Remove the need for two chacha20 implementations

vendor/github.com/jedisct1/xsecretbox/.travis.yml

@@ -1,4 +0,0 @@
-sudo: false
-language: go
-go:
-- 1.x

vendor/github.com/jedisct1/xsecretbox/go.mod

@@ -1,10 +1,5 @@
 module github.com/jedisct1/xsecretbox
 
-go 1.15
+go 1.16
 
-require (
-	github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da
-	github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635
-	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad
-	golang.org/x/sys v0.0.0-20201231184435-2d18734c6014 // indirect
-)
+require golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2

vendor/github.com/jedisct1/xsecretbox/go.sum

@@ -1,15 +1,8 @@
-github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
-github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
-github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635 h1:52m0LGchQBBVqJRyYYufQuIbVqRawmubW3OFGqK1ekw=
-github.com/aead/poly1305 v0.0.0-20180717145839-3fee0db0b635/go.mod h1:lmLxL+FV291OopO93Bwf9fQLQeLyt33VJRUg5VJ30us=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad h1:DN0cp81fZ3njFcrLCytUHRSUkqBjfTo4Tx9RJTWs0EY=
-golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
-golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
-golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193GlqGZbnPFnPV/5Rsb4=
-golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201231184435-2d18734c6014 h1:joucsQqXmyBVxViHCPFjG3hx8JzIFSaym3l3MM/Jsdg=
-golang.org/x/sys v0.0.0-20201231184435-2d18734c6014/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
-golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2 h1:It14KIkyBFYkHkwZ7k45minvA9aorojkyjGk9KJ5B/w=
+golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

vendor/github.com/jedisct1/xsecretbox/sharedkey.go

@@ -2,27 +2,20 @@ package xsecretbox
 
 import (
 	crypto_rand "crypto/rand"
-	"errors"
 
-	"github.com/aead/chacha20/chacha"
 	"golang.org/x/crypto/curve25519"
 )
 
 // SharedKey computes a shared secret compatible with the one used by `crypto_box_xchacha20poly1305``
 func SharedKey(secretKey [32]byte, publicKey [32]byte) ([32]byte, error) {
-	var sharedKey [32]byte
-	curve25519.ScalarMult(&sharedKey, &secretKey, &publicKey)
-	c := byte(0)
-	for i := 0; i < 32; i++ {
-		c |= sharedKey[i]
-	}
-	if c == 0 {
-		if _, err := crypto_rand.Read(sharedKey[:]); err != nil {
-			return sharedKey, err
+	var key [32]byte
+	xKey, err := curve25519.X25519(secretKey[:], publicKey[:])
+	if err != nil {
+		if _, err2 := crypto_rand.Read(key[:]); err != nil {
+			return key, err2
 		}
-		return sharedKey, errors.New("weak public key")
+		return key, err
 	}
-	var nonce [16]byte
-	chacha.HChaCha20(&sharedKey, &nonce, &sharedKey)
-	return sharedKey, nil
+	copy(key[:], xKey)
+	return key, nil
 }

vendor/github.com/jedisct1/xsecretbox/xsecretbox.go

@@ -4,8 +4,8 @@ import (
 	"crypto/subtle"
 	"errors"
 
-	"github.com/aead/chacha20/chacha"
-	"github.com/aead/poly1305"
+	"golang.org/x/crypto/chacha20"
+	"golang.org/x/crypto/poly1305"
 )
 
 const (
@@ -27,7 +27,7 @@ func Seal(out, nonce, message, key []byte) []byte {
 	}
 
 	var firstBlock [64]byte
-	cipher, _ := chacha.NewCipher(nonce, key, 20)
+	cipher, _ := chacha20.NewUnauthenticatedCipher(key, nonce)
 	cipher.XORKeyStream(firstBlock[:], firstBlock[:])
 	var polyKey [32]byte
 	copy(polyKey[:], firstBlock[:32])
@@ -51,7 +51,7 @@ func Seal(out, nonce, message, key []byte) []byte {
 	cipher.XORKeyStream(out, message)
 
 	var tag [TagSize]byte
-	hash := poly1305.New(polyKey)
+	hash := poly1305.New(&polyKey)
 	hash.Write(ciphertext)
 	hash.Sum(tag[:0])
 	copy(tagOut, tag[:])
@@ -72,14 +72,14 @@ func Open(out, nonce, box, key []byte) ([]byte, error) {
 	}
 
 	var firstBlock [64]byte
-	cipher, _ := chacha.NewCipher(nonce, key, 20)
+	cipher, _ := chacha20.NewUnauthenticatedCipher(key, nonce)
 	cipher.XORKeyStream(firstBlock[:], firstBlock[:])
 	var polyKey [32]byte
 	copy(polyKey[:], firstBlock[:32])
 
 	var tag [TagSize]byte
 	ciphertext := box[TagSize:]
-	hash := poly1305.New(polyKey)
+	hash := poly1305.New(&polyKey)
 	hash.Write(ciphertext)
 	hash.Sum(tag[:0])
 	if subtle.ConstantTimeCompare(tag[:], box[:TagSize]) != 1 {