Expose PRNG functions

Other Changes:

* Add tests for `sha256` and `verify_sig_ed25519`

soroban-sdk/src/crypto.rs

@@ -1,5 +1,5 @@
 //! Crypto contains functions for cryptographic functions.
-use crate::{env::internal, unwrap::UnwrapInfallible, Bytes, BytesN, Env};
+use crate::{env::internal, unwrap::UnwrapInfallible, Bytes, BytesN, Env, VecObject};
 
 /// Crypto provides access to cryptographic functions.
 pub struct Crypto {
@@ -22,6 +22,28 @@ impl Crypto {
         unsafe { BytesN::unchecked_new(env.clone(), bin) }
     }
 
+    // Reseeds the pseudorandom number generator (PRNG) with the provided `seed` value.
+    pub fn prng_reseed(&self, seed: &Bytes) {
+        let env = self.env();
+        internal::Env::prng_reseed(env, seed.into()).unwrap_infallible();
+    }
+
+    // Returns a random u64 in the range between `lower` and `upper` inclusive.
+    pub fn u64_in_inclusive_range(&self, lower: u64, upper: u64) -> u64 {
+        let env = self.env();
+        internal::Env::prng_u64_in_inclusive_range(env, lower.into(), upper.into())
+            .unwrap_infallible()
+            .into()
+    }
+
+    // Shuffles a given vector v using the Fisher-Yates algorithm.
+    pub fn vec_shuffle(&self, v: VecObject) -> VecObject {
+        let env = self.env();
+        internal::Env::prng_vec_shuffle(env, v.into())
+            .unwrap_infallible()
+            .into()
+    }
+
     /// Verifies an ed25519 signature.
     ///
     /// The signature is verified as a valid signature of the message by the

soroban-sdk/src/tests.rs

@@ -16,6 +16,7 @@ mod contract_udt_struct;
 mod contract_udt_struct_tuple;
 mod contractimport;
 mod contractimport_with_error;
+mod crypto;
 mod env;
 mod proptest_scval_cmp;
 mod proptest_val_cmp;

soroban-sdk/src/tests/crypto.rs

@@ -0,0 +1,131 @@
+use crate::{self as soroban_sdk};
+use crate::{bytes, bytesn, vec, Bytes, BytesN, Env, IntoVal, Vec};
+use soroban_sdk::{contract, contractimpl};
+
+#[contract]
+pub struct TestCryptoContract;
+
+#[contractimpl]
+impl TestCryptoContract {
+    pub fn sha256(env: Env, bytes: Bytes) -> BytesN<32> {
+        env.crypto().sha256(&bytes)
+    }
+
+    pub fn prng_reseed(env: Env, bytes: Bytes) {
+        env.crypto().prng_reseed(&bytes);
+    }
+
+    pub fn u64_in_inclusive_range(env: Env, min: u64, max: u64) -> u64 {
+        env.crypto().u64_in_inclusive_range(min, max)
+    }
+
+    pub fn vec_shuffle(env: Env, vec: Vec<u32>) -> Vec<u32> {
+        env.crypto().vec_shuffle(vec.into()).into_val(&env)
+    }
+
+    pub fn verify_sig_ed25519(
+        env: Env,
+        public_key: BytesN<32>,
+        message: Bytes,
+        signature: BytesN<64>,
+    ) {
+        env.crypto()
+            .ed25519_verify(&public_key, &message, &signature);
+    }
+}
+
+#[test]
+fn test_prng_reseed() {
+    let env = Env::default();
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    env.host().set_base_prng_seed([0; 32]);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+
+    let seed = bytes!(
+        &env,
+        0x0000000000000000000000000000000000000000000000000000000000000001
+    );
+    assert_eq!(client.u64_in_inclusive_range(&0, &9), 6);
+
+    client.prng_reseed(&seed);
+
+    assert_eq!(client.u64_in_inclusive_range(&0, &9), 8);
+}
+
+#[test]
+fn test_sha256() {
+    let env = Env::default();
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+
+    let bytes = bytes!(&env, 0x01);
+
+    assert_eq!(client.sha256(&bytes), bytesn!(&env, 0x4bf5122f344554c53bde2ebb8cd2b7e3d1600ad631c385a5d7cce23c7785459a));
+}
+
+#[test]
+fn test_vec_shuffle() {
+    let env = Env::default();
+    env.host().set_base_prng_seed([0; 32]);
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+
+    let vec = vec![&env, 1, 2, 3];
+
+    assert_eq!(client.vec_shuffle(&vec), vec![&env, 2, 3, 1]);
+}
+
+#[test]
+fn test_u64_in_inclusive_range() {
+    let env = Env::default();
+    env.host().set_base_prng_seed([0; 32]);
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+
+    assert_eq!(client.u64_in_inclusive_range(&0, &9), 6);
+}
+
+#[test]
+fn test_verify_sig_ed25519() {
+    let env = Env::default();
+    env.host().set_base_prng_seed([0; 32]);
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+    // From https://datatracker.ietf.org/doc/html/rfc8032#section-7.1
+    let public_key: BytesN<32> = bytes!(
+        &env,
+        0x3d4017c3e843895a92b70aa74d1b7ebc9c982ccf2ec4968cc0cd55f12af4660c
+    )
+    .try_into()
+    .unwrap();
+    let signature = bytesn!(
+        &env,
+        0x92a009a9f0d4cab8720e820b5f642540a2b27b5416503f8fb3762223ebdb69da085ac1e43e15996e458f3613d0f11d8c387b2eaeb4302aeeb00d291612bb0c00
+    );
+    let message = bytes!(&env, 0x72);
+
+    assert_eq!(client.verify_sig_ed25519(&public_key, &message, &signature), ());
+}
+
+#[test]
+#[should_panic]
+fn test_verify_sig_ed25519_invalid_sig() {
+    let env = Env::default();
+    env.host().set_base_prng_seed([0; 32]);
+    let contract_id = env.register_contract(None, TestCryptoContract);
+    let client = TestCryptoContractClient::new(&env, &contract_id);
+    // From https://datatracker.ietf.org/doc/html/rfc8032#section-7.1
+    let public_key = bytesn!(
+        &env,
+        0x3d4017c3e843895a92b70aa74d1b7ebc9c982ccf2ec4968cc0cd55f12af4660c
+    )
+    .try_into()
+    .unwrap();
+    let signature = bytesn!(
+        &env,
+        0x92a009a9f0d4cab8720e820b5f642540a2b27b5416503f8fb3762223ebdb69da085ac1e43e15996e458f3613d0f11d8c387b2eaeb4302aeeb00d291612bb0c00
+    );
+    let message = bytes!(&env, 0x73);
+
+    client.verify_sig_ed25519(&public_key, &message, &signature);
+}