diff --git a/src/utils/capi.c b/src/utils/capi.c
index 4bf63ba..83f8356 100644
--- a/src/utils/capi.c
+++ b/src/utils/capi.c
@@ -24,7 +24,6 @@ capi_function_list_init(library_t *lib, capi_function_list_t *fl)
     LIBRARY_RESOLVE(fl->CryptDestroyHash, lib, "CryptDestroyHash");
     LIBRARY_RESOLVE(fl->CryptHashData, lib, "CryptHashData");
     LIBRARY_RESOLVE(fl->CryptReleaseContext, lib, "CryptReleaseContext");
-    LIBRARY_RESOLVE(fl->CryptSignMessage, lib, "CryptSignMessage");
     LIBRARY_RESOLVE(fl->GetLastError, lib, "GetLastError");
     LIBRARY_RESOLVE(fl->CryptImportPublicKeyInfo, lib, "CryptImportPublicKeyInfo");
     LIBRARY_RESOLVE(fl->CryptDestroyKey, lib, "CryptDestroyKey");
diff --git a/src/utils/capi.h b/src/utils/capi.h
index f19b875..4ea512b 100644
--- a/src/utils/capi.h
+++ b/src/utils/capi.h
@@ -15,16 +15,6 @@ typedef struct library_s library_t;
 
 DECLARE_FN(WINBASEAPI, DWORD, GET_LAST_ERROR, (void));
 DECLARE_FN(WINADVAPI, BOOL, CRYPT_RELEASE_CONTEXT, (HCRYPTPROV hProv, DWORD dwFlags));
-DECLARE_FN(WINCRYPT32API,
-           BOOL,
-           CRYPT_SIGN_MESSAGE,
-           (IN PCRYPT_SIGN_MESSAGE_PARA pSignPara,
-            IN BOOL fDetachedSignature,
-            IN DWORD cToBeSigned,
-            IN const BYTE *rgpbToBeSigned[],
-            IN DWORD rgcbToBeSigned[],
-            OUT BYTE *pbSignedBlob,
-            IN OUT DWORD *pcbSignedBlob));
 
 DECLARE_FN(WINCRYPT32API,
            BOOL,
@@ -227,7 +217,6 @@ DECLARE_FN(WINADVAPI,
 
 
 typedef struct {
-    CRYPT_SIGN_MESSAGE_FN CryptSignMessage;
     CERT_FREE_CERTIFICATE_CONTEXT_FN CertFreeCertificateContext;
     CERT_OPEN_STORE_FN CertOpenStore;
     CERT_CLOSE_STORE_FN CertCloseStore;
diff --git a/src/utils/cryptopro.c b/src/utils/cryptopro.c
index 10422f2..f059553 100644
--- a/src/utils/cryptopro.c
+++ b/src/utils/cryptopro.c
@@ -376,11 +376,17 @@ sign_hash_data(const cryptopro_context_t *ctx, const str_t *data, /*out*/ str_t
 
 exit:
     if (hash) {
-        cp_function_list.CryptDestroyHash(hash);
+        if (!cp_function_list.CryptDestroyHash(hash)) {
+            LOG_ERROR("CryptDestroyHash() failed");
+            rc = -1;
+        }
     }
 
     if (bReleaseContext) {
-        cp_function_list.CryptReleaseContext(hCryptProv, 0);
+        if (!cp_function_list.CryptReleaseContext(hCryptProv, 0)) {
+            LOG_ERROR("CryptReleaseContext() failed");
+            rc = -1;
+        }
     }
 
 
@@ -763,15 +769,24 @@ exit:
     str_t_clear(&sign_reversed);
 
     if (hash) {
-        cp_function_list.CryptDestroyHash(hash);
+        if (!cp_function_list.CryptDestroyHash(hash)) {
+            LOG_ERROR("CryptDestroyHash() failed");
+            rc = -1;
+        }
     }
 
     if (hPubKey) {
-        cp_function_list.CryptDestroyKey(hPubKey);
+        if (!cp_function_list.CryptDestroyKey(hPubKey)) {
+            LOG_ERROR("CryptDestroyKey() failed");
+            rc = -1;
+        }
     }
 
     if (hCryptProv) {
-        cp_function_list.CryptReleaseContext(hCryptProv, 0);
+        if (!cp_function_list.CryptReleaseContext(hCryptProv, 0)) {
+            LOG_ERROR("CryptReleaseContext() failed");
+            rc = -1;
+        }
     }
 
     if (certificate) {
@@ -796,7 +811,7 @@ exit:
 int 
 cryptopro_gen_random(unsigned char* data, size_t len)
 {
-    HCRYPTPROV   hCryptProv = 0;
+    HCRYPTPROV hCryptProv = 0;
 
     LOG_TRACE("cryptopro_gen_random enter");
 
@@ -811,14 +826,20 @@ cryptopro_gen_random(unsigned char* data, size_t len)
         goto error;
     }
 
-    cp_function_list.CryptReleaseContext(hCryptProv, 0);
+    if (!cp_function_list.CryptReleaseContext(hCryptProv, 0)) {
+        LOG_ERROR("CryptReleaseContext() failed");
+        hCryptProv = 0;
+        goto error;
+    }
 
     LOG_TRACE("cryptopro_gen_random exit");
     return 0;
 
 error:
     if (hCryptProv) {
-        cp_function_list.CryptReleaseContext(hCryptProv, 0);
+        if (!cp_function_list.CryptReleaseContext(hCryptProv, 0)) {
+            LOG_ERROR("CryptReleaseContext() failed");
+        }
     }
 
     LOG_ERROR("cryptopro_gen_random exit with error. Last error code: 0x%08x",