WIP: intro two binary lengths

Fraunhofer-AISEC · Sep 2, 2024 · 132d5ae · 132d5ae
1 parent 76dff01
commit 132d5ae
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Showing 4 changed files with 20 additions and 25 deletions.
diff --git a/src/constants.rs b/src/constants.rs
@@ -46,16 +46,15 @@ pub const fn prng_len(seed_len: usize) -> usize {
 pub const HSS_COMPRESSED_USED_LEAFS_SIZE: usize = size_of::<u64>();
 pub const REF_IMPL_MAX_ALLOWED_HSS_LEVELS: usize = 8;
 
-pub const REF_IMPL_SSTS_EXT_SIGNING_ENTITY_IDX_SIZE: usize = size_of::<u8>();
-pub const REF_IMPL_SSTS_EXT_L0_TOP_DIV_SIZE: usize = size_of::<u8>();
+pub const SST_SIGNING_ENTITY_IDX_SIZE: usize = size_of::<u8>();
+pub const SST_L0_TOP_DIV_SIZE: usize = size_of::<u8>();
+pub const SST_SIZE: usize = SST_SIGNING_ENTITY_IDX_SIZE + SST_L0_TOP_DIV_SIZE;
 
-pub const REF_IMPL_SSTS_EXT_SIZE: usize =
-    REF_IMPL_SSTS_EXT_SIGNING_ENTITY_IDX_SIZE + REF_IMPL_SSTS_EXT_L0_TOP_DIV_SIZE;
+pub const SST_IMPL_MAX_PRIVATE_KEY_SIZE: usize =
+    SST_SIZE + HSS_COMPRESSED_USED_LEAFS_SIZE + REF_IMPL_MAX_ALLOWED_HSS_LEVELS + MAX_SEED_LEN;
 
-pub const REF_IMPL_MAX_PRIVATE_KEY_SIZE: usize = REF_IMPL_SSTS_EXT_SIZE
-    + HSS_COMPRESSED_USED_LEAFS_SIZE
-    + REF_IMPL_MAX_ALLOWED_HSS_LEVELS
-    + MAX_SEED_LEN;
+pub const REF_IMPL_MAX_PRIVATE_KEY_SIZE: usize =
+    HSS_COMPRESSED_USED_LEAFS_SIZE + REF_IMPL_MAX_ALLOWED_HSS_LEVELS + MAX_SEED_LEN;
 
 pub const MAX_HASH_SIZE: usize = 32;
 pub const MAX_HASH_BLOCK_SIZE: usize = 64;

diff --git a/src/hss/mod.rs b/src/hss/mod.rs
@@ -301,7 +301,7 @@ mod tests {
     use super::parameter::HssParameter;
     use crate::util::helper::test_helper::gen_random_seed;
     use crate::{
-        constants::{HSS_COMPRESSED_USED_LEAFS_SIZE, MAX_HASH_SIZE, REF_IMPL_SSTS_EXT_SIZE},
+        constants::{HSS_COMPRESSED_USED_LEAFS_SIZE, MAX_HASH_SIZE, SST_SIZE},
         hasher::{
             sha256::{Sha256_128, Sha256_192, Sha256_256},
             shake256::{Shake256_128, Shake256_192, Shake256_256},
@@ -348,12 +348,12 @@ mod tests {
         assert_ne!(signing_key.as_slice(), signing_key_const.as_slice());
 
         assert_eq!(
-            signing_key.as_slice()[..REF_IMPL_SSTS_EXT_SIZE],
-            signing_key_const.as_slice()[..REF_IMPL_SSTS_EXT_SIZE]
+            signing_key.as_slice()[..SST_SIZE],
+            signing_key_const.as_slice()[..SST_SIZE]
         );
         assert_eq!(
-            signing_key.as_slice()[REF_IMPL_SSTS_EXT_SIZE + HSS_COMPRESSED_USED_LEAFS_SIZE..],
-            signing_key_const.as_slice()[REF_IMPL_SSTS_EXT_SIZE + HSS_COMPRESSED_USED_LEAFS_SIZE..]
+            signing_key.as_slice()[SST_SIZE + HSS_COMPRESSED_USED_LEAFS_SIZE..],
+            signing_key_const.as_slice()[SST_SIZE + HSS_COMPRESSED_USED_LEAFS_SIZE..]
         );
     }
 
@@ -409,9 +409,7 @@ mod tests {
             );
         }
         assert_eq!(
-            signing_key.as_slice()[(REF_IMPL_MAX_PRIVATE_KEY_SIZE
-                - REF_IMPL_SSTS_EXT_SIZE
-                - H::OUTPUT_SIZE as usize)..],
+            signing_key.as_slice()[(REF_IMPL_MAX_PRIVATE_KEY_SIZE - H::OUTPUT_SIZE as usize)..],
             [0u8; H::OUTPUT_SIZE as usize],
         );
     }

diff --git a/src/hss/reference_impl_private_key.rs b/src/hss/reference_impl_private_key.rs
@@ -1,9 +1,9 @@
 use crate::{
     constants::{
         LmsTreeIdentifier, D_TOPSEED, HSS_COMPRESSED_USED_LEAFS_SIZE, ILEN, MAX_ALLOWED_HSS_LEVELS,
-        MAX_HASH_SIZE, MAX_SEED_LEN, REF_IMPL_MAX_PRIVATE_KEY_SIZE, REF_IMPL_SSTS_EXT_SIZE,
-        SEED_CHILD_SEED, SEED_SIGNATURE_RANDOMIZER_SEED, TOPSEED_D, TOPSEED_LEN, TOPSEED_SEED,
-        TOPSEED_WHICH,
+        MAX_HASH_SIZE, MAX_SEED_LEN, REF_IMPL_MAX_PRIVATE_KEY_SIZE, SEED_CHILD_SEED,
+        SEED_SIGNATURE_RANDOMIZER_SEED, SST_IMPL_MAX_PRIVATE_KEY_SIZE, SST_SIZE, TOPSEED_D,
+        TOPSEED_LEN, TOPSEED_SEED, TOPSEED_WHICH,
     },
     hasher::HashChain,
     hss::{definitions::HssPrivateKey, seed_derive::SeedDerive},
@@ -146,9 +146,7 @@ impl<H: HashChain> ReferenceImplPrivateKey<H> {
 
     pub fn from_binary_representation(data: &[u8]) -> Result<Self, ()> {
         if data.len() != REF_IMPL_MAX_PRIVATE_KEY_SIZE - MAX_SEED_LEN + H::OUTPUT_SIZE as usize
-            && data.len()
-                != REF_IMPL_MAX_PRIVATE_KEY_SIZE - MAX_SEED_LEN + H::OUTPUT_SIZE as usize
-                    - REF_IMPL_SSTS_EXT_SIZE
+            && data.len() != SST_IMPL_MAX_PRIVATE_KEY_SIZE - MAX_SEED_LEN + H::OUTPUT_SIZE as usize
         {
             // TODO/Review: why don't we just use REF_IMPL_MAX_PRIVATE_KEY_SIZE? (as in "SigningKey")?
             return Err(());
@@ -157,8 +155,8 @@ impl<H: HashChain> ReferenceImplPrivateKey<H> {
         let mut result = Self::default();
         let mut index = 0;
 
-        if data.len() == REF_IMPL_MAX_PRIVATE_KEY_SIZE - MAX_SEED_LEN + H::OUTPUT_SIZE as usize {
-            let ssts_ext = read_and_advance(data, REF_IMPL_SSTS_EXT_SIZE, &mut index);
+        if data.len() == SST_IMPL_MAX_PRIVATE_KEY_SIZE - MAX_SEED_LEN + H::OUTPUT_SIZE as usize {
+            let ssts_ext = read_and_advance(data, SST_SIZE, &mut index);
             result.sst_ext = SstExtension::from_slice(ssts_ext)?;
         }
 

diff --git a/src/sst/parameters.rs b/src/sst/parameters.rs
@@ -52,7 +52,7 @@ impl SstExtension {
     //   "this returns a `Result<_, ()>`" and "use a custom `Error` type instead"
     //   see "Result<Self, ()>" in "hss/reference_impl_private_key.rs" -> CompressedParameterSet
     pub fn from_slice(data: &[u8]) -> Result<Self, ()> {
-        if data.len() != constants::REF_IMPL_SSTS_EXT_SIZE {
+        if data.len() != constants::SST_SIZE {
             return Err(());
         }