Initial population of solana-program-sdk

sdk/program/src/hash.rs

@@ -0,0 +1,186 @@
+//! The `hash` module provides functions for creating SHA-256 hashes.
+
+use crate::sanitize::Sanitize;
+use sha2::{Digest, Sha256};
+use std::{convert::TryFrom, fmt, mem, str::FromStr};
+use thiserror::Error;
+
+pub const HASH_BYTES: usize = 32;
+#[derive(
+    Serialize, Deserialize, Clone, Copy, Default, Eq, PartialEq, Ord, PartialOrd, Hash, AbiExample,
+)]
+#[repr(transparent)]
+pub struct Hash(pub [u8; HASH_BYTES]);
+
+#[derive(Clone, Default)]
+pub struct Hasher {
+    hasher: Sha256,
+}
+
+impl Hasher {
+    pub fn hash(&mut self, val: &[u8]) {
+        self.hasher.input(val);
+    }
+    pub fn hashv(&mut self, vals: &[&[u8]]) {
+        for val in vals {
+            self.hash(val);
+        }
+    }
+    pub fn result(self) -> Hash {
+        // At the time of this writing, the sha2 library is stuck on an old version
+        // of generic_array (0.9.0). Decouple ourselves with a clone to our version.
+        Hash(<[u8; HASH_BYTES]>::try_from(self.hasher.result().as_slice()).unwrap())
+    }
+}
+
+impl Sanitize for Hash {}
+
+impl AsRef<[u8]> for Hash {
+    fn as_ref(&self) -> &[u8] {
+        &self.0[..]
+    }
+}
+
+impl fmt::Debug for Hash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", bs58::encode(self.0).into_string())
+    }
+}
+
+impl fmt::Display for Hash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", bs58::encode(self.0).into_string())
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum ParseHashError {
+    #[error("string decoded to wrong size for hash")]
+    WrongSize,
+    #[error("failed to decoded string to hash")]
+    Invalid,
+}
+
+impl FromStr for Hash {
+    type Err = ParseHashError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let bytes = bs58::decode(s)
+            .into_vec()
+            .map_err(|_| ParseHashError::Invalid)?;
+        if bytes.len() != mem::size_of::<Hash>() {
+            Err(ParseHashError::WrongSize)
+        } else {
+            Ok(Hash::new(&bytes))
+        }
+    }
+}
+
+impl Hash {
+    pub fn new(hash_slice: &[u8]) -> Self {
+        Hash(<[u8; HASH_BYTES]>::try_from(hash_slice).unwrap())
+    }
+
+    pub const fn new_from_array(hash_array: [u8; HASH_BYTES]) -> Self {
+        Self(hash_array)
+    }
+
+    /// unique Hash for tests and benchmarks.
+    pub fn new_unique() -> Self {
+        use std::sync::atomic::{AtomicU64, Ordering};
+        static I: AtomicU64 = AtomicU64::new(1);
+
+        let mut b = [0u8; HASH_BYTES];
+        let i = I.fetch_add(1, Ordering::Relaxed);
+        b[0..8].copy_from_slice(&i.to_le_bytes());
+        Self::new(&b)
+    }
+
+    pub fn to_bytes(self) -> [u8; HASH_BYTES] {
+        self.0
+    }
+}
+
+/// Return a Sha256 hash for the given data.
+pub fn hashv(vals: &[&[u8]]) -> Hash {
+    // Perform the calculation inline, calling this from within a program is
+    // not supported
+    #[cfg(not(target_arch = "bpf"))]
+    {
+        let mut hasher = Hasher::default();
+        hasher.hashv(vals);
+        hasher.result()
+    }
+    // Call via a system call to perform the calculation
+    #[cfg(target_arch = "bpf")]
+    {
+        extern "C" {
+            fn sol_sha256(vals: *const u8, val_len: u64, hash_result: *mut u8) -> u64;
+        };
+        let mut hash_result = [0; HASH_BYTES];
+        unsafe {
+            sol_sha256(
+                vals as *const _ as *const u8,
+                vals.len() as u64,
+                &mut hash_result as *mut _ as *mut u8,
+            );
+        }
+        Hash::new_from_array(hash_result)
+    }
+}
+
+/// Return a Sha256 hash for the given data.
+pub fn hash(val: &[u8]) -> Hash {
+    hashv(&[val])
+}
+
+/// Return the hash of the given hash extended with the given value.
+pub fn extend_and_hash(id: &Hash, val: &[u8]) -> Hash {
+    let mut hash_data = id.as_ref().to_vec();
+    hash_data.extend_from_slice(val);
+    hash(&hash_data)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_new_unique() {
+        assert!(Hash::new_unique() != Hash::new_unique());
+    }
+
+    #[test]
+    fn test_hash_fromstr() {
+        let hash = hash(&[1u8]);
+
+        let mut hash_base58_str = bs58::encode(hash).into_string();
+
+        assert_eq!(hash_base58_str.parse::<Hash>(), Ok(hash));
+
+        hash_base58_str.push_str(&bs58::encode(hash.0).into_string());
+        assert_eq!(
+            hash_base58_str.parse::<Hash>(),
+            Err(ParseHashError::WrongSize)
+        );
+
+        hash_base58_str.truncate(hash_base58_str.len() / 2);
+        assert_eq!(hash_base58_str.parse::<Hash>(), Ok(hash));
+
+        hash_base58_str.truncate(hash_base58_str.len() / 2);
+        assert_eq!(
+            hash_base58_str.parse::<Hash>(),
+            Err(ParseHashError::WrongSize)
+        );
+
+        let mut hash_base58_str = bs58::encode(hash.0).into_string();
+        assert_eq!(hash_base58_str.parse::<Hash>(), Ok(hash));
+
+        // throw some non-base58 stuff in there
+        hash_base58_str.replace_range(..1, "I");
+        assert_eq!(
+            hash_base58_str.parse::<Hash>(),
+            Err(ParseHashError::Invalid)
+        );
+    }
+}