Skip to content

Reject UINT32_MAX before size + 1 allocations #1364

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
ejohnstown wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Reject UINT32_MAX before size + 1 allocations #1364

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 7 additions & 1 deletion src/ssh.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@
#include <config.h>
#endif

#include <stdint.h>
#include <wolfssh/ssh.h>
#include <wolfssh/internal.h>
#include <wolfssh/log.h>
Expand Down Expand Up @@ -2154,7 +2155,8 @@ int wolfSSH_SetUsernameRaw(WOLFSSH* ssh,

if (ssh == NULL)
ret = WS_BAD_ARGUMENT;
if (username == NULL || usernameSz == 0)
/* usernameSz + 1 below must not wrap. */
if (username == NULL || usernameSz == 0 || usernameSz == UINT32_MAX)
ret = WS_BAD_ARGUMENT;

if (ret == WS_SUCCESS) {
Expand Down Expand Up @@ -2251,6 +2253,10 @@ static int DoSshPubKey(const byte* in, word32 inSz, byte** out,

allocate a copy to tokenize, add a null terminator.
*/
/* inSz + 1 must not wrap. */
if (inSz == UINT32_MAX)
return WS_BAD_ARGUMENT;

c = (char*)WMALLOC(inSz + 1, heap, DYNTYPE_STRING);
if (c != NULL) {
WMEMCPY(c, in, inSz);
Expand Down
24 changes: 24 additions & 0 deletions tests/api.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@

#include <stdio.h>
#include <string.h>
#include <stdint.h>
#if ((defined(WOLFSSH_SFTP) && !defined(NO_WOLFSSH_CLIENT)) || \
(defined(WOLFSSH_SCP) && defined(WOLFSSH_HAVE_SYMLINK) && \
!defined(WOLFSSH_SCP_USER_CALLBACKS))) && \
Expand Down Expand Up @@ -282,6 +283,9 @@ static void test_wolfSSH_SetUsername(void)
(const byte*)empty, 0));
AssertIntNE(WS_SUCCESS, wolfSSH_SetUsernameRaw(ssh,
(const byte*)username, 0));
/* usernameSz + 1 would wrap to a zero-byte allocation. */
AssertIntEQ(WS_BAD_ARGUMENT, wolfSSH_SetUsernameRaw(ssh,
(const byte*)username, UINT32_MAX));
wolfSSH_free(ssh);
AssertNotNull(ssh = wolfSSH_new(ctx));
AssertIntEQ(WS_SUCCESS, wolfSSH_SetUsername(ssh, username));
Expand Down Expand Up @@ -2887,6 +2891,25 @@ static void test_wolfSSH_ReadKey_sshNoComment(void)
}


static void test_wolfSSH_ReadKey_sshMaxSize(void)
{
/* An SSH format key of size UINT32_MAX must be refused before
* DoSshPubKey() allocates inSz + 1, which wraps to zero. The buffer is
* never read past its end, the size is refused first. */
static const char in[] = "ssh-ed25519 AAAA\n";
byte* key = NULL;
word32 keySz = 0;
const byte* keyType = NULL;
word32 keyTypeSz = 0;
int ret;

ret = wolfSSH_ReadKey_buffer((const byte*)in, UINT32_MAX,
WOLFSSH_FORMAT_SSH, &key, &keySz, &keyType, &keyTypeSz, NULL);
AssertIntEQ(ret, WS_BAD_ARGUMENT);
AssertNull(key);
}


#ifdef WOLFSSH_SCP

static int my_ScpRecv(WOLFSSH* ssh, int state, const char* basePath,
Expand Down Expand Up @@ -9355,6 +9378,7 @@ int wolfSSH_ApiTest(int argc, char** argv)
test_wolfSSH_ReadKey_shortBuffer();
test_wolfSSH_ReadKey_noTrailingNewline();
test_wolfSSH_ReadKey_sshNoComment();
test_wolfSSH_ReadKey_sshMaxSize();
test_wolfSSH_QueryAlgoList();
test_wolfSSH_SetMaxAuthAttempts();
test_wolfSSH_StrictKex();
Expand Down
Loading