diff options
Diffstat (limited to 'base64.c')
| -rw-r--r-- | base64.c | 131 |
1 files changed, 68 insertions, 63 deletions
@@ -1,92 +1,97 @@ -/* from imtest.c -- IMAP/IMSP test client - * Cyrus IMAPd 1.5.2 <URL:ftp://ftp.andrew.cmu.edu/pub/cyrus-mail/cyrus-imapd-v1.5.2.tar.gz> +/* + * base64.c -- base-64 conversion routines. * - * Copyright 1996, Carnegie Mellon University. All Rights Reserved. - * - * This software is made available for academic and research - * purposes only. No commercial license is hereby granted. - * Copying and other reproduction is authorized only for research, - * education, and other non-commercial purposes. No warranties, - * either expressed or implied, are made regarding the operation, - * use, or results of the software. Such a release does not permit - * use of the code for commercial purposes or benefits by anyone - * without specific, additional permission by the owner of the code. + * For license terms, see the file COPYING in this directory. * - * Author: Chris Newman <chrisn+@cmu.edu> - * Start Date: 2/16/93 + * This base 64 encoding is defined in RFC2045 section 6.8, + * "Base64 Content-Transfer-Encoding", but lines must not be broken in the + * scheme used here. */ +#include <ctype.h> -/* base64 tables - */ -static char basis_64[] = +static const char base64digits[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; -static char index_64[128] = { - -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, - -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, - -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63, - 52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1, - -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14, - 15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1, - -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40, - 41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1 + +#define BAD -1 +static const char base64val[] = { + BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, + BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, + BAD,BAD,BAD,BAD, BAD,BAD,BAD,BAD, BAD,BAD,BAD, 62, BAD,BAD,BAD, 63, + 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,BAD,BAD, BAD,BAD,BAD,BAD, + BAD, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, + 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,BAD, BAD,BAD,BAD,BAD, + BAD, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, + 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,BAD, BAD,BAD,BAD,BAD }; -#define CHAR64(c) (((c) < 0 || (c) > 127) ? -1 : index_64[(c)]) +#define DECODE64(c) (isascii(c) ? base64val[c] : BAD) -void to64(out, in, inlen) - unsigned char *out, *in; - int inlen; +void to64frombits(unsigned char *out, const unsigned char *in, int inlen) +/* raw bytes in quasi-big-endian order to base 64 string (NUL-terminated) */ { - unsigned char oval; - - while (inlen >= 3) { - *out++ = basis_64[in[0] >> 2]; - *out++ = basis_64[((in[0] << 4) & 0x30) | (in[1] >> 4)]; - *out++ = basis_64[((in[1] << 2) & 0x3c) | (in[2] >> 6)]; - *out++ = basis_64[in[2] & 0x3f]; + for (; inlen >= 3; inlen -= 3) + { + *out++ = base64digits[in[0] >> 2]; + *out++ = base64digits[((in[0] << 4) & 0x30) | (in[1] >> 4)]; + *out++ = base64digits[((in[1] << 2) & 0x3c) | (in[2] >> 6)]; + *out++ = base64digits[in[2] & 0x3f]; in += 3; - inlen -= 3; } - if (inlen > 0) { - *out++ = basis_64[in[0] >> 2]; - oval = (in[0] << 4) & 0x30; - if (inlen > 1) oval |= in[1] >> 4; - *out++ = basis_64[oval]; - *out++ = (inlen < 2) ? '=' : basis_64[(in[1] << 2) & 0x3c]; + if (inlen > 0) + { + unsigned char fragment; + + *out++ = base64digits[in[0] >> 2]; + fragment = (in[0] << 4) & 0x30; + if (inlen > 1) + fragment |= in[1] >> 4; + *out++ = base64digits[fragment]; + *out++ = (inlen < 2) ? '=' : base64digits[(in[1] << 2) & 0x3c]; *out++ = '='; } *out = '\0'; } -int from64(out, in) - char *out, *in; +int from64tobits(char *out, const char *in) +/* base 64 to raw bytes in quasi-big-endian order, returning count of bytes */ { int len = 0; - int c1, c2, c3, c4; + register char digit1, digit2, digit3, digit4; + + if (in[0] == '+' && in[1] == ' ') + in += 2; + if (*in == '\r') + return(0); - if (in[0] == '+' && in[1] == ' ') in += 2; - if (*in == '\r') return (0); do { - c1 = in[0]; - if (CHAR64(c1) == -1) return (-1); - c2 = in[1]; - if (CHAR64(c2) == -1) return (-1); - c3 = in[2]; - if (c3 != '=' && CHAR64(c3) == -1) return (-1); - c4 = in[3]; - if (c4 != '=' && CHAR64(c4) == -1) return (-1); + digit1 = in[0]; + if (DECODE64(digit1) == BAD) + return(-1); + digit2 = in[1]; + if (DECODE64(digit2) == BAD) + return(-1); + digit3 = in[2]; + if (digit3 != '=' && DECODE64(digit3) == BAD) + return(-1); + digit4 = in[3]; + if (digit4 != '=' && DECODE64(digit4) == BAD) + return(-1); in += 4; - *out++ = (CHAR64(c1) << 2) | (CHAR64(c2) >> 4); + *out++ = (DECODE64(digit1) << 2) | (DECODE64(digit2) >> 4); ++len; - if (c3 != '=') { - *out++ = ((CHAR64(c2) << 4) & 0xf0) | (CHAR64(c3) >> 2); + if (digit3 != '=') + { + *out++ = ((DECODE64(digit2) << 4) & 0xf0) | (DECODE64(digit3) >> 2); ++len; - if (c4 != '=') { - *out++ = ((CHAR64(c3) << 6) & 0xc0) | CHAR64(c4); + if (digit4 != '=') + { + *out++ = ((DECODE64(digit3) << 6) & 0xc0) | DECODE64(digit4); ++len; } } - } while (*in != '\r' && c4 != '='); + } while + (*in != '\r' && digit4 != '='); return (len); } +/* base64.c ends here */ |