http, crypto/tls: followup fixes from 1684051.

(TBR because this is just addressing previous review comments.)

R=r
CC=golang-dev
https://golang.org/cl/1697048

generate_cert.go

@@ -11,30 +11,26 @@ import (
 	"crypto/rsa"
 	"crypto/x509"
 	"encoding/pem"
-	"fmt"
+	"flag"
 	"log"
 	"os"
 	"time"
 )
 
-func main() {
-	if len(os.Args) != 2 {
-		fmt.Printf("Usage: %s <hostname of server>\n", os.Args[0])
-		return
-	}
+var hostName *string = flag.String("host", "127.0.0.1", "Hostname to generate a certificate for")
 
-	hostName := os.Args[1]
+func main() {
+	flag.Parse()
 
 	urandom, err := os.Open("/dev/urandom", os.O_RDONLY, 0)
 	if err != nil {
-		log.Crashf("failed to open /dev/urandom: %s\n", err)
+		log.Exitf("failed to open /dev/urandom: %s", err)
 		return
 	}
 
-	log.Stdoutf("Generating RSA key\n")
 	priv, err := rsa.GenerateKey(urandom, 1024)
 	if err != nil {
-		log.Crashf("failed to generate private key: %s\n", err)
+		log.Exitf("failed to generate private key: %s", err)
 		return
 	}
 
@@ -43,11 +39,11 @@ func main() {
 	template := x509.Certificate{
 		SerialNumber: []byte{0},
 		Subject: x509.Name{
-			CommonName:   hostName,
+			CommonName:   *hostName,
 			Organization: "Acme Co",
 		},
 		NotBefore: time.SecondsToUTC(now - 300),
-		NotAfter:  time.SecondsToUTC(now + 86400*365), // valid for 1 year.
+		NotAfter:  time.SecondsToUTC(now + 60*60*24*365), // valid for 1 year.
 
 		SubjectKeyId: []byte{1, 2, 3, 4},
 		KeyUsage:     x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
@@ -55,13 +51,13 @@ func main() {
 
 	derBytes, err := x509.CreateCertificate(urandom, &template, &template, &priv.PublicKey, priv)
 	if err != nil {
-		log.Crashf("Failed to create certificate: %s", err)
+		log.Exitf("Failed to create certificate: %s", err)
 		return
 	}
 
 	certOut, err := os.Open("cert.pem", os.O_WRONLY|os.O_CREAT, 0644)
 	if err != nil {
-		log.Crashf("failed to open cert.pem for writing: %s\n", err)
+		log.Exitf("failed to open cert.pem for writing: %s", err)
 		return
 	}
 	pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
@@ -70,7 +66,7 @@ func main() {
 
 	keyOut, err := os.Open("key.pem", os.O_WRONLY|os.O_CREAT, 0600)
 	if err != nil {
-		log.Crashf("failed to open key.pem for writing: %s\n", err)
+		log.Exitf("failed to open key.pem for writing: %s", err)
 		return
 	}
 	pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})

tls.go

@@ -79,7 +79,7 @@ func LoadX509KeyPair(certFile string, keyFile string) (cert Certificate, err os.
 
 	certDERBlock, _ := pem.Decode(certPEMBlock)
 	if certDERBlock == nil {
-		err = os.ErrorString("failed to parse certificate PEM data")
+		err = os.ErrorString("crypto/tls: failed to parse certificate PEM data")
 		return
 	}
 
@@ -92,13 +92,13 @@ func LoadX509KeyPair(certFile string, keyFile string) (cert Certificate, err os.
 
 	keyDERBlock, _ := pem.Decode(keyPEMBlock)
 	if keyDERBlock == nil {
-		err = os.ErrorString("failed to parse key PEM data")
+		err = os.ErrorString("crypto/tls: failed to parse key PEM data")
 		return
 	}
 
 	key, err := x509.ParsePKCS1PrivateKey(keyDERBlock.Bytes)
 	if err != nil {
-		err = os.ErrorString("failed to parse key")
+		err = os.ErrorString("crypto/tls: failed to parse key")
 		return
 	}
 
@@ -112,7 +112,7 @@ func LoadX509KeyPair(certFile string, keyFile string) (cert Certificate, err os.
 	}
 
 	if x509Cert.PublicKeyAlgorithm != x509.RSA || x509Cert.PublicKey.(*rsa.PublicKey).N.Cmp(key.PublicKey.N) != 0 {
-		err = os.ErrorString("Private key does not match public key")
+		err = os.ErrorString("crypto/tls: private key does not match public key")
 		return
 	}