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Diffstat (limited to 'MokManager.c')
-rw-r--r--MokManager.c105
1 files changed, 93 insertions, 12 deletions
diff --git a/MokManager.c b/MokManager.c
index f5ed379c..ee29051d 100644
--- a/MokManager.c
+++ b/MokManager.c
@@ -100,8 +100,18 @@ static UINT32 count_keys(void *Data, UINTN DataSize)
EFI_GUID HashType = EFI_CERT_SHA256_GUID;
UINTN dbsize = DataSize;
UINT32 MokNum = 0;
+ void *end = Data + DataSize;
while ((dbsize > 0) && (dbsize >= CertList->SignatureListSize)) {
+
+ /* Use ptr arithmetics to ensure bounded access. Do not allow 0
+ * SignatureListSize that will cause endless loop.
+ */
+ if ((void *)(CertList + 1) > end || CertList->SignatureListSize == 0) {
+ console_notify(L"Invalid MOK detected! Ignoring MOK List.");
+ return 0;
+ }
+
if ((CompareGuid (&CertList->SignatureType, &CertType) != 0) &&
(CompareGuid (&CertList->SignatureType, &HashType) != 0)) {
console_notify(L"Doesn't look like a key or hash");
@@ -137,6 +147,7 @@ static MokListNode *build_mok_list(UINT32 num, void *Data, UINTN DataSize) {
EFI_GUID HashType = EFI_CERT_SHA256_GUID;
UINTN dbsize = DataSize;
UINTN count = 0;
+ void *end = Data + DataSize;
list = AllocatePool(sizeof(MokListNode) * num);
@@ -146,6 +157,11 @@ static MokListNode *build_mok_list(UINT32 num, void *Data, UINTN DataSize) {
}
while ((dbsize > 0) && (dbsize >= CertList->SignatureListSize)) {
+ /* CertList out of bounds? */
+ if ((void *)(CertList + 1) > end || CertList->SignatureListSize == 0) {
+ FreePool(list);
+ return NULL;
+ }
if ((CompareGuid (&CertList->SignatureType, &CertType) != 0) &&
(CompareGuid (&CertList->SignatureType, &HashType) != 0)) {
dbsize -= CertList->SignatureListSize;
@@ -165,10 +181,23 @@ static MokListNode *build_mok_list(UINT32 num, void *Data, UINTN DataSize) {
Cert = (EFI_SIGNATURE_DATA *) (((UINT8 *) CertList) +
sizeof (EFI_SIGNATURE_LIST) + CertList->SignatureHeaderSize);
+ /* Cert out of bounds? */
+ if ((void *)(Cert + 1) > end || CertList->SignatureSize <= sizeof(EFI_GUID)) {
+ FreePool(list);
+ return NULL;
+ }
+
list[count].MokSize = CertList->SignatureSize - sizeof(EFI_GUID);
list[count].Mok = (void *)Cert->SignatureData;
list[count].Type = CertList->SignatureType;
+ /* MOK out of bounds? */
+ if (list[count].MokSize > (unsigned long)end -
+ (unsigned long)list[count].Mok) {
+ FreePool(list);
+ return NULL;
+ }
+
count++;
dbsize -= CertList->SignatureListSize;
CertList = (EFI_SIGNATURE_LIST *) ((UINT8 *) CertList +
@@ -436,7 +465,7 @@ static void show_mok_info (void *Mok, UINTN MokSize)
static EFI_STATUS list_keys (void *KeyList, UINTN KeyListSize, CHAR16 *title)
{
- UINT32 MokNum = 0;
+ INTN MokNum = 0;
MokListNode *keys = NULL;
INTN key_num = 0;
CHAR16 **menu_strings;
@@ -449,6 +478,8 @@ static EFI_STATUS list_keys (void *KeyList, UINTN KeyListSize, CHAR16 *title)
}
MokNum = count_keys(KeyList, KeyListSize);
+ if (MokNum == 0)
+ return 0;
keys = build_mok_list(MokNum, KeyList, KeyListSize);
if (!keys) {
@@ -488,13 +519,19 @@ static EFI_STATUS list_keys (void *KeyList, UINTN KeyListSize, CHAR16 *title)
return EFI_SUCCESS;
}
-static UINT8 get_line (UINT32 *length, CHAR16 *line, UINT32 line_max, UINT8 show)
+static EFI_STATUS get_line (UINT32 *length, CHAR16 *line, UINT32 line_max, UINT8 show)
{
EFI_INPUT_KEY key;
- int count = 0;
+ EFI_STATUS status;
+ unsigned int count = 0;
do {
- key = console_get_keystroke();
+ status = console_get_keystroke(&key);
+ if (EFI_ERROR (status)) {
+ console_error(L"Failed to read the keystroke", status);
+ *length = 0;
+ return status;
+ }
if ((count >= line_max &&
key.UnicodeChar != CHAR_BACKSPACE) ||
@@ -525,7 +562,7 @@ static UINT8 get_line (UINT32 *length, CHAR16 *line, UINT32 line_max, UINT8 show
*length = count;
- return 1;
+ return EFI_SUCCESS;
}
static EFI_STATUS compute_pw_hash (void *Data, UINTN DataSize, UINT8 *password,
@@ -640,7 +677,7 @@ static EFI_STATUS match_password (PASSWORD_CRYPT *pw_crypt,
CHAR16 password[PASSWORD_MAX];
UINT32 pw_length;
UINT8 fail_count = 0;
- int i;
+ unsigned int i;
if (pw_crypt) {
auth_hash = pw_crypt->hash;
@@ -989,6 +1026,7 @@ static INTN mok_deletion_prompt (void *MokDel, UINTN MokDelSize)
static CHAR16 get_password_charater (CHAR16 *prompt)
{
SIMPLE_TEXT_OUTPUT_MODE SavedMode;
+ EFI_STATUS status;
CHAR16 *message[2];
CHAR16 character;
UINTN length;
@@ -1003,7 +1041,9 @@ static CHAR16 get_password_charater (CHAR16 *prompt)
message[1] = NULL;
length = StrLen(message[0]);
console_print_box_at(message, -1, -length-4, -5, length+4, 3, 0, 1);
- get_line(&pw_length, &character, 1, 0);
+ status = get_line(&pw_length, &character, 1, 0);
+ if (EFI_ERROR(status))
+ character = 0;
console_restore_mode(&SavedMode);
@@ -1112,7 +1152,16 @@ static INTN mok_sb_prompt (void *MokSB, UINTN MokSBSize) {
return -1;
}
} else {
- LibDeleteVariable(L"MokSBState", &shim_lock_guid);
+ efi_status = uefi_call_wrapper(RT->SetVariable,
+ 5, L"MokSBState",
+ &shim_lock_guid,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS,
+ 0, NULL);
+ if (efi_status != EFI_SUCCESS) {
+ console_notify(L"Failed to delete Secure Boot state");
+ return -1;
+ }
}
console_notify(L"The system must now be rebooted");
@@ -1224,7 +1273,16 @@ static INTN mok_db_prompt (void *MokDB, UINTN MokDBSize) {
return -1;
}
} else {
- LibDeleteVariable(L"MokDBState", &shim_lock_guid);
+ efi_status = uefi_call_wrapper(RT->SetVariable, 5,
+ L"MokDBState",
+ &shim_lock_guid,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS,
+ 0, NULL);
+ if (efi_status != EFI_SUCCESS) {
+ console_notify(L"Failed to delete DB state");
+ return -1;
+ }
}
console_notify(L"The system must now be rebooted");
@@ -1261,7 +1319,11 @@ static INTN mok_pw_prompt (void *MokPW, UINTN MokPWSize) {
if (console_yes_no((CHAR16 *[]){L"Clear MOK password?", NULL}) == 0)
return 0;
- LibDeleteVariable(L"MokPWStore", &shim_lock_guid);
+ uefi_call_wrapper(RT->SetVariable, 5, L"MokPWStore",
+ &shim_lock_guid,
+ EFI_VARIABLE_NON_VOLATILE
+ | EFI_VARIABLE_BOOTSERVICE_ACCESS,
+ 0, NULL);
LibDeleteVariable(L"MokPW", &shim_lock_guid);
console_notify(L"The system must now be rebooted");
uefi_call_wrapper(RT->ResetSystem, 4, EfiResetWarm, EFI_SUCCESS, 0,
@@ -1306,11 +1368,30 @@ static INTN mok_pw_prompt (void *MokPW, UINTN MokPWSize) {
return -1;
}
-static BOOLEAN verify_certificate(void *cert, UINTN size)
+static BOOLEAN verify_certificate(UINT8 *cert, UINTN size)
{
X509 *X509Cert;
- if (!cert || size == 0)
+ UINTN length;
+ if (!cert || size < 0)
+ return FALSE;
+
+ /*
+ * A DER encoding x509 certificate starts with SEQUENCE(0x30),
+ * the number of length bytes, and the number of value bytes.
+ * The size of a x509 certificate is usually between 127 bytes
+ * and 64KB. For convenience, assume the number of value bytes
+ * is 2, i.e. the second byte is 0x82.
+ */
+ if (cert[0] != 0x30 || cert[1] != 0x82) {
+ console_notify(L"Not a DER encoding X509 certificate");
return FALSE;
+ }
+
+ length = (cert[2]<<8 | cert[3]);
+ if (length != (size - 4)) {
+ console_notify(L"Invalid X509 certificate: Inconsistent size");
+ return FALSE;
+ }
if (!(X509ConstructCertificate(cert, size, (UINT8 **) &X509Cert)) ||
X509Cert == NULL) {
generated by cgit v1.2.3 (git 2.39.1) at 2025-12-16 23:17:05 +0000