Config: Add PHOTOPRISM_HTTP_CORS option for CDN users #3931 #3940

In addition, the Access-Control-Allow-Origin header is set to the same
URL if an Origin header is found in the request (experimental).

Signed-off-by: Michael Mayer <michael@photoprism.app>

internal/config/config_server.go

@@ -83,6 +83,21 @@ func (c *Config) HttpCompression() string {
 	return strings.ToLower(strings.TrimSpace(c.options.HttpCompression))
 }
 
+// HttpCORS checks of Cross-Origin Resource Sharing (CORS) should be allowed,
+// so the "Access-Control-Allow-Origin" response header should be set to "*".
+func (c *Config) HttpCORS() bool {
+	return c.options.HttpCORS
+}
+
+// HttpCachePublic checks whether static content may be cached by a CDN or caching proxy.
+func (c *Config) HttpCachePublic() bool {
+	if c.options.HttpCachePublic {
+		return true
+	}
+
+	return c.options.CdnUrl != ""
+}
+
 // HttpCacheMaxAge returns the time in seconds until cached content expires.
 func (c *Config) HttpCacheMaxAge() ttl.Duration {
 	// Return default cache maxage?
@@ -109,15 +124,6 @@ func (c *Config) HttpVideoMaxAge() ttl.Duration {
 	return ttl.Duration(c.options.HttpVideoMaxAge)
 }
 
-// HttpCachePublic checks whether static content may be cached by a CDN or caching proxy.
-func (c *Config) HttpCachePublic() bool {
-	if c.options.HttpCachePublic {
-		return true
-	}
-
-	return c.options.CdnUrl != ""
-}
-
 // HttpHost returns the built-in HTTP server host name or IP address (empty for all interfaces).
 func (c *Config) HttpHost() string {
 	// when unix socket used as host, make host as default value. or http client will act weirdly.

internal/config/config_server_test.go

@@ -62,6 +62,36 @@ func TestConfig_HttpCompression(t *testing.T) {
 	assert.Equal(t, "", c.HttpCompression())
 }
 
+func TestConfig_HttpCORS(t *testing.T) {
+	c := NewConfig(CliTestContext())
+
+	c.Options().CdnUrl = ""
+	c.Options().HttpCORS = false
+	assert.False(t, c.HttpCORS())
+	c.Options().CdnUrl = "https://cdn.com/"
+	assert.False(t, c.HttpCORS())
+	c.Options().CdnUrl = ""
+	assert.False(t, c.HttpCORS())
+	c.Options().HttpCORS = true
+	assert.True(t, c.HttpCORS())
+	c.Options().HttpCORS = false
+	assert.False(t, c.HttpCORS())
+}
+
+func TestConfig_HttpCachePublic(t *testing.T) {
+	c := NewConfig(CliTestContext())
+
+	assert.False(t, c.HttpCachePublic())
+	c.Options().CdnUrl = "https://cdn.com/"
+	assert.True(t, c.HttpCachePublic())
+	c.Options().CdnUrl = ""
+	assert.False(t, c.HttpCachePublic())
+	c.Options().HttpCachePublic = true
+	assert.True(t, c.HttpCachePublic())
+	c.Options().HttpCachePublic = false
+	assert.False(t, c.HttpCachePublic())
+}
+
 func TestConfig_HttpCacheMaxAge(t *testing.T) {
 	c := NewConfig(CliTestContext())
 
@@ -85,17 +115,3 @@ func TestConfig_HttpVideoMaxAge(t *testing.T) {
 	c.Options().HttpVideoMaxAge = 0
 	assert.Equal(t, ttl.CacheVideo, c.HttpVideoMaxAge())
 }
-
-func TestConfig_HttpCachePublic(t *testing.T) {
-	c := NewConfig(CliTestContext())
-
-	assert.False(t, c.HttpCachePublic())
-	c.Options().CdnUrl = "https://cdn.com/"
-	assert.True(t, c.HttpCachePublic())
-	c.Options().CdnUrl = ""
-	assert.False(t, c.HttpCachePublic())
-	c.Options().HttpCachePublic = true
-	assert.True(t, c.HttpCachePublic())
-	c.Options().HttpCachePublic = false
-	assert.False(t, c.HttpCachePublic())
-}

internal/config/flags.go

@@ -491,6 +491,11 @@ var Flags = CliFlags{
 			Usage:  "Web server compression `METHOD` (gzip, none)",
 			EnvVar: EnvVar("HTTP_COMPRESSION"),
 		}}, {
+		Flag: cli.BoolFlag{
+			Name:   "http-cors",
+			Usage:  "allow Cross-Origin Resource Sharing (CORS)",
+			EnvVar: EnvVar("HTTP_CORS"),
+		}}, {
 		Flag: cli.BoolFlag{
 			Name:   "http-cache-public",
 			Usage:  "allow static content to be cached by a CDN or caching proxy",

internal/config/options.go

@@ -113,6 +113,7 @@ type Options struct {
 	TLSKey                string        `yaml:"TLSKey" json:"TLSKey" flag:"tls-key"`
 	HttpMode              string        `yaml:"HttpMode" json:"-" flag:"http-mode"`
 	HttpCompression       string        `yaml:"HttpCompression" json:"-" flag:"http-compression"`
+	HttpCORS              bool          `yaml:"HttpCORS" json:"-" flag:"http-cors"`
 	HttpCachePublic       bool          `yaml:"HttpCachePublic" json:"HttpCachePublic" flag:"http-cache-public"`
 	HttpCacheMaxAge       int           `yaml:"HttpCacheMaxAge" json:"HttpCacheMaxAge" flag:"http-cache-maxage"`
 	HttpVideoMaxAge       int           `yaml:"HttpVideoMaxAge" json:"HttpVideoMaxAge" flag:"http-video-maxage"`

internal/config/report.go

@@ -160,6 +160,7 @@ func (c *Config) Report() (rows [][]string, cols []string) {
 		{"tls-key", c.TLSKey()},
 		{"http-mode", c.HttpMode()},
 		{"http-compression", c.HttpCompression()},
+		{"http-cors", fmt.Sprintf("%t", c.HttpCORS())},
 		{"http-cache-public", fmt.Sprintf("%t", c.HttpCachePublic())},
 		{"http-cache-maxage", fmt.Sprintf("%d", c.HttpCacheMaxAge())},
 		{"http-video-maxage", fmt.Sprintf("%d", c.HttpVideoMaxAge())},

internal/server/security.go

@@ -4,13 +4,30 @@ import (
 	"github.com/gin-gonic/gin"
 
 	"github.com/photoprism/photoprism/internal/config"
+	"github.com/photoprism/photoprism/pkg/clean"
 	"github.com/photoprism/photoprism/pkg/header"
 )
 
 // Security adds common HTTP security headers to the response.
 var Security = func(conf *config.Config) gin.HandlerFunc {
 	return func(c *gin.Context) {
-		c.Writer.Header().Set(header.ContentSecurityPolicy, header.DefaultContentSecurityPolicy)
-		c.Writer.Header().Set(header.FrameOptions, header.DefaultFrameOptions)
+		// Allow Cross-Origin Resource Sharing (CORS)?
+		// See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin#cors_and_caching
+		if conf.HttpCORS() {
+			c.Header(header.AccessControlAllowOrigin, header.Any)
+		} else if origin := c.GetHeader(header.Origin); origin != "" {
+			// Automatically set the "Access-Control-Allow-Origin" response header
+			// based on the "Origin" value of the request.
+			c.Header(header.AccessControlAllowOrigin, clean.Header(origin))
+			c.Header(header.Vary, header.Origin)
+		}
+
+		// Set Content Security Policy.
+		// See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
+		c.Header(header.ContentSecurityPolicy, header.DefaultContentSecurityPolicy)
+
+		// Set Frame Options.
+		// See: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Frame-Options
+		c.Header(header.FrameOptions, header.DefaultFrameOptions)
 	}
 }

pkg/clean/ascii.go

@@ -2,6 +2,10 @@ package clean
 
 // ASCII removes all non-ascii characters from a string and returns it.
 func ASCII(s string) string {
+	if s == "" {
+		return ""
+	}
+
 	result := make([]rune, 0, len(s))
 
 	for _, r := range s {

pkg/clean/ascii_test.go

@@ -0,0 +1,34 @@
+package clean
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestASCII(t *testing.T) {
+	t.Run("URL", func(t *testing.T) {
+		result := ASCII("https://docs.photoprism.app/getting-started/config-options/#file-converters")
+		assert.Equal(t, "https://docs.photoprism.app/getting-started/config-options/#file-converters", result)
+	})
+	t.Run("Emoji", func(t *testing.T) {
+		result := ASCII("Hello 👍")
+		assert.Equal(t, "Hello ", result)
+	})
+	t.Run("EmojiURL", func(t *testing.T) {
+		result := ASCII("https://docs.photoprism.app/getting-started 👍/config-options/#file-converters")
+		assert.Equal(t, "https://docs.photoprism.app/getting-started /config-options/#file-converters", result)
+	})
+}
+
+func BenchmarkASCII(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		ASCII("https://docs.photoprism.app/getting-started 👍/config-options/#file-converters")
+	}
+}
+
+func BenchmarkASCIIEmpty(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		ASCII("")
+	}
+}

pkg/clean/header.go

@@ -0,0 +1,18 @@
+package clean
+
+// Header sanitizes a string for use in request or response headers.
+func Header(s string) string {
+	if s == "" || len(s) > MaxLength {
+		return ""
+	}
+
+	result := make([]rune, 0, len(s))
+
+	for _, r := range s {
+		if r > 32 && r < 127 {
+			result = append(result, r)
+		}
+	}
+
+	return string(result)
+}

pkg/clean/header_test.go

@@ -0,0 +1,35 @@
+package clean
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHeader(t *testing.T) {
+	t.Run("Ok", func(t *testing.T) {
+		expected := "https://docs.photoprism.app/getting-started/config-options/#file-converters"
+		result := Header(expected)
+		assert.Equal(t, expected, result)
+	})
+	t.Run("Tabs", func(t *testing.T) {
+		result := Header("https://..docs.photoprism.app/gettin\\g-started/config-options/\tfile-converters")
+		assert.Equal(t, "https://..docs.photoprism.app/gettin\\g-started/config-options/file-converters", result)
+	})
+	t.Run("Emoji", func(t *testing.T) {
+		result := Header("Hello 👍")
+		assert.Equal(t, "Hello", result)
+	})
+}
+
+func BenchmarkHeader(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		Header("https://..docs.photoprism.app/gettin\\g-started/config-options/\tfile-converters")
+	}
+}
+
+func BenchmarkHeaderEmpty(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		Header("")
+	}
+}

pkg/clean/uri.go

@@ -7,7 +7,9 @@ import (
 
 // Uri removes invalid character from an uri string.
 func Uri(s string) string {
-	if s == "" || reject(s, 512) || strings.Contains(s, "..") {
+	if s == "" || len(s) > MaxLength {
+		return ""
+	} else if strings.Contains(s, "..") {
 		return ""
 	}
 

pkg/clean/uri_test.go

@@ -15,4 +15,20 @@ func TestUri(t *testing.T) {
 		result := Uri("https://..docs.photoprism.app/gettin\\g-started/config-options/\tfile-converters")
 		assert.Equal(t, "", result)
 	})
+	t.Run("Emoji", func(t *testing.T) {
+		result := Uri("Hello 👍")
+		assert.Equal(t, "Hello%20%F0%9F%91%8D", result)
+	})
+}
+
+func BenchmarkUri(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		Uri("https://docs.photoprism.app/getting-started/config-options/#file-converters")
+	}
+}
+
+func BenchmarkUriEmpty(b *testing.B) {
+	for n := 0; n < b.N; n++ {
+		Uri("")
+	}
 }

pkg/header/auth.go

@@ -12,11 +12,11 @@ import (
 )
 
 const (
-	XAuthToken = "X-Auth-Token"
-	XSessionID = "X-Session-ID"
 	Auth       = "Authorization" // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Authorization
 	AuthBasic  = "Basic"
 	AuthBearer = "Bearer"
+	XAuthToken = "X-Auth-Token"
+	XSessionID = "X-Session-ID"
 )
 
 // AuthToken returns the client authentication token from the request context,

pkg/header/cors.go

@@ -0,0 +1,8 @@
+package header
+
+const (
+	AccessControlAllowOrigin      = "Access-Control-Allow-Origin"      // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
+	AccessControlAllowCredentials = "Access-Control-Allow-Credentials" // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Credentials
+	AccessControlAllowHeaders     = "Access-Control-Allow-Headers"     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers
+	AccessControlAllowMethods     = "Access-Control-Allow-Methods"     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Methods
+)

pkg/header/default.go

@@ -2,5 +2,5 @@ package header
 
 var (
 	DefaultContentSecurityPolicy = "frame-ancestors 'none';"
-	DefaultFrameOptions          = "DENY"
+	DefaultFrameOptions          = Deny
 )

pkg/header/security.go

@@ -1,9 +1,8 @@
 package header
 
 const (
-	AccessControlAllowOrigin = "Access-Control-Allow-Origin" // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Origin
-	ContentSecurityPolicy    = "Content-Security-Policy"     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
 	StrictTransportSecurity = "Strict-Transport-Security"  // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security
+	ContentSecurityPolicy   = "Content-Security-Policy"    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
 	CrossOriginOpenerPolicy = "Cross-Origin-Opener-Policy" // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Opener-Policy
 	ReferrerPolicy          = "Referrer-Policy"            // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy
 	ContentTypeOptions      = "X-Content-Type-Options"     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options

pkg/header/values.go

@@ -0,0 +1,6 @@
+package header
+
+const (
+	Any  = "*"
+	Deny = "DENY"
+)

pkg/header/vary.go

@@ -0,0 +1,6 @@
+package header
+
+const (
+	Vary   = "Vary"
+	Origin = "Origin"
+)