Crypto Requirements

Crypto Requirements		status: draft security: YES safety: QM
tags: crypto version: 1 realizes: wp__requirements_comp
doc__crypto_requirements		Generic Document

Hash Functionality

The requirements in this section specify behavior provided by the Crypto component’s hash API. They do not make qualification claims about a complete deployed system.

Support SHA-2 hash algorithms		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing_algo_sha2 satisfied by: comp__crypto
The Crypto component shall provide SHA-256, SHA-384, and SHA-512 hash operations.
comp_req__crypto__hash_algorithms		Component Requirement

Provide streaming hash operation		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
The Crypto component shall support incremental hashing through the ordered Init(), zero or more Update(), and Finalize() operations.
comp_req__crypto__hash_streaming		Component Requirement

Provide single-shot hash operation		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
The Crypto component shall support hashing an input buffer through SingleShot() and shall produce the same digest as the corresponding streaming operation.
comp_req__crypto__hash_single_shot		Component Requirement

Report hash digest size		status: valid security: YES safety: QM
tags: crypto reqtype: Interface version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
For each supported hash algorithm, the Crypto component shall expose through the hash interface the digest output size, in bytes, required by that algorithm.
comp_req__crypto__hash_digest_size		Component Requirement

Reject undersized hash output buffers		status: valid security: YES safety: QM
tags: crypto reqtype: Interface version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
The Crypto component shall reject a hash operation when the caller-provided output buffer is smaller than the digest size of the configured algorithm.
comp_req__crypto__hash_output_buffer		Component Requirement

Preserve hash state after output-buffer validation		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
When streaming hash finalization reports that the output buffer is too small, the Crypto component shall preserve the active hash state so that Finalize() can be retried with a sufficient output buffer.
comp_req__crypto__hash_output_buffer_retry		Component Requirement

Reject unsupported hash algorithms		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
The Crypto component shall report an unsupported-algorithm error when a hash algorithm cannot be resolved by the selected provider and shall not substitute a digest size or another algorithm.
comp_req__crypto__hash_unsupported_algorithm		Component Requirement

Maintain provider-independent hash results		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
For each supported hash algorithm, the Crypto stack shall return identical digests for identical input bytes independent of the selected provider.
comp_req__crypto__hash_provider_parity		Component Requirement

Provider Selection

Honor preferred-provider fallback for context creation		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__sw_fallback satisfied by: comp__crypto
When context creation requests a preferred provider category, the Crypto component shall use the corresponding fallback category only if the preferred provider is unavailable or does not support the requested operation.
comp_req__crypto__provider_fallback		Component Requirement

Hash Context Lifecycle

Reset reusable hash contexts		status: valid security: YES safety: QM
tags: crypto reqtype: Functional version: 1 derived from: feat_req__sec_crypt__hashing satisfied by: comp__crypto
The Crypto component shall allow an initialized or completed hash context to be reset to the idle state without changing its algorithm or provider binding.
comp_req__crypto__hash_context_reset		Component Requirement