feat: add SHA-256 and SHA-512 wrapper implementations

  Implements Hasher, HasherExt, and ElementHasher traits for SHA2 hash functions.
  Includes NIST test vectors and property-based tests.

  Closes #689

Author: Farukest

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## 0.20.0 (TBD)
 
+- Added SHA-256 and SHA-512 hash function wrappers ([#692](https://github.com/0xMiden/crypto/pull/692)).
 - Added `+ Sync` bound to `StorageError` and `LargeSmtError` ([#680](https://github.com/0xMiden/crypto/pull/680)).
 - 
 ## 0.19.2 (2025-12-04)

miden-crypto/src/hash/mod.rs

@@ -8,6 +8,9 @@ pub mod blake;
 /// Keccak hash function.
 pub mod keccak;
 
+/// SHA-2 hash functions (SHA-256 and SHA-512).
+pub mod sha2;
+
 /// Poseidon2 hash function.
 pub mod poseidon2 {
     pub use super::algebraic_sponge::poseidon2::Poseidon2;