/* base64 routines. * * (C) 2003-2014 Anope Team * Contact us at team@anope.org * * Please read COPYING and README for further details. * * Based on the original code of Epona by Lara. * Based on the original code of Services by Andy Church. * * */ /* This is borrowed from Unreal */ #include "services.h" static char *int_to_base64(long); static long base64_to_int(char *); char *base64enc(long i) { if (i < 0) return ("0"); return int_to_base64(i); } long base64dec(char *b64) { if (b64) return base64_to_int(b64); else return 0; } static const char Base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static const char Pad64 = '='; /* (From RFC1521 and draft-ietf-dnssec-secext-03.txt) The following encoding technique is taken from RFC 1521 by Borenstein and Freed. It is reproduced here in a slightly edited form for convenience. A 65-character subset of US-ASCII is used, enabling 6 bits to be represented per printable character. (The extra 65th character, "=", is used to signify a special processing function.) The encoding process represents 24-bit groups of input bits as output strings of 4 encoded characters. Proceeding from left to right, a 24-bit input group is formed by concatenating 3 8-bit input groups. These 24 bits are then treated as 4 concatenated 6-bit groups, each of which is translated into a single digit in the base64 alphabet. Each 6-bit group is used as an index into an array of 64 printable characters. The character referenced by the index is placed in the output string. Table 1: The Base64 Alphabet Value Encoding Value Encoding Value Encoding Value Encoding 0 A 17 R 34 i 51 z 1 B 18 S 35 j 52 0 2 C 19 T 36 k 53 1 3 D 20 U 37 l 54 2 4 E 21 V 38 m 55 3 5 F 22 W 39 n 56 4 6 G 23 X 40 o 57 5 7 H 24 Y 41 p 58 6 8 I 25 Z 42 q 59 7 9 J 26 a 43 r 60 8 10 K 27 b 44 s 61 9 11 L 28 c 45 t 62 + 12 M 29 d 46 u 63 / 13 N 30 e 47 v 14 O 31 f 48 w (pad) = 15 P 32 g 49 x 16 Q 33 h 50 y Special processing is performed if fewer than 24 bits are available at the end of the data being encoded. A full encoding quantum is always completed at the end of a quantity. When fewer than 24 input bits are available in an input group, zero bits are added (on the right) to form an integral number of 6-bit groups. Padding at the end of the data is performed using the '=' character. Since all base64 input is an integral number of octets, only the ------------------------------------------------- following cases can arise: (1) the final quantum of encoding input is an integral multiple of 24 bits; here, the final unit of encoded output will be an integral multiple of 4 characters with no "=" padding, (2) the final quantum of encoding input is exactly 8 bits; here, the final unit of encoded output will be two characters followed by two "=" padding characters, or (3) the final quantum of encoding input is exactly 16 bits; here, the final unit of encoded output will be three characters followed by one "=" padding character. */ int b64_encode(char *src, size_t srclength, char *target, size_t targsize) { size_t datalength = 0; unsigned char input[3]; unsigned char output[4]; size_t i; while (2 < srclength) { input[0] = *src++; input[1] = *src++; input[2] = *src++; srclength -= 3; output[0] = input[0] >> 2; output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); output[3] = input[2] & 0x3f; if (datalength + 4 > targsize) return (-1); target[datalength++] = Base64[output[0]]; target[datalength++] = Base64[output[1]]; target[datalength++] = Base64[output[2]]; target[datalength++] = Base64[output[3]]; } /* Now we worry about padding. */ if (0 != srclength) { /* Get what's left. */ input[0] = input[1] = input[2] = '\0'; for (i = 0; i < srclength; i++) input[i] = *src++; output[0] = input[0] >> 2; output[1] = ((input[0] & 0x03) << 4) + (input[1] >> 4); output[2] = ((input[1] & 0x0f) << 2) + (input[2] >> 6); if (datalength + 4 > targsize) return (-1); target[datalength++] = Base64[output[0]]; target[datalength++] = Base64[output[1]]; if (srclength == 1) target[datalength++] = Pad64; else target[datalength++] = Base64[output[2]]; target[datalength++] = Pad64; } if (datalength >= targsize) return (-1); target[datalength] = '\0'; /* Returned value doesn't count \0. */ return (datalength); } /* skips all whitespace anywhere. converts characters, four at a time, starting at (or after) src from base - 64 numbers into three 8 bit bytes in the target area. it returns the number of data bytes stored at the target, or -1 on error. */ int b64_decode(char *src, char *target, size_t targsize) { int tarindex, state, ch; char *pos; state = 0; tarindex = 0; while ((ch = *src++) != '\0') { if (isspace(ch)) /* Skip whitespace anywhere. */ continue; if (ch == Pad64) break; pos = strchr(Base64, ch); if (pos == 0) /* A non-base64 character. */ return (-1); switch (state) { case 0: if (target) { if ((size_t) tarindex >= targsize) return (-1); target[tarindex] = (pos - Base64) << 2; } state = 1; break; case 1: if (target) { if ((size_t) tarindex + 1 >= targsize) return (-1); target[tarindex] |= (pos - Base64) >> 4; target[tarindex + 1] = ((pos - Base64) & 0x0f) << 4; } tarindex++; state = 2; break; case 2: if (target) { if ((size_t) tarindex + 1 >= targsize) return (-1); target[tarindex] |= (pos - Base64) >> 2; target[tarindex + 1] = ((pos - Base64) & 0x03) << 6; } tarindex++; state = 3; break; case 3: if (target) { if ((size_t) tarindex >= targsize) return (-1); target[tarindex] |= (pos - Base64); } tarindex++; state = 0; break; default: abort(); } } /* * We are done decoding Base-64 chars. Let's see if we ended * on a byte boundary, and/or with erroneous trailing characters. */ if (ch == Pad64) { /* We got a pad char. */ ch = *src++; /* Skip it, get next. */ switch (state) { case 0: /* Invalid = in first position */ case 1: /* Invalid = in second position */ return (-1); case 2: /* Valid, means one byte of info */ /* Skip any number of spaces. */ for ((void) NULL; ch != '\0'; ch = *src++) if (!isspace(ch)) break; /* Make sure there is another trailing = sign. */ if (ch != Pad64) return (-1); ch = *src++; /* Skip the = */ /* Fall through to "single trailing =" case. */ /* FALLTHROUGH */ case 3: /* Valid, means two bytes of info */ /* * We know this char is an =. Is there anything but * whitespace after it? */ for ((void) NULL; ch != '\0'; ch = *src++) if (!isspace(ch)) return (-1); /* * Now make sure for cases 2 and 3 that the "extra" * bits that slopped past the last full byte were * zeros. If we don't check them, they become a * subliminal channel. */ if (target && target[tarindex] != 0) return (-1); } } else { /* * We ended by seeing the end of the string. Make sure we * have no partial bytes lying around. */ if (state != 0) return (-1); } return (tarindex); } char *encode_ip(unsigned char *ip) { static char buf[25]; unsigned char *cp; struct in_addr ia; /* For IPv4 */ char *s_ip; /* Signed ip string */ if (!ip) return "*"; if (strchr((char *) ip, ':')) { return NULL; } else { s_ip = str_signed(ip); ia.s_addr = inet_addr(s_ip); cp = (unsigned char *) &ia.s_addr; b64_encode((char *) &cp, sizeof(struct in_addr), buf, 25); } return buf; } int decode_ip(char *buf) { int len = strlen(buf); char targ[25]; struct in_addr *ia; b64_decode(buf, targ, 25); ia = (struct in_addr *) targ; if (len == 24) { /* IPv6 */ return 0; } else if (len == 8) /* IPv4 */ return ia->s_addr; else /* Error?? */ return 0; } /* ':' and '#' and '&' and '+' and '@' must never be in this table. */ /* these tables must NEVER CHANGE! >) */ char int6_to_base64_map[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '}' }; char base64_to_int6_map[] = { -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, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1, -1, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, -1, 63, -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, -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, -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, -1 }; static char *int_to_base64(long val) { /* 32/6 == max 6 bytes for representation, * +1 for the null, +1 for byte boundaries */ static char base64buf[8]; long i = 7; base64buf[i] = '\0'; /* Temporary debugging code.. remove before 2038 ;p. * This might happen in case of 64bit longs (opteron/ia64), * if the value is then too large it can easily lead to * a buffer underflow and thus to a crash. -- Syzop */ if (val > 2147483647L) { abort(); } do { base64buf[--i] = int6_to_base64_map[val & 63]; } while (val >>= 6); return base64buf + i; } static long base64_to_int(char *b64) { int v = base64_to_int6_map[(unsigned char) *b64++]; if (!b64) return 0; while (*b64) { v <<= 6; v += base64_to_int6_map[(unsigned char) *b64++]; } return v; } long base64dects(char *ts) { char *token; long value; if (!ts) { return 0; } token = myStrGetToken(ts, '!', 1); if (!token) { return strtoul(ts, NULL, 10); } value = base64dec(token); Anope_Free(token); return value; }