Add/correct a couple definitions, allow hashing nothing.

dlls/advapi32/crypt.c

diff --git a/dlls/advapi32/crypt.c b/dlls/advapi32/crypt.c
index f365c7b..45d36ce 100644
--- a/dlls/advapi32/crypt.c
+++ b/dlls/advapi32/crypt.c
@@ -1455,7 +1455,7 @@
  *  Success: TRUE
  *  Failure: FALSE
  */
-BOOL WINAPI CryptHashData (HCRYPTHASH hHash, BYTE *pbData, DWORD dwDataLen, DWORD dwFlags)
+BOOL WINAPI CryptHashData (HCRYPTHASH hHash, const BYTE *pbData, DWORD dwDataLen, DWORD dwFlags)
 {
 	PCRYPTHASH hash = (PCRYPTHASH)hHash;
 	PCRYPTPROV prov;
@@ -1464,7 +1464,7 @@
 
 	if (!hash)
 		CRYPT_ReturnLastError(ERROR_INVALID_HANDLE);
-	if (!pbData || !dwDataLen || !hash->pProvider || hash->pProvider->dwMagic != MAGIC_CRYPTPROV)
+	if (!hash->pProvider || hash->pProvider->dwMagic != MAGIC_CRYPTPROV)
 		CRYPT_ReturnLastError(ERROR_INVALID_PARAMETER);
 
 	prov = hash->pProvider;

include/wincrypt.h

diff --git a/include/wincrypt.h b/include/wincrypt.h
index d9ef13e..3521114 100644
--- a/include/wincrypt.h
+++ b/include/wincrypt.h
@@ -708,6 +708,7 @@
 #define ALG_SID_MD4                     2
 #define ALG_SID_MD5                     3
 #define ALG_SID_SHA                     4
+#define ALG_SID_SHA1                    CALG_SHA
 #define ALG_SID_MAC                     5
 #define ALG_SID_RIPEMD                  6
 #define ALG_SID_RIPEMD160               7
@@ -728,6 +729,7 @@
 #define CALG_MD4                  (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_MD4)
 #define CALG_MD5                  (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_MD5)
 #define CALG_SHA                  (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_SHA)
+#define CALG_SHA1 CALG_SHA
 #define CALG_MAC                  (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_MAC)
 #define CALG_SSL3_SHAMD5          (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_SSL3SHAMD5)
 #define CALG_HMAC                 (ALG_CLASS_HASH         | ALG_TYPE_ANY           | ALG_SID_HMAC)
@@ -1812,7 +1814,7 @@
 		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, 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,
 		HCRYPTKEY hPubKey, DWORD dwFlags, HCRYPTKEY *phKey);