/* * 使用方法大致如下: innbbsd 中 在 SUBJECT 從 news 讀進來後, 呼叫 * str_decode_M3(SUBJECT) 就行了 */ /* * bsd 底下使用要編譯時要加 -I/usr/local/include -L/usr/local/lib -liconv * 並安裝 libiconv, 若真的沒有iconv就把底下的 #define USE_ICONV 1 刪了 */ /*-------------------------------------------------------*/ /* lib/str_decode.c ( NTHU CS MapleBBS Ver 3.00 ) */ /*-------------------------------------------------------*/ /* target : included C for QP/BASE64 decoding */ /* create : 95/03/29 */ /* update : 97/03/29 */ /*-------------------------------------------------------*/ /* ----------------------------------------------------- */ /* QP code : "0123456789ABCDEF" */ /* ----------------------------------------------------- */ #include #include #include #define USE_ICONV 1 /* * bsd 底下使用要編譯時要加 -I/usr/local/include -L/usr/local/lib -liconv * 若真的沒有iconv就把上面這行 #define 刪了 */ #ifdef USE_ICONV #include #endif static int qp_code(int x) { if (x >= '0' && x <= '9') return x - '0'; if (x >= 'a' && x <= 'f') return x - 'a' + 10; if (x >= 'A' && x <= 'F') return x - 'A' + 10; return -1; } /* ------------------------------------------------------------------ */ /* BASE64 : */ /* "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" */ /* ------------------------------------------------------------------ */ static int base64_code(int x) { if (x >= 'A' && x <= 'Z') return x - 'A'; if (x >= 'a' && x <= 'z') return x - 'a' + 26; if (x >= '0' && x <= '9') return x - '0' + 52; if (x == '+') return 62; if (x == '/') return 63; return -1; } /* ----------------------------------------------------- */ /* judge & decode QP / BASE64 */ /* ----------------------------------------------------- */ static inline int isreturn(unsigned char c) { return c == '\r' || c == '\n'; } static inline int isspace(unsigned char c) { return c == ' ' || c == '\t' || isreturn(c); } /* static inline */ int mmdecode(unsigned char *src, unsigned char encode, unsigned char *dst) { /* Thor.980901: src和dst可相同, 但src 一定有?或\0結束 */ /* Thor.980901: 注意, decode出的結果不會自己加上 \0 */ unsigned char *t = dst; int pattern = 0, bits = 0; encode |= 0x20; /* Thor: to lower */ switch (encode) { case 'q': /* Thor: quoted-printable */ while (*src && *src != '?') { /* Thor: delimiter *//* Thor.980901: * 0 算是 delimiter */ if (*src == '=') { int x = *++src, y = x ? *++src : 0; if (isreturn(x)) continue; if ((x = qp_code(x)) < 0 || (y = qp_code(y)) < 0) return -1; *t++ = (x << 4) + y, src++; } else if (*src == '_') *t++ = ' ', src++; #if 0 else if (!*src) /* Thor: no delimiter is not successful */ return -1; #endif else /* Thor: *src != '=' '_' */ *t++ = *src++; } return t - dst; case 'b': /* Thor: base 64 */ while (*src && *src != '?') { /* Thor: delimiter */ /* * Thor.980901: 0也算 *//* Thor: pattern & bits are cleared * outside */ int x; #if 0 if (!*src) return -1; /* Thor: no delimiter is not successful */ #endif x = base64_code(*src++); if (x < 0) continue; /* Thor: ignore everything not in the * base64,=,.. */ pattern = (pattern << 6) | x; bits += 6; /* Thor: 1 code gains 6 bits */ if (bits >= 8) { /* Thor: enough to form a byte */ bits -= 8; *t++ = (pattern >> bits) & 0xff; } } return t - dst; } return -1; } #ifdef USE_ICONV int str_iconv( const char *fromcode, /* charset of source string */ const char *tocode, /* charset of destination string */ char *src, /* source string */ int srclen, /* source string length */ char *dst, /* destination string */ int dstlen) { /* destination string length */ /* * 這個函式會將一個字串 (src) 從 charset=fromcode 轉成 charset=tocode, * srclen 是 src 的長度, dst 是輸出的buffer, dstlen 則指定了 dst 的大小, * 最後會補 '\0', 所以要留一個byte給'\0'. 如果遇到 src 中有非字集的字, * 或是 src 中有未完整的 byte, 都會砍掉. */ iconv_t iconv_descriptor; int iconv_ret, dstlen_old; dstlen--; /* keep space for '\0' */ dstlen_old = dstlen; /* Open a descriptor for iconv */ iconv_descriptor = iconv_open(tocode, fromcode); if (iconv_descriptor == ((iconv_t) (-1))) { /* if open fail */ strncpy(dst, src, dstlen); return dstlen; } /* Start translation */ while (srclen > 0 && dstlen > 0) { iconv_ret = iconv(iconv_descriptor, (const char **)&src, &srclen, &dst, &dstlen); if (iconv_ret != 0) { switch (errno) { /* invalid multibyte happened */ case EILSEQ: /* forward that byte */ *dst = *src; src++; srclen--; dst++; dstlen--; break; /* incomplete multibyte happened */ case EINVAL: /* forward that byte (maybe wrong) */ *dst = *src; src++; srclen--; dst++; dstlen--; break; /* dst no rooms */ case E2BIG: /* break out the while loop */ srclen = 0; break; } } } *dst = '\0'; /* close descriptor of iconv */ iconv_close(iconv_descriptor); return (dstlen_old - dstlen); } #endif void str_decode_M3(unsigned char *str) { int adj; int i; unsigned char *src, *dst; unsigned char buf[512]; unsigned char charset[512], dst1[512]; src = str; dst = buf; adj = 0; while (*src && (dst - buf) < sizeof(buf) - 1) { if (*src != '=') { /* Thor: not coded */ unsigned char *tmp = src; while (adj && *tmp && isspace(*tmp)) tmp++; if (adj && *tmp == '=') { /* Thor: jump over space */ adj = 0; src = tmp; } else *dst++ = *src++; /* continue; *//* Thor: take out */ } else { /* Thor: *src == '=' */ unsigned char *tmp = src + 1; if (*tmp == '?') { /* Thor: =? coded */ /* "=?%s?Q?" for QP, "=?%s?B?" for BASE64 */ tmp++; i = 0; while (*tmp && *tmp != '?') { if (i + 1 < sizeof(charset)) { charset[i] = *tmp; charset[i + 1] = '\0'; i++; } tmp++; } if (*tmp && tmp[1] && tmp[2] == '?') { /* Thor: *tmp == '?' */ #ifdef USE_ICONV int i = mmdecode(tmp + 3, tmp[1], dst1); i = str_iconv(charset, "big5", dst1, i, dst, sizeof(buf) - ((int)(dst - buf))); #else int i = mmdecode(tmp + 3, tmp[1], dst); #endif if (i >= 0) { tmp += 3; /* Thor: decode's src */ #if 0 while (*tmp++ != '?'); /* Thor: no ? end, mmdecode * -1 */ #endif while (*tmp && *tmp++ != '?'); /* Thor: no ? end, * mmdecode -1 */ /* Thor.980901: 0 也算 decode 結束 */ if (*tmp == '=') tmp++; src = tmp; /* Thor: decode over */ dst += i; adj = 1;/* Thor: adjcent */ } } } while (src != tmp) /* Thor: not coded */ *dst++ = *src++; } } *dst = 0; strcpy(str, buf); }