2016/05

2016/05/src/main.rs

@@ -0,0 +1,109 @@
+extern crate crypto;
+
+use std::u64;
+
+use crypto::md5::Md5;
+use crypto::digest::Digest;
+
+
+struct Hasher {
+    md5: Md5,
+    index: u64,
+    secret: String
+}
+
+impl Hasher {
+    pub fn new(secret: &str) -> Self {
+        Hasher {
+            md5: Md5::new(),
+            index: 0,
+            secret: String::from(secret)
+        }
+    }
+}
+
+impl Iterator for Hasher {
+    type Item = String;
+
+    fn next(&mut self) -> Option<String> {
+        let input = format!("{}{}", self.secret, self.index);
+
+        self.md5.reset();
+        self.md5.input(input.as_bytes());
+
+        self.index += 1;
+
+        Some(self.md5.result_str())
+    }
+}
+
+
+fn main() {
+    let password = generate_week_password("ojvtpuvg");
+
+    println!("week_password={}", password);
+
+    let password = generate_strong_password("ojvtpuvg");
+
+    println!("strong_password={}", password);
+}
+
+pub fn generate_week_password(sector_id: &str) -> String {
+    Hasher::new(sector_id)
+        .filter(|x| x.starts_with("00000"))
+        .map(|x| x.as_bytes()[5] as char)
+        .take(8)
+        .collect::<String>()
+}
+
+pub fn generate_strong_password(sector_id: &str) -> String {
+    let iter = Hasher::new(sector_id)
+        .filter(|x| x.starts_with("00000"))
+        .filter_map(|x| {
+            let bytes = x.as_bytes();
+
+            if (bytes[5] as char) < '8' {
+                Some(((bytes[5] - 48) as usize, bytes[6] as char))
+            } else {
+                None
+            }
+        });
+
+    let mut password: Vec<Option<char>> = vec![None; 8];
+
+    let mut i = 0;
+
+    for (pos, ch) in iter {
+        if password[pos].is_some() {
+            continue;
+        }
+
+        password[pos] = Some(ch);
+
+        i += 1;
+
+        if i >= 8 {
+            break;
+        }
+    }
+
+    password.iter()
+        .filter_map(|x| *x)
+        .collect::<String>()
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn example_01() {
+        assert_eq!(String::from("18f47a30"), generate_week_password("abc"));
+    }
+
+    #[test]
+    fn example_02() {
+        assert_eq!(String::from("05ace8e3"), generate_strong_password("abc"));
+    }
+}