mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
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Kuan-Wei Chiu
f1e2ca801c
Patch series " lib/base64: add generic encoder/decoder, migrate users", v5. This series introduces a generic Base64 encoder/decoder to the kernel library, eliminating duplicated implementations and delivering significant performance improvements. The Base64 API has been extended to support multiple variants (Standard, URL-safe, and IMAP) as defined in RFC 4648 and RFC 3501. The API now takes a variant parameter and an option to control padding. As part of this series, users are migrated to the new interface while preserving their specific formats: fscrypt now uses BASE64_URLSAFE, Ceph uses BASE64_IMAP, and NVMe is updated to BASE64_STD. On the encoder side, the implementation processes input in 3-byte blocks, mapping 24 bits directly to 4 output symbols. This avoids bit-by-bit streaming and reduces loop overhead, achieving about a 2.7x speedup compared to previous implementations. On the decoder side, replace strchr() lookups with per-variant reverse tables and process input in 4-character groups. Each group is mapped to numeric values and combined into 3 bytes. Padded and unpadded forms are validated explicitly, rejecting invalid '=' usage and enforcing tail rules. This improves throughput by ~43-52x. This patch (of 6): Extend the base64 API to support multiple variants (standard, URL-safe, and IMAP) as defined in RFC 4648 and RFC 3501. The API now takes a variant parameter and an option to control padding. Update NVMe auth code to use the new interface with BASE64_STD. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Kuan-Wei Chiu <[email protected]> Co-developed-by: Guan-Chun Wu <[email protected]> Signed-off-by: Guan-Chun Wu <[email protected]> Reviewed-by: David Laight <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Eric Biggers <[email protected]> Cc: Ilya Dryomov <[email protected]> Cc: Jaegeuk Kim <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Keith Busch <[email protected]> Cc: Sagi Grimberg <[email protected]> Cc: "Theodore Y. Ts'o" <[email protected]> Cc: Viacheslav Dubeyko <[email protected]> Cc: Xiubo Li <[email protected]> Cc: Yu-Sheng Huang <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
23 lines
607 B
C
23 lines
607 B
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* base64 encoding, lifted from fs/crypto/fname.c.
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*/
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#ifndef _LINUX_BASE64_H
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#define _LINUX_BASE64_H
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#include <linux/types.h>
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enum base64_variant {
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BASE64_STD, /* RFC 4648 (standard) */
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BASE64_URLSAFE, /* RFC 4648 (base64url) */
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BASE64_IMAP, /* RFC 3501 */
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};
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#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3)
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int base64_encode(const u8 *src, int len, char *dst, bool padding, enum base64_variant variant);
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int base64_decode(const char *src, int len, u8 *dst, bool padding, enum base64_variant variant);
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#endif /* _LINUX_BASE64_H */
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