Merge branch 'alex/rm-csprng-seed-from-random-tape' into 'master'

chore(crypto): CRP-2106 remove unused `Csprng::seed_from_random_tape`

Closes CRP-2106. 

Closes CRP-2106

See merge request dfinity-lab/public/ic!19290

rs/crypto/prng/src/lib.rs

@@ -1,6 +1,6 @@
 //! Offers cryptographically secure pseudorandom number generation (CSPRNG).
 use ic_crypto_sha2::{DomainSeparationContext, Sha256};
-use ic_types::consensus::{RandomBeacon, RandomTape};
+use ic_types::consensus::RandomBeacon;
 use ic_types::crypto::CryptoHashable;
 use ic_types::Randomness;
 use rand::{CryptoRng, Error, RngCore, SeedableRng};
@@ -54,14 +54,6 @@ impl Csprng {
         }
     }
 
-    /// Creates a CSPRNG seed from the given random tape.
-    ///
-    /// The returned seed can be used to create a CSPRNG with
-    /// `Csprng::from_seed_and_purpose`.
-    pub fn seed_from_random_tape(random_tape: &RandomTape) -> Randomness {
-        Csprng::seed_from_crypto_hashable(random_tape)
-    }
-
     /// Creates a CSPRNG seed from the given crypto hashable.
     fn seed_from_crypto_hashable<T: CryptoHashable>(crypto_hashable: &T) -> Randomness {
         let mut hasher =

rs/crypto/prng/tests/tests.rs

@@ -2,8 +2,8 @@ use ic_crypto_prng::RandomnessPurpose::{
     BlockmakerRanking, CommitteeSampling, DkgCommitteeSampling, ExecutionThread,
 };
 use ic_crypto_prng::{Csprng, RandomnessPurpose};
-use ic_types::consensus::{RandomBeacon, RandomTape};
-use ic_types::consensus::{RandomBeaconContent, RandomTapeContent};
+use ic_types::consensus::RandomBeacon;
+use ic_types::consensus::RandomBeaconContent;
 use ic_types::crypto::{
     CombinedThresholdSig, CombinedThresholdSigOf, CryptoHash, CryptoHashOf, Signed,
 };
@@ -62,23 +62,6 @@ fn should_produce_deterministic_randomness_from_seed_and_purpose() {
     assert_eq!(rng.next_u32(), 196_996_056);
 }
 
-#[test]
-fn should_produce_deterministic_randomness_from_seed_from_random_tape() {
-    fix_replica_version();
-
-    let random_tape = fake_random_tape(1);
-
-    let randomness = Csprng::seed_from_random_tape(&random_tape);
-
-    assert_eq!(
-        randomness.get(),
-        [
-            109, 145, 169, 77, 62, 78, 152, 146, 147, 81, 94, 181, 213, 81, 105, 131, 60, 109, 217,
-            138, 33, 26, 94, 209, 110, 76, 228, 189, 126, 119, 13, 2
-        ]
-    );
-}
-
 #[test]
 fn should_offer_methods_of_rng_trait() {
     use rand::Rng;
@@ -181,19 +164,6 @@ fn should_produce_different_randomness_for_different_execution_threads_for_rando
     assert_ne!(csprng1.next_u32(), csprng2.next_u32());
 }
 
-#[test]
-fn should_produce_different_seeds_for_different_random_tapes() {
-    fix_replica_version();
-
-    let (tape_1, tape_2) = (random_tape(), random_tape_2());
-    assert_ne!(tape_1, tape_2);
-
-    let seed_1 = Csprng::seed_from_random_tape(&tape_1);
-    let seed_2 = Csprng::seed_from_random_tape(&tape_2);
-
-    assert_ne!(seed_1, seed_2);
-}
-
 fn fake_random_beacon(height: u64) -> RandomBeacon {
     Signed {
         content: RandomBeaconContent::new(
@@ -215,14 +185,6 @@ fn random_beacon_2() -> RandomBeacon {
     fake_random_beacon(2)
 }
 
-fn random_tape() -> RandomTape {
-    fake_random_tape(1)
-}
-
-fn random_tape_2() -> RandomTape {
-    fake_random_tape(2)
-}
-
 fn seed() -> Randomness {
     Randomness::new([123; 32])
 }
@@ -239,13 +201,3 @@ fn fake_dkg_id(h: u64) -> NiDkgId {
         target_subnet: NiDkgTargetSubnet::Local,
     }
 }
-
-fn fake_random_tape(height: u64) -> RandomTape {
-    Signed {
-        content: RandomTapeContent::new(Height::from(height)),
-        signature: ThresholdSignature {
-            signer: fake_dkg_id(0),
-            signature: CombinedThresholdSigOf::new(CombinedThresholdSig(vec![])),
-        },
-    }
-}