be3 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -94,7 +94,7 @@ github.com/zmap/zcrypto/x509/pkix
 github.com/zmap/zlint
 github.com/zmap/zlint/lints
 github.com/zmap/zlint/util
-# golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4
+# golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68
 golang.org/x/crypto/cryptobyte
 golang.org/x/crypto/cryptobyte/asn1
 golang.org/x/crypto/ed25519