add derive methods to Pbkdf2 secrets

sasl/src/secret.rs

@@ -18,6 +18,20 @@ pub struct Pbkdf2Sha1 {
     pub digest: Vec<u8>,
 }
 
+impl Pbkdf2Sha1 {
+    #[cfg(feature = "openssl")]
+    pub fn derive(password: &str, salt: &[u8], iterations: usize) -> Result<Pbkdf2Sha1, String> {
+        use common::scram::{ScramProvider, Sha1};
+        use common::Password;
+        let digest = Sha1::derive(&Password::Plain(password.to_owned()), salt, iterations)?;
+        Ok(Pbkdf2Sha1 {
+            salt: salt.to_vec(),
+            iterations: iterations,
+            digest: digest,
+        })
+    }
+}
+
 impl Secret for Pbkdf2Sha1 {}
 
 impl Pbkdf2Secret for Pbkdf2Sha1 {
@@ -33,6 +47,20 @@ pub struct Pbkdf2Sha256 {
     pub digest: Vec<u8>,
 }
 
+impl Pbkdf2Sha256 {
+    #[cfg(feature = "openssl")]
+    pub fn derive(password: &str, salt: &[u8], iterations: usize) -> Result<Pbkdf2Sha256, String> {
+        use common::scram::{ScramProvider, Sha256};
+        use common::Password;
+        let digest = Sha256::derive(&Password::Plain(password.to_owned()), salt, iterations)?;
+        Ok(Pbkdf2Sha256 {
+            salt: salt.to_vec(),
+            iterations: iterations,
+            digest: digest,
+        })
+    }
+}
+
 impl Secret for Pbkdf2Sha256 {}
 
 impl Pbkdf2Secret for Pbkdf2Sha256 {