unbound/sldns/parseutil.c

842 lines
20 KiB
C

/*
* parseutil.c - parse utilities for string and wire conversion
*
* (c) NLnet Labs, 2004-2006
*
* See the file LICENSE for the license
*/
/**
* \file
*
* Utility functions for parsing, base32(DNS variant) and base64 encoding
* and decoding, Hex, Time units, Escape codes.
*/
#include "config.h"
#include "sldns/parseutil.h"
#include <sys/time.h>
#include <time.h>
#include <ctype.h>
sldns_lookup_table *
sldns_lookup_by_name(sldns_lookup_table *table, const char *name)
{
while (table->name != NULL) {
if (strcasecmp(name, table->name) == 0)
return table;
table++;
}
return NULL;
}
sldns_lookup_table *
sldns_lookup_by_id(sldns_lookup_table *table, int id)
{
while (table->name != NULL) {
if (table->id == id)
return table;
table++;
}
return NULL;
}
/* Number of days per month (except for February in leap years). */
static const int mdays[] = {
31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
#define LDNS_MOD(x,y) (((x) % (y) < 0) ? ((x) % (y) + (y)) : ((x) % (y)))
#define LDNS_DIV(x,y) (((x) % (y) < 0) ? ((x) / (y) - 1 ) : ((x) / (y)))
static int
is_leap_year(int year)
{
return LDNS_MOD(year, 4) == 0 && (LDNS_MOD(year, 100) != 0
|| LDNS_MOD(year, 400) == 0);
}
static int
leap_days(int y1, int y2)
{
--y1;
--y2;
return (LDNS_DIV(y2, 4) - LDNS_DIV(y1, 4)) -
(LDNS_DIV(y2, 100) - LDNS_DIV(y1, 100)) +
(LDNS_DIV(y2, 400) - LDNS_DIV(y1, 400));
}
/*
* Code adapted from Python 2.4.1 sources (Lib/calendar.py).
*/
time_t
sldns_mktime_from_utc(const struct tm *tm)
{
int year = 1900 + tm->tm_year;
time_t days = 365 * ((time_t) year - 1970) + leap_days(1970, year);
time_t hours;
time_t minutes;
time_t seconds;
int i;
for (i = 0; i < tm->tm_mon; ++i) {
days += mdays[i];
}
if (tm->tm_mon > 1 && is_leap_year(year)) {
++days;
}
days += tm->tm_mday - 1;
hours = days * 24 + tm->tm_hour;
minutes = hours * 60 + tm->tm_min;
seconds = minutes * 60 + tm->tm_sec;
return seconds;
}
#if SIZEOF_TIME_T <= 4
static void
sldns_year_and_yday_from_days_since_epoch(int64_t days, struct tm *result)
{
int year = 1970;
int new_year;
while (days < 0 || days >= (int64_t) (is_leap_year(year) ? 366 : 365)) {
new_year = year + (int) LDNS_DIV(days, 365);
days -= (new_year - year) * 365;
days -= leap_days(year, new_year);
year = new_year;
}
result->tm_year = year;
result->tm_yday = (int) days;
}
/* Number of days per month in a leap year. */
static const int leap_year_mdays[] = {
31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};
static void
sldns_mon_and_mday_from_year_and_yday(struct tm *result)
{
int idays = result->tm_yday;
const int *mon_lengths = is_leap_year(result->tm_year) ?
leap_year_mdays : mdays;
result->tm_mon = 0;
while (idays >= mon_lengths[result->tm_mon]) {
idays -= mon_lengths[result->tm_mon++];
}
result->tm_mday = idays + 1;
}
static void
sldns_wday_from_year_and_yday(struct tm *result)
{
result->tm_wday = 4 /* 1-1-1970 was a thursday */
+ LDNS_MOD((result->tm_year - 1970), 7) * LDNS_MOD(365, 7)
+ leap_days(1970, result->tm_year)
+ result->tm_yday;
result->tm_wday = LDNS_MOD(result->tm_wday, 7);
if (result->tm_wday < 0) {
result->tm_wday += 7;
}
}
static struct tm *
sldns_gmtime64_r(int64_t clock, struct tm *result)
{
result->tm_isdst = 0;
result->tm_sec = (int) LDNS_MOD(clock, 60);
clock = LDNS_DIV(clock, 60);
result->tm_min = (int) LDNS_MOD(clock, 60);
clock = LDNS_DIV(clock, 60);
result->tm_hour = (int) LDNS_MOD(clock, 24);
clock = LDNS_DIV(clock, 24);
sldns_year_and_yday_from_days_since_epoch(clock, result);
sldns_mon_and_mday_from_year_and_yday(result);
sldns_wday_from_year_and_yday(result);
result->tm_year -= 1900;
return result;
}
#endif /* SIZEOF_TIME_T <= 4 */
static int64_t
sldns_serial_arithmetics_time(int32_t time, time_t now)
{
int32_t offset = (int32_t)((uint32_t) time - (uint32_t) now);
return (int64_t) now + offset;
}
struct tm *
sldns_serial_arithmetics_gmtime_r(int32_t time, time_t now, struct tm *result)
{
#if SIZEOF_TIME_T <= 4
int64_t secs_since_epoch = sldns_serial_arithmetics_time(time, now);
return sldns_gmtime64_r(secs_since_epoch, result);
#else
time_t secs_since_epoch = sldns_serial_arithmetics_time(time, now);
return gmtime_r(&secs_since_epoch, result);
#endif
}
int
sldns_hexdigit_to_int(char ch)
{
switch (ch) {
case '0': return 0;
case '1': return 1;
case '2': return 2;
case '3': return 3;
case '4': return 4;
case '5': return 5;
case '6': return 6;
case '7': return 7;
case '8': return 8;
case '9': return 9;
case 'a': case 'A': return 10;
case 'b': case 'B': return 11;
case 'c': case 'C': return 12;
case 'd': case 'D': return 13;
case 'e': case 'E': return 14;
case 'f': case 'F': return 15;
default:
return -1;
}
}
uint32_t
sldns_str2period(const char *nptr, const char **endptr, int* overflow)
{
int sign = 0;
uint32_t i = 0;
uint32_t seconds = 0;
const uint32_t maxint = 0xffffffff;
*overflow = 0;
for(*endptr = nptr; **endptr; (*endptr)++) {
switch (**endptr) {
case ' ':
case '\t':
break;
case '-':
if(sign == 0) {
sign = -1;
} else {
return seconds;
}
break;
case '+':
if(sign == 0) {
sign = 1;
} else {
return seconds;
}
break;
case 's':
case 'S':
if(seconds > maxint-i) {
*overflow = 1;
return 0;
}
seconds += i;
i = 0;
break;
case 'm':
case 'M':
if(i > maxint/60 || seconds > maxint-(i*60)) {
*overflow = 1;
return 0;
}
seconds += i * 60;
i = 0;
break;
case 'h':
case 'H':
if(i > maxint/(60*60) || seconds > maxint-(i*60*60)) {
*overflow = 1;
return 0;
}
seconds += i * 60 * 60;
i = 0;
break;
case 'd':
case 'D':
if(i > maxint/(60*60*24) || seconds > maxint-(i*60*60*24)) {
*overflow = 1;
return 0;
}
seconds += i * 60 * 60 * 24;
i = 0;
break;
case 'w':
case 'W':
if(i > maxint/(60*60*24*7) || seconds > maxint-(i*60*60*24*7)) {
*overflow = 1;
return 0;
}
seconds += i * 60 * 60 * 24 * 7;
i = 0;
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if(i > maxint/10 || i*10 > maxint - (**endptr - '0')) {
*overflow = 1;
return 0;
}
i *= 10;
i += (**endptr - '0');
break;
default:
if(seconds > maxint-i) {
*overflow = 1;
return 0;
}
seconds += i;
/* disregard signedness */
return seconds;
}
}
if(seconds > maxint-i) {
*overflow = 1;
return 0;
}
seconds += i;
/* disregard signedness */
return seconds;
}
int
sldns_parse_escape(uint8_t *ch_p, const char** str_p)
{
uint16_t val;
if ((*str_p)[0] && isdigit((unsigned char)(*str_p)[0]) &&
(*str_p)[1] && isdigit((unsigned char)(*str_p)[1]) &&
(*str_p)[2] && isdigit((unsigned char)(*str_p)[2])) {
val = (uint16_t)(((*str_p)[0] - '0') * 100 +
((*str_p)[1] - '0') * 10 +
((*str_p)[2] - '0'));
if (val > 255) {
goto error;
}
*ch_p = (uint8_t)val;
*str_p += 3;
return 1;
} else if ((*str_p)[0] && !isdigit((unsigned char)(*str_p)[0])) {
*ch_p = (uint8_t)*(*str_p)++;
return 1;
}
error:
*str_p = NULL;
return 0; /* LDNS_WIREPARSE_ERR_SYNTAX_BAD_ESCAPE */
}
/** parse one character, with escape codes */
int
sldns_parse_char(uint8_t *ch_p, const char** str_p)
{
switch (**str_p) {
case '\0': return 0;
case '\\': *str_p += 1;
return sldns_parse_escape(ch_p, str_p);
default: *ch_p = (uint8_t)*(*str_p)++;
return 1;
}
}
size_t sldns_b32_ntop_calculate_size(size_t src_data_length)
{
return src_data_length == 0 ? 0 : ((src_data_length - 1) / 5 + 1) * 8;
}
size_t sldns_b32_ntop_calculate_size_no_padding(size_t src_data_length)
{
return ((src_data_length + 3) * 8 / 5) - 4;
}
static int
sldns_b32_ntop_base(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz,
int extended_hex, int add_padding)
{
size_t ret_sz;
const char* b32 = extended_hex ? "0123456789abcdefghijklmnopqrstuv"
: "abcdefghijklmnopqrstuvwxyz234567";
size_t c = 0; /* c is used to carry partial base32 character over
* byte boundaries for sizes with a remainder.
* (i.e. src_sz % 5 != 0)
*/
ret_sz = add_padding ? sldns_b32_ntop_calculate_size(src_sz)
: sldns_b32_ntop_calculate_size_no_padding(src_sz);
/* Do we have enough space? */
if (dst_sz < ret_sz + 1)
return -1;
/* We know the size; terminate the string */
dst[ret_sz] = '\0';
/* First process all chunks of five */
while (src_sz >= 5) {
/* 00000... ........ ........ ........ ........ */
dst[0] = b32[(src[0] ) >> 3];
/* .....111 11...... ........ ........ ........ */
dst[1] = b32[(src[0] & 0x07) << 2 | src[1] >> 6];
/* ........ ..22222. ........ ........ ........ */
dst[2] = b32[(src[1] & 0x3e) >> 1];
/* ........ .......3 3333.... ........ ........ */
dst[3] = b32[(src[1] & 0x01) << 4 | src[2] >> 4];
/* ........ ........ ....4444 4....... ........ */
dst[4] = b32[(src[2] & 0x0f) << 1 | src[3] >> 7];
/* ........ ........ ........ .55555.. ........ */
dst[5] = b32[(src[3] & 0x7c) >> 2];
/* ........ ........ ........ ......66 666..... */
dst[6] = b32[(src[3] & 0x03) << 3 | src[4] >> 5];
/* ........ ........ ........ ........ ...77777 */
dst[7] = b32[(src[4] & 0x1f) ];
src_sz -= 5;
src += 5;
dst += 8;
}
/* Process what remains */
switch (src_sz) {
case 4: /* ........ ........ ........ ......66 666..... */
dst[6] = b32[(src[3] & 0x03) << 3];
/* ........ ........ ........ .55555.. ........ */
dst[5] = b32[(src[3] & 0x7c) >> 2];
/* ........ ........ ....4444 4....... ........ */
c = src[3] >> 7 ;
/* fallthrough */
case 3: dst[4] = b32[(src[2] & 0x0f) << 1 | c];
/* ........ .......3 3333.... ........ ........ */
c = src[2] >> 4 ;
/* fallthrough */
case 2: dst[3] = b32[(src[1] & 0x01) << 4 | c];
/* ........ ..22222. ........ ........ ........ */
dst[2] = b32[(src[1] & 0x3e) >> 1];
/* .....111 11...... ........ ........ ........ */
c = src[1] >> 6 ;
/* fallthrough */
case 1: dst[1] = b32[(src[0] & 0x07) << 2 | c];
/* 00000... ........ ........ ........ ........ */
dst[0] = b32[ src[0] >> 3];
}
/* Add padding */
if (add_padding) {
switch (src_sz) {
case 1: dst[2] = '=';
dst[3] = '=';
/* fallthrough */
case 2: dst[4] = '=';
/* fallthrough */
case 3: dst[5] = '=';
dst[6] = '=';
/* fallthrough */
case 4: dst[7] = '=';
}
}
return (int)ret_sz;
}
int
sldns_b32_ntop(const uint8_t* src, size_t src_sz, char* dst, size_t dst_sz)
{
return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 0, 1);
}
int
sldns_b32_ntop_extended_hex(const uint8_t* src, size_t src_sz,
char* dst, size_t dst_sz)
{
return sldns_b32_ntop_base(src, src_sz, dst, dst_sz, 1, 1);
}
size_t sldns_b32_pton_calculate_size(size_t src_text_length)
{
return src_text_length * 5 / 8;
}
static int
sldns_b32_pton_base(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz,
int extended_hex, int check_padding)
{
size_t i = 0;
char ch = '\0';
uint8_t buf[8];
uint8_t* start = dst;
while (src_sz) {
/* Collect 8 characters in buf (if possible) */
for (i = 0; i < 8; i++) {
do {
ch = *src++;
--src_sz;
} while (isspace((unsigned char)ch) && src_sz > 0);
if (ch == '=' || ch == '\0')
break;
else if (extended_hex)
if (ch >= '0' && ch <= '9')
buf[i] = (uint8_t)ch - '0';
else if (ch >= 'a' && ch <= 'v')
buf[i] = (uint8_t)ch - 'a' + 10;
else if (ch >= 'A' && ch <= 'V')
buf[i] = (uint8_t)ch - 'A' + 10;
else
return -1;
else if (ch >= 'a' && ch <= 'z')
buf[i] = (uint8_t)ch - 'a';
else if (ch >= 'A' && ch <= 'Z')
buf[i] = (uint8_t)ch - 'A';
else if (ch >= '2' && ch <= '7')
buf[i] = (uint8_t)ch - '2' + 26;
else
return -1;
}
/* Less that 8 characters. We're done. */
if (i < 8)
break;
/* Enough space available at the destination? */
if (dst_sz < 5)
return -1;
/* 00000... ........ ........ ........ ........ */
/* .....111 11...... ........ ........ ........ */
dst[0] = buf[0] << 3 | buf[1] >> 2;
/* .....111 11...... ........ ........ ........ */
/* ........ ..22222. ........ ........ ........ */
/* ........ .......3 3333.... ........ ........ */
dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
/* ........ .......3 3333.... ........ ........ */
/* ........ ........ ....4444 4....... ........ */
dst[2] = buf[3] << 4 | buf[4] >> 1;
/* ........ ........ ....4444 4....... ........ */
/* ........ ........ ........ .55555.. ........ */
/* ........ ........ ........ ......66 666..... */
dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
/* ........ ........ ........ ......66 666..... */
/* ........ ........ ........ ........ ...77777 */
dst[4] = buf[6] << 5 | buf[7];
dst += 5;
dst_sz -= 5;
}
/* Not ending on a eight byte boundary? */
if (i > 0 && i < 8) {
/* Enough space available at the destination? */
if (dst_sz < (i + 1) / 2)
return -1;
switch (i) {
case 7: /* ........ ........ ........ ......66 666..... */
/* ........ ........ ........ .55555.. ........ */
/* ........ ........ ....4444 4....... ........ */
dst[3] = buf[4] << 7 | buf[5] << 2 | buf[6] >> 3;
/* fallthrough */
case 5: /* ........ ........ ....4444 4....... ........ */
/* ........ .......3 3333.... ........ ........ */
dst[2] = buf[3] << 4 | buf[4] >> 1;
/* fallthrough */
case 4: /* ........ .......3 3333.... ........ ........ */
/* ........ ..22222. ........ ........ ........ */
/* .....111 11...... ........ ........ ........ */
dst[1] = buf[1] << 6 | buf[2] << 1 | buf[3] >> 4;
/* fallthrough */
case 2: /* .....111 11...... ........ ........ ........ */
/* 00000... ........ ........ ........ ........ */
dst[0] = buf[0] << 3 | buf[1] >> 2;
break;
default:
return -1;
}
dst += (i + 1) / 2;
if (check_padding) {
/* Check remaining padding characters */
if (ch != '=')
return -1;
/* One down, 8 - i - 1 more to come... */
for (i = 8 - i - 1; i > 0; i--) {
do {
if (src_sz == 0)
return -1;
ch = *src++;
src_sz--;
} while (isspace((unsigned char)ch));
if (ch != '=')
return -1;
}
}
}
return dst - start;
}
int
sldns_b32_pton(const char* src, size_t src_sz, uint8_t* dst, size_t dst_sz)
{
return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 0, 1);
}
int
sldns_b32_pton_extended_hex(const char* src, size_t src_sz,
uint8_t* dst, size_t dst_sz)
{
return sldns_b32_pton_base(src, src_sz, dst, dst_sz, 1, 1);
}
size_t sldns_b64_ntop_calculate_size(size_t srcsize)
{
return ((((srcsize + 2) / 3) * 4) + 1);
}
/* RFC 1521, section 5.2.
*
* 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.
*
* This routine does not insert spaces or linebreaks after 76 characters.
*/
static int sldns_b64_ntop_base(uint8_t const *src, size_t srclength,
char *target, size_t targsize, int base64url, int padding)
{
char* b64;
const char pad64 = '=';
size_t i = 0, o = 0;
if(base64url)
b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
"456789-_";
else
b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123"
"456789+/";
if(targsize < sldns_b64_ntop_calculate_size(srclength))
return -1;
/* whole chunks: xxxxxxyy yyyyzzzz zzwwwwww */
while(i+3 <= srclength) {
if(o+4 > targsize) return -1;
target[o] = b64[src[i] >> 2];
target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
target[o+2] = b64[ ((src[i+1]&0x0f)<<2) | (src[i+2]>>6) ];
target[o+3] = b64[ (src[i+2]&0x3f) ];
i += 3;
o += 4;
}
/* remainder */
switch(srclength - i) {
case 2:
/* two at end, converted into A B C = */
target[o] = b64[src[i] >> 2];
target[o+1] = b64[ ((src[i]&0x03)<<4) | (src[i+1]>>4) ];
target[o+2] = b64[ ((src[i+1]&0x0f)<<2) ];
if(padding) {
target[o+3] = pad64;
/* i += 2; */
o += 4;
} else {
o += 3;
}
break;
case 1:
/* one at end, converted into A B = = */
target[o] = b64[src[i] >> 2];
target[o+1] = b64[ ((src[i]&0x03)<<4) ];
if(padding) {
target[o+2] = pad64;
target[o+3] = pad64;
/* i += 1; */
o += 4;
} else {
o += 2;
}
break;
case 0:
default:
/* nothing */
break;
}
/* assert: i == srclength */
if(o+1 > targsize) return -1;
target[o] = 0;
return (int)o;
}
int sldns_b64_ntop(uint8_t const *src, size_t srclength, char *target,
size_t targsize)
{
return sldns_b64_ntop_base(src, srclength, target, targsize,
0 /* no base64url */, 1 /* padding */);
}
int sldns_b64url_ntop(uint8_t const *src, size_t srclength, char *target,
size_t targsize)
{
return sldns_b64_ntop_base(src, srclength, target, targsize,
1 /* base64url */, 0 /* no padding */);
}
size_t sldns_b64_pton_calculate_size(size_t srcsize)
{
return (((((srcsize + 3) / 4) * 3)) + 1);
}
/* padding not required if srcsize is set */
static int sldns_b64_pton_base(char const *src, size_t srcsize, uint8_t *target,
size_t targsize, int base64url)
{
const uint8_t pad64 = 64; /* is 64th in the b64 array */
const char* s = src;
uint8_t in[4];
size_t o = 0, incount = 0;
int check_padding = (srcsize) ? 0 : 1;
while(*s && (check_padding || srcsize)) {
/* skip any character that is not base64 */
/* conceptually we do:
const char* b64 = pad'=' is appended to array
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
const char* d = strchr(b64, *s++);
and use d-b64;
*/
char d = *s++;
srcsize--;
if(d <= 'Z' && d >= 'A')
d -= 'A';
else if(d <= 'z' && d >= 'a')
d = d - 'a' + 26;
else if(d <= '9' && d >= '0')
d = d - '0' + 52;
else if(!base64url && d == '+')
d = 62;
else if(base64url && d == '-')
d = 62;
else if(!base64url && d == '/')
d = 63;
else if(base64url && d == '_')
d = 63;
else if(d == '=') {
if(!check_padding)
continue;
d = 64;
} else continue;
in[incount++] = (uint8_t)d;
/* work on block of 4, unless padding is not used and there are
* less than 4 chars left */
if(incount != 4 && (check_padding || srcsize))
continue;
assert(!check_padding || incount==4);
/* process whole block of 4 characters into 3 output bytes */
if((incount == 2 ||
(incount == 4 && in[3] == pad64 && in[2] == pad64))) { /* A B = = */
if(o+1 > targsize)
return -1;
target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
o += 1;
break; /* we are done */
} else if(incount == 3 ||
(incount == 4 && in[3] == pad64)) { /* A B C = */
if(o+2 > targsize)
return -1;
target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
o += 2;
break; /* we are done */
} else {
if(incount != 4 || o+3 > targsize)
return -1;
/* write xxxxxxyy yyyyzzzz zzwwwwww */
target[o] = (in[0]<<2) | ((in[1]&0x30)>>4);
target[o+1]= ((in[1]&0x0f)<<4) | ((in[2]&0x3c)>>2);
target[o+2]= ((in[2]&0x03)<<6) | in[3];
o += 3;
}
incount = 0;
}
return (int)o;
}
int sldns_b64_pton(char const *src, uint8_t *target, size_t targsize)
{
return sldns_b64_pton_base(src, 0, target, targsize, 0);
}
int sldns_b64url_pton(char const *src, size_t srcsize, uint8_t *target,
size_t targsize)
{
if(!srcsize) {
return 0;
}
return sldns_b64_pton_base(src, srcsize, target, targsize, 1);
}
int sldns_b64_contains_nonurl(char const *src, size_t srcsize)
{
const char* s = src;
while(*s && srcsize) {
char d = *s++;
srcsize--;
/* the '+' and the '/' and padding '=' is not allowed in b64
* url encoding */
if(d == '+' || d == '/' || d == '=') {
return 1;
}
}
return 0;
}