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combine: Multiple events per event ID #77

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26 changes: 17 additions & 9 deletions lib/src/tpmevents/combine.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ mod tests;
#[derive(Clone, Debug)]
pub struct EventCombinationError {}

pub type EventNode = tree::ResultNode<TPMEvent, EventCombinationError>;
pub type EventNode = tree::ResultNode<Vec<TPMEvent>, EventCombinationError>;

pub fn combine_images(images: &[Vec<TPMEvent>]) -> Vec<Vec<Pcr>> {
if images.len() == 1 {
Expand All @@ -101,16 +101,16 @@ pub fn combine(this: &[TPMEvent], that: &[TPMEvent]) -> Vec<Vec<Pcr>> {
Some(st) => st
.iter()
.flat_map(|t| t.valid_branches())
.map(|e| compile_pcrs(&e))
.map(|e| compile_pcrs(&e.into_iter().flatten().collect::<Vec<_>>()))
.collect(),
None => vec![],
}
}

fn event_subtree(
event_id: &TPMEventID,
map_this: &HashMap<TPMEventID, TPMEvent>,
map_that: &HashMap<TPMEventID, TPMEvent>,
map_this: &HashMap<TPMEventID, Vec<TPMEvent>>,
map_that: &HashMap<TPMEventID, Vec<TPMEvent>>,
group_this: u32,
group_that: u32,
) -> Option<Vec<EventNode>> {
Expand All @@ -119,7 +119,7 @@ fn event_subtree(
let opt_this = map_this.get(event_id);
let opt_that = map_that.get(event_id);
// Divergences contains tuples with events, and this/that masked groups
let mut divs: Vec<(&TPMEvent, u32, u32)> = vec![];
let mut divs: Vec<(&Vec<TPMEvent>, u32, u32)> = vec![];
let mut nodes: Vec<EventNode> = vec![];
let mut event_required = false;
let event_groups = event_id.groups();
Expand Down Expand Up @@ -182,8 +182,8 @@ fn event_subtree(
}
}

for (event, g_this, g_that) in divs {
let mut node = EventNode::new_ok(event.clone());
for (events, g_this, g_that) in divs {
let mut node = EventNode::new_ok(events.clone());
if let Some(children) = event_subtree(&event_id.next()?, map_this, map_that, g_this, g_that)
{
for c in children {
Expand All @@ -196,6 +196,14 @@ fn event_subtree(
Some(nodes)
}

fn tpm_event_id_hashmap(events: &[TPMEvent]) -> HashMap<TPMEventID, TPMEvent> {
events.iter().map(|e| (e.id.clone(), e.clone())).collect()
fn tpm_event_id_hashmap(events: &[TPMEvent]) -> HashMap<TPMEventID, Vec<TPMEvent>> {
let mut lookup = HashMap::<TPMEventID, Vec<TPMEvent>>::new();
for event in events {
lookup
.entry(event.id.clone())
.or_default()
.push(event.clone());
}

lookup
}
69 changes: 65 additions & 4 deletions lib/src/tpmevents/combine/tests.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -30,15 +30,21 @@ fn test_tpm_event_id_hashmap() {
hash: vec![1, 2, 3, 4, 5],
id: TPMEventID::Pcr11UnameContent,
};
let events = vec![foo.clone(), bar.clone(), foobar.clone()];
let foobaz = TPMEvent {
name: "FOOBAR".into(),
pcr: 0xe8,
hash: vec![6, 7, 8, 9, 10],
id: TPMEventID::Pcr11UnameContent,
};
let events = vec![foo.clone(), bar.clone(), foobar.clone(), foobaz.clone()];

let res = tpm_event_id_hashmap(&events);
assert_eq!(
res,
HashMap::from([
(TPMEventID::PcrRootNodeEvent, foo),
(TPMEventID::Pcr11Sbat, bar),
(TPMEventID::Pcr11UnameContent, foobar),
(TPMEventID::PcrRootNodeEvent, vec![foo]),
(TPMEventID::Pcr11Sbat, vec![bar]),
(TPMEventID::Pcr11UnameContent, vec![foobar, foobaz]),
])
);
}
Expand Down Expand Up @@ -1682,3 +1688,58 @@ fn test_all_pcrs_2_images() {
]
);
}

#[test]
fn test_combine_multiple_events_same_id() {
let this = vec![
TPMEvent {
pcr: 4,
name: "EV_EFI_ACTION".to_string(),
hash: hex::decode("0000000000000000000000000000000000000000000000000000000000000000")
.unwrap(),
id: TPMEventID::Pcr4EfiCall,
},
TPMEvent {
pcr: 4,
name: "EV_EFI_ACTION".to_string(),
hash: hex::decode("1111111111111111111111111111111111111111111111111111111111111111")
.unwrap(),
id: TPMEventID::Pcr4EfiCall,
},
];
let that = vec![
TPMEvent {
pcr: 4,
name: "EV_EFI_ACTION".to_string(),
hash: hex::decode("2222222222222222222222222222222222222222222222222222222222222222")
.unwrap(),
id: TPMEventID::Pcr4EfiCall,
},
TPMEvent {
pcr: 4,
name: "EV_EFI_ACTION".to_string(),
hash: hex::decode("3333333333333333333333333333333333333333333333333333333333333333")
.unwrap(),
id: TPMEventID::Pcr4EfiCall,
},
];
let foobar = vec![this, that];

let res = combine_images(&foobar);
let pcr_values: Vec<Vec<String>> = res
.iter()
.map(|i| {
i.iter()
.map(|p| hex::encode(p.value.clone()))
.collect::<Vec<_>>()
})
.collect();

assert_eq!(
pcr_values,
vec![
vec!["4cb4c04374037e0ddde15a714a4295501e2cbc3b0971e4c3eebce23ef433dc4d",],
vec!["22d0d408147e904fa9fe6feba5fc51374e44f07101e208e62fd5453841595ade",],
],
);
}