1 files changed, 73 insertions, 0 deletions
diff --git a/src/token.rs b/src/token.rs
new file mode 100644
index 0000000..2a2e446
--- /dev/null
+++ b/src/token.rs
@@ -0,0 +1,73 @@
+///! Token generation
+use std::iter::*;
+
+use crypto::bcrypt::bcrypt;
+
+pub struct TokenGenerator {
+    /// Salt for bcrypt
+    salt: Vec<u8>,
+    /// bcrypt cost factor, defaults to 10
+    bcrypt_cost: u32,
+    // length of a tokens valid time in seconds
+    pub valid_duration_secs: i64,
+}
+
+impl TokenGenerator {
+    pub fn new(valid_duration_secs: i64, salt: Vec<u8>) -> TokenGenerator {
+        TokenGenerator {
+            salt: salt,
+            bcrypt_cost: 10,
+            valid_duration_secs: valid_duration_secs
+        }
+    }
+
+    /// Return (from, to, token)
+    pub fn generate_token(&self, username: &str, at_time: i64) -> (i64, i64, String) {
+        let timeslot = at_time - (at_time % self.valid_duration_secs);
+        let input: String = format!("{}{}", username, timeslot);
+        return (timeslot, timeslot + self.valid_duration_secs, self.make_hash_token(&input.as_bytes()))
+    }
+
+    #[inline(always)]
+    pub fn generate_token_norm(&self, username: &str, at_time: i64) -> (i64, i64, String) {
+        let (valid_from, valid_to, tok) = self.generate_token(username, at_time);
+        return (valid_from, valid_to, normalize_token(tok.as_str()));
+    }
+
+    fn make_hash_token(&self, input: &[u8]) -> String {
+        let mut out = [0u8; 24];
+        bcrypt(self.bcrypt_cost, &self.salt, input, &mut out);
+        let fold_func = { |acc, &e| acc ^ e };
+        return format!("{:02X}-{:02X}-{:02X}",
+                       out[0..7].into_iter().fold(0xff, &fold_func),
+                       out[8..15].into_iter().fold(0xff, &fold_func),
+                       out[16..23].into_iter().fold(0xff, &fold_func))
+    }
+}
+
+
+pub fn normalize_token(token: &str) -> String {
+    token.to_lowercase().chars().filter(|c| c.is_digit(16)).collect::<String>()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+
+    #[test]
+    fn test_normalize_token() {
+        assert_eq!(normalize_token(&"7A-74-F4".to_string()), "7a74f4");
+    }
+
+    #[test]
+    fn test_generate_token() {
+        use time;
+        let tg = TokenGenerator::new(time::Duration::hours(2).num_seconds(),
+                                     vec!(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16));
+        let (valid_from, valid_until, result) = tg.generate_token("a", 99999999);
+        assert_eq!( valid_from, 99993600);
+        assert_eq!( valid_until, 100000800);
+        assert_eq!( result, "7A-74-F4");
+    }
+}
+\ No newline at end of file