Use caddy's certmagic library for extensible/robust ACME handling (#14177)

* use certmagic for more extensible/robust ACME cert handling

* accept TOS based on config option

Signed-off-by: Andrew Thornton <art27@cantab.net>

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>

Author: 3 people

.drone.yml

@@ -69,7 +69,7 @@ steps:
 
   - name: checks-backend
     pull: always
-    image: golang:1.14
+    image: golang:1.15
     commands:
       - make checks-backend
     depends_on: [lint-backend]
@@ -82,7 +82,7 @@ steps:
 
   - name: build-backend-no-gcc
     pull: always
-    image: golang:1.13 # this step is kept as the lowest version of golang that we support
+    image: golang:1.14 # this step is kept as the lowest version of golang that we support
     environment:
       GO111MODULE: on
       GOPROXY: off

Makefile

@@ -25,7 +25,7 @@ HAS_GO = $(shell hash $(GO) > /dev/null 2>&1 && echo "GO" || echo "NOGO" )
 COMMA := ,
 
 XGO_VERSION := go-1.15.x
-MIN_GO_VERSION := 001013000
+MIN_GO_VERSION := 001014000
 MIN_NODE_VERSION := 010013000
 
 DOCKER_IMAGE ?= gitea/gitea

cmd/web.go

@@ -22,7 +22,6 @@ import (
 
 	context2 "github.com/gorilla/context"
 	"github.com/urfave/cli"
-	"golang.org/x/crypto/acme/autocert"
 	ini "gopkg.in/ini.v1"
 )
 
@@ -72,36 +71,6 @@ func runHTTPRedirector() {
 	}
 }
 
-func runLetsEncrypt(listenAddr, domain, directory, email string, m http.Handler) error {
-	certManager := autocert.Manager{
-		Prompt:     autocert.AcceptTOS,
-		HostPolicy: autocert.HostWhitelist(domain),
-		Cache:      autocert.DirCache(directory),
-		Email:      email,
-	}
-	go func() {
-		log.Info("Running Let's Encrypt handler on %s", setting.HTTPAddr+":"+setting.PortToRedirect)
-		// all traffic coming into HTTP will be redirect to HTTPS automatically (LE HTTP-01 validation happens here)
-		var err = runHTTP("tcp", setting.HTTPAddr+":"+setting.PortToRedirect, certManager.HTTPHandler(http.HandlerFunc(runLetsEncryptFallbackHandler)))
-		if err != nil {
-			log.Fatal("Failed to start the Let's Encrypt handler on port %s: %v", setting.PortToRedirect, err)
-		}
-	}()
-	return runHTTPSWithTLSConfig("tcp", listenAddr, certManager.TLSConfig(), context2.ClearHandler(m))
-}
-
-func runLetsEncryptFallbackHandler(w http.ResponseWriter, r *http.Request) {
-	if r.Method != "GET" && r.Method != "HEAD" {
-		http.Error(w, "Use HTTPS", http.StatusBadRequest)
-		return
-	}
-	// Remove the trailing slash at the end of setting.AppURL, the request
-	// URI always contains a leading slash, which would result in a double
-	// slash
-	target := strings.TrimSuffix(setting.AppURL, "/") + r.URL.RequestURI()
-	http.Redirect(w, r, target, http.StatusFound)
-}
-
 func runWeb(ctx *cli.Context) error {
 	managerCtx, cancel := context.WithCancel(context.Background())
 	graceful.InitManager(managerCtx)

cmd/web_letsencrypt.go

@@ -0,0 +1,69 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"net/http"
+	"strings"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+
+	"github.com/caddyserver/certmagic"
+	context2 "github.com/gorilla/context"
+)
+
+func runLetsEncrypt(listenAddr, domain, directory, email string, m http.Handler) error {
+
+	// If HTTP Challenge enabled, needs to be serving on port 80. For TLSALPN needs 443.
+	// Due to docker port mapping this can't be checked programatically
+	// TODO: these are placeholders until we add options for each in settings with appropriate warning
+	enableHTTPChallenge := true
+	enableTLSALPNChallenge := true
+
+	magic := certmagic.NewDefault()
+	magic.Storage = &certmagic.FileStorage{Path: directory}
+	myACME := certmagic.NewACMEManager(magic, certmagic.ACMEManager{
+		Email:                   email,
+		Agreed:                  setting.LetsEncryptTOS,
+		DisableHTTPChallenge:    !enableHTTPChallenge,
+		DisableTLSALPNChallenge: !enableTLSALPNChallenge,
+	})
+
+	magic.Issuer = myACME
+
+	// this obtains certificates or renews them if necessary
+	err := magic.ManageSync([]string{domain})
+	if err != nil {
+		return err
+	}
+
+	tlsConfig := magic.TLSConfig()
+
+	if enableHTTPChallenge {
+		go func() {
+			log.Info("Running Let's Encrypt handler on %s", setting.HTTPAddr+":"+setting.PortToRedirect)
+			// all traffic coming into HTTP will be redirect to HTTPS automatically (LE HTTP-01 validation happens here)
+			var err = runHTTP("tcp", setting.HTTPAddr+":"+setting.PortToRedirect, myACME.HTTPChallengeHandler(http.HandlerFunc(runLetsEncryptFallbackHandler)))
+			if err != nil {
+				log.Fatal("Failed to start the Let's Encrypt handler on port %s: %v", setting.PortToRedirect, err)
+			}
+		}()
+	}
+
+	return runHTTPSWithTLSConfig("tcp", listenAddr, tlsConfig, context2.ClearHandler(m))
+}
+
+func runLetsEncryptFallbackHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" && r.Method != "HEAD" {
+		http.Error(w, "Use HTTPS", http.StatusBadRequest)
+		return
+	}
+	// Remove the trailing slash at the end of setting.AppURL, the request
+	// URI always contains a leading slash, which would result in a double
+	// slash
+	target := strings.TrimSuffix(setting.AppURL, "/") + r.URL.RequestURI()
+	http.Redirect(w, r, target, http.StatusFound)
+}

docs/config.yaml

@@ -19,7 +19,7 @@ params:
   author: The Gitea Authors
   website: https://docs.gitea.io
   version: 1.13.1
-  minGoVersion: 1.13
+  minGoVersion: 1.14
   goVersion: 1.15
   minNodeVersion: 10.13
 

go.mod

@@ -24,6 +24,7 @@ require (
 	github.com/andybalholm/brotli v1.0.1 // indirect
 	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
 	github.com/blevesearch/bleve/v2 v2.0.1
+	github.com/caddyserver/certmagic v0.12.0
 	github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect
 	github.com/denisenkom/go-mssqldb v0.9.0
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible

go.sum

@@ -196,6 +196,8 @@ github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc h1:biVzkmvwrH8
 github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bradfitz/gomemcache v0.0.0-20190329173943-551aad21a668 h1:U/lr3Dgy4WK+hNk4tyD+nuGjpVLPEHuJSFXMw11/HPA=
 github.com/bradfitz/gomemcache v0.0.0-20190329173943-551aad21a668/go.mod h1:H0wQNHz2YrLsuXOZozoeDmnHXkNCRmMW0gwFWDfEZDA=
+github.com/caddyserver/certmagic v0.12.0 h1:1f7kxykaJkOVVpXJ8ZrC6RAO5F6+kKm9U7dBFbLNeug=
+github.com/caddyserver/certmagic v0.12.0/go.mod h1:tr26xh+9fY5dN0J6IPAlMj07qpog22PJKa7Nw7j835U=
 github.com/casbin/casbin/v2 v2.1.2/go.mod h1:YcPU1XXisHhLzuxH9coDNf2FbKpjGlbCg3n9yuLkIJQ=
 github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
@@ -668,6 +670,7 @@ github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGAR
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
 github.com/jmespath/go-jmespath v0.3.0/go.mod h1:9QtRXoHjLGCJ5IBSaohpXITPlowMeeYCZ7fLUTSywik=
+github.com/joho/godotenv v1.3.0 h1:Zjp+RcGpHhGlrMbJzXTrZZPrWj+1vfm90La1wgB6Bhc=
 github.com/joho/godotenv v1.3.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
@@ -704,6 +707,7 @@ github.com/klauspost/compress v1.11.3 h1:dB4Bn0tN3wdCzQxnS8r06kV74qN/TAfaIS0bVE8
 github.com/klauspost/compress v1.11.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
 github.com/klauspost/cpuid v1.2.3/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
+github.com/klauspost/cpuid v1.2.5/go.mod h1:bYW4mA6ZgKPob1/Dlai2LviZJO7KGI3uoWLd42rAQw4=
 github.com/klauspost/cpuid v1.3.1 h1:5JNjFYYQrZeKRJ0734q51WCEEn2huer72Dc7K+R/b6s=
 github.com/klauspost/cpuid v1.3.1/go.mod h1:bYW4mA6ZgKPob1/Dlai2LviZJO7KGI3uoWLd42rAQw4=
 github.com/klauspost/pgzip v1.2.4/go.mod h1:Ch1tH69qFZu15pkjo5kYi6mth2Zzwzt50oCQKQE9RUs=
@@ -734,6 +738,8 @@ github.com/lib/pq v1.3.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.7.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lib/pq v1.8.1-0.20200908161135-083382b7e6fc h1:ERSU1OvZ6MdWhHieo2oT7xwR/HCksqKdgK6iYPU5pHI=
 github.com/lib/pq v1.8.1-0.20200908161135-083382b7e6fc/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/libdns/libdns v0.1.0 h1:0ctCOrVJsVzj53mop1angHp/pE3hmAhP7KiHvR0HD04=
+github.com/libdns/libdns v0.1.0/go.mod h1:yQCXzk1lEZmmCPa857bnk4TsOiqYasqpyOEeSObbb40=
 github.com/lightstep/lightstep-tracer-common/golang/gogo v0.0.0-20190605223551-bc2310a04743/go.mod h1:qklhhLq1aX+mtWk9cPHPzaBjWImj5ULL6C7HFJtXQMM=
 github.com/lightstep/lightstep-tracer-go v0.18.1/go.mod h1:jlF1pusYV4pidLvZ+XD0UBX0ZE6WURAspgAczcDHrL4=
 github.com/lunny/bluemonday v1.0.5-0.20201227154428-ca34796141e8 h1:1omo92DLtxQu6VwVPSZAmduHaK5zssed6cvkHyl1XOg=
@@ -790,9 +796,13 @@ github.com/mgechev/dots v0.0.0-20190921121421-c36f7dcfbb81 h1:QASJXOGm2RZ5Ardbc8
 github.com/mgechev/dots v0.0.0-20190921121421-c36f7dcfbb81/go.mod h1:KQ7+USdGKfpPjXk4Ga+5XxQM4Lm4e3gAogrreFAYpOg=
 github.com/mgechev/revive v1.0.3-0.20200921231451-246eac737dc7 h1:ydVkpU/M4/c45yT3e5lzMeguKJm9GxGgsawx4/XlwK0=
 github.com/mgechev/revive v1.0.3-0.20200921231451-246eac737dc7/go.mod h1:no/hfevHbndpXR5CaJahkYCfM/FFpmM/dSOwFGU7Z1o=
+github.com/mholt/acmez v0.1.1 h1:KQODCqk+hBn3O7qfCRPj6L96uG65T5BSS95FKNEqtdA=
+github.com/mholt/acmez v0.1.1/go.mod h1:8qnn8QA/Ewx8E3ZSsmscqsIjhhpxuy9vqdgbX2ceceM=
 github.com/mholt/archiver/v3 v3.5.0 h1:nE8gZIrw66cu4osS/U7UW7YDuGMHssxKutU8IfWxwWE=
 github.com/mholt/archiver/v3 v3.5.0/go.mod h1:qqTTPUK/HZPFgFQ/TJ3BzvTpF/dPtFVJXdQbCmeMxwc=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
+github.com/miekg/dns v1.1.30 h1:Qww6FseFn8PRfw07jueqIXqodm0JKiiKuK0DeXSqfyo=
+github.com/miekg/dns v1.1.30/go.mod h1:KNUDUusw/aVsxyTYZM1oqvCicbwhgbNgztCETuNZ7xM=
 github.com/minio/md5-simd v1.1.0 h1:QPfiOqlZH+Cj9teu0t9b1nTBfPbyTl16Of5MeuShdK4=
 github.com/minio/md5-simd v1.1.0/go.mod h1:XpBqgZULrMYD3R+M28PcmP0CkI7PEMzB3U77ZrKZ0Gw=
 github.com/minio/minio-go/v7 v7.0.6 h1:9czXaG0LEZ9s74smSqy0rm034MxngQoP6HTTuSc5GEs=
@@ -1124,12 +1134,19 @@ go.opentelemetry.io/otel v0.14.0/go.mod h1:vH5xEuwy7Rts0GNtsCW3HYQoZDY+OmBJ6t1bF
 go.uber.org/atomic v1.3.2/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.4.0/go.mod h1:gD2HeocX3+yG+ygLZcrzQJaqmWj9AIm7n08wl/qW/PE=
 go.uber.org/atomic v1.5.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
+go.uber.org/atomic v1.6.0 h1:Ezj3JGmsOnG1MoRWQkPBsKLe9DwWD9QeXzTRzzldNVk=
+go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.3.0/go.mod h1:VgVr7evmIr6uPjLBxg28wmKNXyqE9akIJ5XnfpiKl+4=
+go.uber.org/multierr v1.5.0 h1:KCa4XfM8CWFCpxXRGok+Q0SS/0XBhMDbHHGABQLvD2A=
+go.uber.org/multierr v1.5.0/go.mod h1:FeouvMocqHpRaaGuG9EjoKcStLC43Zu/fmqdUMPcKYU=
+go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee h1:0mgffUl7nfd+FpvXMVz4IDEaUSmT1ysygQC7qYo7sG4=
 go.uber.org/tools v0.0.0-20190618225709-2cfd321de3ee/go.mod h1:vJERXedbb3MVM5f9Ejo0C68/HhF8uaILCdgjnY+goOA=
 go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.13.0/go.mod h1:zwrFLgMcdUuIBviXEYEH1YKNaOBnKXsx2IPda5bBwHM=
+go.uber.org/zap v1.15.0 h1:ZZCA22JRF2gQE5FoNmhmrf7jeJJ2uhqDUNRYKm8dvmM=
+go.uber.org/zap v1.15.0/go.mod h1:Mb2vm2krFEG5DV0W9qcHBYFtp/Wku1cvYaqPsS/WYfc=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181029021203-45a5f77698d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -1153,6 +1170,8 @@ golang.org/x/crypto v0.0.0-20200323165209-0ec3e9974c59/go.mod h1:LzIPMQfyMNhhGPh
 golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200709230013-948cd5f35899/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200728195943-123391ffb6de/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a h1:vclmkQCjlDX5OydZ9wv8rBCcS0QyQY66Mpf/7BZbInM=
 golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201217014255-9d1352758620 h1:3wPMTskHO3+O6jqTEXyFcsnuxMQOqYSaHsDxcbUXpqA=
@@ -1178,6 +1197,7 @@ golang.org/x/lint v0.0.0-20190909230951-414d861bb4ac/go.mod h1:6SW0HCj/g11FgYtHl
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/lint v0.0.0-20191125180803-fdd1cda4f05f/go.mod h1:5qLYkcX4OjUUV8bRuDixDT3tpyyb+LUpUlRWLxfhWrs=
 golang.org/x/lint v0.0.0-20200130185559-910be7a94367/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
+golang.org/x/lint v0.0.0-20200302205851-738671d3881b h1:Wh+f8QHJXR411sJR8/vRBTZ7YapZaRvUcLFFJhusH0k=
 golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
 golang.org/x/mobile v0.0.0-20190312151609-d3739f865fa6/go.mod h1:z+o9i4GpDbdi3rU15maQ/Ox0txvL9dWGYEHz965HBQE=
 golang.org/x/mobile v0.0.0-20190719004257-d2bd2a29d028/go.mod h1:E/iHnbuqvinMTCcRqshq8CkpyQDoeVncDDYHnLhea+o=
@@ -1254,6 +1274,7 @@ golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20200625203802-6e8e738ad208/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 h1:SQFwaSi55rU7vdNs9Yr0Z324VNlrF+0wMqRXT4St8ck=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -1286,6 +1307,7 @@ golang.org/x/sys v0.0.0-20190730183949-1393eb018365/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20190813064441-fde4db37ae7a/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190826190057-c7b8b68b1456/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190904154756-749cb33beabd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191001151750-bb3f8db39f24/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191005200804-aed5e4c7ecf9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -1368,6 +1390,7 @@ golang.org/x/tools v0.0.0-20191115202509-3a792d9c32b2/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191125144606-a911d9008d1f/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/tools v0.0.0-20191130070609-6e064ea0cf2d/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20191216052735-49a3e744a425/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/tools v0.0.0-20191216173652-a0e659d51361/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/tools v0.0.0-20191227053925-7b8e75db28f4/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/tools v0.0.0-20200103221440-774c71fcf114/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
@@ -1546,6 +1569,7 @@ honnef.co/go/tools v0.0.0-20190418001031-e561f6794a2a/go.mod h1:rf3lG4BRIbNafJWh
 honnef.co/go/tools v0.0.0-20190523083050-ea95bdfd59fc/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
 honnef.co/go/tools v0.0.1-2019.2.3/go.mod h1:a3bituU0lyd329TUQxRnasdCoJDkEUEAqEt0JzvZhAg=
 honnef.co/go/tools v0.0.1-2020.1.3/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
+honnef.co/go/tools v0.0.1-2020.1.4 h1:UoveltGrhghAA7ePc+e+QYDHXrBps2PqFZiHkGR/xK8=
 honnef.co/go/tools v0.0.1-2020.1.4/go.mod h1:X/FiERA/W4tHapMX5mGpAtMSVEeEUOyHaw9vFzvIQ3k=
 mvdan.cc/xurls/v2 v2.2.0 h1:NSZPykBXJFCetGZykLAxaL6SIpvbVy/UFEniIfHAa8A=
 mvdan.cc/xurls/v2 v2.2.0/go.mod h1:EV1RMtya9D6G5DMYPGD8zTQzaHet6Jh8gFlRgGRJeO8=