Skip to content

Fix handling empty AllowedMechanisms attribute #324

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
wants to merge 2 commits into
base: main
Choose a base branch
from
Open

Fix handling empty AllowedMechanisms attribute #324

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
d00c97d
object: Avoid crashing on zero-length AllowedMechanisms attribute
Jakuje Nov 20, 2025
0204b08
tests: Reproducer for empty AllowedMechanisms issue with SoftHSM
Jakuje Nov 20, 2025
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
31 changes: 19 additions & 12 deletions cryptoki/src/object.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1114,18 +1114,25 @@ impl TryFrom<CK_ATTRIBUTE> for Attribute {
Ok(Attribute::ValidationVersion(Version::new(val[0], val[1])))
}
AttributeType::AllowedMechanisms => {
let val = unsafe {
std::slice::from_raw_parts(
attribute.pValue as *const CK_MECHANISM_TYPE,
attribute.ulValueLen.try_into()?,
)
};
let types: Vec<MechanismType> = val
.iter()
.copied()
.map(|t| t.try_into())
.collect::<Result<Vec<MechanismType>>>()?;
Ok(Attribute::AllowedMechanisms(types))
if attribute.ulValueLen == 0 {
/* For zero-length attributes we are getting pointer to static
* buffer of length zero, which can not be used to create slices.
* Short-circuit here to avoid crash (#324) */
Ok(Attribute::AllowedMechanisms(Vec::<MechanismType>::new()))
} else {
let val = unsafe {
std::slice::from_raw_parts(
attribute.pValue as *const CK_MECHANISM_TYPE,
attribute.ulValueLen.try_into()?,
)
};
let types: Vec<MechanismType> = val
.iter()
.copied()
.map(|t| t.try_into())
.collect::<Result<Vec<MechanismType>>>()?;
Ok(Attribute::AllowedMechanisms(types))
}
}
AttributeType::EndDate => {
if val.is_empty() {
Expand Down
14 changes: 14 additions & 0 deletions cryptoki/tests/basic.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1113,6 +1113,20 @@ fn import_export() -> TestResult {
panic!("Expected the Modulus attribute.");
}

let mut attrs =
session.get_attributes(is_it_the_public_key, &[AttributeType::AllowedMechanisms])?;

if is_softhsm() {
let attr = attrs.remove(0);
if let Attribute::AllowedMechanisms(v) = attr {
assert_eq!(v, Vec::<MechanismType>::new());
} else {
panic!("Expected the AllowedMechanisms attribute.");
}
} else {
assert_eq!(attrs, Vec::<Attribute>::new());
}

// delete key
session.destroy_object(is_it_the_public_key)?;

Expand Down
Loading