crc32 impl

src/hashes.rs

@@ -54,7 +54,7 @@ pub enum HashReturn {
 impl HashReturn {
     pub fn into_bytes(self) -> Arc<[u8]> {
         match self {
-            HashReturn::CRC32(inner) => Arc::new(inner.to_le_bytes()),
+            HashReturn::CRC32(inner) => Arc::new(inner.to_be_bytes()),
             HashReturn::SHA256(inner) => Arc::new(inner),
             HashReturn::SHA3_256(inner) => Arc::new(inner),
             HashReturn::BLAKE256(inner) => Arc::new(inner),

src/hashes/crc32.rs

@@ -1,20 +1,63 @@
 use super::*;
+use crc::Table;
+
+pub enum CRC32TYPE {
+    CKSUM,
+    XFER,
+    ISO,
+}
 
 pub struct CRC32 {
     hash: BITS32,
+    crc32type: CRC32TYPE,
+    digester: ::crc::Digest<'static, u32, Table<16>>,
 }
 
+/// CRC_32_ISO_HDLC
+const CRC32_ISO: ::crc::Crc<u32, Table<16>> =
+    ::crc::Crc::<u32, Table<16>>::new(&::crc::CRC_32_ISO_HDLC);
+pub fn crc32_iso() -> CRC32 {
+    CRC32 {
+        hash: 0,
+        crc32type: CRC32TYPE::ISO,
+        digester: CRC32_ISO.digest(),
+    }
+}
+
+/// CRC_32_XFER
+const CRC32_XFER: ::crc::Crc<u32, Table<16>> =
+    ::crc::Crc::<u32, Table<16>>::new(&::crc::CRC_32_XFER);
+pub fn crc32_xfer() -> CRC32 {
+    CRC32 {
+        hash: 0,
+        crc32type: CRC32TYPE::XFER,
+        digester: CRC32_XFER.digest(),
+    }
+}
+
+/// CRC_32_CKSUM
+const CRC32_CKSUM: ::crc::Crc<u32, Table<16>> =
+    ::crc::Crc::<u32, Table<16>>::new(&::crc::CRC_32_CKSUM);
+pub fn crc32_cksum() -> CRC32 {
+    CRC32 {
+        hash: 0,
+        crc32type: CRC32TYPE::CKSUM,
+        digester: CRC32_CKSUM.digest(),
+    }
+}
 impl Hasher for CRC32 {
+    /// Defaults to CRC32_ISO_HDLC, most likely choice for CRC32
+    /// Use the other crc32_* fns to get other crc32 hasher types
     fn new() -> Self {
-        CRC32 { hash: 0 }
+        crc32_iso()
     }
 
     fn digest(&mut self, bytes: impl AsRef<[u8]>) {
-        todo!()
+        self.digester.update(bytes.as_ref())
     }
 
     fn complete(self) -> HashReturn {
-        todo!()
+        HashReturn::CRC32(self.digester.finalize())
     }
 }
 
@@ -23,7 +66,35 @@ mod test {
     use super::*;
 
     #[test]
-    fn test_crc32_hash() {
-        todo!();
+    fn test_crc32_hashes() {
+        let input_1 = "Hello";
+        let input_2 = "World";
+
+        let expected_iso = "77770c79";
+        let expected_cksum = "b9e23d07";
+        let expected_xfer = "9810e2bb";
+
+        let mut iso = CRC32::new();
+        let mut cksum = crc32_cksum();
+        let mut xfer = crc32_xfer();
+
+        iso.digest(input_1);
+        iso.digest(input_2);
+        cksum.digest(input_1);
+        cksum.digest(input_2);
+        xfer.digest(input_1);
+        xfer.digest(input_2);
+
+        let iso_result = iso.complete().into_bytes();
+        let cksum_result = cksum.complete().into_bytes();
+        let xfer_result = xfer.complete().into_bytes();
+
+        let iso_hash = crate::hex_table::u8_array_to_lower_hex_string(&iso_result).unwrap();
+        let cksum_hash = crate::hex_table::u8_array_to_lower_hex_string(&cksum_result).unwrap();
+        let xfer_hash = crate::hex_table::u8_array_to_lower_hex_string(&xfer_result).unwrap();
+
+        assert_eq!(iso_hash, expected_iso);
+        assert_eq!(cksum_hash, expected_cksum);
+        assert_eq!(xfer_hash, expected_xfer);
     }
 }