kmwebnet/OpenSK
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Wipe sensitive data on entry deletion

Browse Source 
When inserting (or replacing) entries in the store, the data may be marked as
sensitive. When that entry is deleted, the data is wiped by overwritting it with
zeroes. This may cost a few bytes of overhead per entry with sensitive data to
satisfy the constraint that words may only be written twice.
This commit is contained in:
Julien Cretin
2020-03-04 18:50:24 +01:00
parent fa4271104d
commit 61a4fb9784
4 changed files with 233 additions and 49 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
src/ctap/storage.rs
View File

@@ -198,6 +198,7 @@ impl PersistentStore {
.insert(StoreEntry {
tag: MASTER_KEYS,
data: &master_keys,
sensitive: true,
})
.unwrap();
}
@@ -206,6 +207,7 @@ impl PersistentStore {
.insert(StoreEntry {
tag: PIN_RETRIES,
data: &[MAX_PIN_RETRIES],
sensitive: false,
})
.unwrap();
}
@@ -245,6 +247,7 @@ impl PersistentStore {
let new_entry = StoreEntry {
tag: TAG_CREDENTIAL,
data: &credential,
sensitive: true,
};
match old_entry {
None => self.store.insert(new_entry)?,
@@ -299,6 +302,7 @@ impl PersistentStore {
.insert(StoreEntry {
tag: GLOBAL_SIGNATURE_COUNTER,
data: &buffer,
sensitive: false,
})
.unwrap();
}
@@ -312,6 +316,7 @@ impl PersistentStore {
StoreEntry {
tag: GLOBAL_SIGNATURE_COUNTER,
data: &buffer,
sensitive: false,
},
)
.unwrap();
@@ -339,6 +344,7 @@ impl PersistentStore {
let entry = StoreEntry {
tag: PIN_HASH,
data: pin_hash,
sensitive: true,
};
match self.store.find_one(&Key::PinHash) {
None => self.store.insert(entry).unwrap(),
@@ -368,6 +374,7 @@ impl PersistentStore {
StoreEntry {
tag: PIN_RETRIES,
data: &[new_value],
sensitive: false,
},
)
.unwrap();
@@ -381,6 +388,7 @@ impl PersistentStore {
StoreEntry {
tag: PIN_RETRIES,
data: &[MAX_PIN_RETRIES],
sensitive: false,
},
)
.unwrap();
@@ -465,9 +473,9 @@ mod test {
let storage = Storage::new(store, options);
let store = embedded_flash::Store::new(storage, Config).unwrap();
// We can replace 3 bytes with minimal overhead.
assert_eq!(store.replace_len(0), 2 * WORD_SIZE);
assert_eq!(store.replace_len(3), 2 * WORD_SIZE);
assert_eq!(store.replace_len(4), 3 * WORD_SIZE);
assert_eq!(store.replace_len(false, 0), 2 * WORD_SIZE);
assert_eq!(store.replace_len(false, 3), 3 * WORD_SIZE);
assert_eq!(store.replace_len(false, 4), 3 * WORD_SIZE);
}
#[test]