httpUtils.py

"""Library to manipulate HTTP messages.
The main purpose is to help developing burp extensions.
Since jython does not handle exceptions well ('except' does not work), we do
not raise any exception explicitly and check values to avoid raising any.
"""

import urllib


class Request(object):
    """Request represents an HTTP request."""

    Method = ''
    Version = ''
    Path = ''
    Query = ''
    Headers = None
    Body = ''

    @classmethod
    def Parse(cls, content):
        parsed = parse(content)
        if not parsed:
            return
        first, headers, body = parsed
        w = first.split(' ')
        if len(w) != 3:
            return
        r = cls()
        r.Method = w[0]
        r.Version = w[2]
        q = w[1].split('?')
        r.Path = q[0]
        r.Query = q[1] if len(q) > 1 else ''
        r.Headers = Headers(headers)
        r.Body = body
        return r

    def String(self):
        path = self.Path
        return '%s %s %s\r\n%s\r\n%s' % (
                    self.Method,
                    '%s?%s' % (path, self.Query) if self.Query else path,
                    self.Version,
                    self.Headers.String(),
                    self.Body
            )


class Response(object):
    """Response represents an HTTP response."""

    Version = ''
    Status = 0
    Message = ''
    Headers = None
    Body = ''
    Request = None

    @classmethod
    def Parse(cls, content, request=None):
        parsed = parse(content)
        if not parsed:
            return
        first, headers, body = parsed
        w = first.split(' ', 2)
        if len(w) < 3:
            return
        r = cls()
        r.Version = w[0]
        r.Status = int(w[1])
        r.Message = w[2]
        r.Headers = Headers(headers)
        r.Body = body
        r.Request = request
        return r

    def String(self):
        return '%s %i %s\r\n%s\r\n%s' % (
            self.Version,
            self.Status,
            self.Message,
            self.Headers.String(),
            self.Body
        )


class Headers(object):
    """Headers represents headers of an HTTP message."""

    def __init__(self, headers=''):
        self.h = []
        for line in headers.split('\r\n'):
            w = line.split(':', 1)
            if not w[0]:
                continue
            if len(w) == 1:
                self.Add(w[0], '')
            else:
                self.Add(w[0], w[1].lstrip())

    def Add(self, name, value):
        self.h.append((name, value))

    def Del(self, name):
        for key, value in self.h:
            if key.lower() == name.lower():
                self.h.remove((key, value))

    def Get(self, name):
        for key, value in self.h:
            if key.lower() == name.lower():
                return value

    def Set(self, name, value):
        self.Del(name)
        self.Add(name, value)

    def String(self):
        if not self.h:
            return ''
        return '\r\n'.join('%s: %s' % (k, v) for k, v in self.h) + '\r\n'


class Values(object):
    """Values represents values in a query parameter."""

    def __init__(self, q=''):
        self.v = []
        p = q.find('#')
        if p != -1:
            q = q[:p]
        for a in q.split('&'):
            w = a.split('=', 1)
            if not w[0]:
                continue
            if len(w) == 1:
                self.Add(w[0], '')
            else:
                self.Add(queryUnescape(w[0]), queryUnescape(w[1]))

    def Add(self, name, value):
        self.v.append((name, value))

    def Del(self, name):
        for key, value in self.v:
            if key == name:
                self.v.remove((key, value))

    def Get(self, name):
        for key, value in self.v:
            if key == name:
                return value

    def Set(self, name, value):
        self.Del(name)
        self.Add(name, value)

    def Encode(self):
        v = []
        for key, value in self.v:
            if value:
                v.append('%s=%s' % (queryEscape(key), queryEscape(value)))
            else:
                v.append(queryEscape(key))
        return '&'.join(v)


def parse(m):
    """parse parses an HTTP message into 3 parts: first line, headers, body."""
    while m.startswith('HTTP/1.1 100 Continue\r\n'):
        m = m[m.find('\r\n\r\n')+4:]
    p = m.find('\r\n')
    if p == -1:
        return
    first = m[:p]
    q = m.find('\r\n\r\n')
    headers = m[p+2:q]
    body = m[q+4:]
    return first, headers, body


def queryEscape(s):
    return urllib.quote_plus(s)


def queryUnescape(s):
return urllib.unquote_plus(s)