From patchwork Thu Dec 2 15:23:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 520610 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 515BDC43219 for ; Thu, 2 Dec 2021 15:24:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358954AbhLBP1f (ORCPT ); Thu, 2 Dec 2021 10:27:35 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:46490 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358941AbhLBP1c (ORCPT ); Thu, 2 Dec 2021 10:27:32 -0500 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 9A3652170C; Thu, 2 Dec 2021 15:24:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1638458648; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B8Qbo2fngQHipAYE3FGwgL+Z3ZBEEH39Dg3B5tQ1+pI=; b=WxbC5iQR8i1nlzOxaFnq+2B1s+zJmkkHDbdhslW60HaWsPd4cwCmBU5CFN+cocjXdvTM3H XebmcddPMfVtPwF9TE7ZbMRlOubDCzdN/GVUtMj9YfNAdWRMB5GKQh8j1oC7rb8w8+ppKS t3y3pHPNRhfnvN9UCyoXz2hlyQbd/GI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1638458648; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=B8Qbo2fngQHipAYE3FGwgL+Z3ZBEEH39Dg3B5tQ1+pI=; b=uZFurLqLnHn5f3o1cEdcUqHdH/t5d6At/p1MK5ooC9fY44PwFpaR6kFtk1DX9MpD9gmzce tA0BKkzBTuYhKWAA== Received: from adalid.arch.suse.de (adalid.arch.suse.de [10.161.8.13]) by relay2.suse.de (Postfix) with ESMTP id E2517A3B8B; Thu, 2 Dec 2021 15:24:07 +0000 (UTC) Received: by adalid.arch.suse.de (Postfix, from userid 16045) id 308155191DF0; Thu, 2 Dec 2021 16:24:07 +0100 (CET) From: Hannes Reinecke To: Sagi Grimberg Cc: Christoph Hellwig , Keith Busch , linux-nvme@lists.infradead.org, linux-crypto@vger.kernel.org, Hannes Reinecke , Himanshu Madhani Subject: [PATCH 04/12] lib/base64: RFC4648-compliant base64 encoding Date: Thu, 2 Dec 2021 16:23:50 +0100 Message-Id: <20211202152358.60116-5-hare@suse.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20211202152358.60116-1-hare@suse.de> References: <20211202152358.60116-1-hare@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add RFC4648-compliant base64 encoding and decoding routines, based on the base64url encoding in fs/crypto/fname.c. Signed-off-by: Hannes Reinecke Reviewed-by: Himanshu Madhani Reviewed-by: Sagi Grimberg --- include/linux/base64.h | 16 +++++++ lib/Makefile | 2 +- lib/base64.c | 103 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 120 insertions(+), 1 deletion(-) create mode 100644 include/linux/base64.h create mode 100644 lib/base64.c diff --git a/include/linux/base64.h b/include/linux/base64.h new file mode 100644 index 000000000000..660d4cb1ef31 --- /dev/null +++ b/include/linux/base64.h @@ -0,0 +1,16 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * base64 encoding, lifted from fs/crypto/fname.c. + */ + +#ifndef _LINUX_BASE64_H +#define _LINUX_BASE64_H + +#include + +#define BASE64_CHARS(nbytes) DIV_ROUND_UP((nbytes) * 4, 3) + +int base64_encode(const u8 *src, int len, char *dst); +int base64_decode(const char *src, int len, u8 *dst); + +#endif /* _LINUX_BASE64_H */ diff --git a/lib/Makefile b/lib/Makefile index 364c23f15578..ddc5cb4c6eb8 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -46,7 +46,7 @@ obj-y += bcd.o sort.o parser.o debug_locks.o random32.o \ bust_spinlocks.o kasprintf.o bitmap.o scatterlist.o \ list_sort.o uuid.o iov_iter.o clz_ctz.o \ bsearch.o find_bit.o llist.o memweight.o kfifo.o \ - percpu-refcount.o rhashtable.o \ + percpu-refcount.o rhashtable.o base64.o \ once.o refcount.o usercopy.o errseq.o bucket_locks.o \ generic-radix-tree.o obj-$(CONFIG_STRING_SELFTEST) += test_string.o diff --git a/lib/base64.c b/lib/base64.c new file mode 100644 index 000000000000..b736a7a431c5 --- /dev/null +++ b/lib/base64.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * base64.c - RFC4648-compliant base64 encoding + * + * Copyright (c) 2020 Hannes Reinecke, SUSE + * + * Based on the base64url routines from fs/crypto/fname.c + * (which are using the URL-safe base64 encoding), + * modified to use the standard coding table from RFC4648 section 4. + */ + +#include +#include +#include +#include +#include + +static const char base64_table[65] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +/** + * base64_encode() - base64-encode some binary data + * @src: the binary data to encode + * @srclen: the length of @src in bytes + * @dst: (output) the base64-encoded string. Not NUL-terminated. + * + * Encodes data using base64 encoding, i.e. the "Base 64 Encoding" specified + * by RFC 4648, including the '='-padding. + * + * Return: the length of the resulting base64-encoded string in bytes. + */ +int base64_encode(const u8 *src, int srclen, char *dst) +{ + u32 ac = 0; + int bits = 0; + int i; + char *cp = dst; + + for (i = 0; i < srclen; i++) { + ac = (ac << 8) | src[i]; + bits += 8; + do { + bits -= 6; + *cp++ = base64_table[(ac >> bits) & 0x3f]; + } while (bits >= 6); + } + if (bits) { + *cp++ = base64_table[(ac << (6 - bits)) & 0x3f]; + bits -= 6; + } + while (bits < 0) { + *cp++ = '='; + bits += 2; + } + return cp - dst; +} +EXPORT_SYMBOL_GPL(base64_encode); + +/** + * base64_decode() - base64-decode a string + * @src: the string to decode. Doesn't need to be NUL-terminated. + * @srclen: the length of @src in bytes + * @dst: (output) the decoded binary data + * + * Decodes a string using base64 encoding, i.e. the "Base 64 Encoding" + * specified by RFC 4648, including the '='-padding. + * + * This implementation hasn't been optimized for performance. + * + * Return: the length of the resulting decoded binary data in bytes, + * or -1 if the string isn't a valid base64 string. + */ +int base64_decode(const char *src, int srclen, u8 *dst) +{ + u32 ac = 0; + int bits = 0; + int i; + u8 *bp = dst; + + for (i = 0; i < srclen; i++) { + const char *p = strchr(base64_table, src[i]); + + if (src[i] == '=') { + ac = (ac << 6); + bits += 6; + if (bits >= 8) + bits -= 8; + continue; + } + if (p == NULL || src[i] == 0) + return -1; + ac = (ac << 6) | (p - base64_table); + bits += 6; + if (bits >= 8) { + bits -= 8; + *bp++ = (u8)(ac >> bits); + } + } + if (ac & ((1 << bits) - 1)) + return -1; + return bp - dst; +} +EXPORT_SYMBOL_GPL(base64_decode);