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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /lib/base64.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'lib/base64.c')
-rw-r--r--lib/base64.c185
1 files changed, 185 insertions, 0 deletions
diff --git a/lib/base64.c b/lib/base64.c
new file mode 100644
index 000000000..325c7332b
--- /dev/null
+++ b/lib/base64.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * base64.c - Base64 with support for multiple variants
+ *
+ * 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 support multiple Base64 variants.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/string.h>
+#include <linux/base64.h>
+
+static const char base64_tables[][65] = {
+ [BASE64_STD] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
+ [BASE64_URLSAFE] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_",
+ [BASE64_IMAP] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,",
+};
+
+/*
+ * Initialize the base64 reverse mapping for a single character
+ * This macro maps a character to its corresponding base64 value,
+ * returning -1 if the character is invalid.
+ * char 'A'-'Z' maps to 0-25, 'a'-'z' maps to 26-51, '0'-'9' maps to 52-61,
+ * ch_62 maps to 62, ch_63 maps to 63, and other characters return -1
+ */
+#define INIT_1(v, ch_62, ch_63) \
+ [v] = (v) >= 'A' && (v) <= 'Z' ? (v) - 'A' \
+ : (v) >= 'a' && (v) <= 'z' ? (v) - 'a' + 26 \
+ : (v) >= '0' && (v) <= '9' ? (v) - '0' + 52 \
+ : (v) == (ch_62) ? 62 : (v) == (ch_63) ? 63 : -1
+
+/*
+ * Recursive macros to generate multiple Base64 reverse mapping table entries.
+ * Each macro generates a sequence of entries in the lookup table:
+ * INIT_2 generates 2 entries, INIT_4 generates 4, INIT_8 generates 8, and so on up to INIT_32.
+ */
+#define INIT_2(v, ...) INIT_1(v, __VA_ARGS__), INIT_1((v) + 1, __VA_ARGS__)
+#define INIT_4(v, ...) INIT_2(v, __VA_ARGS__), INIT_2((v) + 2, __VA_ARGS__)
+#define INIT_8(v, ...) INIT_4(v, __VA_ARGS__), INIT_4((v) + 4, __VA_ARGS__)
+#define INIT_16(v, ...) INIT_8(v, __VA_ARGS__), INIT_8((v) + 8, __VA_ARGS__)
+#define INIT_32(v, ...) INIT_16(v, __VA_ARGS__), INIT_16((v) + 16, __VA_ARGS__)
+
+#define BASE64_REV_INIT(ch_62, ch_63) { \
+ [0 ... 0x1f] = -1, \
+ INIT_32(0x20, ch_62, ch_63), \
+ INIT_32(0x40, ch_62, ch_63), \
+ INIT_32(0x60, ch_62, ch_63), \
+ [0x80 ... 0xff] = -1 }
+
+static const s8 base64_rev_maps[][256] = {
+ [BASE64_STD] = BASE64_REV_INIT('+', '/'),
+ [BASE64_URLSAFE] = BASE64_REV_INIT('-', '_'),
+ [BASE64_IMAP] = BASE64_REV_INIT('+', ',')
+};
+
+#undef BASE64_REV_INIT
+#undef INIT_32
+#undef INIT_16
+#undef INIT_8
+#undef INIT_4
+#undef INIT_2
+#undef INIT_1
+/**
+ * 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.
+ * @padding: whether to append '=' padding characters
+ * @variant: which base64 variant to use
+ *
+ * Encodes data using the selected Base64 variant.
+ *
+ * Return: the length of the resulting Base64-encoded string in bytes.
+ */
+int base64_encode(const u8 *src, int srclen, char *dst, bool padding, enum base64_variant variant)
+{
+ u32 ac = 0;
+ char *cp = dst;
+ const char *base64_table = base64_tables[variant];
+
+ while (srclen >= 3) {
+ ac = src[0] << 16 | src[1] << 8 | src[2];
+ *cp++ = base64_table[ac >> 18];
+ *cp++ = base64_table[(ac >> 12) & 0x3f];
+ *cp++ = base64_table[(ac >> 6) & 0x3f];
+ *cp++ = base64_table[ac & 0x3f];
+
+ src += 3;
+ srclen -= 3;
+ }
+
+ switch (srclen) {
+ case 2:
+ ac = src[0] << 16 | src[1] << 8;
+ *cp++ = base64_table[ac >> 18];
+ *cp++ = base64_table[(ac >> 12) & 0x3f];
+ *cp++ = base64_table[(ac >> 6) & 0x3f];
+ if (padding)
+ *cp++ = '=';
+ break;
+ case 1:
+ ac = src[0] << 16;
+ *cp++ = base64_table[ac >> 18];
+ *cp++ = base64_table[(ac >> 12) & 0x3f];
+ if (padding) {
+ *cp++ = '=';
+ *cp++ = '=';
+ }
+ break;
+ }
+ 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
+ * @padding: whether the input is expected to include '=' padding characters
+ * @variant: which base64 variant to use
+ *
+ * Decodes a string using the selected Base64 variant.
+ *
+ * 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, bool padding, enum base64_variant variant)
+{
+ u8 *bp = dst;
+ s8 input[4];
+ s32 val;
+ const u8 *s = (const u8 *)src;
+ const s8 *base64_rev_tables = base64_rev_maps[variant];
+
+ while (srclen >= 4) {
+ input[0] = base64_rev_tables[s[0]];
+ input[1] = base64_rev_tables[s[1]];
+ input[2] = base64_rev_tables[s[2]];
+ input[3] = base64_rev_tables[s[3]];
+
+ val = input[0] << 18 | input[1] << 12 | input[2] << 6 | input[3];
+
+ if (unlikely(val < 0)) {
+ if (!padding || srclen != 4 || s[3] != '=')
+ return -1;
+ padding = 0;
+ srclen = s[2] == '=' ? 2 : 3;
+ break;
+ }
+
+ *bp++ = val >> 16;
+ *bp++ = val >> 8;
+ *bp++ = val;
+
+ s += 4;
+ srclen -= 4;
+ }
+
+ if (likely(!srclen))
+ return bp - dst;
+ if (padding || srclen == 1)
+ return -1;
+
+ val = (base64_rev_tables[s[0]] << 12) | (base64_rev_tables[s[1]] << 6);
+
+ if (srclen == 2) {
+ if (val & 0x800003ff)
+ return -1;
+ *bp++ = val >> 10;
+ } else {
+ val |= base64_rev_tables[s[2]];
+ if (val & 0x80000003)
+ return -1;
+ *bp++ = val >> 10;
+ *bp++ = val >> 2;
+ }
+ return bp - dst;
+}
+EXPORT_SYMBOL_GPL(base64_decode);