diff --git a/libs/sign-sdk/src/CIEEngine.c b/libs/sign-sdk/src/CIEEngine.c
index f90140cd..056e2114 100644
--- a/libs/sign-sdk/src/CIEEngine.c
+++ b/libs/sign-sdk/src/CIEEngine.c
@@ -17,7 +17,7 @@
 
 #include "CIEEngineHelper.h"
 
-unsigned char *cie_certificate;
+const unsigned char *cie_certificate;
 unsigned long cie_certlen;
 unsigned char *cie_pin;
 unsigned long cie_pinlen;
@@ -53,8 +53,9 @@ static const ENGINE_CMD_DEFN cie_engine_cmd_defns[] = {
     {0, NULL, NULL, 0}};
 
 // Make Digest Info
-int makeDigestInfo(int algid, unsigned char *pbtDigest, size_t btDigestLen,
-                   unsigned char *pbtDigestInfo, size_t *pbtDigestInfoLen) {
+int makeDigestInfo(int algid, const unsigned char *pbtDigest,
+                   size_t btDigestLen, unsigned char *pbtDigestInfo,
+                   size_t *pbtDigestInfoLen) {
   size_t requestedLen;
   switch (algid) {
     case NID_sha1:
@@ -202,7 +203,7 @@ static int cie_pkey_rsa_sign(EVP_PKEY_CTX *evp_pkey_ctx, unsigned char *sig,
   printf("call cie_pkey_rsa_sign\n");
 
   EVP_PKEY *pkey;
-  RSA *rsa;
+  const RSA *rsa;
   const EVP_MD *sig_md;
 
   printf(
@@ -308,6 +309,8 @@ EC_KEY_METHOD *cie_get_ec_key_method(void) {
   int (*orig_sign)(int, const unsigned char *, int, unsigned char *,
                    unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) =
       NULL;
+  ECDSA_SIG *(*do_sign)(const unsigned char *, int, const BIGNUM *,
+                        const BIGNUM *, EC_KEY *) = NULL;
 
   compute_key_fn ossl_ecdh_compute_key;
 
@@ -315,7 +318,7 @@ EC_KEY_METHOD *cie_get_ec_key_method(void) {
   if (!ops) {
     ops = EC_KEY_METHOD_new((EC_KEY_METHOD *)EC_KEY_OpenSSL());
     EC_KEY_METHOD_get_sign(ops, &orig_sign, NULL, NULL);
-    EC_KEY_METHOD_set_sign(ops, orig_sign, NULL, &orig_sign);
+    EC_KEY_METHOD_set_sign(ops, orig_sign, NULL, do_sign);
     EC_KEY_METHOD_get_compute_key(ops, &ossl_ecdh_compute_key);
     EC_KEY_METHOD_set_compute_key(ops, cie_ecdh_compute_key);