src/go.mod                                          | 2 +-
 src/go.sum                                          | 4 ++--
 src/vendor/golang.org/x/crypto/cryptobyte/asn1.go   | 5 +++--
 src/vendor/golang.org/x/crypto/cryptobyte/string.go | 7 +------
 src/vendor/modules.txt                              | 2 +-

diff --git a/src/go.mod b/src/go.mod
index 90af2a7ea0f80f15596d85d224b9858191d075ac..9c9026f0d800d7888ed0038011439e4e1580e3f7 100644
--- a/src/go.mod
+++ b/src/go.mod
@@ -3,7 +3,7 @@
 go 1.12
 
 require (
-	golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8
+	golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68
 	golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7
 	golang.org/x/sys v0.0.0-20190529130038-5219a1e1c5f8 // indirect
 	golang.org/x/text v0.3.2 // indirect
diff --git a/src/go.sum b/src/go.sum
index e358118e4cbd6845086f195ad1cf3e43cd6c32df..e408f66328d8879d7a8c8222643363bd7e52fced 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 v0.0.0-20190611184440-5c40567a22f8 h1:1wopBVtVdWnn03fZelqdXTqk7U7zPQCb+T4rbU9ZEoU=
-golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/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/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7 h1:fHDIZ2oxGnUZRN6WgWFCbYBjH9uqVPRCUVUDhs0wnbA=
 golang.org/x/net v0.0.0-20190813141303-74dc4d7220e7/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
diff --git a/src/vendor/golang.org/x/crypto/cryptobyte/asn1.go b/src/vendor/golang.org/x/crypto/cryptobyte/asn1.go
index 528b9bff671e53a9c8b695064f7cebcffcd8469f..f930f7e5266c6cb31f241d7fc94bad603e562c22 100644
--- a/src/vendor/golang.org/x/crypto/cryptobyte/asn1.go
+++ b/src/vendor/golang.org/x/crypto/cryptobyte/asn1.go
@@ -470,7 +470,8 @@ // ReadASN1BitString decodes an ASN.1 BIT STRING into out and advances.
 // 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 @@ 		}
 		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/src/vendor/golang.org/x/crypto/cryptobyte/string.go b/src/vendor/golang.org/x/crypto/cryptobyte/string.go
index 39bf98aeead8160094c007d8edb4066b5720283c..589d297e6be8f6d5f2a179a02f2216536263efb5 100644
--- a/src/vendor/golang.org/x/crypto/cryptobyte/string.go
+++ b/src/vendor/golang.org/x/crypto/cryptobyte/string.go
@@ -24,7 +24,7 @@
 // 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]
@@ -104,11 +104,6 @@ 	var length uint32
 	for _, b := range lenBytes {
 		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 {
diff --git a/src/vendor/modules.txt b/src/vendor/modules.txt
index 453a3126613e7007ccf260072fcaf364ce416244..cff8acd02e2159f65580482854f2474d798fb090 100644
--- a/src/vendor/modules.txt
+++ b/src/vendor/modules.txt
@@ -1,4 +1,4 @@
-# golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8
+# golang.org/x/crypto v0.0.0-20200124225646-8b5121be2f68
 golang.org/x/crypto/chacha20poly1305
 golang.org/x/crypto/cryptobyte
 golang.org/x/crypto/cryptobyte/asn1