Modify the S2K interface. Instead of being stateful in terms of the salt

and iteration count, force it to be passed to each call to derive_key.
So remove current_salt, set_iterations, new_random_salt, and change_salt
functions from S2K interface.

Update examples and test application to match.

While I was in there, change the passhash example to use 64 bit salts
and 128 bit PBKDF2 outputs.

1 files changed, 9 insertions, 49 deletions

diff --git a/src/s2k/s2k.h b/src/s2k/s2k.h
index 7af92519b..82f5abeef 100644
--- a/src/s2k/s2k.h
+++ b/src/s2k/s2k.h
@@ -39,62 +39,22 @@ class BOTAN_DLL S2K
       /**
       * Derive a key from a passphrase with this S2K object. It will use
       * the salt value and number of iterations configured in this object.
-      * @param key_len the desired length of the key to produce
+      * @param output_len the desired length of the key to produce
       * @param passphrase the password to derive the key from
+      * @param salt the randomly chosen salt
+      * @param salt_len length of salt in bytes
+      * @param iterations the number of iterations to use (use 10K or more)
       */
-      OctetString derive_key(u32bit key_len,
-                             const std::string& passphrase) const;
+      virtual OctetString derive_key(u32bit output_len,
+                                     const std::string& passphrase,
+                                     const byte salt[], u32bit salt_len,
+                                     u32bit iterations) const = 0;
 
-      /**
-      * Set the number of iterations for the one-way function during
-      * key generation.
-      * @param n the desired number of iterations
-      */
-      void set_iterations(u32bit n);
-
-      /**
-      * Set a new salt value.
-      * @param new_salt a byte array defining the new salt value
-      * @param len the length of the above byte array
-      */
-      void change_salt(const byte new_salt[], u32bit len);
-
-      /**
-      * Set a new salt value.
-      * @param new_salt the new salt value
-      */
-      void change_salt(const MemoryRegion<byte>& new_salt);
-
-      /**
-      * Create a new random salt value using the rng
-      * @param rng the random number generator to use
-      * @param len the desired length of the new salt value
-      */
-      void new_random_salt(RandomNumberGenerator& rng, u32bit len);
-
-      /**
-      * Get the number of iterations for the key derivation currently
-      * configured in this S2K object.
-      * @return the current number of iterations
-      */
-      u32bit iterations() const { return iter; }
-
-      /**
-      * Get the currently configured salt value of this S2K object.
-      * @return the current salt value
-      */
-      SecureVector<byte> current_salt() const { return salt; }
-
-      S2K() { iter = 0; }
+      S2K() {}
       virtual ~S2K() {}
    private:
       S2K(const S2K&) {}
       S2K& operator=(const S2K&) { return (*this); }
-
-      virtual OctetString derive(u32bit, const std::string&,
-                                 const byte[], u32bit, u32bit) const = 0;
-      SecureVector<byte> salt;
-      u32bit iter;
    };
 
 }