From e2536433865c6d85affd457b14933fab32cc6f5c Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Fri, 30 Jan 2026 22:03:10 +0100
Subject: [PATCH] [winpr,smartcard] simplify PCSC_ReadDeviceSystemName

* If we read SCARD_ATTR_DEVICE_SYSTEM_NAME_A just pass the actual
  destination buffer, no further processing required.
* In case of SCARD_ATTR_DEVICE_SYSTEM_NAME_W allocate a WCHAR version of
  the result, copy back to destination buffer.
---
 winpr/libwinpr/smartcard/smartcard_pcsc.c | 117 +++++++---------------
 1 file changed, 36 insertions(+), 81 deletions(-)

diff --git a/winpr/libwinpr/smartcard/smartcard_pcsc.c b/winpr/libwinpr/smartcard/smartcard_pcsc.c
index afac57934..e2ba5beb2 100644
--- a/winpr/libwinpr/smartcard/smartcard_pcsc.c
+++ b/winpr/libwinpr/smartcard/smartcard_pcsc.c
@@ -48,6 +48,10 @@
 #include "../log.h"
 #define TAG WINPR_TAG("smartcard")
 
+#ifndef MIN
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+#endif
+
 #define WINSCARD_LOAD_PROC_EX(module, pcsc, _fname, _name)                   \
 	do                                                                       \
 	{                                                                        \
@@ -2506,102 +2510,53 @@ static LONG WINAPI PCSC_SCardGetAttrib_FriendlyName(SCARDHANDLE hCard, DWORD dwA
 	return status;
 }
 
-static LONG PCSC_ReadDeviceSystemName(SCARDHANDLE hCard, DWORD dwAttrId, LPBYTE pbAttr,
-                                      LPDWORD pcbAttrLen)
+static LONG PCSC_ReadDeviceSystemName(SCARDCONTEXT hContext, SCARDHANDLE hCard, DWORD dwAttrId,
+                                      LPBYTE pbAttr, LPDWORD pcbAttrLen)
 {
 	/* Get reader name from SCardStatus */
 	CHAR* szReader = NULL;
-	PCSC_DWORD cchReader = 0;
 	PCSC_DWORD dwState = 0;
 	PCSC_DWORD dwProtocol = 0;
 	LONG status = 0;
 
-	const DWORD cbAttrLen = *pcbAttrLen;
+	DWORD cbAttrLen = *pcbAttrLen;
 	if (cbAttrLen == SCARD_AUTOALLOCATE)
 		return SCARD_E_UNEXPECTED;
-	else
-	{
-		PCSC_DWORD cbAtr = 0;
-		const PCSC_LONG rc =
-		    g_PCSC.pfnSCardStatus(hCard, NULL, &cchReader, &dwState, &dwProtocol, NULL, &cbAtr);
-		status = WINPR_ASSERTING_INT_CAST(LONG, rc);
-		if (status != SCARD_S_SUCCESS)
-			return status;
-		switch (dwAttrId)
-		{
-			case SCARD_ATTR_DEVICE_SYSTEM_NAME_A:
-				if (cchReader > cbAttrLen)
-					return SCARD_E_INSUFFICIENT_BUFFER;
-				break;
-			case SCARD_ATTR_DEVICE_SYSTEM_NAME_W:
-				if (cchReader > cbAttrLen / sizeof(WCHAR))
-					return SCARD_E_INSUFFICIENT_BUFFER;
-				break;
-			default:
-				return SCARD_E_INVALID_PARAMETER;
-		}
 
-		if (cchReader == 0)
-		{
-			*pcbAttrLen = 0;
-			return SCARD_S_SUCCESS;
-		}
+	if (dwAttrId == SCARD_ATTR_DEVICE_SYSTEM_NAME_W)
+		cbAttrLen /= sizeof(WCHAR);
 
-		if (!pbAttr)
-			return SCARD_E_INVALID_VALUE;
+	PCSC_DWORD cbAtr = 0;
+	PCSC_DWORD cchReader = cbAttrLen;
+	const PCSC_LONG rc = g_PCSC.pfnSCardStatus(hCard, (LPSTR)pbAttr, &cchReader, &dwState,
+	                                           &dwProtocol, NULL, &cbAtr);
 
-		szReader = calloc(cchReader, sizeof(CHAR));
-		if (!szReader)
-			return SCARD_E_NO_MEMORY;
-	}
-
-	{
-		PCSC_DWORD rlen = cchReader;
-		PCSC_DWORD cbAtr = 0;
-		const PCSC_LONG rc =
-		    g_PCSC.pfnSCardStatus(hCard, szReader, &rlen, &dwState, &dwProtocol, NULL, &cbAtr);
-		status = WINPR_ASSERTING_INT_CAST(LONG, rc);
-		if (status != SCARD_S_SUCCESS)
-			goto out;
-
-		if (cchReader != rlen)
-		{
-			status = SCARD_E_INVALID_VALUE;
-			goto out;
-		}
-	}
 	*pcbAttrLen = cchReader;
+	status = WINPR_ASSERTING_INT_CAST(LONG, rc);
+	if (status != SCARD_S_SUCCESS)
+		return status;
 
-	switch (dwAttrId)
+	if (cchReader > cbAttrLen)
+		return SCARD_E_INSUFFICIENT_BUFFER;
+
+	if (dwAttrId == SCARD_ATTR_DEVICE_SYSTEM_NAME_W)
 	{
-		case SCARD_ATTR_DEVICE_SYSTEM_NAME_A:
-			if (!strncpy((char*)pbAttr, szReader, *pcbAttrLen))
-			{
-				status = SCARD_E_NO_MEMORY;
-				goto out;
-			}
-			break;
-		case SCARD_ATTR_DEVICE_SYSTEM_NAME_W:
-			if (cchReader > cbAttrLen / sizeof(WCHAR))
-			{
-				status = SCARD_E_INSUFFICIENT_BUFFER;
-				goto out;
-			}
-			if (ConvertUtf8NToWChar(szReader, *pcbAttrLen, (WCHAR*)pbAttr, *pcbAttrLen) !=
-			    *pcbAttrLen)
-			{
-				status = SCARD_E_NO_MEMORY;
-				goto out;
-			}
-			*pcbAttrLen *= sizeof(WCHAR);
-			break;
-		default:
-			status = SCARD_E_INVALID_PARAMETER;
-			break;
+		size_t wlen = 0;
+		WCHAR* tmp = ConvertMszUtf8NToWCharAlloc((LPSTR)pbAttr, cchReader, &wlen);
+		if (!tmp)
+			return SCARD_E_NO_MEMORY;
+
+		/* utf-8 to utf-16 is no simple y=x*2, check again if the size fits. */
+		if (wlen > cbAttrLen)
+		{
+			free(tmp);
+			return SCARD_E_INSUFFICIENT_BUFFER;
+		}
+		*pcbAttrLen = MIN(wlen, cchReader) * sizeof(WCHAR);
+		memcpy(pbAttr, tmp, *pcbAttrLen);
+		free(tmp);
 	}
 
-out:
-	free(szReader);
 	return status;
 }
 
@@ -2742,12 +2697,12 @@ static LONG WINAPI PCSC_SCardGetAttrib(SCARDHANDLE hCard, DWORD dwAttrId, LPBYTE
 		else if (dwAttrId == SCARD_ATTR_DEVICE_SYSTEM_NAME_A)
 		{
 			if (!pcbAttrLenAlloc)
-				status = PCSC_ReadDeviceSystemName(hCard, dwAttrId, pbAttr, pcbAttrLen);
+				status = PCSC_ReadDeviceSystemName(hContext, hCard, dwAttrId, pbAttr, pcbAttrLen);
 		}
 		else if (dwAttrId == SCARD_ATTR_DEVICE_SYSTEM_NAME_W)
 		{
 			if (!pcbAttrLenAlloc)
-				status = PCSC_ReadDeviceSystemName(hCard, dwAttrId, pbAttr, pcbAttrLen);
+				status = PCSC_ReadDeviceSystemName(hContext, hCard, dwAttrId, pbAttr, pcbAttrLen);
 		}
 		else if (dwAttrId == SCARD_ATTR_DEVICE_UNIT)
 		{