Update SHA-256 examples

Author: Avaneesh-axiom

examples/sha2/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "sha2-example"
+version = "0.0.0"
+edition = "2021"
+
+[workspace]
+members = []
+
+[dependencies]
+# TODO: update rev after PR is merged
+openvm = { git = "https://github.com/openvm-org/openvm.git", features = [
+    "std",
+], rev = "5180cea6342f43ac6523e0057e73e0dc9ecece3a"}
+# TODO: update rev after PR is merged
+openvm-sha2-guest = { git = "https://github.com/openvm-org/openvm.git", rev = "5180cea6342f43ac6523e0057e73e0dc9ecece3a" }
+hex = { version = "0.4.3" }
+
+[features]
+default = []

examples/sha2/openvm.toml

@@ -0,0 +1,4 @@
+[app_vm_config.rv32i]
+[app_vm_config.rv32m]
+[app_vm_config.io]
+[app_vm_config.sha256]

examples/sha2/src/main.rs

@@ -0,0 +1,39 @@
+// ANCHOR: imports
+use core::hint::black_box;
+
+use hex::FromHex;
+use openvm_sha2_guest::{sha256, sha384, sha512};
+// ANCHOR_END: imports
+
+// ANCHOR: main
+openvm::entry!(main);
+
+pub fn main() {
+    let test_vectors = [(
+        "",
+        "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
+        "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e",
+        "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b",
+    )];
+    for (input, expected_output_sha256, expected_output_sha512, expected_output_sha384) in
+        test_vectors.iter()
+    {
+        let input = Vec::from_hex(input).unwrap();
+        let expected_output_sha256 = Vec::from_hex(expected_output_sha256).unwrap();
+        let expected_output_sha512 = Vec::from_hex(expected_output_sha512).unwrap();
+        let expected_output_sha384 = Vec::from_hex(expected_output_sha384).unwrap();
+        let output = sha256(black_box(&input));
+        if output != *expected_output_sha256 {
+            panic!();
+        }
+        let output = sha512(black_box(&input));
+        if output != *expected_output_sha512 {
+            panic!();
+        }
+        let output = sha384(black_box(&input));
+        if output != *expected_output_sha384 {
+            panic!();
+        }
+    }
+}
+// ANCHOR_END: main