FIX: CHECKSUM/KEY argument doesn't allow binary! keys

Fixes: metaeducation/rebol-issues#1910

Author: Oldes

src/boot/natives.r

@@ -383,7 +383,7 @@ checksum: native [
 	/method {Method to use}
 	word [word!] {Methods: SHA1 SHA256 MD5 CRC32}
 	/key {Returns keyed HMAC value}
-	key-value [any-string!] {Key to use}
+	key-value [any-string! binary!] {Key to use}
 ]
 
 compress: native [

src/core/n-strings.c

@@ -170,7 +170,7 @@ static struct digest {
 **		/method {Method to use}
 **		word [word!] {Method: SHA1 MD5}
 **		/key {Returns keyed HMAC value}
-**		key-value [any-string!] {Key to use}
+**		key-value [any-string! binary!] {Key to use}
 **
 ***********************************************************************/
 {

src/tests/run-tests.r3

@@ -16,6 +16,7 @@ wrap load %units/mezz-crypt-test.r3
 wrap load %units/rsa-test.r3
 wrap load %units/dh-test.r3
 wrap load %units/port-test.r3
+wrap load %units/checksum-test.r3
 
 wrap load %units/crash-test.r3
 

src/tests/units/checksum-test.r3

@@ -0,0 +1,22 @@
+Rebol [
+	Title:   "Rebol checksum test script"
+	Author:  "Olds"
+	File: 	 %checksum-test.red
+	Tabs:	 4
+	Needs:   [%../quick-test-module.r3]
+]
+
+~~~start-file~~~ "Checksum"
+
+===start-group=== "Checksum with binary key (issue #1910)"
+;@@ https://github.com/rebol/rebol-issues/issues/1910
+	--test-- "checksum-1"
+		--assert  #{800A1BC1B53CAA795F4DF39DC57652209239E1F1}
+					 = checksum/key to binary! "Hello world" "mykey"
+		--assert  #{800A1BC1B53CAA795F4DF39DC57652209239E1F1}
+					 = checksum/key to binary! "Hello world" to binary! "mykey"
+
+
+===end-group===
+
+~~~end-file~~~