fixed compat of steamid generation with reunion2015 version, when authkey was shortest

Author: s1lentq

reunion/src/client_auth.cpp

@@ -61,15 +61,10 @@ void SaltSteamId(authdata_t* authdata) {
 	byte buf[MAX_HASHDATA_LEN];
 	CSizeBuf szbuf(buf, sizeof buf);
 
-	// deprecated auth version reunion2015 has a truncated ticket buffer
-	const uint32_t MAX_RAWAUTHDATA_TRUNC = 16;
-	uint32_t authKeyMaxLen = (g_ReunionConfig->getAuthVersion() == av_reunion2015)
-		? MAX_RAWAUTHDATA_TRUNC : authdata->authKeyLen;
-
 	if (g_ReunionConfig->getAuthVersion() < av_reunion2018)
 		szbuf.WriteLong(authdata->steamId);
 	if (g_ReunionConfig->getAuthVersion() > av_dproto)
-		szbuf.Write(authdata->authKey, authKeyMaxLen);
+		szbuf.Write(authdata->authKey, Reunion_AuthKeyMaxLen(authdata));
 
 	szbuf.Write(g_ReunionConfig->getSteamIdSalt(), g_ReunionConfig->getSteamIdSaltLen());
 

reunion/src/reunion_authorizers.cpp

@@ -37,17 +37,27 @@ int g_NumClientAuthorizers = 0;
 const char *g_RevEmuCryptKey = "_YOU_SERIOUSLY_NEED_TO_GET_LAID_";
 const uint32_t g_SteamEmuHashKey = 0xC9710266;
 
-static uint32_t revHash(const char* str)
+static uint32_t revHash(const char* str, int n = -1)
 {
 	uint32_t hash = 0x4E67C6A7;
 
-	for (int cc = *str; cc; cc = *++str) {
+	for (int cc = *str; cc && n != 0; cc = *++str, --n) {
 		hash ^= (hash >> 2) + cc + 32 * hash;
 	}
 
 	return hash;
 }
 
+// deprecated auth version reunion2015 has a truncated ticket buffer
+size_t Reunion_AuthKeyMaxLen(authdata_t* authdata)
+{
+	const uint32_t MAX_RAWAUTHDATA_TRUNCATED = 16;
+	uint32_t authKeyMaxLen = (g_ReunionConfig->getAuthVersion() == av_reunion2015)
+		? min(authdata->authKeyLen, MAX_RAWAUTHDATA_TRUNCATED) : authdata->authKeyLen;
+
+	return authKeyMaxLen;
+}
+
 void RevEmuFinishAuthorization(authdata_t* authdata, const char* authStr, size_t authKeyMaxLen, bool stripSpecialChars)
 {
 	uint32_t volumeId;
@@ -86,7 +96,7 @@ void RevEmuFinishAuthorization(authdata_t* authdata, const char* authStr, size_t
 		memcpy(authdata->authKey, authStr, authdata->authKeyLen);
 		authdata->authKey[authdata->authKeyLen] = '\0';
 
-		authdata->steamId = revHash(authdata->authKey) << 1;
+		authdata->steamId = revHash(authdata->authKey, Reunion_AuthKeyMaxLen(authdata)) << 1;
 
 		if (authStr == (char *)&volumeId)
 			LCPrintf(false, "RevEmu auth key: '%u' steamid: %u\n", (uint32_t)authStr, authdata->steamId);

reunion/src/reunion_authorizers.h

@@ -85,3 +85,4 @@ class CNoSteam48Authorizer : public IClientAuthorizer {
 extern void Reunion_Init_Authorizers();
 extern client_auth_kind Reunion_Authorize_Client(authdata_t* authdata);
 extern const char* Reunion_GetAuthorizerName(client_auth_kind authKind);
+extern size_t Reunion_AuthKeyMaxLen(authdata_t* authdata);