Implement remaining_operations() for LMS

randombit · Dec 8, 2023 · f4f6168 · f4f6168
1 parent 6c11f31
commit f4f6168
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Showing 3 changed files with 7 additions and 7 deletions.
diff --git a/src/lib/pubkey/hss_lms/hss_lms.cpp b/src/lib/pubkey/hss_lms/hss_lms.cpp
@@ -146,7 +146,7 @@ AlgorithmIdentifier HSS_LMS_PrivateKey::pkcs8_algorithm_identifier() const {
  return AlgorithmIdentifier(OID::from_string("HSS-LMS-Private-Key"), AlgorithmIdentifier::USE_EMPTY_PARAM);
 }
 
-uint64_t HSS_LMS_PrivateKey::remaining_signatures() const {
+std::optional<uint64_t> HSS_LMS_PrivateKey::remaining_operations() const {
  return (m_private->hss_params().max_sig_count() - m_private->get_idx()).get();
 }
 

diff --git a/src/lib/pubkey/hss_lms/hss_lms.h b/src/lib/pubkey/hss_lms/hss_lms.h
@@ -138,7 +138,7 @@ class BOTAN_PUBLIC_API(3, 2) HSS_LMS_PrivateKey final : public virtual HSS_LMS_P
  /**
  * Retrieves the number of remaining signatures for this private key.
  */
- uint64_t remaining_signatures() const;
+ std::optional<uint64_t> remaining_operations() const override;
 
  std::unique_ptr<Private_Key> generate_another(RandomNumberGenerator& rng) const override;
 

diff --git a/src/tests/test_hss_lms.cpp b/src/tests/test_hss_lms.cpp
@@ -215,7 +215,7 @@ class HSS_LMS_Statefulness_Test final : public Test {
  // Tree hights: 5,5 => 2^(5+5) = 1024 signatures available
  const uint64_t expected_total = 1024;
  result.confirm("Fresh key starts with total number of remaining signatures.",
- sk.remaining_signatures() == expected_total);
+ sk.remaining_operations() == expected_total);
 
  // Creating a signature should update the private key's state
  auto sig_0 = signer.sign_message(mes, Test::rng());
@@ -226,7 +226,7 @@ class HSS_LMS_Statefulness_Test final : public Test {
  auto sk_bytes_after_sig = sk.private_key_bits();
 
  result.confirm("Signature decreases number of remaining signatures.",
- sk.remaining_signatures() == expected_total - 1);
+ sk.remaining_operations() == expected_total - 1);
  result.test_ne("Signature updates private key.", sk_bytes_after_sig, sk_bytes_begin);
 
  auto sig_1 = signer.sign_message(mes, Test::rng());
@@ -247,11 +247,11 @@ class HSS_LMS_Statefulness_Test final : public Test {
  std::vector<uint8_t> mes = {0xde, 0xad, 0xbe, 0xef};
  auto sk_bytes_begin = sk.private_key_bits();
 
- result.confirm("One remaining signature.", sk.remaining_signatures() == uint64_t(1));
+ result.confirm("One remaining signature.", sk.remaining_operations() == uint64_t(1));
  result.test_no_throw("Use last signature index.", [&]() { signer.sign_message(mes, Test::rng()); });
- result.confirm("No remaining signatures.", sk.remaining_signatures() == uint64_t(0));
+ result.confirm("No remaining signatures.", sk.remaining_operations() == uint64_t(0));
  result.test_throws("Cannot sign with exhausted key.", [&]() { signer.sign_message(mes, Test::rng()); });
- result.confirm("Still zero remaining signatures.", sk.remaining_signatures() == uint64_t(0));
+ result.confirm("Still zero remaining signatures.", sk.remaining_operations() == uint64_t(0));
 
  return result;
  }