diff --git a/dlls/advapi32/crypt.c b/dlls/advapi32/crypt.c
index 27ca768383c..bd1a9c767eb 100644
--- a/dlls/advapi32/crypt.c
+++ b/dlls/advapi32/crypt.c
@@ -1741,7 +1741,7 @@ BOOL WINAPI CryptHashSessionKey (HCRYPTHASH hHash, HCRYPTKEY hKey, DWORD dwFlags
  *  Success: TRUE
  *  Failure: FALSE
  */
-BOOL WINAPI CryptImportKey (HCRYPTPROV hProv, BYTE *pbData, DWORD dwDataLen,
+BOOL WINAPI CryptImportKey (HCRYPTPROV hProv, CONST BYTE *pbData, DWORD dwDataLen,
 		HCRYPTKEY hPubKey, DWORD dwFlags, HCRYPTKEY *phKey)
 {
 	PCRYPTPROV prov = (PCRYPTPROV)hProv;
@@ -1856,7 +1856,7 @@ BOOL WINAPI CryptSignHashA (HCRYPTHASH hHash, DWORD dwKeySpec, LPCSTR sDescripti
  *  Success: TRUE
  *  Failure: FALSE
  */
-BOOL WINAPI CryptSetHashParam (HCRYPTHASH hHash, DWORD dwParam, BYTE *pbData, DWORD dwFlags)
+BOOL WINAPI CryptSetHashParam (HCRYPTHASH hHash, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags)
 {
 	PCRYPTPROV prov;
 	PCRYPTHASH hash = (PCRYPTHASH)hHash;
@@ -1889,7 +1889,7 @@ BOOL WINAPI CryptSetHashParam (HCRYPTHASH hHash, DWORD dwParam, BYTE *pbData, DW
  *  Success: TRUE
  *  Failure: FALSE
  */
-BOOL WINAPI CryptSetKeyParam (HCRYPTKEY hKey, DWORD dwParam, BYTE *pbData, DWORD dwFlags)
+BOOL WINAPI CryptSetKeyParam (HCRYPTKEY hKey, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags)
 {
 	PCRYPTPROV prov;
 	PCRYPTKEY key = (PCRYPTKEY)hKey;
@@ -2063,7 +2063,7 @@ BOOL WINAPI CryptSetProviderExA (LPCSTR pszProvName, DWORD dwProvType, DWORD *pd
  *  Success: TRUE
  *  Failure: FALSE
  */
-BOOL WINAPI CryptSetProvParam (HCRYPTPROV hProv, DWORD dwParam, BYTE *pbData, DWORD dwFlags)
+BOOL WINAPI CryptSetProvParam (HCRYPTPROV hProv, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags)
 {
 	PCRYPTPROV prov = (PCRYPTPROV)hProv;
 
@@ -2122,7 +2122,7 @@ BOOL WINAPI CryptSetProvParam (HCRYPTPROV hProv, DWORD dwParam, BYTE *pbData, DW
  *  NULL. It is supported only for compatibility with Microsoft's Cryptographic
  *  Providers.
  */
-BOOL WINAPI CryptVerifySignatureW (HCRYPTHASH hHash, BYTE *pbSignature, DWORD dwSigLen,
+BOOL WINAPI CryptVerifySignatureW (HCRYPTHASH hHash, CONST BYTE *pbSignature, DWORD dwSigLen,
 		HCRYPTKEY hPubKey, LPCWSTR sDescription, DWORD dwFlags)
 {
 	PCRYPTHASH hash = (PCRYPTHASH)hHash;
@@ -2155,7 +2155,7 @@ BOOL WINAPI CryptVerifySignatureW (HCRYPTHASH hHash, BYTE *pbSignature, DWORD dw
  *
  * See CryptVerifySignatureW.
  */
-BOOL WINAPI CryptVerifySignatureA (HCRYPTHASH hHash, BYTE *pbSignature, DWORD dwSigLen,
+BOOL WINAPI CryptVerifySignatureA (HCRYPTHASH hHash, CONST BYTE *pbSignature, DWORD dwSigLen,
 		HCRYPTKEY hPubKey, LPCSTR sDescription, DWORD dwFlags)
 {
 	LPWSTR wsDescription;
diff --git a/dlls/advapi32/crypt.h b/dlls/advapi32/crypt.h
index 310c350ea4b..fcfb0b0f16a 100644
--- a/dlls/advapi32/crypt.h
+++ b/dlls/advapi32/crypt.h
@@ -49,9 +49,9 @@ typedef struct tagPROVFUNCS
 	BOOL (WINAPI *pCPHashSessionKey)(HCRYPTPROV hProv, HCRYPTHASH hHash, HCRYPTKEY hKey, DWORD dwFlags);
 	BOOL (WINAPI *pCPImportKey)(HCRYPTPROV hProv, CONST BYTE *pbData, DWORD dwDataLen, HCRYPTKEY hPubKey, DWORD dwFlags, HCRYPTKEY *phKey);
 	BOOL (WINAPI *pCPReleaseContext)(HCRYPTPROV hProv, DWORD dwFlags);
-	BOOL (WINAPI *pCPSetHashParam)(HCRYPTPROV hProv, HCRYPTHASH hHash, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
-	BOOL (WINAPI *pCPSetKeyParam)(HCRYPTPROV hProv, HCRYPTKEY hKey, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
-	BOOL (WINAPI *pCPSetProvParam)(HCRYPTPROV hProv, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
+	BOOL (WINAPI *pCPSetHashParam)(HCRYPTPROV hProv, HCRYPTHASH hHash, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
+	BOOL (WINAPI *pCPSetKeyParam)(HCRYPTPROV hProv, HCRYPTKEY hKey, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
+	BOOL (WINAPI *pCPSetProvParam)(HCRYPTPROV hProv, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
 	BOOL (WINAPI *pCPSignHash)(HCRYPTPROV hProv, HCRYPTHASH hHash, DWORD dwKeySpec, LPCWSTR sDescription, DWORD dwFlags, BYTE *pbSignature, DWORD *pdwSigLen);
 	BOOL (WINAPI *pCPVerifySignature)(HCRYPTPROV hProv, HCRYPTHASH hHash, CONST BYTE *pbSignature, DWORD dwSigLen, HCRYPTKEY hPubKey, LPCWSTR sDescription, DWORD dwFlags);
 } PROVFUNCS, *PPROVFUNCS;
diff --git a/include/wincrypt.h b/include/wincrypt.h
index e5cc031381d..6554376dae7 100644
--- a/include/wincrypt.h
+++ b/include/wincrypt.h
@@ -3052,28 +3052,28 @@ BOOL WINAPI CryptGetDefaultProviderW (DWORD dwProvType, DWORD *pdwReserved,
 		DWORD dwFlags, LPWSTR pszProvName, DWORD *pcbProvName);
 #define CryptGetDefaultProvider WINELIB_NAME_AW(CryptGetDefaultProvider)
 BOOL WINAPI CryptGetUserKey (HCRYPTPROV hProv, DWORD dwKeySpec, HCRYPTKEY *phUserKey);
-BOOL WINAPI CryptHashData (HCRYPTHASH hHash, const BYTE *pbData, DWORD dwDataLen, DWORD dwFlags);
+BOOL WINAPI CryptHashData (HCRYPTHASH hHash, CONST BYTE *pbData, DWORD dwDataLen, DWORD dwFlags);
 BOOL WINAPI CryptHashSessionKey (HCRYPTHASH hHash, HCRYPTKEY hKey, DWORD dwFlags);
-BOOL WINAPI CryptImportKey (HCRYPTPROV hProv, BYTE *pbData, DWORD dwDataLen,
+BOOL WINAPI CryptImportKey (HCRYPTPROV hProv, CONST BYTE *pbData, DWORD dwDataLen,
 		HCRYPTKEY hPubKey, DWORD dwFlags, HCRYPTKEY *phKey);
 BOOL WINAPI CryptReleaseContext (HCRYPTPROV hProv, DWORD dwFlags);
-BOOL WINAPI CryptSetHashParam (HCRYPTHASH hHash, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
-BOOL WINAPI CryptSetKeyParam (HCRYPTKEY hKey, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
+BOOL WINAPI CryptSetHashParam (HCRYPTHASH hHash, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
+BOOL WINAPI CryptSetKeyParam (HCRYPTKEY hKey, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
 BOOL WINAPI CryptSetProviderA (LPCSTR pszProvName, DWORD dwProvType);
 BOOL WINAPI CryptSetProviderW (LPCWSTR pszProvName, DWORD dwProvType);
 #define CryptSetProvider WINELIB_NAME_AW(CryptSetProvider)
 BOOL WINAPI CryptSetProviderExA (LPCSTR pszProvName, DWORD dwProvType, DWORD *pdwReserved, DWORD dwFlags);
 BOOL WINAPI CryptSetProviderExW (LPCWSTR pszProvName, DWORD dwProvType, DWORD *pdwReserved, DWORD dwFlags);
 #define CryptSetProviderEx WINELIB_NAME_AW(CryptSetProviderEx)
-BOOL WINAPI CryptSetProvParam (HCRYPTPROV hProv, DWORD dwParam, BYTE *pbData, DWORD dwFlags);
+BOOL WINAPI CryptSetProvParam (HCRYPTPROV hProv, DWORD dwParam, CONST BYTE *pbData, DWORD dwFlags);
 BOOL WINAPI CryptSignHashA (HCRYPTHASH hHash, DWORD dwKeySpec, LPCSTR sDescription,
 		DWORD dwFlags, BYTE *pbSignature, DWORD *pdwSigLen);
 BOOL WINAPI CryptSignHashW (HCRYPTHASH hHash, DWORD dwKeySpec, LPCWSTR sDescription,
 		DWORD dwFlags, BYTE *pbSignature, DWORD *pdwSigLen);
 #define CryptSignHash WINELIB_NAME_AW(CryptSignHash)
-BOOL WINAPI CryptVerifySignatureA (HCRYPTHASH hHash, BYTE *pbSignature, DWORD dwSigLen,
+BOOL WINAPI CryptVerifySignatureA (HCRYPTHASH hHash, CONST BYTE *pbSignature, DWORD dwSigLen,
 		HCRYPTKEY hPubKey, LPCSTR sDescription, DWORD dwFlags);
-BOOL WINAPI CryptVerifySignatureW (HCRYPTHASH hHash, BYTE *pbSignature, DWORD dwSigLen,
+BOOL WINAPI CryptVerifySignatureW (HCRYPTHASH hHash, CONST BYTE *pbSignature, DWORD dwSigLen,
 		HCRYPTKEY hPubKey, LPCWSTR sDescription, DWORD dwFlags);
 #define CryptVerifySignature WINELIB_NAME_AW(CryptVerifySignature)