BIP360: Pay to Merkle Root (P2MR) (#1670)

Review comments and assistance by:
  Armin Sabouri <armins88@gmail.com>
  D++ <82842780+dplusplus1024@users.noreply.github.com>
  Jameson Lopp <jameson.lopp@gmail.com>
  jbride <jbride2001@yahoo.com>
  Joey Yandle <xoloki@gmail.com>
  Jon Atack <jon@atack.com>
  Jonas Nick <jonasd.nick@gmail.com>
  Kyle Crews <kylecrews@Kyles-Mac-Studio.local>
  Mark "Murch" Erhardt <murch@murch.one>
  notmike-5 <notmike-5@users.noreply.github.com>
  Vojtěch Strnad <43024885+vostrnad@users.noreply.github.com>

Co-authored-by: Ethan Heilman <ethan.r.heilman@gmail.com>
Co-authored-by: Isabel Foxen Duke <110147802+Isabelfoxenduke@users.noreply.github.com>

bip-0360/ref-impl/rust/src/bin/slh_dsa_key_gen.rs

@@ -0,0 +1,33 @@
+use std::env;
+use log::info;
+use rand::{rng, RngCore};
+
+use bitcoinpqc::{
+    generate_keypair, public_key_size, secret_key_size, Algorithm, KeyPair,
+};
+
+fn main() {
+    let _ = env_logger::try_init();
+
+    /*
+      In SPHINCS+ (underlying algorithm of SLH-DSA), the random data is used to:
+        * Initialize hash function parameters within the key generation
+        * Seed the Merkle tree construction that forms the public key
+        * Generate the secret key components that enable signing
+     */
+    let random_data = get_random_bytes(128);
+    println!("Generated random data of size {}", random_data.len());
+
+    let keypair: KeyPair = generate_keypair(Algorithm::SLH_DSA_128S, &random_data)
+        .expect("Failed to generate SLH-DSA-128S keypair");
+
+    info!("public key size / value = {}, {}", public_key_size(Algorithm::SLH_DSA_128S), hex::encode(&keypair.public_key.bytes));
+    info!("private key size / value = {}, {}", secret_key_size(Algorithm::SLH_DSA_128S), hex::encode(&keypair.secret_key.bytes));
+
+}
+
+fn get_random_bytes(size: usize) -> Vec<u8> {
+    let mut bytes = vec![0u8; size];
+    rng().fill_bytes(&mut bytes);
+    bytes
+}