add pow_mod for DHM-Exchange

rust/server/Cargo.lock

@@ -11,6 +11,12 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "bincode"
 version = "1.3.3"
@@ -96,6 +102,8 @@ dependencies = [
  "bincode",
  "byteorder",
  "crc32fast",
+ "num-bigint",
+ "rand",
  "regex",
  "serde",
  "sha2",
@@ -113,6 +121,42 @@ version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
 
+[[package]]
+name = "num-bigint"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f93ab6289c7b344a8a9f60f88d80aa20032336fe78da341afc91c8a2341fc75f"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.59"
@@ -131,6 +175,32 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+
 [[package]]
 name = "regex"
 version = "1.8.3"

rust/server/Cargo.toml

@@ -12,6 +12,8 @@ byteorder = { default-features = false, version = "1.4.3" }
 sha2 = { default-features = false, version = "0.10.6" }
 regex = { default-features = true, version = "1.8.3" }
 crc32fast = { default-features = false, version = "1.3.2" }
+rand = { default-features = false, features = ["std_rng"], version = "0.8.5" }
+num-bigint = { default-features = true, version = "0.4.3" }
 
 [profile.release]
 lto = true          # Enable link-time optimization

rust/server/src/main.rs

@@ -4,6 +4,8 @@ use serde::{Serialize, Deserialize};
 use sha2::{Digest,Sha512};
 use regex::Regex;
 use crc32fast;
+use rand::{rngs::StdRng, RngCore, SeedableRng};
+use num_bigint::BigUint;
 
 mod big_array;
 use big_array::BigArray;
@@ -36,6 +38,18 @@ struct StrPacket {
     payload: [u8; MAX_PAYLOAD_U]
 }
 
+fn pow_mod(num: BigUint, pow: BigUint, modulo: BigUint) -> BigUint {
+    let mut result = BigUint::from(1u8);
+    let one = BigUint::from(1u8);
+    let mut i = BigUint::from(0u8);
+    while i < pow {
+        result = (result * &num) % &modulo;
+        i += &one;
+    }
+
+    result
+}
+
 fn main() {
     let port = "1337";
     let timeout = 100; //ms