C++: Make the encryption words a tiny bit more flexible.

Author: geoffw0

cpp/ql/src/experimental/Security/CWE/CWE-1240/CustomCryptographicPrimitive.ql

@@ -29,7 +29,7 @@ string encryptionWord() {
         "Camellia",
         //"(?<!Bit|Type)Cast",
         "Chacha", "ChaCha", "Poly[0-9]", "Ripemd", "Whirlpool", "Sbox", "SBox", "Cblock", "CBlock",
-        "Sub.?Byte", "Mix.?Column", "ECDH", "ECDSA", "EdDSA", "ECMQV", "ECQV", "Curve[0-9][0-9]"
+        "Sub.?Bytes?", "Mix.?Columns?", "ECDH", "ECDSA", "EdDSA", "ECMQV", "ECQV", "Curve[0-9][0-9]"
       ] and
     (
       result = word or

cpp/ql/test/experimental/query-tests/Security/CWE/CWE-1240/CustomCryptographicPrimitive.expected

@@ -1,3 +1,4 @@
 | tests_crypto.cpp:11:6:11:18 | encryptString | This function, "encryptString", may be a custom implementation of a cryptographic primitive. |
 | tests_crypto.cpp:30:6:30:14 | MyEncrypt | This function, "MyEncrypt", may be a custom implementation of a cryptographic primitive. |
+| tests_crypto.cpp:51:6:51:16 | mix_columns | This function, "mix_columns", may be a custom implementation of a cryptographic primitive. |
 | tests_crypto.cpp:83:6:83:18 | init_aes_sbox | This function, "init_aes_sbox", may be a custom implementation of a cryptographic primitive. |