| 1 | /* |
| 2 | ** Copyright 2003-2004 Double Precision, Inc. See COPYING for |
| 3 | ** distribution information. |
| 4 | */ |
| 5 | |
| 6 | /* |
| 7 | */ |
| 8 | #include "encode.h" |
| 9 | #include <string.h> |
| 10 | #include <stdlib.h> |
| 11 | |
| 12 | static int quoted_printable(struct libmail_encode_info *, |
| 13 | const char *, size_t); |
| 14 | static int base64(struct libmail_encode_info *, |
| 15 | const char *, size_t); |
| 16 | static int eflush(struct libmail_encode_info *, |
| 17 | const char *, size_t); |
| 18 | |
| 19 | void libmail_encode_start(struct libmail_encode_info *info, |
| 20 | const char *transfer_encoding, |
| 21 | int (*callback_func)(const char *, size_t, void *), |
| 22 | void *callback_arg) |
| 23 | { |
| 24 | info->output_buf_cnt=0; |
| 25 | info->input_buf_cnt=0; |
| 26 | |
| 27 | switch (*transfer_encoding) { |
| 28 | case 'q': |
| 29 | case 'Q': |
| 30 | info->encoding_func=quoted_printable; |
| 31 | info->input_buffer[0]=0; /* Recycle for qp encoding */ |
| 32 | break; |
| 33 | case 'b': |
| 34 | case 'B': |
| 35 | info->encoding_func=base64; |
| 36 | break; |
| 37 | default: |
| 38 | info->encoding_func=eflush; |
| 39 | break; |
| 40 | } |
| 41 | info->callback_func=callback_func; |
| 42 | info->callback_arg=callback_arg; |
| 43 | } |
| 44 | |
| 45 | int libmail_encode(struct libmail_encode_info *info, |
| 46 | const char *ptr, |
| 47 | size_t cnt) |
| 48 | { |
| 49 | return ((*info->encoding_func)(info, ptr, cnt)); |
| 50 | } |
| 51 | |
| 52 | int libmail_encode_end(struct libmail_encode_info *info) |
| 53 | { |
| 54 | int rc=(*info->encoding_func)(info, NULL, 0); |
| 55 | |
| 56 | if (rc == 0 && info->output_buf_cnt > 0) |
| 57 | { |
| 58 | rc= (*info->callback_func)(info->output_buffer, |
| 59 | info->output_buf_cnt, |
| 60 | info->callback_arg); |
| 61 | info->output_buf_cnt=0; |
| 62 | } |
| 63 | |
| 64 | return rc; |
| 65 | } |
| 66 | |
| 67 | static int eflush(struct libmail_encode_info *info, const char *ptr, size_t n) |
| 68 | { |
| 69 | while (n > 0) |
| 70 | { |
| 71 | size_t i; |
| 72 | |
| 73 | if (info->output_buf_cnt == sizeof(info->output_buffer)) |
| 74 | { |
| 75 | int rc= (*info->callback_func)(info->output_buffer, |
| 76 | info->output_buf_cnt, |
| 77 | info->callback_arg); |
| 78 | |
| 79 | info->output_buf_cnt=0; |
| 80 | if (rc) |
| 81 | return rc; |
| 82 | } |
| 83 | |
| 84 | i=n; |
| 85 | |
| 86 | if (i > sizeof(info->output_buffer) - info->output_buf_cnt) |
| 87 | i=sizeof(info->output_buffer) - info->output_buf_cnt; |
| 88 | |
| 89 | memcpy(info->output_buffer + info->output_buf_cnt, ptr, i); |
| 90 | info->output_buf_cnt += i; |
| 91 | ptr += i; |
| 92 | n -= i; |
| 93 | } |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | static int base64_flush(struct libmail_encode_info *); |
| 98 | |
| 99 | static int base64(struct libmail_encode_info *info, |
| 100 | const char *buf, size_t n) |
| 101 | { |
| 102 | if (!buf) |
| 103 | { |
| 104 | int rc=0; |
| 105 | |
| 106 | if (info->input_buf_cnt > 0) |
| 107 | rc=base64_flush(info); |
| 108 | |
| 109 | return rc; |
| 110 | } |
| 111 | |
| 112 | while (n) |
| 113 | { |
| 114 | size_t i; |
| 115 | |
| 116 | if (info->input_buf_cnt == sizeof(info->input_buffer)) |
| 117 | { |
| 118 | int rc=base64_flush(info); |
| 119 | |
| 120 | if (rc != 0) |
| 121 | return rc; |
| 122 | } |
| 123 | |
| 124 | i=n; |
| 125 | if (i > sizeof(info->input_buffer) - info->input_buf_cnt) |
| 126 | i=sizeof(info->input_buffer) - info->input_buf_cnt; |
| 127 | |
| 128 | memcpy(info->input_buffer + info->input_buf_cnt, |
| 129 | buf, i); |
| 130 | info->input_buf_cnt += i; |
| 131 | buf += i; |
| 132 | n -= i; |
| 133 | } |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | static const char base64tab[]= |
| 138 | "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| 139 | |
| 140 | static int base64_flush(struct libmail_encode_info *info) |
| 141 | { |
| 142 | int a=0,b=0,c=0; |
| 143 | int i, j; |
| 144 | int d, e, f, g; |
| 145 | char output_buf[ sizeof(info->input_buffer) / 3 * 4+1]; |
| 146 | |
| 147 | for (j=i=0; i<info->input_buf_cnt; i += 3) |
| 148 | { |
| 149 | a=(unsigned char)info->input_buffer[i]; |
| 150 | b= i+1 < info->input_buf_cnt ? |
| 151 | (unsigned char)info->input_buffer[i+1]:0; |
| 152 | c= i+2 < info->input_buf_cnt ? |
| 153 | (unsigned char)info->input_buffer[i+2]:0; |
| 154 | |
| 155 | d=base64tab[ a >> 2 ]; |
| 156 | e=base64tab[ ((a & 3 ) << 4) | (b >> 4)]; |
| 157 | f=base64tab[ ((b & 15) << 2) | (c >> 6)]; |
| 158 | g=base64tab[ c & 63 ]; |
| 159 | if (i + 1 >= info->input_buf_cnt) f='='; |
| 160 | if (i + 2 >= info->input_buf_cnt) g='='; |
| 161 | output_buf[j++]=d; |
| 162 | output_buf[j++]=e; |
| 163 | output_buf[j++]=f; |
| 164 | output_buf[j++]=g; |
| 165 | } |
| 166 | |
| 167 | info->input_buf_cnt=0; |
| 168 | |
| 169 | output_buf[j++]='\n'; |
| 170 | return eflush(info, output_buf, j); |
| 171 | } |
| 172 | |
| 173 | static const char xdigit[]="0123456789ABCDEF"; |
| 174 | |
| 175 | static int quoted_printable(struct libmail_encode_info *info, |
| 176 | const char *p, size_t n) |
| 177 | { |
| 178 | char local_buf[256]; |
| 179 | int local_buf_cnt=0; |
| 180 | |
| 181 | #define QPUT(c) do { if (local_buf_cnt == sizeof(local_buf)) \ |
| 182 | { int rc=eflush(info, local_buf, local_buf_cnt); \ |
| 183 | local_buf_cnt=0; if (rc) return (rc); } \ |
| 184 | local_buf[local_buf_cnt]=(c); ++local_buf_cnt; } while(0) |
| 185 | |
| 186 | if (!p) |
| 187 | return (0); |
| 188 | |
| 189 | while (n) |
| 190 | { |
| 191 | |
| 192 | |
| 193 | /* |
| 194 | ** Repurpose input_buffer[0] as a flag whether the previous |
| 195 | ** character was a space. |
| 196 | ** |
| 197 | ** A space before a newline gets escaped. |
| 198 | */ |
| 199 | |
| 200 | if (info->input_buffer[0]) |
| 201 | { |
| 202 | if (*p == '\n') |
| 203 | { |
| 204 | QPUT('='); |
| 205 | QPUT('2'); |
| 206 | QPUT('0'); |
| 207 | } |
| 208 | else |
| 209 | { |
| 210 | QPUT(' '); |
| 211 | } |
| 212 | ++info->input_buf_cnt; |
| 213 | } |
| 214 | |
| 215 | info->input_buffer[0]=0; |
| 216 | |
| 217 | if (*p == ' ') |
| 218 | { |
| 219 | info->input_buffer[0]=1; |
| 220 | p++; |
| 221 | --n; |
| 222 | continue; |
| 223 | } |
| 224 | |
| 225 | if (info->input_buf_cnt > 72 && *p != '\n') |
| 226 | { |
| 227 | QPUT('='); |
| 228 | QPUT('\n'); |
| 229 | info->input_buf_cnt=0; |
| 230 | } |
| 231 | |
| 232 | if ( *p == '\n') |
| 233 | info->input_buf_cnt=0; |
| 234 | else if (*p < ' ' || *p == '=' || *p >= 0x7F) |
| 235 | { |
| 236 | QPUT('='); |
| 237 | QPUT(xdigit[ (*p >> 4) & 15]); |
| 238 | QPUT(xdigit[ *p & 15 ]); |
| 239 | info->input_buf_cnt += 3; |
| 240 | p++; |
| 241 | --n; |
| 242 | continue; |
| 243 | } |
| 244 | else info->input_buf_cnt++; |
| 245 | |
| 246 | QPUT( *p); |
| 247 | p++; |
| 248 | --n; |
| 249 | } |
| 250 | |
| 251 | if (local_buf_cnt > 0) |
| 252 | return eflush(info, local_buf, local_buf_cnt); |
| 253 | |
| 254 | return 0; |
| 255 | } |