category

block_cipher_modes_common

Shared validation, block, XOR, and PKCS#7 predicates for block cipher modes.

Availability:

logtalk_load(block_ciphers(loader))

Author: Paulo Moura

Version: 1:0:0

Date: 2026-08-08

Compilation flags:

static

Uses:

list

type

Remarks:

(none)

Inherited public predicates:

(none)

Public predicates

(no local declarations; see entity ancestors if any)

Protected predicates

prepare_cipher/4

Validates a cipher object, queries its block size, and prepares a key.

Compilation flags:

static

Template:

prepare_cipher(Cipher,Key,BlockSize,PreparedKey)

Mode and number of proofs:

prepare_cipher(+object_identifier,+list(byte),--positive_integer,--compound) - one_or_error

Exceptions:

Cipher is a variable:

instantiation_error

Cipher is not a variable but does not implement the prepared-key block cipher protocol:

domain_error(block_cipher,Cipher)

Cipher implements he prepared-key block cipher protocol but reports an invalid block size:

domain_error(block_cipher_block_size,BlockSize)

Key is invalid for Cipher:

type_error(list(byte,KeySize),Key)

---

check_bytes/1

Checks a list of bytes.

Compilation flags:

static

Template:

check_bytes(Bytes)

Mode and number of proofs:

check_bytes(+list(byte)) - one_or_error

Exceptions:

Bytes is a variable or a partial list:

instantiation_error

Bytes is neither a partial list nor a list:

type_error(list,Bytes)

An element Byte of the Bytes list is neither a variable nor an integer:

type_error(integer,Byte)

An element Byte of the Bytes list is an integer but not a valid byte:

domain_error(byte,Byte)

---

check_block/2

Checks a byte list whose length is exactly one block.

Compilation flags:

static

Template:

check_block(BlockSize,Block)

Mode and number of proofs:

check_block(+positive_integer,+list(byte)) - one_or_error

Exceptions:

BlockSize is a variable:

instantiation_error

BlockSize is neither a variable nor an integer:

type_error(integer,BlockSize)

BlockSize is an integer but not a positive integer:

domain_error(positive_integer,BlockSize)

Block is a variable or a partial list:

instantiation_error

Block is not a list of exactly BlockSize bytes:

type_error(list(byte,BlockSize),Block)

An element Byte of the Block` list is neither a variable nor an integer:

type_error(integer,Byte)

An element Byte of the Block list is an integer but not a valid byte:

domain_error(byte,Byte)

---

check_aligned/2

Checks that a byte-list length is a multiple of the block size.

Compilation flags:

static

Template:

check_aligned(BlockSize,Bytes)

Mode and number of proofs:

check_aligned(+positive_integer,+list(byte)) - one_or_error

Exceptions:

BlockSize is a variable:

instantiation_error

BlockSize is neither a variable nor an integer:

type_error(integer,BlockSize)

BlockSize is an integer but not a positive integer:

domain_error(positive_integer,BlockSize)

Bytes length is not a multiple of BlockSize:

domain_error(block_aligned_byte_length(BlockSize),Bytes)

---

blocks/3

Splits an aligned byte list into blocks.

Compilation flags:

static

Template:

blocks(BlockSize,Bytes,Blocks)

Mode and number of proofs:

blocks(+positive_integer,+list(byte),--list(list(byte))) - one

---

xor_bytes/3

XORs equal-length byte lists.

Compilation flags:

static

Template:

xor_bytes(Bytes1,Bytes2,Bytes)

Mode and number of proofs:

xor_bytes(+list(byte),+list(byte),--list(byte)) - one

---

pkcs7_pad/3

Pads bytes using PKCS#7.

Compilation flags:

static

Template:

pkcs7_pad(BlockSize,Bytes,PaddedBytes)

Mode and number of proofs:

pkcs7_pad(+positive_integer,+list(byte),--list(byte)) - one_or_error

Exceptions:

BlockSize exceeds the maximum PKCS#7 block size:

domain_error(pkcs7_block_size,BlockSize)

---

pkcs7_unpad/4

Validates and removes PKCS#7 padding, reporting the supplied error value when padding is invalid.

Compilation flags:

static

Template:

pkcs7_unpad(BlockSize,PaddedBytes,ErrorValue,Bytes)

Mode and number of proofs:

pkcs7_unpad(+positive_integer,+list(byte),+term,--list(byte)) - one_or_error

Exceptions:

BlockSize exceeds the maximum PKCS#7 block size:

domain_error(pkcs7_block_size,BlockSize)

PaddedBytes does not contain valid PKCS#7 padding:

domain_error(pkcs7_padding,ErrorValue)

---

Private predicates

(no local declarations; see entity ancestors if any)

Operators

(none)