Use crypto_rand() everywhere

dnscrypt-proxy/crypto.go

@@ -5,7 +5,6 @@ import (
 	crypto_rand "crypto/rand"
 	"crypto/sha512"
 	"errors"
-	"math/rand"
 
 	"github.com/jedisct1/dlog"
 	"github.com/jedisct1/xsecretbox"
@@ -102,7 +101,7 @@ func (proxy *Proxy) Encrypt(
 		minQuestionSize = Max(proxy.questionSizeEstimator.MinQuestionSize(), minQuestionSize)
 	} else {
 		var xpad [1]byte
-		rand.Read(xpad[:])
+		crypto_rand.Read(xpad[:])
 		minQuestionSize += int(xpad[0])
 	}
 	paddedLength := Min(MaxDNSUDPPacketSize, (Max(minQuestionSize, QueryOverhead)+1+63) & ^63)

go.mod

@@ -1,6 +1,6 @@
 module github.com/dnscrypt/dnscrypt-proxy
 
-go 1.19
+go 1.20
 
 require (
 	github.com/BurntSushi/toml v1.2.1