[18.09 backport] Mask proxy credentials from URL when displayed in system info

api/swagger.yaml

@@ -3747,18 +3747,22 @@ definitions:
         description: |
           HTTP-proxy configured for the daemon. This value is obtained from the
           [`HTTP_PROXY`](https://www.gnu.org/software/wget/manual/html_node/Proxies.html) environment variable.
+          Credentials ([user info component](https://tools.ietf.org/html/rfc3986#section-3.2.1)) in the proxy URL
+          are masked in the API response.
 
           Containers do not automatically inherit this configuration.
         type: "string"
-        example: "http://user:pass@proxy.corp.example.com:8080"
+        example: "http://xxxxx:xxxxx@proxy.corp.example.com:8080"
       HttpsProxy:
         description: |
           HTTPS-proxy configured for the daemon. This value is obtained from the
           [`HTTPS_PROXY`](https://www.gnu.org/software/wget/manual/html_node/Proxies.html) environment variable.
+          Credentials ([user info component](https://tools.ietf.org/html/rfc3986#section-3.2.1)) in the proxy URL
+          are masked in the API response.
 
           Containers do not automatically inherit this configuration.
         type: "string"
-        example: "https://user:pass@proxy.corp.example.com:4443"
+        example: "https://xxxxx:xxxxx@proxy.corp.example.com:4443"
       NoProxy:
         description: |
           Comma-separated list of domain extensions for which no proxy should be

daemon/info.go

@@ -2,6 +2,7 @@ package daemon // import "github.com/docker/docker/daemon"
 
 import (
 	"fmt"
+	"net/url"
 	"os"
 	"runtime"
 	"strings"
@@ -61,8 +62,8 @@ func (daemon *Daemon) SystemInfo() (*types.Info, error) {
 		ServerVersion:      dockerversion.Version,
 		ClusterStore:       daemon.configStore.ClusterStore,
 		ClusterAdvertise:   daemon.configStore.ClusterAdvertise,
-		HTTPProxy:          sockets.GetProxyEnv("http_proxy"),
-		HTTPSProxy:         sockets.GetProxyEnv("https_proxy"),
+		HTTPProxy:          maskCredentials(sockets.GetProxyEnv("http_proxy")),
+		HTTPSProxy:         maskCredentials(sockets.GetProxyEnv("https_proxy")),
 		NoProxy:            sockets.GetProxyEnv("no_proxy"),
 		LiveRestoreEnabled: daemon.configStore.LiveRestoreEnabled,
 		Isolation:          daemon.defaultIsolation,
@@ -245,3 +246,13 @@ func operatingSystem() string {
 	}
 	return operatingSystem
 }
+
+func maskCredentials(rawURL string) string {
+	parsedURL, err := url.Parse(rawURL)
+	if err != nil || parsedURL.User == nil {
+		return rawURL
+	}
+	parsedURL.User = url.UserPassword("xxxxx", "xxxxx")
+	maskedURL := parsedURL.String()
+	return maskedURL
+}

daemon/info_test.go

@@ -0,0 +1,53 @@
+package daemon
+
+import (
+	"testing"
+
+	"gotest.tools/assert"
+)
+
+func TestMaskURLCredentials(t *testing.T) {
+	tests := []struct {
+		rawURL    string
+		maskedURL string
+	}{
+		{
+			rawURL:    "",
+			maskedURL: "",
+		}, {
+			rawURL:    "invalidURL",
+			maskedURL: "invalidURL",
+		}, {
+			rawURL:    "http://proxy.example.com:80/",
+			maskedURL: "http://proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER:PASSWORD@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://PASSWORD:PASSWORD@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER:@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://:PASSWORD@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER@docker:password@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER%40docker:password@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER%40docker:pa%3Fsword@proxy.example.com:80/",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/",
+		}, {
+			rawURL:    "http://USER%40docker:pa%3Fsword@proxy.example.com:80/hello%20world",
+			maskedURL: "http://xxxxx:xxxxx@proxy.example.com:80/hello%20world",
+		},
+	}
+	for _, test := range tests {
+		maskedURL := maskCredentials(test.rawURL)
+		assert.Equal(t, maskedURL, test.maskedURL)
+	}
+}