# HG changeset patch # User Simon Josefsson # Date 1101847612 0 # Node ID ac6438eb46c66e3b964f55a29b4f343142528335 # Parent 9e5eab61b552e44b63056822220a694848bb964f Add base64. diff --git a/ChangeLog b/ChangeLog --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,12 @@ +2004-11-30 Simon Josefsson + + * MODULES.html.sh (Extra functions based on ANSI C 89): Add + base64. + + * tests/test-base64.c: New file. + + * modules/base64: New file. + 2004-11-30 Simon Josefsson * modules/restrict (License): Change to LGPL. diff --git a/MODULES.html.sh b/MODULES.html.sh --- a/MODULES.html.sh +++ b/MODULES.html.sh @@ -1605,6 +1605,7 @@ func_echo "$element" func_begin_table + func_module base64 func_module diacrit func_module getline func_module getnline diff --git a/lib/ChangeLog b/lib/ChangeLog --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,7 @@ +2004-11-28 Simon Josefsson + + * base64.h, base64.c: New file. + 2004-11-27 Paul Eggert * getcwd.h: New file, which I forgot to check in on 2004-11-25. diff --git a/lib/base64.c b/lib/base64.c new file mode 100644 --- /dev/null +++ b/lib/base64.c @@ -0,0 +1,403 @@ +/* base64.c -- Encode binary data using printable characters. + Copyright (C) 1999, 2000, 2001, 2004 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +/* 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 . + * + * 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/LEN. + * + */ + +#ifdef HAVE_CONFIG_H +# include +#endif + +/* Get prototype. */ +#include "base64.h" + +/* Get malloc. */ +#include + +/* 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) +{ + const char b64[64] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + + while (inlen && outlen) + { + *out++ = b64[to_uchar (in[0]) >> 2]; + if (!--outlen) + break; + *out++ = b64[((to_uchar (in[0]) << 4) + + (--inlen ? to_uchar (in[1]) >> 4 : 0)) & 0x3f]; + if (!--outlen) + break; + *out++ = + (inlen + ? b64[((to_uchar (in[1]) << 2) + + (--inlen ? to_uchar (in[2]) >> 6 : 0)) & 0x3f] : '='); + if (!--outlen) + break; + *out++ = inlen ? b64[to_uchar (in[2]) & 0x3f] : '='; + if (!--outlen) + break; + if (inlen) + 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 fail, OUT is set to NULL, and the return value + indicate 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) + 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. */ +#define B64(x) \ + ((x) == 'A' ? 0 \ + : (x) == 'B' ? 1 \ + : (x) == 'C' ? 2 \ + : (x) == 'D' ? 3 \ + : (x) == 'E' ? 4 \ + : (x) == 'F' ? 5 \ + : (x) == 'G' ? 6 \ + : (x) == 'H' ? 7 \ + : (x) == 'I' ? 8 \ + : (x) == 'J' ? 9 \ + : (x) == 'K' ? 10 \ + : (x) == 'L' ? 11 \ + : (x) == 'M' ? 12 \ + : (x) == 'N' ? 13 \ + : (x) == 'O' ? 14 \ + : (x) == 'P' ? 15 \ + : (x) == 'Q' ? 16 \ + : (x) == 'R' ? 17 \ + : (x) == 'S' ? 18 \ + : (x) == 'T' ? 19 \ + : (x) == 'U' ? 20 \ + : (x) == 'V' ? 21 \ + : (x) == 'W' ? 22 \ + : (x) == 'X' ? 23 \ + : (x) == 'Y' ? 24 \ + : (x) == 'Z' ? 25 \ + : (x) == 'a' ? 26 \ + : (x) == 'b' ? 27 \ + : (x) == 'c' ? 28 \ + : (x) == 'd' ? 29 \ + : (x) == 'e' ? 30 \ + : (x) == 'f' ? 31 \ + : (x) == 'g' ? 32 \ + : (x) == 'h' ? 33 \ + : (x) == 'i' ? 34 \ + : (x) == 'j' ? 35 \ + : (x) == 'k' ? 36 \ + : (x) == 'l' ? 37 \ + : (x) == 'm' ? 38 \ + : (x) == 'n' ? 39 \ + : (x) == 'o' ? 40 \ + : (x) == 'p' ? 41 \ + : (x) == 'q' ? 42 \ + : (x) == 'r' ? 43 \ + : (x) == 's' ? 44 \ + : (x) == 't' ? 45 \ + : (x) == 'u' ? 46 \ + : (x) == 'v' ? 47 \ + : (x) == 'w' ? 48 \ + : (x) == 'x' ? 49 \ + : (x) == 'y' ? 50 \ + : (x) == 'z' ? 51 \ + : (x) == '0' ? 52 \ + : (x) == '1' ? 53 \ + : (x) == '2' ? 54 \ + : (x) == '3' ? 55 \ + : (x) == '4' ? 56 \ + : (x) == '5' ? 57 \ + : (x) == '6' ? 58 \ + : (x) == '7' ? 59 \ + : (x) == '8' ? 60 \ + : (x) == '9' ? 61 \ + : (x) == '+' ? 62 \ + : (x) == '/' ? 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) +}; + +static inline bool +isb64 (unsigned char ch) +{ + return ch <= 255 && 0 <= b64[ch]; +} + +/* Decode base64 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 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 characters are + encountered, decoding is stopped and false is returned. */ +bool +base64_decode (const char *restrict in, size_t inlen, + char *restrict out, size_t * outlen) +{ + size_t outleft = *outlen; + + while (inlen >= 2) + { + if (!isb64 (in[0]) || !isb64 (in[1])) + break; + + if (outleft) + { + *out++ = ((b64[to_uchar (in[0])] << 2) + | (b64[to_uchar (in[1])] >> 4)); + outleft--; + } + + if (inlen == 2) + break; + + if (in[2] == '=') + { + if (inlen != 4) + break; + + if (in[3] != '=') + break; + + } + else + { + if (!isb64 (in[2])) + break; + + if (outleft) + { + *out++ = (((b64[to_uchar (in[1])] << 4) & 0xf0) + | (b64[to_uchar (in[2])] >> 2)); + outleft--; + } + + if (inlen == 3) + break; + + if (in[3] == '=') + { + if (inlen != 4) + break; + } + else + { + if (!isb64 (in[3])) + break; + + if (outleft) + { + *out++ = (((b64[to_uchar (in[2])] << 6) & 0xc0) + | b64[to_uchar (in[3])]); + outleft--; + } + } + } + + in += 4; + inlen -= 4; + } + + *outlen -= outleft; + + if (inlen != 0) + return false; + + return true; +} + +/* 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 + contain the size of the memory block needed. The function return + true on successful decoding and memory allocation errors. (Use the + *OUT and *OUTLEN parameters to differentiate between successful + decoding and memory error.) The function return false if the input + was invalid, in which case *OUT is NULL and *OUTLEN is + undefined. */ +bool +base64_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 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 (in, inlen, *out, &needlen)) + { + free (*out); + *out = NULL; + return false; + } + + if (outlen) + *outlen = needlen; + + return true; +} diff --git a/lib/base64.h b/lib/base64.h new file mode 100644 --- /dev/null +++ b/lib/base64.h @@ -0,0 +1,43 @@ +/* base64.h -- Encode binary data using printable characters. + Copyright (C) 2004 Free Software Foundation, Inc. + Written by Simon Josefsson. + + 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + +#ifndef BASE64_H +# define BASE64_H + +/* Get size_t. */ +#include + +/* Get bool. */ +#include + +/* This uses that the expression (n+(k-1))/k means the smallest + integer >= n/k, i.e., the ceiling of n/k. */ +#define BASE64_LENGTH(inlen) ((((inlen) + 2) / 3) * 4) + +extern void base64_encode (const char *restrict in, size_t inlen, + char *restrict out, size_t outlen); + +extern size_t base64_encode_alloc (const char *in, size_t inlen, char **out); + +extern bool base64_decode (const char *restrict in, size_t inlen, + char *restrict out, size_t * outlen); + +extern bool base64_decode_alloc (const char *in, size_t inlen, + char **out, size_t * outlen); + +#endif /* BASE64_H */ diff --git a/m4/ChangeLog b/m4/ChangeLog --- a/m4/ChangeLog +++ b/m4/ChangeLog @@ -1,3 +1,7 @@ +2004-11-30 Simon Josefsson + + * base64.m4: New file. + 2004-11-30 Simon Josefsson * restrict.m4: Add copyright and copying conditions. diff --git a/m4/base64.m4 b/m4/base64.m4 new file mode 100644 --- /dev/null +++ b/m4/base64.m4 @@ -0,0 +1,18 @@ +# base64.m4 serial 1 +dnl Copyright (C) 2004 Free Software Foundation, Inc. +dnl This file is free software, distributed under the terms of the GNU +dnl General Public License. As a special exception to the GNU General +dnl Public License, this file may be distributed as part of a program +dnl that contains a configuration script generated by Autoconf, under +dnl the same distribution terms as the rest of that program. + +AC_DEFUN([gl_FUNC_BASE64], +[ + gl_PREREQ_BASE64 +]) + +# Prerequisites of lib/base64.c. +AC_DEFUN([gl_PREREQ_BASE64], [ + AC_REQUIRE([AC_C_INLINE]) + AC_REQUIRE([gl_C_RESTRICT]) +]) diff --git a/modules/base64 b/modules/base64 new file mode 100644 --- /dev/null +++ b/modules/base64 @@ -0,0 +1,26 @@ +Description: +Encode binary data using printable characters (base64). + +Files: +lib/base64.h +lib/base64.c +m4/base64.m4 + +Depends-on: +stdbool +restrict + +configure.ac: +gl_FUNC_BASE64 + +Makefile.am: +lib_SOURCES += base64.h base64.c + +Include: +"base64.h" + +License: +LGPL + +Maintainer: +Simon Josefsson diff --git a/tests/test-base64.c b/tests/test-base64.c new file mode 100755 --- /dev/null +++ b/tests/test-base64.c @@ -0,0 +1,159 @@ +#include "base64.h" + +#include +#include + +int +main (int argc, char *argv[]) +{ + const char *in = "abcdefghijklmnop"; + const char *b64in = "YWJjZGVmZw=="; + char out[255]; + char *p; + size_t len; + bool ok; + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 0, out, 0); + if (out[0] != '\x42') + fprintf (stderr, "failure\n"); + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 1, out, 1); + if (memcmp (out, "YQ==", 1) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 1, out, 2); + if (memcmp (out, "YQ==", 2) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 1, out, 3); + if (memcmp (out, "YQ==", 3) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 1, out, 4); + if (memcmp (out, "YQ==", 4) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 1, out, 8); + if (memcmp (out, "YQ==", 4) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 2, out, 4); + if (memcmp (out, "YWI=", 4) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 3, out, 4); + if (memcmp (out, "YWJj", 4) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 4, out, 5); + if (memcmp (out, "YWJjZA==", 5) != 0) + { + out[5] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + memset (out, 0x42, sizeof (out)); + base64_encode (in, 4, out, 100); + if (memcmp (out, "YWJjZA==", 6) != 0) + { + out[6] = '\0'; + fprintf (stderr, "failure (%s)\n", out); + } + + /* Decode. */ + + memset (out, 0x42, sizeof (out)); + len = 0; + ok = base64_decode (b64in, 4, out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 0) + fprintf (stderr, "failure (%d)\n", len); + + memset (out, 0x42, sizeof (out)); + len = 1; + ok = base64_decode (b64in, 4, out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 1 || memcmp (out, "abcdefg", 1) != 0) + { + out[2] = '\0'; + fprintf (stderr, "failure (%d: %s)\n", len, out); + } + + memset (out, 0x42, sizeof (out)); + len = 2; + ok = base64_decode (b64in, 4, out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 2 || memcmp (out, "abcdefg", 2) != 0) + { + out[3] = '\0'; + fprintf (stderr, "failure (%d: %s)\n", len, out); + } + + memset (out, 0x42, sizeof (out)); + len = 3; + ok = base64_decode (b64in, 4, out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 3 || memcmp (out, "abcdefg", 3) != 0) + { + out[4] = '\0'; + fprintf (stderr, "failure (%d: %s)\n", len, out); + } + + memset (out, 0x42, sizeof (out)); + len = 4; + ok = base64_decode (b64in, 4, out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 3 || memcmp (out, "abcdefg", 3) != 0) + { + out[3] = '\0'; + fprintf (stderr, "failure (%d: %s)\n", len, out); + } + + memset (out, 0x42, sizeof (out)); + len = 100; + ok = base64_decode (b64in, strlen (b64in), out, &len); + if (!ok) + fprintf (stderr, "decode failed\n"); + if (len != 7 || memcmp (out, "abcdefg", 7) != 0) + { + out[7] = '\0'; + fprintf (stderr, "failure (%d: %s)\n", len, out); + } + + return 0; +}