1 files changed, 47 insertions, 0 deletions
diff --git a/src/k_anon.rs b/src/k_anon.rs
new file mode 100644
index 0000000..b8b7757
--- /dev/null
+++ b/src/k_anon.rs
@@ -0,0 +1,47 @@
+// checkpw - Check passwords against pwnedpasswords.com
+// Copyright (C) 2018  Harald Eilertsen <haraldei@anduin.net>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+use ring::digest;
+
+//
+// Convert a slice of bytes into a string of hex values
+//
+fn to_hex(data: &[u8]) -> String {
+    data.iter().map(|b| format!("{:02X}", b)).collect()
+}
+
+#[test]
+fn test_to_hex() {
+    let input = [0x01, 0x00, 0xff, 0xaa, 0x10, 0x07];
+    assert_eq!(to_hex(&input), "0100FFAA1007");
+}
+
+///
+/// Split the digest into the range and rest parts for k-anonymity
+///
+pub fn to_k_anon(d: digest::Digest) -> (String, String) {
+    let mut hash = to_hex(d.as_ref());
+    let rest = hash.split_off(5);
+    (hash, rest)
+}
+
+#[test]
+fn test_k_anon() {
+    let input = digest::digest(&digest::SHA1, "Passw0rd".as_bytes());
+    let (range, rest) = to_k_anon(input);
+    assert_eq!(&range, "EBFC7");
+    assert_eq!(&rest, "910077770C8340F63CD2DCA2AC1F120444F");
+}