view src/core/ngx_parse.c @ 7667:1ece2ac2555a

OCSP: fixed use-after-free on error. When validating second and further certificates, ssl callback could be called twice to report the error. After the first call client connection is terminated and its memory is released. Prior to the second call and in it released connection memory is accessed. Errors triggering this behavior: - failure to create the request - failure to start resolving OCSP responder name - failure to start connecting to the OCSP responder The fix is to rearrange the code to eliminate the second call.
author Roman Arutyunyan <arut@nginx.com>
date Mon, 15 Jun 2020 20:17:16 +0300
parents 87cf6ddb41c2
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>


ssize_t
ngx_parse_size(ngx_str_t *line)
{
    u_char   unit;
    size_t   len;
    ssize_t  size, scale, max;

    len = line->len;

    if (len == 0) {
        return NGX_ERROR;
    }

    unit = line->data[len - 1];

    switch (unit) {
    case 'K':
    case 'k':
        len--;
        max = NGX_MAX_SIZE_T_VALUE / 1024;
        scale = 1024;
        break;

    case 'M':
    case 'm':
        len--;
        max = NGX_MAX_SIZE_T_VALUE / (1024 * 1024);
        scale = 1024 * 1024;
        break;

    default:
        max = NGX_MAX_SIZE_T_VALUE;
        scale = 1;
    }

    size = ngx_atosz(line->data, len);
    if (size == NGX_ERROR || size > max) {
        return NGX_ERROR;
    }

    size *= scale;

    return size;
}


off_t
ngx_parse_offset(ngx_str_t *line)
{
    u_char  unit;
    off_t   offset, scale, max;
    size_t  len;

    len = line->len;

    if (len == 0) {
        return NGX_ERROR;
    }

    unit = line->data[len - 1];

    switch (unit) {
    case 'K':
    case 'k':
        len--;
        max = NGX_MAX_OFF_T_VALUE / 1024;
        scale = 1024;
        break;

    case 'M':
    case 'm':
        len--;
        max = NGX_MAX_OFF_T_VALUE / (1024 * 1024);
        scale = 1024 * 1024;
        break;

    case 'G':
    case 'g':
        len--;
        max = NGX_MAX_OFF_T_VALUE / (1024 * 1024 * 1024);
        scale = 1024 * 1024 * 1024;
        break;

    default:
        max = NGX_MAX_OFF_T_VALUE;
        scale = 1;
    }

    offset = ngx_atoof(line->data, len);
    if (offset == NGX_ERROR || offset > max) {
        return NGX_ERROR;
    }

    offset *= scale;

    return offset;
}


ngx_int_t
ngx_parse_time(ngx_str_t *line, ngx_uint_t is_sec)
{
    u_char      *p, *last;
    ngx_int_t    value, total, scale;
    ngx_int_t    max, cutoff, cutlim;
    ngx_uint_t   valid;
    enum {
        st_start = 0,
        st_year,
        st_month,
        st_week,
        st_day,
        st_hour,
        st_min,
        st_sec,
        st_msec,
        st_last
    } step;

    valid = 0;
    value = 0;
    total = 0;
    cutoff = NGX_MAX_INT_T_VALUE / 10;
    cutlim = NGX_MAX_INT_T_VALUE % 10;
    step = is_sec ? st_start : st_month;

    p = line->data;
    last = p + line->len;

    while (p < last) {

        if (*p >= '0' && *p <= '9') {
            if (value >= cutoff && (value > cutoff || *p - '0' > cutlim)) {
                return NGX_ERROR;
            }

            value = value * 10 + (*p++ - '0');
            valid = 1;
            continue;
        }

        switch (*p++) {

        case 'y':
            if (step > st_start) {
                return NGX_ERROR;
            }
            step = st_year;
            max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 365);
            scale = 60 * 60 * 24 * 365;
            break;

        case 'M':
            if (step >= st_month) {
                return NGX_ERROR;
            }
            step = st_month;
            max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 30);
            scale = 60 * 60 * 24 * 30;
            break;

        case 'w':
            if (step >= st_week) {
                return NGX_ERROR;
            }
            step = st_week;
            max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24 * 7);
            scale = 60 * 60 * 24 * 7;
            break;

        case 'd':
            if (step >= st_day) {
                return NGX_ERROR;
            }
            step = st_day;
            max = NGX_MAX_INT_T_VALUE / (60 * 60 * 24);
            scale = 60 * 60 * 24;
            break;

        case 'h':
            if (step >= st_hour) {
                return NGX_ERROR;
            }
            step = st_hour;
            max = NGX_MAX_INT_T_VALUE / (60 * 60);
            scale = 60 * 60;
            break;

        case 'm':
            if (p < last && *p == 's') {
                if (is_sec || step >= st_msec) {
                    return NGX_ERROR;
                }
                p++;
                step = st_msec;
                max = NGX_MAX_INT_T_VALUE;
                scale = 1;
                break;
            }

            if (step >= st_min) {
                return NGX_ERROR;
            }
            step = st_min;
            max = NGX_MAX_INT_T_VALUE / 60;
            scale = 60;
            break;

        case 's':
            if (step >= st_sec) {
                return NGX_ERROR;
            }
            step = st_sec;
            max = NGX_MAX_INT_T_VALUE;
            scale = 1;
            break;

        case ' ':
            if (step >= st_sec) {
                return NGX_ERROR;
            }
            step = st_last;
            max = NGX_MAX_INT_T_VALUE;
            scale = 1;
            break;

        default:
            return NGX_ERROR;
        }

        if (step != st_msec && !is_sec) {
            scale *= 1000;
            max /= 1000;
        }

        if (value > max) {
            return NGX_ERROR;
        }

        value *= scale;

        if (total > NGX_MAX_INT_T_VALUE - value) {
            return NGX_ERROR;
        }

        total += value;

        value = 0;

        while (p < last && *p == ' ') {
            p++;
        }
    }

    if (!valid) {
        return NGX_ERROR;
    }

    if (!is_sec) {
        if (value > NGX_MAX_INT_T_VALUE / 1000) {
            return NGX_ERROR;
        }

        value *= 1000;
    }

    if (total > NGX_MAX_INT_T_VALUE - value) {
        return NGX_ERROR;
    }

    return total + value;
}