openssl: Use proper EVP macro to determine size of a hash

src/libstrongswan/plugins/openssl/openssl_hasher.c

@@ -43,7 +43,7 @@ struct private_openssl_hasher_t {
 METHOD(hasher_t, get_hash_size, size_t,
 	private_openssl_hasher_t *this)
 {
-	return this->hasher->md_size;
+	return EVP_MD_size(this->hasher);
 }
 
 METHOD(hasher_t, reset, bool,

src/libstrongswan/plugins/openssl/openssl_util.c

@@ -51,7 +51,7 @@ bool openssl_hash_chunk(int hash_type, chunk_t data, chunk_t *hash)
 		goto error;
 	}
 
-	*hash = chunk_alloc(hasher->md_size);
+	*hash = chunk_alloc(EVP_MD_size(hasher));
 	if (!EVP_DigestFinal_ex(ctx, hash->ptr, NULL))
 	{
 		chunk_free(hash);