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-rw-r--r--src/common/base32.c539
1 files changed, 539 insertions, 0 deletions
diff --git a/src/common/base32.c b/src/common/base32.c
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--- /dev/null
+++ b/src/common/base32.c
@@ -0,0 +1,539 @@
+/* base32.c -- Encode binary data using printable characters.
+ Copyright (C) 1999, 2000, 2001, 2004, 2005, 2006, 2010 Free Software
+ Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software Foundation,
+ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+/* Adapted from base64.{h,c} by Ondřej Surý. base64.{h,c} was written
+ * by Simon Josefsson. Partially adapted from GNU MailUtils
+ * (mailbox/filter_trans.c, as of 2004-11-28). Improved by review
+ * from Paul Eggert, Bruno Haible, and Stepan Kasal.
+ *
+ * See also RFC 4648 <http://www.ietf.org/rfc/rfc4648.txt>.
+ *
+ * Be careful with error checking. Here is how you would typically
+ * use these functions:
+ *
+ * bool ok = base32_decode_alloc (in, inlen, &out, &outlen);
+ * if (!ok)
+ * FAIL: input was not valid base32
+ * if (out == NULL)
+ * FAIL: memory allocation error
+ * OK: data in OUT/OUTLEN
+ *
+ * size_t outlen = base32_encode_alloc (in, inlen, &out);
+ * if (out == NULL && outlen == 0 && inlen != 0)
+ * FAIL: input too long
+ * if (out == NULL)
+ * FAIL: memory allocation error
+ * OK: data in OUT/OUTLEN.
+ *
+ */
+
+/* Get prototype. */
+#include "base32.h"
+
+/* Get malloc. */
+#include <stdlib.h>
+
+/* Get UCHAR_MAX. */
+#include <limits.h>
+
+/* C89 compliant way to cast 'char' to 'unsigned char'. */
+static inline unsigned char to_uchar(char ch)
+{
+ return ch;
+}
+
+/* Base32 encode IN array of size INLEN into OUT array of size OUTLEN.
+ If OUTLEN is less than BASE32_LENGTH(INLEN), write as many bytes as
+ possible. If OUTLEN is larger than BASE32_LENGTH(INLEN), also zero
+ terminate the output buffer. */
+void base32_encode(const char *in, size_t inlen, char *out, size_t outlen)
+{
+ static const char b32str[32] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+ while (inlen && outlen) {
+ *out++ = b32str[(to_uchar(in[0]) >> 3) & 0x1f];
+ if (!--outlen) {
+ break;
+ }
+ *out++ = b32str[((to_uchar(in[0]) << 2)
+ + (--inlen ? to_uchar(in[1]) >> 6 : 0))
+ & 0x1f];
+ if (!--outlen) {
+ break;
+ }
+ *out++ =(inlen
+ ? b32str[(to_uchar(in[1]) >> 1) & 0x1f]
+ : '=');
+ if (!--outlen) {
+ break;
+ }
+ *out++ = (inlen
+ ? b32str[((to_uchar(in[1]) << 4)
+ + (--inlen ? to_uchar(in[2]) >> 4 : 0))
+ & 0x1f]
+ : '=');
+ if (!--outlen) {
+ break;
+ }
+ *out++ = (inlen
+ ? b32str[((to_uchar(in[2]) << 1)
+ + (--inlen ? to_uchar(in[3]) >> 7 : 0))
+ & 0x1f]
+ : '=');
+ if (!--outlen) {
+ break;
+ }
+ *out++ = (inlen
+ ? b32str[(to_uchar(in[3]) >> 2) & 0x1f]
+ : '=');
+ if (!--outlen)
+ {
+ break;
+ }
+ *out++ = (inlen
+ ? b32str[((to_uchar(in[3]) << 3)
+ + (--inlen ? to_uchar(in[4]) >> 5 : 0))
+ & 0x1f]
+ : '=');
+ if (!--outlen) {
+ break;
+ }
+ *out++ = inlen ? b32str[to_uchar(in[4]) & 0x1f] : '=';
+ if (!--outlen) {
+ break;
+ }
+ if (inlen) {
+ inlen--;
+ }
+ if (inlen) {
+ in += 5;
+ }
+ }
+
+ if (outlen) {
+ *out = '\0';
+ }
+}
+
+/* Allocate a buffer and store zero terminated base32 encoded data
+ from array IN of size INLEN, returning BASE32_LENGTH(INLEN), i.e.,
+ the length of the encoded data, excluding the terminating zero. On
+ return, the OUT variable will hold a pointer to newly allocated
+ memory that must be deallocated by the caller. If output string
+ length would overflow, 0 is returned and OUT is set to NULL. If
+ memory allocation failed, OUT is set to NULL, and the return value
+ indicates length of the requested memory block, i.e.,
+ BASE32_LENGTH(inlen) + 1. */
+size_t base32_encode_alloc(const char *in, size_t inlen, char **out)
+{
+ size_t outlen = 1 + BASE32_LENGTH (inlen);
+
+ /* Check for overflow in outlen computation.
+ *
+ * If there is no overflow, outlen >= inlen.
+ *
+ * If the operation (inlen + 2) overflows then it yields at most +1, so
+ * outlen is 0.
+ *
+ * If the multiplication overflows, we lose at least half of the
+ * correct value, so the result is < ((inlen + 2) / 3) * 2, which is
+ * less than (inlen + 2) * 0.66667, which is less than inlen as soon as
+ * (inlen > 4).
+ */
+ if (inlen > outlen)
+ {
+ *out = NULL;
+ return 0;
+ }
+
+ *out = malloc(outlen);
+ if (!*out) {
+ return outlen;
+ }
+
+ base32_encode(in, inlen, *out, outlen);
+
+ return outlen - 1;
+}
+
+/* With this approach this file works independent of the charset used
+ (think EBCDIC). However, it does assume that the characters in the
+ Base32 alphabet (A-Z2-7) are encoded in 0..255. POSIX
+ 1003.1-2001 require that char and unsigned char are 8-bit
+ quantities, though, taking care of that problem. But this may be a
+ potential problem on non-POSIX C99 platforms.
+
+ IBM C V6 for AIX mishandles "#define B32(x) ...'x'...", so use "_"
+ as the formal parameter rather than "x". */
+#define B32(_) \
+ ((_) == 'A' ? 0 \
+ : (_) == 'B' ? 1 \
+ : (_) == 'C' ? 2 \
+ : (_) == 'D' ? 3 \
+ : (_) == 'E' ? 4 \
+ : (_) == 'F' ? 5 \
+ : (_) == 'G' ? 6 \
+ : (_) == 'H' ? 7 \
+ : (_) == 'I' ? 8 \
+ : (_) == 'J' ? 9 \
+ : (_) == 'K' ? 10 \
+ : (_) == 'L' ? 11 \
+ : (_) == 'M' ? 12 \
+ : (_) == 'N' ? 13 \
+ : (_) == 'O' ? 14 \
+ : (_) == 'P' ? 15 \
+ : (_) == 'Q' ? 16 \
+ : (_) == 'R' ? 17 \
+ : (_) == 'S' ? 18 \
+ : (_) == 'T' ? 19 \
+ : (_) == 'U' ? 20 \
+ : (_) == 'V' ? 21 \
+ : (_) == 'W' ? 22 \
+ : (_) == 'X' ? 23 \
+ : (_) == 'Y' ? 24 \
+ : (_) == 'Z' ? 25 \
+ : (_) == '2' ? 26 \
+ : (_) == '3' ? 27 \
+ : (_) == '4' ? 28 \
+ : (_) == '5' ? 29 \
+ : (_) == '6' ? 30 \
+ : (_) == '7' ? 31 \
+ : -1)
+
+static const signed char b32[0x100] = {
+ B32 (0), B32 (1), B32 (2), B32 (3),
+ B32 (4), B32 (5), B32 (6), B32 (7),
+ B32 (8), B32 (9), B32 (10), B32 (11),
+ B32 (12), B32 (13), B32 (14), B32 (15),
+ B32 (16), B32 (17), B32 (18), B32 (19),
+ B32 (20), B32 (21), B32 (22), B32 (23),
+ B32 (24), B32 (25), B32 (26), B32 (27),
+ B32 (28), B32 (29), B32 (30), B32 (31),
+ B32 (32), B32 (33), B32 (34), B32 (35),
+ B32 (36), B32 (37), B32 (38), B32 (39),
+ B32 (40), B32 (41), B32 (42), B32 (43),
+ B32 (44), B32 (45), B32 (46), B32 (47),
+ B32 (48), B32 (49), B32 (50), B32 (51),
+ B32 (52), B32 (53), B32 (54), B32 (55),
+ B32 (56), B32 (57), B32 (58), B32 (59),
+ B32 (60), B32 (61), B32 (62), B32 (63),
+ B32 (64), B32 (65), B32 (66), B32 (67),
+ B32 (68), B32 (69), B32 (70), B32 (71),
+ B32 (72), B32 (73), B32 (74), B32 (75),
+ B32 (76), B32 (77), B32 (78), B32 (79),
+ B32 (80), B32 (81), B32 (82), B32 (83),
+ B32 (84), B32 (85), B32 (86), B32 (87),
+ B32 (88), B32 (89), B32 (90), B32 (91),
+ B32 (92), B32 (93), B32 (94), B32 (95),
+ B32 (96), B32 (97), B32 (98), B32 (99),
+ B32 (100), B32 (101), B32 (102), B32 (103),
+ B32 (104), B32 (105), B32 (106), B32 (107),
+ B32 (108), B32 (109), B32 (110), B32 (111),
+ B32 (112), B32 (113), B32 (114), B32 (115),
+ B32 (116), B32 (117), B32 (118), B32 (119),
+ B32 (120), B32 (121), B32 (122), B32 (123),
+ B32 (124), B32 (125), B32 (126), B32 (127),
+ B32 (128), B32 (129), B32 (130), B32 (131),
+ B32 (132), B32 (133), B32 (134), B32 (135),
+ B32 (136), B32 (137), B32 (138), B32 (139),
+ B32 (140), B32 (141), B32 (142), B32 (143),
+ B32 (144), B32 (145), B32 (146), B32 (147),
+ B32 (148), B32 (149), B32 (150), B32 (151),
+ B32 (152), B32 (153), B32 (154), B32 (155),
+ B32 (156), B32 (157), B32 (158), B32 (159),
+ B32 (160), B32 (161), B32 (162), B32 (163),
+ B32 (164), B32 (165), B32 (166), B32 (167),
+ B32 (168), B32 (169), B32 (170), B32 (171),
+ B32 (172), B32 (173), B32 (174), B32 (175),
+ B32 (176), B32 (177), B32 (178), B32 (179),
+ B32 (180), B32 (181), B32 (182), B32 (183),
+ B32 (184), B32 (185), B32 (186), B32 (187),
+ B32 (188), B32 (189), B32 (190), B32 (191),
+ B32 (192), B32 (193), B32 (194), B32 (195),
+ B32 (196), B32 (197), B32 (198), B32 (199),
+ B32 (200), B32 (201), B32 (202), B32 (203),
+ B32 (204), B32 (205), B32 (206), B32 (207),
+ B32 (208), B32 (209), B32 (210), B32 (211),
+ B32 (212), B32 (213), B32 (214), B32 (215),
+ B32 (216), B32 (217), B32 (218), B32 (219),
+ B32 (220), B32 (221), B32 (222), B32 (223),
+ B32 (224), B32 (225), B32 (226), B32 (227),
+ B32 (228), B32 (229), B32 (230), B32 (231),
+ B32 (232), B32 (233), B32 (234), B32 (235),
+ B32 (236), B32 (237), B32 (238), B32 (239),
+ B32 (240), B32 (241), B32 (242), B32 (243),
+ B32 (244), B32 (245), B32 (246), B32 (247),
+ B32 (248), B32 (249), B32 (250), B32 (251),
+ B32 (252), B32 (253), B32 (254), B32 (255)
+};
+
+#if UCHAR_MAX == 255
+#define uchar_in_range(c) true
+#else
+#define uchar_in_range(c) ((c) <= 255)
+#endif
+
+/* Return true if CH is a character from the Base32 alphabet, and
+ false otherwise. Note that '=' is padding and not considered to be
+ part of the alphabet. */
+bool isbase32(char ch)
+{
+ return uchar_in_range(to_uchar(ch)) && 0 <= b32[to_uchar(ch)];
+}
+
+/* Decode base32 encoded input array IN of length INLEN to output
+ array OUT that can hold *OUTLEN bytes. Return true if decoding was
+ successful, i.e. if the input was valid base32 data, false
+ otherwise. If *OUTLEN is too small, as many bytes as possible will
+ be written to OUT. On return, *OUTLEN holds the length of decoded
+ bytes in OUT. Note that as soon as any non-alphabet characters are
+ encountered, decoding is stopped and false is returned. This means
+ that, when applicable, you must remove any line terminators that is
+ part of the data stream before calling this function. */
+bool base32_decode(const char *in, size_t inlen, char *out, size_t *outlen)
+{
+ size_t outleft = *outlen;
+
+ while (inlen >= 2) {
+ if (!isbase32(in[0]) || !isbase32(in[1])) {
+ break;
+ }
+
+ if (outleft) {
+ *out++ = ((b32[to_uchar(in[0])] << 3)
+ | (b32[to_uchar(in[1])] >> 2));
+ outleft--;
+ }
+
+ if (inlen == 2) {
+ break;
+ }
+
+ if (in[2] == '=') {
+ if (inlen != 8) {
+ break;
+ }
+
+ if ((in[3] != '=') ||
+ (in[4] != '=') ||
+ (in[5] != '=') ||
+ (in[6] != '=') ||
+ (in[7] != '=')) {
+ break;
+ }
+ } else {
+ if (!isbase32(in[2]) || !isbase32(in[3])) {
+ break;
+ }
+
+ if (outleft) {
+ *out++ = ((b32[to_uchar(in[1])] << 6)
+ | ((b32[to_uchar(in[2])] << 1) & 0x3E)
+ | (b32[to_uchar(in[3])] >> 4));
+ outleft--;
+ }
+
+ if (inlen == 4) {
+ break;
+ }
+
+ if (in[4] == '=') {
+ if (inlen != 8) {
+ break;
+ }
+
+ if ((in[5] != '=') ||
+ (in[6] != '=') ||
+ (in[7] != '=')) {
+ break;
+ }
+ } else {
+ if (!isbase32 (in[3]) || !isbase32(in[4])) {
+ break;
+ }
+
+ if (outleft) {
+ *out++ = ((b32[to_uchar(in[3])] << 4)
+ | (b32[to_uchar(in[4])] >> 1));
+ outleft--;
+ }
+
+ if (inlen == 5) {
+ break;
+ }
+
+ if (in[5] == '=') {
+ if (inlen != 8) {
+ break;
+ }
+
+ if ((in[6] != '=')
+ || (in[7] != '=')) {
+ break;
+ }
+ } else {
+ if (!isbase32 (in[5])
+ || !isbase32 (in[6])) {
+ break;
+ }
+
+ if (outleft) {
+ *out++ = ((b32[to_uchar(in[4])]
+ << 7)
+ | (b32[to_uchar(in[5])] << 2)
+ | (b32[to_uchar(in[6])]
+ >> 3));
+ outleft--;
+ }
+
+ if (inlen == 7) {
+ break;
+ }
+
+ if (in[7] == '=') {
+ if (inlen != 8) {
+ break;
+ }
+ } else {
+ if (!isbase32 (in[7])) {
+ break;
+ }
+
+ if (outleft) {
+ *out++ =
+ ((b32[to_uchar(in[6])]
+ << 5) | (b32[
+ to_uchar(in[7])]));
+ outleft--;
+ }
+ }
+ }
+ }
+ }
+
+ in += 8;
+ inlen -= 8;
+ }
+
+ *outlen -= outleft;
+
+ if (inlen != 0) {
+ return false;
+ }
+
+ return true;
+}
+
+/* Allocate an output buffer in *OUT, and decode the base32 encoded
+ data stored in IN of size INLEN to the *OUT buffer. On return, the
+ size of the decoded data is stored in *OUTLEN. OUTLEN may be NULL,
+ if the caller is not interested in the decoded length. *OUT may be
+ NULL to indicate an out of memory error, in which case *OUTLEN
+ contains the size of the memory block needed. The function returns
+ true on successful decoding and memory allocation errors. (Use the
+ *OUT and *OUTLEN parameters to differentiate between successful
+ decoding and memory error.) The function returns false if the
+ input was invalid, in which case *OUT is NULL and *OUTLEN is
+ undefined. */
+bool base32_decode_alloc(const char *in, size_t inlen, char **out,
+ size_t *outlen)
+{
+ /* This may allocate a few bytes too much, depending on input,
+ but it's not worth the extra CPU time to compute the exact amount.
+ The exact amount is 5 * inlen / 8, minus 1 if the input ends
+ with "=" and minus another 1 if the input ends with "==", etc.
+ Dividing before multiplying avoids the possibility of overflow. */
+ size_t needlen = 5 * (inlen / 8) + 4;
+
+ *out = malloc(needlen);
+ if (!*out) {
+ return true;
+ }
+
+ if (!base32_decode(in, inlen, *out, &needlen)) {
+ free (*out);
+ *out = NULL;
+ return false;
+ }
+
+ if (outlen) {
+ *outlen = needlen;
+ }
+
+ return true;
+}
+
+#ifdef MAIN
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdio.h>
+#include "base32.h"
+
+int main(int argc, char **argv) {
+ int i = 1;
+ size_t inlen, outlen, argvlen;
+ char *out;
+ char *in;
+ bool ok;
+
+ while (argc > 1) {
+ argv++; argc--;
+ argvlen = strlen(*argv);
+
+ outlen = base32_encode_alloc(*argv, argvlen, &out);
+
+ if (out == NULL && outlen == 0 && inlen != 0) {
+ fprintf(stderr, "ERROR(encode): input too long: %zd\n",
+ outlen);
+ return 1;
+ }
+
+ if (out == NULL) {
+ fprintf(stderr, "ERROR(encode): memory allocation error"
+ "\n");
+ return 1;
+ }
+
+ ok = base32_decode_alloc(out, outlen, &in, &inlen);
+
+ if (!ok) {
+ fprintf(stderr, "ERROR(decode): input was not valid "
+ "base32: `%s'\n", out);
+ return 1;
+ }
+
+ if (in == NULL) {
+ fprintf(stderr, "ERROR(decode): memory allocation "
+ "error\n");
+ }
+
+ if ((inlen != argvlen) ||
+ strcmp(*argv, in) != 0) {
+ fprintf(stderr, "ERROR(encode/decode): input `%s' and "
+ "output `%s'\n", *argv, in);
+ return 1;
+ }
+ printf("INPUT: `%s'\nENCODE: `%s'\nDECODE: `%s'\n", *argv, out,
+ in);
+ }
+}
+
+#endif
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