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authorSteffen Trumtrar <s.trumtrar@pengutronix.de>2015-09-02 13:57:23 +0200
committerSascha Hauer <s.hauer@pengutronix.de>2019-04-12 11:58:39 +0200
commitfa414f6c610eb7b48928312db466fbed14cc8c2a (patch)
treed67920b25f6ca873bcf326edabb941b294921bd8 /lib
parentfd99872262951066b13753eac8d1351c9ee0fa54 (diff)
downloadbarebox-fa414f6c610eb7b48928312db466fbed14cc8c2a.tar.gz
barebox-fa414f6c610eb7b48928312db466fbed14cc8c2a.tar.xz
lib: add base64 helpers
Import the busybox-1.23.1 uuencode/base64 helper functions. Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/Makefile1
-rw-r--r--lib/base64.c154
3 files changed, 158 insertions, 0 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 27f62461f0..35f208cbc1 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -57,6 +57,9 @@ config XZ_DEC_SPARC
config REED_SOLOMON
bool
+config BASE64
+ bool "include base64 encode/decode support"
+
config GENERIC_FIND_NEXT_BIT
def_bool n
diff --git a/lib/Makefile b/lib/Makefile
index 8dabf4ae77..31e66de33f 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_LZ4_DECOMPRESS) += decompress_unlz4.o
obj-$(CONFIG_PROCESS_ESCAPE_SEQUENCE) += process_escape_sequence.o
obj-$(CONFIG_UNCOMPRESS) += uncompress.o
obj-$(CONFIG_BCH) += bch.o
+obj-$(CONFIG_BASE64) += base64.o
obj-$(CONFIG_BITREV) += bitrev.o
obj-$(CONFIG_QSORT) += qsort.o
obj-$(CONFIG_LIBSCAN) += libscan.o
diff --git a/lib/base64.c b/lib/base64.c
new file mode 100644
index 0000000000..ac165ab168
--- /dev/null
+++ b/lib/base64.c
@@ -0,0 +1,154 @@
+/*
+ * Code based on busybox-1.23.2
+ *
+ * Copyright 2003, Glenn McGrath
+ * Copyright 2006, Rob Landley <rob@landley.net>
+ * Copyright 2010, Denys Vlasenko
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include <common.h>
+#include <base64.h>
+
+/* Conversion table. for base 64 */
+static const char uuenc_tbl_base64[65 + 1] = {
+ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+ 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+ 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+ 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+ 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+ 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+ 'w', 'x', 'y', 'z', '0', '1', '2', '3',
+ '4', '5', '6', '7', '8', '9', '+', '/',
+ '=' /* termination character */,
+ '\0' /* needed for uudecode.c only */
+};
+
+/*
+ * Encode bytes at S of length LENGTH to uuencode or base64 format and place it
+ * to STORE. STORE will be 0-terminated, and must point to a writable
+ * buffer of at least 1+BASE64_LENGTH(length) bytes.
+ * where BASE64_LENGTH(len) = (4 * ((LENGTH + 2) / 3))
+ */
+void uuencode(char *p, const char *src, int length)
+{
+ const unsigned char *s = src;
+ const char *tbl = uuenc_tbl_base64;
+
+ /* Transform the 3x8 bits to 4x6 bits */
+ while (length > 0) {
+ unsigned s1, s2;
+
+ /* Are s[1], s[2] valid or should be assumed 0? */
+ s1 = s2 = 0;
+ length -= 3; /* can be >=0, -1, -2 */
+ if (length >= -1) {
+ s1 = s[1];
+ if (length >= 0)
+ s2 = s[2];
+ }
+ *p++ = tbl[s[0] >> 2];
+ *p++ = tbl[((s[0] & 3) << 4) + (s1 >> 4)];
+ *p++ = tbl[((s1 & 0xf) << 2) + (s2 >> 6)];
+ *p++ = tbl[s2 & 0x3f];
+ s += 3;
+ }
+ /* Zero-terminate */
+ *p = '\0';
+ /* If length is -2 or -1, pad last char or two */
+ while (length) {
+ *--p = tbl[64];
+ length++;
+ }
+}
+EXPORT_SYMBOL(uuencode);
+
+/*
+ * Decode base64 encoded string. Stops on '\0'.
+ *
+ */
+int decode_base64(char *p_dst, int dst_len, const char *src)
+{
+ const char *src_tail;
+ char *dst = p_dst;
+ int length = 0;
+
+ while (dst_len > 0) {
+ unsigned char six_bit[4];
+ int count = 0;
+
+ /* Fetch up to four 6-bit values */
+ src_tail = src;
+ while (count < 4) {
+ const char *table_ptr;
+ int ch;
+
+ /*
+ * Get next _valid_ character.
+ * uuenc_tbl_base64[] contains this string:
+ * 0 1 2 3 4 5 6
+ * 01234567890123456789012345678901234567890123456789012345678901234
+ * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
+ */
+ do {
+ ch = *src;
+ if (ch == '\0') {
+ /*
+ * Example:
+ * If we decode "QUJD <NUL>", we want
+ * to return ptr to NUL, not to ' ',
+ * because we did fully decode
+ * the string (to "ABC").
+ */
+ if (count == 0)
+ src_tail = src;
+ goto ret;
+ }
+ src++;
+ table_ptr = strchr(uuenc_tbl_base64, ch);
+ } while (!table_ptr);
+
+ /* Convert encoded character to decimal */
+ ch = table_ptr - uuenc_tbl_base64;
+
+ /* ch is 64 if char was '=', otherwise 0..63 */
+ if (ch == 64)
+ break;
+
+ six_bit[count] = ch;
+ count++;
+ }
+
+ /*
+ * Transform 6-bit values to 8-bit ones.
+ * count can be < 4 when we decode the tail:
+ * "eQ==" -> "y", not "y NUL NUL".
+ * Note that (count > 1) is always true,
+ * "x===" encoding is not valid:
+ * even a single zero byte encodes as "AA==".
+ * However, with current logic we come here with count == 1
+ * when we decode "==" tail.
+ */
+ if (count > 1)
+ *dst++ = six_bit[0] << 2 | six_bit[1] >> 4;
+ if (count > 2)
+ *dst++ = six_bit[1] << 4 | six_bit[2] >> 2;
+ if (count > 3)
+ *dst++ = six_bit[2] << 6 | six_bit[3];
+ /*
+ * Note that if we decode "AA==" and ate first '=',
+ * we just decoded one char (count == 2) and now we'll
+ * do the loop once more to decode second '='.
+ */
+ dst_len -= count-1;
+ /* last character was "=" */
+ if (count != 0)
+ length += count - 1;
+ }
+ret:
+ p_dst = dst;
+
+ return length;
+}
+EXPORT_SYMBOL(decode_base64);