#include "putty.h"
+#ifndef NO_SECURITY
+#include <aclapi.h>
+#endif
+
#define AGENT_COPYDATA_ID 0x804e50ba /* random goop */
#define AGENT_MAX_MSGLEN 8192
#endif
+/*
+ * Dynamically load advapi32.dll for SID manipulation. In its absence,
+ * we degrade gracefully.
+ */
+#ifndef NO_SECURITY
+int advapi_initialised = FALSE;
+static HMODULE advapi;
+DECL_WINDOWS_FUNCTION(static, BOOL, OpenProcessToken,
+ (HANDLE, DWORD, PHANDLE));
+DECL_WINDOWS_FUNCTION(static, BOOL, GetTokenInformation,
+ (HANDLE, TOKEN_INFORMATION_CLASS,
+ LPVOID, DWORD, PDWORD));
+DECL_WINDOWS_FUNCTION(static, BOOL, InitializeSecurityDescriptor,
+ (PSECURITY_DESCRIPTOR, DWORD));
+DECL_WINDOWS_FUNCTION(static, BOOL, SetSecurityDescriptorOwner,
+ (PSECURITY_DESCRIPTOR, PSID, BOOL));
+DECL_WINDOWS_FUNCTION(, DWORD, GetSecurityInfo,
+ (HANDLE, SE_OBJECT_TYPE, SECURITY_INFORMATION,
+ PSID *, PSID *, PACL *, PACL *,
+ PSECURITY_DESCRIPTOR *));
+int init_advapi(void)
+{
+ advapi = load_system32_dll("advapi32.dll");
+ return advapi &&
+ GET_WINDOWS_FUNCTION(advapi, GetSecurityInfo) &&
+ GET_WINDOWS_FUNCTION(advapi, OpenProcessToken) &&
+ GET_WINDOWS_FUNCTION(advapi, GetTokenInformation) &&
+ GET_WINDOWS_FUNCTION(advapi, InitializeSecurityDescriptor) &&
+ GET_WINDOWS_FUNCTION(advapi, SetSecurityDescriptorOwner);
+}
+
+PSID get_user_sid(void)
+{
+ HANDLE proc = NULL, tok = NULL;
+ TOKEN_USER *user = NULL;
+ DWORD toklen, sidlen;
+ PSID sid = NULL, ret = NULL;
+
+ if ((proc = OpenProcess(MAXIMUM_ALLOWED, FALSE,
+ GetCurrentProcessId())) == NULL)
+ goto cleanup;
+
+ if (!p_OpenProcessToken(proc, TOKEN_QUERY, &tok))
+ goto cleanup;
+
+ if (!p_GetTokenInformation(tok, TokenUser, NULL, 0, &toklen) &&
+ GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+ goto cleanup;
+
+ if ((user = (TOKEN_USER *)LocalAlloc(LPTR, toklen)) == NULL)
+ goto cleanup;
+
+ if (!p_GetTokenInformation(tok, TokenUser, user, toklen, &toklen))
+ goto cleanup;
+
+ sidlen = GetLengthSid(user->User.Sid);
+
+ sid = (PSID)smalloc(sidlen);
+
+ if (!CopySid(sidlen, sid, user->User.Sid))
+ goto cleanup;
+
+ /* Success. Move sid into the return value slot, and null it out
+ * to stop the cleanup code freeing it. */
+ ret = sid;
+ sid = NULL;
+
+ cleanup:
+ if (proc != NULL)
+ CloseHandle(proc);
+ if (tok != NULL)
+ CloseHandle(tok);
+ if (user != NULL)
+ LocalFree(user);
+ if (sid != NULL)
+ sfree(sid);
+
+ return ret;
+}
+
+#endif
+
int agent_query(void *in, int inlen, void **out, int *outlen,
void (*callback)(void *, void *, int), void *callback_ctx)
{
unsigned char *p, *ret;
int id, retlen;
COPYDATASTRUCT cds;
+ SECURITY_ATTRIBUTES sa, *psa;
+ PSECURITY_DESCRIPTOR psd = NULL;
+ PSID usersid = NULL;
*out = NULL;
*outlen = 0;
if (!hwnd)
return 1; /* *out == NULL, so failure */
mapname = dupprintf("PageantRequest%08x", (unsigned)GetCurrentThreadId());
- filemap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE,
+
+ psa = NULL;
+#ifndef NO_SECURITY
+ if (advapi_initialised || init_advapi()) {
+ /*
+ * Make the file mapping we create for communication with
+ * Pageant owned by the user SID rather than the default. This
+ * should make communication between processes with slightly
+ * different contexts more reliable: in particular, command
+ * prompts launched as administrator should still be able to
+ * run PSFTPs which refer back to the owning user's
+ * unprivileged Pageant.
+ */
+ usersid = get_user_sid();
+
+ if (usersid) {
+ psd = (PSECURITY_DESCRIPTOR)
+ LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
+ if (psd) {
+ if (p_InitializeSecurityDescriptor
+ (psd, SECURITY_DESCRIPTOR_REVISION) &&
+ p_SetSecurityDescriptorOwner(psd, usersid, FALSE)) {
+ sa.nLength = sizeof(sa);
+ sa.bInheritHandle = TRUE;
+ sa.lpSecurityDescriptor = psd;
+ psa = &sa;
+ } else {
+ LocalFree(psd);
+ psd = NULL;
+ }
+ }
+ }
+ }
+#endif /* NO_SECURITY */
+
+ filemap = CreateFileMapping(INVALID_HANDLE_VALUE, psa, PAGE_READWRITE,
0, AGENT_MAX_MSGLEN, mapname);
- if (!filemap)
+ if (filemap == NULL || filemap == INVALID_HANDLE_VALUE) {
+ sfree(mapname);
return 1; /* *out == NULL, so failure */
+ }
p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0);
memcpy(p, in, inlen);
cds.dwData = AGENT_COPYDATA_ID;
data->hwnd = hwnd;
if (CreateThread(NULL, 0, agent_query_thread, data, 0, &threadid))
return 0;
+ sfree(mapname);
sfree(data);
}
#endif
}
UnmapViewOfFile(p);
CloseHandle(filemap);
+ sfree(mapname);
+ if (psd)
+ LocalFree(psd);
+ sfree(usersid);
return 1;
}