add MD5 hashing to generic digest class

Change-Id: If3abc80f8511d9c7bf0d5197ce28ef4cf60a6b45
Reviewed-on: https://gerrit.libreoffice.org/36792Reviewed-by: Markus Mohrhard <markus.mohrhard@googlemail.com>
Tested-by: Markus Mohrhard <markus.mohrhard@googlemail.com>

comphelper/source/misc/hash.cxx

@@ -31,6 +31,8 @@ struct HashImpl
     {
         switch (meType)
         {
+            case HashType::MD5:
+                return HASH_AlgMD5;
             case HashType::SHA1:
                 return HASH_AlgSHA1;
             case HashType::SHA256:
@@ -48,6 +50,8 @@ struct HashImpl
     {
         switch (meType)
         {
+            case HashType::MD5:
+                return EVP_md5();
             case HashType::SHA1:
                 return EVP_sha1();
             case HashType::SHA256:
@@ -121,6 +125,8 @@ size_t Hash::getLength() const
 {
     switch (mpImpl->meType)
     {
+        case HashType::MD5:
+            return 16;
         case HashType::SHA1:
             return 20;
         case HashType::SHA256:

include/comphelper/hash.hxx

@@ -16,6 +16,7 @@ namespace comphelper {
 
 enum class HashType
 {
+    MD5,
     SHA1,
     SHA256,
     SHA512