lib/crypto/des.c

Source file repositories/reference/linux-study-clean/lib/crypto/des.c

File Facts

System: Linux kernel
Corpus path: lib/crypto/des.c
Extension: .c
Size: 33749 bytes
Lines: 903
Domain: Kernel Services
Bucket: lib
Inferred role: Kernel Services: exported/initcall integration point
Status: integration implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.
Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

crypto/des.h
crypto/internal/des.h
linux/bitops.h
linux/compiler.h
linux/crypto.h
linux/errno.h
linux/export.h
linux/fips.h
linux/init.h
linux/module.h
linux/string.h
linux/types.h
linux/unaligned.h

Detected Declarations

function des_ekey
function des_expand_key
function dkey
function des_encrypt
function des_decrypt
function des3_ede_expand_key
function des3_ede_encrypt
function des3_ede_decrypt
export des_expand_key
export des_encrypt
export des_decrypt
export des3_ede_expand_key
export des3_ede_encrypt
export des3_ede_decrypt

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API.
 *
 * DES & Triple DES EDE Cipher Algorithms.
 *
 * Copyright (c) 2005 Dag Arne Osvik <da@osvik.no>
 */

#include <crypto/des.h>
#include <crypto/internal/des.h>
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/export.h>
#include <linux/fips.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/unaligned.h>

#define ROL(x, r) ((x) = rol32((x), (r)))
#define ROR(x, r) ((x) = ror32((x), (r)))

/* Lookup tables for key expansion */

static const u8 pc1[256] = {
	0x00, 0x00, 0x40, 0x04, 0x10, 0x10, 0x50, 0x14,
	0x04, 0x40, 0x44, 0x44, 0x14, 0x50, 0x54, 0x54,
	0x02, 0x02, 0x42, 0x06, 0x12, 0x12, 0x52, 0x16,
	0x06, 0x42, 0x46, 0x46, 0x16, 0x52, 0x56, 0x56,
	0x80, 0x08, 0xc0, 0x0c, 0x90, 0x18, 0xd0, 0x1c,
	0x84, 0x48, 0xc4, 0x4c, 0x94, 0x58, 0xd4, 0x5c,
	0x82, 0x0a, 0xc2, 0x0e, 0x92, 0x1a, 0xd2, 0x1e,
	0x86, 0x4a, 0xc6, 0x4e, 0x96, 0x5a, 0xd6, 0x5e,
	0x20, 0x20, 0x60, 0x24, 0x30, 0x30, 0x70, 0x34,
	0x24, 0x60, 0x64, 0x64, 0x34, 0x70, 0x74, 0x74,
	0x22, 0x22, 0x62, 0x26, 0x32, 0x32, 0x72, 0x36,
	0x26, 0x62, 0x66, 0x66, 0x36, 0x72, 0x76, 0x76,
	0xa0, 0x28, 0xe0, 0x2c, 0xb0, 0x38, 0xf0, 0x3c,
	0xa4, 0x68, 0xe4, 0x6c, 0xb4, 0x78, 0xf4, 0x7c,
	0xa2, 0x2a, 0xe2, 0x2e, 0xb2, 0x3a, 0xf2, 0x3e,
	0xa6, 0x6a, 0xe6, 0x6e, 0xb6, 0x7a, 0xf6, 0x7e,
	0x08, 0x80, 0x48, 0x84, 0x18, 0x90, 0x58, 0x94,
	0x0c, 0xc0, 0x4c, 0xc4, 0x1c, 0xd0, 0x5c, 0xd4,
	0x0a, 0x82, 0x4a, 0x86, 0x1a, 0x92, 0x5a, 0x96,
	0x0e, 0xc2, 0x4e, 0xc6, 0x1e, 0xd2, 0x5e, 0xd6,
	0x88, 0x88, 0xc8, 0x8c, 0x98, 0x98, 0xd8, 0x9c,
	0x8c, 0xc8, 0xcc, 0xcc, 0x9c, 0xd8, 0xdc, 0xdc,
	0x8a, 0x8a, 0xca, 0x8e, 0x9a, 0x9a, 0xda, 0x9e,
	0x8e, 0xca, 0xce, 0xce, 0x9e, 0xda, 0xde, 0xde,
	0x28, 0xa0, 0x68, 0xa4, 0x38, 0xb0, 0x78, 0xb4,
	0x2c, 0xe0, 0x6c, 0xe4, 0x3c, 0xf0, 0x7c, 0xf4,
	0x2a, 0xa2, 0x6a, 0xa6, 0x3a, 0xb2, 0x7a, 0xb6,
	0x2e, 0xe2, 0x6e, 0xe6, 0x3e, 0xf2, 0x7e, 0xf6,
	0xa8, 0xa8, 0xe8, 0xac, 0xb8, 0xb8, 0xf8, 0xbc,
	0xac, 0xe8, 0xec, 0xec, 0xbc, 0xf8, 0xfc, 0xfc,
	0xaa, 0xaa, 0xea, 0xae, 0xba, 0xba, 0xfa, 0xbe,
	0xae, 0xea, 0xee, 0xee, 0xbe, 0xfa, 0xfe, 0xfe
};

static const u8 rs[256] = {
	0x00, 0x00, 0x80, 0x80, 0x02, 0x02, 0x82, 0x82,
	0x04, 0x04, 0x84, 0x84, 0x06, 0x06, 0x86, 0x86,
	0x08, 0x08, 0x88, 0x88, 0x0a, 0x0a, 0x8a, 0x8a,
	0x0c, 0x0c, 0x8c, 0x8c, 0x0e, 0x0e, 0x8e, 0x8e,
	0x10, 0x10, 0x90, 0x90, 0x12, 0x12, 0x92, 0x92,
	0x14, 0x14, 0x94, 0x94, 0x16, 0x16, 0x96, 0x96,
	0x18, 0x18, 0x98, 0x98, 0x1a, 0x1a, 0x9a, 0x9a,
	0x1c, 0x1c, 0x9c, 0x9c, 0x1e, 0x1e, 0x9e, 0x9e,
	0x20, 0x20, 0xa0, 0xa0, 0x22, 0x22, 0xa2, 0xa2,
	0x24, 0x24, 0xa4, 0xa4, 0x26, 0x26, 0xa6, 0xa6,
	0x28, 0x28, 0xa8, 0xa8, 0x2a, 0x2a, 0xaa, 0xaa,
	0x2c, 0x2c, 0xac, 0xac, 0x2e, 0x2e, 0xae, 0xae,
	0x30, 0x30, 0xb0, 0xb0, 0x32, 0x32, 0xb2, 0xb2,
	0x34, 0x34, 0xb4, 0xb4, 0x36, 0x36, 0xb6, 0xb6,
	0x38, 0x38, 0xb8, 0xb8, 0x3a, 0x3a, 0xba, 0xba,
	0x3c, 0x3c, 0xbc, 0xbc, 0x3e, 0x3e, 0xbe, 0xbe,
	0x40, 0x40, 0xc0, 0xc0, 0x42, 0x42, 0xc2, 0xc2,
	0x44, 0x44, 0xc4, 0xc4, 0x46, 0x46, 0xc6, 0xc6,
	0x48, 0x48, 0xc8, 0xc8, 0x4a, 0x4a, 0xca, 0xca,
	0x4c, 0x4c, 0xcc, 0xcc, 0x4e, 0x4e, 0xce, 0xce,
	0x50, 0x50, 0xd0, 0xd0, 0x52, 0x52, 0xd2, 0xd2,
	0x54, 0x54, 0xd4, 0xd4, 0x56, 0x56, 0xd6, 0xd6,
	0x58, 0x58, 0xd8, 0xd8, 0x5a, 0x5a, 0xda, 0xda,
	0x5c, 0x5c, 0xdc, 0xdc, 0x5e, 0x5e, 0xde, 0xde,
	0x60, 0x60, 0xe0, 0xe0, 0x62, 0x62, 0xe2, 0xe2,
	0x64, 0x64, 0xe4, 0xe4, 0x66, 0x66, 0xe6, 0xe6,

Annotation

Immediate include surface: `crypto/des.h`, `crypto/internal/des.h`, `linux/bitops.h`, `linux/compiler.h`, `linux/crypto.h`, `linux/errno.h`, `linux/export.h`, `linux/fips.h`.
Detected declarations: `function des_ekey`, `function des_expand_key`, `function dkey`, `function des_encrypt`, `function des_decrypt`, `function des3_ede_expand_key`, `function des3_ede_encrypt`, `function des3_ede_decrypt`, `export des_expand_key`, `export des_encrypt`.
Atlas domain: Kernel Services / lib.
Implementation status: integration implementation candidate.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.