Mercurial > hg > nginx-quic
view src/core/ngx_parse_time.c @ 7977:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +0300 |
parents | b38a8f0ca4a2 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> static ngx_uint_t mday[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; time_t ngx_parse_http_time(u_char *value, size_t len) { u_char *p, *end; ngx_int_t month; ngx_uint_t day, year, hour, min, sec; uint64_t time; enum { no = 0, rfc822, /* Tue, 10 Nov 2002 23:50:13 */ rfc850, /* Tuesday, 10-Dec-02 23:50:13 */ isoc /* Tue Dec 10 23:50:13 2002 */ } fmt; fmt = 0; end = value + len; #if (NGX_SUPPRESS_WARN) day = 32; year = 2038; #endif for (p = value; p < end; p++) { if (*p == ',') { break; } if (*p == ' ') { fmt = isoc; break; } } for (p++; p < end; p++) { if (*p != ' ') { break; } } if (end - p < 18) { return NGX_ERROR; } if (fmt != isoc) { if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9') { return NGX_ERROR; } day = (*p - '0') * 10 + (*(p + 1) - '0'); p += 2; if (*p == ' ') { if (end - p < 18) { return NGX_ERROR; } fmt = rfc822; } else if (*p == '-') { fmt = rfc850; } else { return NGX_ERROR; } p++; } switch (*p) { case 'J': month = *(p + 1) == 'a' ? 0 : *(p + 2) == 'n' ? 5 : 6; break; case 'F': month = 1; break; case 'M': month = *(p + 2) == 'r' ? 2 : 4; break; case 'A': month = *(p + 1) == 'p' ? 3 : 7; break; case 'S': month = 8; break; case 'O': month = 9; break; case 'N': month = 10; break; case 'D': month = 11; break; default: return NGX_ERROR; } p += 3; if ((fmt == rfc822 && *p != ' ') || (fmt == rfc850 && *p != '-')) { return NGX_ERROR; } p++; if (fmt == rfc822) { if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9' || *(p + 2) < '0' || *(p + 2) > '9' || *(p + 3) < '0' || *(p + 3) > '9') { return NGX_ERROR; } year = (*p - '0') * 1000 + (*(p + 1) - '0') * 100 + (*(p + 2) - '0') * 10 + (*(p + 3) - '0'); p += 4; } else if (fmt == rfc850) { if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9') { return NGX_ERROR; } year = (*p - '0') * 10 + (*(p + 1) - '0'); year += (year < 70) ? 2000 : 1900; p += 2; } if (fmt == isoc) { if (*p == ' ') { p++; } if (*p < '0' || *p > '9') { return NGX_ERROR; } day = *p++ - '0'; if (*p != ' ') { if (*p < '0' || *p > '9') { return NGX_ERROR; } day = day * 10 + (*p++ - '0'); } if (end - p < 14) { return NGX_ERROR; } } if (*p++ != ' ') { return NGX_ERROR; } if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9') { return NGX_ERROR; } hour = (*p - '0') * 10 + (*(p + 1) - '0'); p += 2; if (*p++ != ':') { return NGX_ERROR; } if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9') { return NGX_ERROR; } min = (*p - '0') * 10 + (*(p + 1) - '0'); p += 2; if (*p++ != ':') { return NGX_ERROR; } if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9') { return NGX_ERROR; } sec = (*p - '0') * 10 + (*(p + 1) - '0'); if (fmt == isoc) { p += 2; if (*p++ != ' ') { return NGX_ERROR; } if (*p < '0' || *p > '9' || *(p + 1) < '0' || *(p + 1) > '9' || *(p + 2) < '0' || *(p + 2) > '9' || *(p + 3) < '0' || *(p + 3) > '9') { return NGX_ERROR; } year = (*p - '0') * 1000 + (*(p + 1) - '0') * 100 + (*(p + 2) - '0') * 10 + (*(p + 3) - '0'); } if (hour > 23 || min > 59 || sec > 59) { return NGX_ERROR; } if (day == 29 && month == 1) { if ((year & 3) || ((year % 100 == 0) && (year % 400) != 0)) { return NGX_ERROR; } } else if (day > mday[month]) { return NGX_ERROR; } /* * shift new year to March 1 and start months from 1 (not 0), * it is needed for Gauss' formula */ if (--month <= 0) { month += 12; year -= 1; } /* Gauss' formula for Gregorian days since March 1, 1 BC */ time = (uint64_t) ( /* days in years including leap years since March 1, 1 BC */ 365 * year + year / 4 - year / 100 + year / 400 /* days before the month */ + 367 * month / 12 - 30 /* days before the day */ + day - 1 /* * 719527 days were between March 1, 1 BC and March 1, 1970, * 31 and 28 days were in January and February 1970 */ - 719527 + 31 + 28) * 86400 + hour * 3600 + min * 60 + sec; #if (NGX_TIME_T_SIZE <= 4) if (time > 0x7fffffff) { return NGX_ERROR; } #endif return (time_t) time; }