From 987d11188f3956e56cdf6fb13f83d82cd048a66f Mon Sep 17 00:00:00 2001
From: darmiel <71837281+darmiel@users.noreply.github.com>
Date: Thu, 1 Apr 2021 21:02:06 +0200
Subject: [PATCH] Implemented custom hashes (#7)

---
 cmd/serve.go                       |  2 +-
 internal/common/validators.go      | 40 +++++++++++++++++++-----------
 internal/common/validators_test.go |  8 ++++++
 internal/server/request_get.go     |  2 +-
 internal/server/request_post.go    | 19 +++++++++++++-
 internal/server/server.go          | 10 +++++++-
 6 files changed, 62 insertions(+), 19 deletions(-)

diff --git a/cmd/serve.go b/cmd/serve.go
index 718a542..4fb1141 100644
--- a/cmd/serve.go
+++ b/cmd/serve.go
@@ -108,7 +108,7 @@ func init() {
 	regDurP(serveCmd, "max-ttl", "s", 60*time.Minute, "Max TTL")
 
 	// other
-	regIntP(serveCmd, "max-body-length", "x", 1024, "Max Body Length")
+	regIntP(serveCmd, "max-body-length", "x", 8192, "Max Body Length")
 	regBoolP(serveCmd, "enable-encryption", "e", true, "Enable Encryption")
 	regStr(serveCmd, "proxy-header", "", "Proxy Header")
 }
diff --git a/internal/common/validators.go b/internal/common/validators.go
index 5959ff8..70ec4da 100644
--- a/internal/common/validators.go
+++ b/internal/common/validators.go
@@ -11,28 +11,38 @@ const (
 )
 
 var (
-	APAllowedChars = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789:.-_+*!$%~@")
+	APAllowedChars  = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789:.-_+*!$%~@")
+	HexAllowedChars = []byte("0123456789abcdef")
 )
 
+func ContainsOtherThan(str string, allowed []byte) bool {
+	for _, c := range str {
+		b := byte(c)
+		v := false
+		// check if allowed array contains
+		for _, a := range allowed {
+			if b == a {
+				v = true
+				break
+			}
+		}
+		if !v {
+			return true
+		}
+	}
+	return false
+}
+
 func ValidateAnywherePath(anywhere string) bool {
 	l := len(anywhere)
 	if l < APMinLength || l > APMaxLength {
 		return false
 	}
-	for _, c := range anywhere {
-		b := byte(c)
-		f := false
-		for _, a := range APAllowedChars {
-			if a == b {
-				f = true
-				break
-			}
-		}
-		if !f {
-			return false
-		}
-	}
-	return true
+	return !ContainsOtherThan(anywhere, APAllowedChars)
+}
+
+func ValidateHex(anywhere string) bool {
+	return !ContainsOtherThan(anywhere, HexAllowedChars)
 }
 
 var p *regexp.Regexp
diff --git a/internal/common/validators_test.go b/internal/common/validators_test.go
index a923b68..a65f017 100644
--- a/internal/common/validators_test.go
+++ b/internal/common/validators_test.go
@@ -64,6 +64,14 @@ func TestValidateAnywherePath(t *testing.T) {
 	}
 }
 
+func TestContainsOtherThan(t *testing.T) {
+	AssertFalse(t, ContainsOtherThan("hello", []byte("hello")))
+	AssertTrue(t, ContainsOtherThan("hello!", []byte("hello")))
+	AssertFalse(t, ContainsOtherThan("Hello", []byte("helloH")))
+	AssertTrue(t, ContainsOtherThan("Hello", []byte("hello")))
+	AssertTrue(t, ContainsOtherThan("Hello!", []byte("hello!")))
+}
+
 // AssertEqual checks if values are equal
 func AssertEqual(t *testing.T, a interface{}, b interface{}) {
 	if a == b {
diff --git a/internal/server/request_get.go b/internal/server/request_get.go
index 092c94a..823e8e6 100644
--- a/internal/server/request_get.go
+++ b/internal/server/request_get.go
@@ -47,7 +47,7 @@ func (s *yAxCServer) handleGetHashAnywhere(ctx *fiber.Ctx) (err error) {
 		return
 	}
 
-	log.Warning(ctx.IP(), "requested HASH", path)
+	log.Warning(ctx.IP(), "requested HASH", path, "with result", res)
 
 	if res == "" {
 		ctx.Status(404)
diff --git a/internal/server/request_post.go b/internal/server/request_post.go
index ce3160a..7d562f0 100644
--- a/internal/server/request_post.go
+++ b/internal/server/request_post.go
@@ -13,7 +13,21 @@ var errEncryptionNotEnabled = errors.New("encryption not enabled")
 
 func (s *yAxCServer) handlePostAnywhere(ctx *fiber.Ctx) (err error) {
 	path := strings.TrimSpace(ctx.Params("anywhere"))
+	log.Debug("requested path", path)
+	return s.setAnywhereWithHash(ctx, path, "")
+}
 
+func (s *yAxCServer) handlePostAnywhereWithHash(ctx *fiber.Ctx) (err error) {
+	path := strings.TrimSpace(ctx.Params("anywhere"))
+	hash := strings.TrimSpace(ctx.Params("hash"))
+	// validate hash
+	if !common.ValidateHex(hash) {
+		return ctx.Status(400).SendString("ERROR: Invalid hash")
+	}
+	return s.setAnywhereWithHash(ctx, path, hash)
+}
+
+func (s *yAxCServer) setAnywhereWithHash(ctx *fiber.Ctx, path, hash string) (err error) {
 	// validate path
 	if !common.ValidateAnywherePath(path) {
 		return ctx.Status(400).SendString("ERROR: Invalid path")
@@ -52,7 +66,10 @@ func (s *yAxCServer) handlePostAnywhere(ctx *fiber.Ctx) (err error) {
 		return ctx.Status(400).SendString("ERROR: TTL out of range")
 	}
 
-	hash := common.MD5Hash(content)
+	// generate hash
+	if hash == "" {
+		hash = common.MD5Hash(content)
+	}
 
 	// Set contents
 	errVal := s.Backend.Set(path, content, ttl)
diff --git a/internal/server/server.go b/internal/server/server.go
index f131238..bce038d 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -39,10 +39,18 @@ func (s *yAxCServer) Start() {
 		return ctx.SendString(body)
 	})
 
+	// GET contents
 	s.App.Get("/:anywhere", s.handleGetAnywhere)
-	s.App.Post("/:anywhere", s.handlePostAnywhere)
+
+	// GET hash
 	s.App.Get("/hash/:anywhere", s.handleGetHashAnywhere)
 
+	// SET contents, auto hash
+	s.App.Post("/:anywhere", s.handlePostAnywhere)
+
+	// SET contents, custom hash
+	s.App.Post("/:anywhere/:hash", s.handlePostAnywhereWithHash)
+
 	if err := s.App.Listen(s.BindAddress); err != nil {
 		log.Critical(err)
 	}