Import the busybox-1.23.1 uuencode/base64 helper functions.

Signed-off-by: Steffen Trumtrar <s.trumt...@pengutronix.de>
---
 include/base64.h |   9 ++++
 lib/Kconfig      |   3 ++
 lib/Makefile     |   1 +
 lib/base64.c     | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 167 insertions(+)
 create mode 100644 include/base64.h
 create mode 100644 lib/base64.c

diff --git a/include/base64.h b/include/base64.h
new file mode 100644
index 000000000000..0df510281df4
--- /dev/null
+++ b/include/base64.h
@@ -0,0 +1,9 @@
+#ifndef __BASE64_H
+#define __BASE64_H
+
+void uuencode(char *p, const char *src, int length);
+int decode_base64(char *dst, int dst_len, const char *src);
+
+#define BASE64_LENGTH(len)     (4 * (((len) + 2) / 3))
+
+#endif /* __BASE64_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index fbf9f0f34849..c5f81e8a187e 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -22,6 +22,9 @@ config XZ_DECOMPRESS
        bool "include xz uncompression support"
        select UNCOMPRESS
 
+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 abb34cfbdbeb..fdcf74d9757b 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -56,3 +56,4 @@ obj-y                 += gcd.o
 obj-y                  += hexdump.o
 obj-$(CONFIG_FONTS)    += fonts/
 obj-$(CONFIG_BAREBOX_LOGO)     += logo/
+obj-$(CONFIG_BASE64)   += base64.o
diff --git a/lib/base64.c b/lib/base64.c
new file mode 100644
index 000000000000..e7242864bb79
--- /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 <r...@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 const 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);
-- 
2.6.1


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