+++ /dev/null
-/* base64.c -- Encode binary data using printable characters.
- Copyright (C) 1999, 2000, 2001, 2004, 2005, 2006, 2007 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */
-
-/* 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 3548 <http://www.ietf.org/rfc/rfc3548.txt>.
- *
- * Be careful with error checking. Here is how you would typically
- * use these functions:
- *
- * bool ok = base64_decode_alloc (in, inlen, &out, &outlen);
- * if (!ok)
- * FAIL: input was not valid base64
- * if (out == NULL)
- * FAIL: memory allocation error
- * OK: data in OUT/OUTLEN
- *
- * size_t outlen = base64_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.
- *
- */
-
-#include <config.h>
-
-/* Get prototype. */
-#include "base64.h"
-
-/* Get malloc. */
-#include <stdlib.h>
-
-/* Get UCHAR_MAX. */
-#include <limits.h>
-
-#include <string.h>
-
-/* C89 compliant way to cast 'char' to 'unsigned char'. */
-static inline unsigned char
-to_uchar (char ch)
-{
- return ch;
-}
-
-/* Base64 encode IN array of size INLEN into OUT array of size OUTLEN.
- If OUTLEN is less than BASE64_LENGTH(INLEN), write as many bytes as
- possible. If OUTLEN is larger than BASE64_LENGTH(INLEN), also zero
- terminate the output buffer. */
-void
-base64_encode (const char *restrict in, size_t inlen,
- char *restrict out, size_t outlen)
-{
- static const char b64str[64] =
- "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-
- while (inlen && outlen)
- {
- *out++ = b64str[(to_uchar (in[0]) >> 2) & 0x3f];
- if (!--outlen)
- break;
- *out++ = b64str[((to_uchar (in[0]) << 4)
- + (--inlen ? to_uchar (in[1]) >> 4 : 0))
- & 0x3f];
- if (!--outlen)
- break;
- *out++ =
- (inlen
- ? b64str[((to_uchar (in[1]) << 2)
- + (--inlen ? to_uchar (in[2]) >> 6 : 0))
- & 0x3f]
- : '=');
- if (!--outlen)
- break;
- *out++ = inlen ? b64str[to_uchar (in[2]) & 0x3f] : '=';
- if (!--outlen)
- break;
- if (inlen)
- inlen--;
- if (inlen)
- in += 3;
- }
-
- if (outlen)
- *out = '\0';
-}
-
-/* Allocate a buffer and store zero terminated base64 encoded data
- from array IN of size INLEN, returning BASE64_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.,
- BASE64_LENGTH(inlen) + 1. */
-size_t
-base64_encode_alloc (const char *in, size_t inlen, char **out)
-{
- size_t outlen = 1 + BASE64_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;
-
- base64_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
- Base64 alphabet (A-Za-z0-9+/) 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 B64(x) ...'x'...", so use "_"
- as the formal parameter rather than "x". */
-#define B64(_) \
- ((_) == '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 \
- : (_) == 'a' ? 26 \
- : (_) == 'b' ? 27 \
- : (_) == 'c' ? 28 \
- : (_) == 'd' ? 29 \
- : (_) == 'e' ? 30 \
- : (_) == 'f' ? 31 \
- : (_) == 'g' ? 32 \
- : (_) == 'h' ? 33 \
- : (_) == 'i' ? 34 \
- : (_) == 'j' ? 35 \
- : (_) == 'k' ? 36 \
- : (_) == 'l' ? 37 \
- : (_) == 'm' ? 38 \
- : (_) == 'n' ? 39 \
- : (_) == 'o' ? 40 \
- : (_) == 'p' ? 41 \
- : (_) == 'q' ? 42 \
- : (_) == 'r' ? 43 \
- : (_) == 's' ? 44 \
- : (_) == 't' ? 45 \
- : (_) == 'u' ? 46 \
- : (_) == 'v' ? 47 \
- : (_) == 'w' ? 48 \
- : (_) == 'x' ? 49 \
- : (_) == 'y' ? 50 \
- : (_) == 'z' ? 51 \
- : (_) == '0' ? 52 \
- : (_) == '1' ? 53 \
- : (_) == '2' ? 54 \
- : (_) == '3' ? 55 \
- : (_) == '4' ? 56 \
- : (_) == '5' ? 57 \
- : (_) == '6' ? 58 \
- : (_) == '7' ? 59 \
- : (_) == '8' ? 60 \
- : (_) == '9' ? 61 \
- : (_) == '+' ? 62 \
- : (_) == '/' ? 63 \
- : -1)
-
-static const signed char b64[0x100] = {
- B64 (0), B64 (1), B64 (2), B64 (3),
- B64 (4), B64 (5), B64 (6), B64 (7),
- B64 (8), B64 (9), B64 (10), B64 (11),
- B64 (12), B64 (13), B64 (14), B64 (15),
- B64 (16), B64 (17), B64 (18), B64 (19),
- B64 (20), B64 (21), B64 (22), B64 (23),
- B64 (24), B64 (25), B64 (26), B64 (27),
- B64 (28), B64 (29), B64 (30), B64 (31),
- B64 (32), B64 (33), B64 (34), B64 (35),
- B64 (36), B64 (37), B64 (38), B64 (39),
- B64 (40), B64 (41), B64 (42), B64 (43),
- B64 (44), B64 (45), B64 (46), B64 (47),
- B64 (48), B64 (49), B64 (50), B64 (51),
- B64 (52), B64 (53), B64 (54), B64 (55),
- B64 (56), B64 (57), B64 (58), B64 (59),
- B64 (60), B64 (61), B64 (62), B64 (63),
- B64 (64), B64 (65), B64 (66), B64 (67),
- B64 (68), B64 (69), B64 (70), B64 (71),
- B64 (72), B64 (73), B64 (74), B64 (75),
- B64 (76), B64 (77), B64 (78), B64 (79),
- B64 (80), B64 (81), B64 (82), B64 (83),
- B64 (84), B64 (85), B64 (86), B64 (87),
- B64 (88), B64 (89), B64 (90), B64 (91),
- B64 (92), B64 (93), B64 (94), B64 (95),
- B64 (96), B64 (97), B64 (98), B64 (99),
- B64 (100), B64 (101), B64 (102), B64 (103),
- B64 (104), B64 (105), B64 (106), B64 (107),
- B64 (108), B64 (109), B64 (110), B64 (111),
- B64 (112), B64 (113), B64 (114), B64 (115),
- B64 (116), B64 (117), B64 (118), B64 (119),
- B64 (120), B64 (121), B64 (122), B64 (123),
- B64 (124), B64 (125), B64 (126), B64 (127),
- B64 (128), B64 (129), B64 (130), B64 (131),
- B64 (132), B64 (133), B64 (134), B64 (135),
- B64 (136), B64 (137), B64 (138), B64 (139),
- B64 (140), B64 (141), B64 (142), B64 (143),
- B64 (144), B64 (145), B64 (146), B64 (147),
- B64 (148), B64 (149), B64 (150), B64 (151),
- B64 (152), B64 (153), B64 (154), B64 (155),
- B64 (156), B64 (157), B64 (158), B64 (159),
- B64 (160), B64 (161), B64 (162), B64 (163),
- B64 (164), B64 (165), B64 (166), B64 (167),
- B64 (168), B64 (169), B64 (170), B64 (171),
- B64 (172), B64 (173), B64 (174), B64 (175),
- B64 (176), B64 (177), B64 (178), B64 (179),
- B64 (180), B64 (181), B64 (182), B64 (183),
- B64 (184), B64 (185), B64 (186), B64 (187),
- B64 (188), B64 (189), B64 (190), B64 (191),
- B64 (192), B64 (193), B64 (194), B64 (195),
- B64 (196), B64 (197), B64 (198), B64 (199),
- B64 (200), B64 (201), B64 (202), B64 (203),
- B64 (204), B64 (205), B64 (206), B64 (207),
- B64 (208), B64 (209), B64 (210), B64 (211),
- B64 (212), B64 (213), B64 (214), B64 (215),
- B64 (216), B64 (217), B64 (218), B64 (219),
- B64 (220), B64 (221), B64 (222), B64 (223),
- B64 (224), B64 (225), B64 (226), B64 (227),
- B64 (228), B64 (229), B64 (230), B64 (231),
- B64 (232), B64 (233), B64 (234), B64 (235),
- B64 (236), B64 (237), B64 (238), B64 (239),
- B64 (240), B64 (241), B64 (242), B64 (243),
- B64 (244), B64 (245), B64 (246), B64 (247),
- B64 (248), B64 (249), B64 (250), B64 (251),
- B64 (252), B64 (253), B64 (254), B64 (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 Base64 alphabet, and
- false otherwise. Note that '=' is padding and not considered to be
- part of the alphabet. */
-bool
-isbase64 (char ch)
-{
- return uchar_in_range (to_uchar (ch)) && 0 <= b64[to_uchar (ch)];
-}
-
-/* Initialize decode-context buffer, CTX. */
-void
-base64_decode_ctx_init (struct base64_decode_context *ctx)
-{
- ctx->i = 0;
-}
-
-/* If CTX->i is 0 or 4, there are four or more bytes in [*IN..IN_END), and
- none of those four is a newline, then return *IN. Otherwise, copy up to
- 4 - CTX->i non-newline bytes from that range into CTX->buf, starting at
- index CTX->i and setting CTX->i to reflect the number of bytes copied,
- and return CTX->buf. In either case, advance *IN to point to the byte
- after the last one processed, and set *N_NON_NEWLINE to the number of
- verified non-newline bytes accessible through the returned pointer. */
-static inline char *
-get_4 (struct base64_decode_context *ctx,
- char const *restrict *in, char const *restrict in_end,
- size_t *n_non_newline)
-{
- if (ctx->i == 4)
- ctx->i = 0;
-
- if (ctx->i == 0)
- {
- char const *t = *in;
- if (4 <= in_end - *in && memchr (t, '\n', 4) == NULL)
- {
- /* This is the common case: no newline. */
- *in += 4;
- *n_non_newline = 4;
- return (char *) t;
- }
- }
-
- {
- /* Copy non-newline bytes into BUF. */
- char const *p = *in;
- while (p < in_end)
- {
- char c = *p++;
- if (c != '\n')
- {
- ctx->buf[ctx->i++] = c;
- if (ctx->i == 4)
- break;
- }
- }
-
- *in = p;
- *n_non_newline = ctx->i;
- return ctx->buf;
- }
-}
-
-#define return_false \
- do \
- { \
- *outp = out; \
- return false; \
- } \
- while (false)
-
-/* Decode up to four bytes of base64-encoded data, IN, of length INLEN
- into the output buffer, *OUT, of size *OUTLEN bytes. Return true if
- decoding is successful, false otherwise. If *OUTLEN is too small,
- as many bytes as possible are written to *OUT. On return, advance
- *OUT to point to the byte after the last one written, and decrement
- *OUTLEN to reflect the number of bytes remaining in *OUT. */
-static inline bool
-decode_4 (char const *restrict in, size_t inlen,
- char *restrict *outp, size_t *outleft)
-{
- char *out = *outp;
- if (inlen < 2)
- return false;
-
- if (!isbase64 (in[0]) || !isbase64 (in[1]))
- return false;
-
- if (*outleft)
- {
- *out++ = ((b64[to_uchar (in[0])] << 2)
- | (b64[to_uchar (in[1])] >> 4));
- --*outleft;
- }
-
- if (inlen == 2)
- return_false;
-
- if (in[2] == '=')
- {
- if (inlen != 4)
- return_false;
-
- if (in[3] != '=')
- return_false;
- }
- else
- {
- if (!isbase64 (in[2]))
- return_false;
-
- if (*outleft)
- {
- *out++ = (((b64[to_uchar (in[1])] << 4) & 0xf0)
- | (b64[to_uchar (in[2])] >> 2));
- --*outleft;
- }
-
- if (inlen == 3)
- return_false;
-
- if (in[3] == '=')
- {
- if (inlen != 4)
- return_false;
- }
- else
- {
- if (!isbase64 (in[3]))
- return_false;
-
- if (*outleft)
- {
- *out++ = (((b64[to_uchar (in[2])] << 6) & 0xc0)
- | b64[to_uchar (in[3])]);
- --*outleft;
- }
- }
- }
-
- *outp = out;
- return true;
-}
-
-/* Decode base64-encoded input array IN of length INLEN to output array
- OUT that can hold *OUTLEN bytes. The input data may be interspersed
- with newlines. Return true if decoding was successful, i.e. if the
- input was valid base64 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, non-newline character is encountered, decoding
- is stopped and false is returned. If INLEN is zero, then process
- only whatever data is stored in CTX.
-
- Initially, CTX must have been initialized via base64_decode_ctx_init.
- Subsequent calls to this function must reuse whatever state is recorded
- in that buffer. It is necessary for when a quadruple of base64 input
- bytes spans two input buffers.
-
- If CTX is NULL then newlines are treated as garbage and the input
- buffer is processed as a unit. */
-
-bool
-base64_decode_ctx (struct base64_decode_context *ctx,
- const char *restrict in, size_t inlen,
- char *restrict out, size_t *outlen)
-{
- size_t outleft = *outlen;
- bool ignore_newlines = ctx != NULL;
- bool flush_ctx = false;
- unsigned int ctx_i = 0;
-
- if (ignore_newlines)
- {
- ctx_i = ctx->i;
- flush_ctx = inlen == 0;
- }
-
-
- while (true)
- {
- size_t outleft_save = outleft;
- if (ctx_i == 0 && !flush_ctx)
- {
- while (true)
- {
- /* Save a copy of outleft, in case we need to re-parse this
- block of four bytes. */
- outleft_save = outleft;
- if (!decode_4 (in, inlen, &out, &outleft))
- break;
-
- in += 4;
- inlen -= 4;
- }
- }
-
- if (inlen == 0 && !flush_ctx)
- break;
-
- /* Handle the common case of 72-byte wrapped lines.
- This also handles any other multiple-of-4-byte wrapping. */
- if (inlen && *in == '\n' && ignore_newlines)
- {
- ++in;
- --inlen;
- continue;
- }
-
- /* Restore OUT and OUTLEFT. */
- out -= outleft_save - outleft;
- outleft = outleft_save;
-
- {
- char const *in_end = in + inlen;
- char const *non_nl;
-
- if (ignore_newlines)
- non_nl = get_4 (ctx, &in, in_end, &inlen);
- else
- non_nl = in; /* Might have nl in this case. */
-
- /* If the input is empty or consists solely of newlines (0 non-newlines),
- then we're done. Likewise if there are fewer than 4 bytes when not
- flushing context and not treating newlines as garbage. */
- if (inlen == 0 || (inlen < 4 && !flush_ctx && ignore_newlines))
- {
- inlen = 0;
- break;
- }
- if (!decode_4 (non_nl, inlen, &out, &outleft))
- break;
-
- inlen = in_end - in;
- }
- }
-
- *outlen -= outleft;
-
- return inlen == 0;
-}
-
-/* Allocate an output buffer in *OUT, and decode the base64 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
-base64_decode_alloc_ctx (struct base64_decode_context *ctx,
- const char *in, size_t inlen, char **out,
- size_t *outlen)
-{
- /* This may allocate a few bytes too many, depending on input,
- but it's not worth the extra CPU time to compute the exact size.
- The exact size is 3 * inlen / 4, minus 1 if the input ends
- with "=" and minus another 1 if the input ends with "==".
- Dividing before multiplying avoids the possibility of overflow. */
- size_t needlen = 3 * (inlen / 4) + 2;
-
- *out = malloc (needlen);
- if (!*out)
- return true;
-
- if (!base64_decode_ctx (ctx, in, inlen, *out, &needlen))
- {
- free (*out);
- *out = NULL;
- return false;
- }
-
- if (outlen)
- *outlen = needlen;
-
- return true;
-}
projects / platform / upstream / coreutils.git / commitdiff