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//! # padding_128bit //! `padding_128bit` is a padding mod for encryption and decryption which use 128 bits blocks, //! especially the `aes_core` mod. /// PKCS #7 padding /// # Examples /// ``` /// use aes_frast::padding_128bit::pa_pkcs7; /// /// let mut origin = vec![0xFFu8; 7]; /// /// pa_pkcs7(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x09u8, /// 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8]); /// ``` pub fn pa_pkcs7(input_vec: &mut Vec<u8>) { let r = 16 - (input_vec.len() & 0b1111); input_vec.append(&mut vec![r as u8; r]); } /// ANSIX923 padding /// # Examples /// ``` /// use aes_frast::padding_128bit::pa_ansix923; /// /// let mut origin = vec![0xFFu8; 7]; /// /// pa_ansix923(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x09u8]); /// ``` pub fn pa_ansix923(input_vec: &mut Vec<u8>) { let r = 16 - (input_vec.len() & 0b1111); let mut tail = vec![0u8; r]; tail[r - 1] = r as u8; input_vec.append(&mut tail); } /// ANSIX923 or PKCS #7 depadding /// /// **[Attention!]** Please be sure the parameter ends with exactly the ANSIX923 or PKCS #7 padding string. /// # Examples /// ``` /// use aes_frast::padding_128bit::de_ansix923_pkcs7; /// /// let mut ansix923 = vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x09u8]; /// /// de_ansix923_pkcs7(&mut ansix923); /// /// let mut pkcs7 = vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x09u8, /// 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8, 0x09u8]; /// /// de_ansix923_pkcs7(&mut pkcs7); /// /// let expected = vec![0xFFu8; 7]; /// assert_eq!(ansix923, expected); /// assert_eq!(pkcs7, expected); /// ``` pub fn de_ansix923_pkcs7(input_vec: &mut Vec<u8>) { let r = input_vec.pop().unwrap(); for _ in 1..r { input_vec.pop(); } } /// Zeros padding /// /// This padding has never been standardized in cryptography specifications. So, **NOT** recommended. /// This padding here maybe differ from it in other implements, because this function still adds a /// complete block after the complete end-block, while maybe some other implements don't and only add /// to the incomplete end-block. If you are looking for function like that, see [`pa_zeros_ifnotcomplete`]. /// /// **[Attention!]** If the origin data ends with zero(s) (one or more 0xFF), depadding will remove all these zeros. /// # Examples /// ``` /// use aes_frast::padding_128bit::pa_zeros; /// /// let mut origin = vec![0xFFu8; 7]; /// pa_zeros(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8]); /// /// origin = vec![0xFFu8; 16]; /// pa_zeros(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, /// 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8]); /// ``` /// /// [`pa_zeros_ifnotcomplete`]: ../padding_128bit/fn.pa_zeros_ifnotcomplete.html pub fn pa_zeros(input_vec: &mut Vec<u8>) { let r = 16 - (input_vec.len() & 0b1111); input_vec.append(&mut vec![0u8; r]); } /// Zeros padding only if not complete /// /// This padding has never been standardized in cryptography specifications. So, **NOT** recommended. /// Different from the [`pa_zeros`] function, this function only adds zeros to the incomplete end-block. /// When the end-block is complete, it keeps it unchanged. /// /// **[Attention!]** If the origin data ends with zero(s) (one or more 0xFF), depadding will remove all these zeros. /// # Examples /// ``` /// use aes_frast::padding_128bit::pa_zeros_ifnotcomplete; /// /// let mut origin = vec![0xFFu8; 7]; /// pa_zeros_ifnotcomplete(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8]); /// /// origin = vec![0xFFu8; 16]; /// pa_zeros_ifnotcomplete(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, /// 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8]); /// ``` /// /// [`pa_zeros`]: ../padding_128bit/fn.pa_zeros.html pub fn pa_zeros_ifnotcomplete(input_vec: &mut Vec<u8>) { let r = 16 - (input_vec.len() & 0b1111); if r != 16 { input_vec.append(&mut vec![0u8; r]); } } /// Zeros depadding /// /// **[Attention!]** If the origin data ends with zero(s) (one or more 0xFF), depadding will remove all these zeros. /// # Examples /// ``` /// use aes_frast::padding_128bit::de_zeros; /// /// let mut zeros = vec![0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0xFFu8, 0x00u8, /// 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8, 0x00u8]; /// /// de_zeros(&mut zeros); /// /// assert_eq!(zeros, vec![0xFFu8; 7]); /// ``` pub fn de_zeros(input_vec: &mut Vec<u8>) { let mut tmp: u8; loop { tmp = input_vec.pop().unwrap(); if tmp != 0 { input_vec.push(tmp); break; } } } /// Drop the last incomplete or complete block. /// # Examples /// ``` /// use aes_frast::padding_128bit::drop_last_block; /// /// // Drop the last incomplete block. /// let mut origin = vec![0xFFu8; 21]; /// drop_last_block(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8; 16]); /// /// // Drop the last incomplete block. /// origin = vec![0xFFu8; 32]; /// drop_last_block(&mut origin); /// /// assert_eq!(origin, vec![0xFFu8; 16]); /// ``` pub fn drop_last_block(input_vec: &mut Vec<u8>) { let r = match input_vec.len() & 0b1111 { 0 => 16, r @ _ => r, }; for _ in 0..r { input_vec.pop(); } }