diff --git a/Cargo.toml b/Cargo.toml
index 9a66afc..2261f59 100755
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -29,6 +29,8 @@ hmac-sha512 = "1"
 # used while rust doesn't have native benchmarking capability
 brunch = { version = "0.5.3", default-features = false }
 
+# used for testing our crc implementations
+crc = "3"
 
 [features]
 default = ["visual_data"]
@@ -66,6 +68,3 @@ bitflags = { version = "1.3", optional = true }
 
 # needed for dxt/bc decompression
 texture2ddecoder = { version = "0.0.5", optional = true }
-
-# used for testing our jamcrc implementation and currently SHPK
-crc = "3"
\ No newline at end of file
diff --git a/src/crc.rs b/src/crc.rs
index bd687f1..37e08f2 100644
--- a/src/crc.rs
+++ b/src/crc.rs
@@ -1,6 +1,10 @@
 // SPDX-FileCopyrightText: 2023 Joshua Goins <josh@redstrate.com>
 // SPDX-License-Identifier: GPL-3.0-or-later
 
+use std::ops::{Add, AddAssign, BitXor, BitXorAssign};
+use libz_ng_sys::z_off_t;
+
+/// CRC used for filepath hashes in index file
 pub(crate) struct Jamcrc {
     table: [u32; 256],
 }
@@ -40,12 +44,86 @@ impl Jamcrc {
     }
 }
 
+fn crc32(crc: u32, s: &[u8]) -> u32 {
+    unsafe { libz_ng_sys::crc32(crc, s.as_ptr(), s.len() as u32) as u32 }
+}
+
+fn crc32_combine(crc1: u32, crc2: u32, len2: usize) -> u32 {
+    unsafe {  libz_ng_sys::crc32_combine(crc1, crc2, len2 as z_off_t) as u32 }
+}
+
+/// CRC used for shader keys
+/// Credit to https://github.com/NotNite/crcracker/ for the original Rust code
+#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, Default)]
+pub(crate) struct XivCrc32 {
+    pub crc: u32,
+    pub len: usize,
+}
+
+impl XivCrc32 {
+    pub(crate) fn new(crc: u32, len: usize) -> Self {
+        Self {
+            crc,
+            len,
+        }
+    }
+}
+
+impl From<&[u8]> for XivCrc32 {
+    fn from(s: &[u8]) -> Self {
+        Self::new(!crc32(0xFFFFFFFF, s), s.len())
+    }
+}
+
+impl <const N: usize> From<&[u8; N]> for XivCrc32 {
+    fn from(s: &[u8; N]) -> Self {
+        Self::new(!crc32(0xFFFFFFFF, s), N)
+    }
+}
+
+impl From<&str> for XivCrc32 {
+    fn from(s: &str) -> Self {
+        Self::from(s.as_bytes())
+    }
+}
+
+impl Add<XivCrc32> for XivCrc32 {
+    type Output = XivCrc32;
+
+    fn add(self, rhs: XivCrc32) -> Self::Output {
+        Self::new(crc32_combine(self.crc, rhs.crc, rhs.len), self.len + rhs.len)
+    }
+}
+
+impl AddAssign<XivCrc32> for XivCrc32 {
+    fn add_assign(&mut self, rhs: XivCrc32) {
+        self.crc = crc32_combine(self.crc, rhs.crc, rhs.len);
+        self.len += rhs.len;
+    }
+}
+
+impl BitXor<XivCrc32> for XivCrc32 {
+    type Output = XivCrc32;
+
+    fn bitxor(self, rhs: XivCrc32) -> Self::Output {
+        Self::new(self.crc ^ rhs.crc, self.len.max(rhs.len))
+    }
+}
+
+impl BitXorAssign<XivCrc32> for XivCrc32 {
+    fn bitxor_assign(&mut self, rhs: XivCrc32) {
+        self.crc ^= rhs.crc;
+        self.len = self.len.max(rhs.len);
+    }
+}
+
 #[cfg(test)]
 mod tests {
+    use crc::{Algorithm, Crc};
     use super::*;
 
     #[test]
-    fn check_library() {
+    fn check_jamcrc() {
         use crc::{Crc, CRC_32_JAMCRC};
 
         const JAMCR: Crc<u32> = Crc::<u32>::new(&CRC_32_JAMCRC);
@@ -56,4 +134,14 @@ mod tests {
 
         assert_eq!(JAMCR.checksum(&bytes), CRC.checksum(&bytes))
     }
+
+    #[test]
+    fn check_xivcrc() {
+        const CRC_32_TEST: Algorithm<u32> = Algorithm { width: 32, poly: 0x04c11db7, init: 0x00000000, refin: true, refout: true, xorout: 0x00000000, check: 0x765e7680, residue: 0xc704dd7b };
+        const JAMCR: Crc<u32> = Crc::<u32>::new(&CRC_32_TEST);
+
+        let str = "Default";
+
+        assert_eq!(XivCrc32::from(str).crc, JAMCR.checksum(str.as_bytes()));
+    }
 }
diff --git a/src/shpk.rs b/src/shpk.rs
index b2ef658..5e88b44 100644
--- a/src/shpk.rs
+++ b/src/shpk.rs
@@ -5,7 +5,7 @@ use std::io::{Cursor, SeekFrom};
 
 use crate::ByteSpan;
 use binrw::{binread, BinRead};
-use crc::{Algorithm, Crc};
+use crate::crc::XivCrc32;
 
 #[binread]
 #[br(little, import {
@@ -209,10 +209,6 @@ pub struct ShaderPackage {
 
 const SELECTOR_MULTIPLER: u32 = 31;
 
-// TODO: replace use of crc crate here
-const CRC_32_TEST: Algorithm<u32> = Algorithm { width: 32, poly: 0x04c11db7, init: 0x00000000, refin: true, refout: true, xorout: 0x00000000, check: 0x765e7680, residue: 0xc704dd7b };
-const JAMCR: Crc<u32> = Crc::<u32>::new(&CRC_32_TEST);
-
 impl ShaderPackage {
     /// Reads an existing SHPK file
     pub fn from_existing(buffer: ByteSpan) -> Option<ShaderPackage> {
@@ -275,7 +271,7 @@ impl ShaderPackage {
     }
 
     pub fn crc(str: &str) -> u32 {
-        return JAMCR.checksum(str.as_bytes());
+        return XivCrc32::from(str).crc;
     }
 }
 
@@ -283,7 +279,6 @@ impl ShaderPackage {
 mod tests {
     use std::fs::read;
     use std::path::PathBuf;
-    use crate::repository::Category::Shader;
 
     use super::*;