4 files changed, 125 insertions, 0 deletions
diff --git a/src/demo_hash.rs b/src/demo_hash.rs
new file mode 100644
index 0000000..115a10f
--- /dev/null
+++ b/src/demo_hash.rs
@@ -0,0 +1,23 @@
+use sha2::Digest;
+
+pub fn hash_bigint(n: usize, i: &num::BigInt) -> Vec<u8>
+{
+    let (_, bytes) = i.to_bytes_be();
+    assert!(bytes.len() <= n);
+
+    let mut hash = sha2::Sha512::new();
+    hash.input(vec![0; n - bytes.len()]);
+    hash.input(bytes);
+
+    hash.result().to_vec()
+}
+
+pub fn show_hash(h: &Vec<u8>)
+{
+    for x in h
+    {
+        print!("{:02x}", x);
+    }
+
+    println!();
+}
diff --git a/src/iter.rs b/src/iter.rs
new file mode 100644
index 0000000..f8aa6cb
--- /dev/null
+++ b/src/iter.rs
@@ -0,0 +1,10 @@
+use num::BigInt;
+
+pub fn next(v: &BigInt) -> BigInt
+{
+    /*let t: BigUint = v | (v - 1);
+    (t + 1) | (((!t & -!t) - 1) >> (v.trailing_zeros() + 1))*/
+
+    let t: BigInt = (v | (v - 1u32)) + 1u32;
+    &t | ((((&t & -&t) / (v & -v)) >> 1) - 1u32)
+}
diff --git a/src/load_file.rs b/src/load_file.rs
new file mode 100644
index 0000000..0fd1541
--- /dev/null
+++ b/src/load_file.rs
@@ -0,0 +1,12 @@
+use std::fs::File;
+use std::io::Read;
+
+pub fn load_file_vec(path: &String) -> std::io::Result<Vec<u8>>
+{
+    let mut file = File::open(path)?;
+    let mut data = Vec::new();
+
+    file.read_to_end(&mut data)?;
+
+    Ok(data)
+}
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..bfed16b
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,80 @@
+mod iter;
+mod load_file;
+mod demo_hash;
+
+use num::BigInt;
+use num::bigint::Sign;
+
+fn vec_pop_cnt(v: &Vec<u8>) -> u32
+{
+    let mut cnt = 0;
+
+    for x in v
+    {
+        cnt += x.count_ones();
+    }
+
+    cnt
+}
+
+fn pop_cnt_vec(c: u32) -> Vec<u8>
+{
+    let mut v = Vec::new();
+    v.push(2u8.pow(c % 8) - 1);
+    for _ in 0..(c / 8)
+    {
+        v.push(0xff);
+    }
+
+    v
+}
+
+fn main()
+{
+    /* "Compression" setup */
+    let raw_file = load_file::load_file_vec(&"data.bin".to_owned()).unwrap();
+    let size = raw_file.len();
+    let popcnt = vec_pop_cnt(&raw_file);
+    let bi_file = BigInt::from_bytes_be(Sign::Plus, &raw_file);
+    let solution_hash = demo_hash::hash_bigint(size, &bi_file);
+
+    println!("Length: {}", size);
+    print!("SHA512: ");
+    demo_hash::show_hash(&solution_hash);
+    println!("popcnt: {}", popcnt);
+
+    /*
+    //           ,  ,
+    for _ in 0..1000000
+    {
+        bi = iter::next(&bi);
+    }
+
+    println!("{:x}", bi);
+    panic!("stopping after benchmark");
+    */
+
+    //panic!("Performing compress only");
+
+    /* "Decompression" loop */
+    let raw = pop_cnt_vec(popcnt);
+    let mut bi = BigInt::from_bytes_be(Sign::Plus, &raw);
+
+    loop
+    {
+        let iteration_hash = demo_hash::hash_bigint(size, &bi);
+        //println!("{:b}", bi);
+        //println!();
+
+        if iteration_hash == solution_hash
+        {
+            demo_hash::show_hash(&iteration_hash);
+            break;
+        }
+
+        bi = iter::next(&bi);
+    }
+
+    println!("Found hash (data follows)!!!");
+    println!("{:x}", bi);
+}