''' Function decompresses, decrypts and verifies the received message'''

try:

payload = email.message_from_string(raw_payload)

micContent = None

models.Log.objects.create(message=message, status='S', text=_(u'Begin Processing of received AS2 message'))

if not models.Organization.objects.filter(as2_name=as2utils.unescape_as2name(payload.get('as2-to'))).exists():

raise as2utils.as2partnernotfound('Unknown AS2 organization with id %s'%payload.get('as2-to'))

message.organization = models.Organization.objects.get(as2_name=as2utils.unescape_as2name(payload.get('as2-to')))

if not models.Partner.objects.filter(as2_name=as2utils.unescape_as2name(payload.get('as2-from'))).exists():

raise as2utils.as2partnernotfound('Unknown AS2 Trading partner with id %s'%payload.get('as2-from'))

message.partner = models.Partner.objects.get(as2_name=as2utils.unescape_as2name(payload.get('as2-from')))

models.Log.objects.create(

message=message,

status='S',

text=_(u'Message is for Organization "%s" from partner "%s"'%(message.organization, message.partner))

)

#micContent = payload.get_payload()

filename = payload.get_filename()

if message.partner.encryption and payload.get_content_type() != 'application/pkcs7-mime':

raise as2utils.as2insufficientsecurity('Incoming messages from AS2 partner %s are defined to be encrypted'%message.partner.as2_name)

if payload.get_content_type() == 'application/pkcs7-mime' and payload.get_param('smime-type') == 'enveloped-data':

models.Log.objects.create(message=message, status='S', text=_(u'Decrypting the payload using private key %s'%message.organization.encryption_key))

message.encrypted = True

### Check if data is base64, if not then encode

try:

payload.get_payload().encode('ascii')

except Exception,e:

payload.set_payload(payload.get_payload().encode('base64'))

pyas2init.logger.debug('Decrypting the payload :\n%s'%payload.get_payload())

try:

decrypted_content = as2utils.decrypt_payload(

as2utils.mimetostring(payload,78),

str(message.organization.encryption_key.certificate.path),

str(message.organization.encryption_key.certificate_passphrase)

)

#micContent,raw_payload = as2utils.canonicalize(decrypted_content),decrypted_content

raw_payload = decrypted_content

payload = email.message_from_string(decrypted_content)

### Check if decrypted content is the actual content

if payload.get_content_type() == 'text/plain':

payload = email.Message.Message()

payload.set_payload(decrypted_content)

payload.set_type('application/edi-consent')

if filename:

payload.add_header('Content-Disposition', 'attachment', filename=filename)

except Exception, msg:

raise as2utils.as2decryptionfailed('Failed to decrypt message, exception message is %s' %msg)

if message.partner.signature and payload.get_content_type() != 'multipart/signed':

raise as2utils.as2insufficientsecurity('Incoming messages from AS2 partner %s are defined to be signed'%message.partner.as2_name)

if payload.get_content_type() == 'multipart/signed':

if not message.partner.signature_key:

raise as2utils.as2insufficientsecurity('Partner has no signature verification key defined')

micalg = payload.get_param('micalg').lower() or 'sha1'

models.Log.objects.create(message=message, status='S', text=_(u'Message is signed, Verifying it using public key %s'%message.partner.signature_key))

pyas2init.logger.debug('Verifying the signed payload:\n%s'%payload.as_string())

message.signed = True

main_boundary = '--' + payload.get_boundary()

cert = str(message.partner.signature_key.certificate.path)

ca_cert = cert

if message.partner.signature_key.ca_cert:

ca_cert = str(message.partner.signature_key.ca_cert.path)

verify_cert = message.partner.signature_key.verify_cert

### Extract the base64 encoded signature

for part in payload.walk():

if part.get_content_type() == "application/pkcs7-signature":

try:

raw_sig = part.get_payload().encode('ascii').strip()

except Exception,e:

raw_sig = part.get_payload().encode('base64').strip()

else:

payload = part

### Verify message using complete raw payload received from partner

try:

as2utils.verify_payload(as2utils.canonicalize2(payload),raw_sig,cert,ca_cert,verify_cert)

except Exception, e:

### Verify message using extracted signature and stripped message

try:

as2utils.verify_payload(as2utils.extractpayload_fromstring1(raw_payload,main_boundary),raw_sig,cert,ca_cert,verify_cert)

except Exception, e:

### Verify message using extracted signature and message without extra trailing new line

try:

as2utils.verify_payload(as2utils.extractpayload_fromstring2(raw_payload,main_boundary),raw_sig,cert,ca_cert,verify_cert)

except Exception, e:

raise as2utils.as2invalidsignature('Signature Verification Failed, exception message is %s'%str(e))

micContent = as2utils.canonicalize2(payload)

#micContent = as2utils.extractpayload_fromstring2(raw_payload,main_boundary)

if payload.get_content_type() == 'application/pkcs7-mime' and payload.get_param('smime-type') == 'compressed-data':

models.Log.objects.create(message=message, status='S', text=_(u'Decompressing the payload'))

message.compressed = True

### Decode the data if its base64

try:

payload.get_payload().encode('ascii')

cdata = base64.b64decode(payload.get_payload())

except Exception,e:

cdata = payload.get_payload()

pyas2init.logger.debug('Decompressing the payload:\n%s'%cdata)

try:

dcontent = as2utils.decompress_payload(cdata)

#if not message.signed :

#micContent = as2utils.canonicalize(dcontent)

payload = email.message_from_string(dcontent)

except Exception, e:

raise as2utils.as2decompressionfailed('Failed to decompress message,exception message is %s' %e)

### Saving the message mic for sending it in the MDN

if micContent:

pyas2init.logger.debug("Calcualting MIC with alg %s for content:\n%s"%(micalg,micContent))

calcMIC = getattr(hashlib, micalg.replace('-',''), hashlib.sha1)

message.mic = '%s, %s'%(calcMIC(micContent).digest().encode('base64').strip(), micalg)

return payload

finally:

''' Function builds AS2 MDN report '''

try:

hparser = HeaderParser()

message_header = hparser.parsestr(message.headers)

text = str()

# check for default orginization message

if message.organization.confirmation_message:

text = message.organization.confirmation_message

# overwrite with partner specific message

if message.partner.confirmation_message:

text = message.partner.confirmation_message

# default message

if text.strip() == '':

text = _(u'The AS2 message has been processed. Thank you for exchanging AS2 messages with Pyas2.')

if status != 'success':

#### Send mail here

as2utils.senderrorreport(message, _(u'Failure in processing message from partner,\n Basic status : %s \n Advanced Status: %s'%(kwargs['adv_status'],kwargs['status_message'])))

text = _(u'The AS2 message could not be processed. The disposition-notification report has additional details.')

models.Log.objects.create(message=message, status='E', text = kwargs['status_message'])

message.status = 'E'

else:

message.status = 'S'

if not message_header.get('disposition-notification-to'):

models.Log.objects.create(message=message, status='S', text=_(u'MDN not requested by partner, closing request.'))

return None, None

models.Log.objects.create(message=message, status='S', text=_(u'Building the MDN response to the request'))

main = MIMEMultipart('report', report_type="disposition-notification")

textmessage = email.Message.Message()

textmessage.set_payload("%s\n"%text)

textmessage.set_type('text/plain')

textmessage.set_charset('us-ascii')

del textmessage['MIME-Version']

main.attach(textmessage)

mdnbase = email.Message.Message()

mdnbase.set_type('message/disposition-notification')

mdnbase.set_charset('us-ascii')

mdn = 'Reporting-UA: Bots Opensource EDI Translator\n'

mdn = mdn + 'Original-Recipient: rfc822; %s\n'%message_header.get('as2-to')

mdn = mdn + 'Final-Recipient: rfc822; %s\n'%message_header.get('as2-to')

mdn = mdn + 'Original-Message-ID: <%s>\n'%message.message_id

if status != 'success':

mdn = mdn + 'Disposition: automatic-action/MDN-sent-automatically; processed/%s: %s\n'%(status, kwargs['adv_status'])

else:

mdn = mdn + 'Disposition: automatic-action/MDN-sent-automatically; processed\n'

if message.mic:

mdn = mdn + 'Received-content-MIC: %s\n'%message.mic

mdnbase.set_payload(mdn)

del mdnbase['MIME-Version']

main.attach(mdnbase)

del main['MIME-Version']

pyas2init.logger.debug('MDN for message %s created:\n%s'%(message.message_id,main.as_string()))

mdnsigned = False

if message_header.get('disposition-notification-options') and message.organization and message.organization.signature_key:

models.Log.objects.create(message=message, status='S', text=_(u'Signing the MDN using private key %s'%message.organization.signature_key))

mdnsigned = True

options = message_header.get('disposition-notification-options').split(";")

algorithm = options[1].split(",")[1].strip()

signed = MIMEMultipart('signed', protocol="application/pkcs7-signature")

signed.attach(main)

micalg, signature = as2utils.sign_payload(

as2utils.canonicalize(as2utils.mimetostring(main, 0)+'\n'),

str(message.organization.signature_key.certificate.path),

str(message.organization.signature_key.certificate_passphrase)

)

pyas2init.logger.debug('Signature for MDN created:\n%s'%signature.as_string())

signed.set_param('micalg',micalg)

signed.attach(signature)

mdnmessage = signed

else:

mdnmessage = main

### Add new line between the MDN message and the signature

mdnbody = as2utils.extractpayload(mdnmessage)

mainboundary = '--' + main.get_boundary() + '--'

mdnbody = as2utils.canonicalize(mdnbody.replace(mainboundary, mainboundary + '\n'))

mdnmessage.add_header('ediint-features', 'CEM')

mdnmessage.add_header('as2-from', message_header.get('as2-to'))

mdnmessage.add_header('as2-to', message_header.get('as2-from'))

mdnmessage.add_header('AS2-Version', '1.2')

mdnmessage.add_header('date', email.Utils.formatdate(localtime=True))

mdnmessage.add_header('Message-ID', email.utils.make_msgid())

mdnmessage.add_header('user-agent', 'PYAS2, A pythonic AS2 server')

filename = mdnmessage.get('message-id').strip('<>') + '.mdn'

fullfilename = as2utils.storefile(pyas2init.gsettings['mdn_send_store'],filename,mdnbody,True)

mdn_headers = ''

for key in mdnmessage.keys():

mdn_headers = mdn_headers + '%s: %s\n'%(key, mdnmessage[key])

if message_header.get('receipt-delivery-option'):

message.mdn = models.MDN.objects.create(message_id=filename, file=fullfilename, status='P', signed=mdnsigned, headers=mdn_headers, return_url= message_header['receipt-delivery-option'])

message.mdn_mode = 'ASYNC'

mdnbody, mdnmessage = None, None

models.Log.objects.create(message=message, status='S', text=_(u'Asynchronous MDN requested, setting status to pending'))

else:

message.mdn = models.MDN.objects.create(message_id=filename,file=fullfilename, status='S', signed=mdnsigned, headers=mdn_headers)

message.mdn_mode = 'SYNC'

models.Log.objects.create(message=message, status='S', text=_(u'MDN created successfully and sent to partner'))

return mdnbody, mdnmessage

finally:

''' Build the AS2 mime message to be sent to partner'''

models.Log.objects.create(message=message, status='S', text=_(u'Build the AS2 message and header to send to the partner'))

reference = '<%s>'%message.message_id

micContent = None

email_datetime = email.Utils.formatdate(localtime=True)

as2Header = {

'AS2-Version' : '1.2',

'ediint-features' : 'CEM',

'MIME-Version' : '1.0',

'Message-ID' : reference,

'AS2-From' : as2utils.escape_as2name(message.organization.as2_name),

'AS2-To' : as2utils.escape_as2name(message.partner.as2_name),

'Subject' : message.partner.subject,

'Date' : email_datetime,

'recipient-address' : message.partner.target_url,

'user-agent' : 'PYAS2, A pythonic AS2 server'

}

payload = email.Message.Message()

with open(message.payload.file, 'rb') as fh:

payload.set_payload(fh.read())

fh.close()

payload.set_type(message.partner.content_type)

payload.add_header('Content-Disposition', 'attachment', filename=message.payload.name)

del payload['MIME-Version']

#micContent,cmicContent,content = payload.get_payload(),None,payload.get_payload()

content = payload.get_payload()

if message.partner.compress:

models.Log.objects.create(message=message, status='S', text=_(u'Compressing the payload.'))

message.compressed = True

#micContent = as2utils.canonicalize(as2utils.mimetostring(payload, 0))

cmessage = email.Message.Message()

cmessage.set_type('application/pkcs7-mime')

cmessage.set_param('name', 'smime.p7z')

cmessage.set_param('smime-type', 'compressed-data')

cmessage.add_header('Content-Transfer-Encoding', 'base64')

cmessage.add_header('Content-Disposition', 'attachment', filename='smime.p7z')

cmessage.set_payload(as2utils.compress_payload(as2utils.canonicalize(as2utils.mimetostring(payload, 0))))

content,payload = cmessage.get_payload(),cmessage

pyas2init.logger.debug('Compressed message %s payload as:\n%s'%(message.message_id,payload.as_string()))

if message.partner.signature:

models.Log.objects.create(message=message, status='S', text=_(u'Signing the message using organzation key %s'%message.organization.signature_key))

message.signed = True

multipart = MIMEMultipart('signed',protocol="application/pkcs7-signature")

del multipart['MIME-Version']

#micContent = as2utils.canonicalize2(payload)

micContent = as2utils.canonicalize(as2utils.mimetostring(payload, 0))

multipart.attach(payload)

micalg, signature = as2utils.sign_payload(micContent, str(message.organization.signature_key.certificate.path), str(message.organization.signature_key.certificate_passphrase))

multipart.set_param('micalg',micalg)

multipart.attach(signature)

multipart.as_string()

content = as2utils.canonicalize(as2utils.extractpayload(multipart))

payload = multipart

pyas2init.logger.debug('Signed message %s payload as:\n%s'%(message.message_id,payload.as_string()))

if message.partner.encryption:

#if not message.compressed and not message.signed:

#micContent = as2utils.canonicalize(as2utils.mimetostring(payload, 0))

models.Log.objects.create(message=message, status='S', text=_(u'Encrypting the message using partner key %s'%message.partner.encryption_key))

message.encrypted = True

payload = as2utils.encrypt_payload(as2utils.canonicalize(as2utils.mimetostring(payload, 0)), message.partner.encryption_key.certificate.path , message.partner.encryption)

payload.set_type('application/pkcs7-mime')

content = payload.get_payload()

pyas2init.logger.debug('Encrypted message %s payload as:\n%s'%(message.message_id,payload.as_string()))

if message.partner.mdn:

as2Header['disposition-notification-to'] = 'no-reply@pyas2.com'

if message.partner.mdn_sign:

as2Header['disposition-notification-options'] = 'signed-receipt-protocol=required, pkcs7-signature; signed-receipt-micalg=optional, %s'%message.partner.mdn_sign

message.mdn_mode = 'SYNC'

if message.partner.mdn_mode == 'ASYNC':

as2Header['receipt-delivery-option'] = pyas2init.gsettings['mdn_url']

message.mdn_mode = 'ASYNC'

if micContent:

pyas2init.logger.debug("Calcualting MIC with alg %s for content:\n%s"%(micalg,micContent))

calcMIC = getattr(hashlib, micalg.replace('-',''), hashlib.sha1)

message.mic = calcMIC(micContent).digest().encode('base64').strip()

as2Header.update(payload.items())

message.headers = ''

for key in as2Header:

message.headers = message.headers + '%s: %s\n'%(key, as2Header[key])

message.save()

models.Log.objects.create(message=message, status='S', text=_(u'AS2 message has been built successfully, sending it to the partner'))

''' Sends the AS2 message to the partner '''

try:

hparser = HeaderParser()

message_header = hparser.parsestr(message.headers)

auth = None

if message.partner.http_auth:

auth = (message.partner.http_auth_user, message.partner.http_auth_pass)

verify = True

if message.partner.https_ca_cert:

verify = message.partner.https_ca_cert.path

try:

response = requests.post(message.partner.target_url, auth = auth, verify=verify, headers = dict(message_header.items()), data = payload)

response.raise_for_status()

except Exception,e:

### Send mail here

as2utils.senderrorreport(message, _(u'Failure during transmission of message to partner with error "%s".\n\nTo retry transmission run the management command "retryfailedas2comms".'%e))

message.status = 'R'

models.Log.objects.create(message=message, status='E', text=_(u'Message send failed with error %s'%e))

return

models.Log.objects.create(message=message, status='S', text=_(u'AS2 message successfully sent to partner'))

if message.partner.mdn:

if message.partner.mdn_mode == 'ASYNC':

models.Log.objects.create(message=message, status='S', text=_(u'Requested ASYNC MDN from partner, waiting for it ........'))

message.status = 'P'

return

mdnContent = '';

for key in response.headers:

mdnContent = mdnContent + '%s: %s\n'%(key, response.headers[key])

mdnContent = mdnContent + '\n' + response.content

models.Log.objects.create(message=message, status='S', text=_(u'Synchronous mdn received from partner'))

pyas2init.logger.debug('Synchronus MDN from message %s received:\n%s'%(message.message_id,mdnContent))

save_mdn(message, mdnContent)

else:

message.status = 'S'

models.Log.objects.create(message=message, status='S', text=_(u'No MDN needed, File Transferred successfully to the partner'))

run_postsend(message)

finally:

''' Process the received MDN and check status of sent message '''

try:

mdnMessage = email.message_from_string(mdnContent)

mdnHeaders = ''

for key in mdnMessage.keys():

mdnHeaders = mdnHeaders + '%s: %s\n'%(key, mdnMessage[key])

messageId = mdnMessage.get('message-id')

if message.partner.mdn_sign and mdnMessage.get_content_type() != 'multipart/signed':

models.Log.objects.create(message=message, status='W', text=_(u'Expected signed MDN but unsigned MDN returned'))

mdnsigned = False

if mdnMessage.get_content_type() == 'multipart/signed':

models.Log.objects.create(message=message, status='S', text=_(u'Verifying the signed MDN with partner key %s'%message.partner.signature_key))

mdnsigned = True

cert = str(message.partner.signature_key.certificate.path)

ca_cert = cert

if message.partner.signature_key.ca_cert:

ca_cert = str(message.partner.signature_key.ca_cert.path)

verify_cert = message.partner.signature_key.verify_cert

main_boundary = '--' + mdnMessage.get_boundary()

### Extract the mssage and signature

for part in mdnMessage.get_payload():

if part.get_content_type().lower() == "application/pkcs7-signature":

sig = part

else:

mdnMessage = part

### check if signature is base64 encoded and if not encode

try:

raw_sig = sig.get_payload().encode('ascii').strip()

except Exception,e:

raw_sig = sig.get_payload().encode('base64').strip()

### Verify the signature using raw contents

try:

as2utils.verify_payload(mdnContent,None,cert,ca_cert,verify_cert)

except Exception, e:

### Verify the signature using extracted signature and message

try:

as2utils.verify_payload(as2utils.extractpayload_fromstring1(mdnContent,main_boundary),raw_sig,cert,ca_cert,verify_cert)

except Exception, e:

### Verify the signature using extracted signature and message without extra trailing new line in message

try:

as2utils.verify_payload(as2utils.extractpayload_fromstring2(mdnContent,main_boundary),raw_sig,cert,ca_cert,verify_cert)

except Exception, e:

raise as2utils.as2exception(_(u'MDN Signature Verification Error, exception message is %s' %e))

filename = messageId.strip('<>') + '.mdn'

fullfilename = as2utils.storefile(pyas2init.gsettings['mdn_receive_store'],filename,as2utils.extractpayload(mdnMessage),True)

message.mdn = models.MDN.objects.create(message_id=messageId.strip('<>'),file=fullfilename, status='R', headers=mdnHeaders, signed=mdnsigned)

if mdnMessage.get_content_type() == 'multipart/report':

for part in mdnMessage.walk():

if (part.get_content_type() == 'message/disposition-notification'):

pyas2init.logger.debug('Found MDN report for message %s:\n%s'%(message.message_id,part.as_string()))

models.Log.objects.create(message=message, status='S', text=_(u'Checking the MDN for status of the message'))

mdn = part.get_payload().pop()

mdnOMessageId = mdn.get('Original-Message-ID')

mdnStatus = mdn.get('Disposition').split(';')

if (mdnStatus[1].strip() == 'processed'):

models.Log.objects.create(message=message, status='S', text=_(u'Message has been successfully processed, verifying the MIC if present.'))

if mdn.get('Received-Content-MIC') and message.mic:

mdnMIC = mdn.get('Received-Content-MIC').split(',');

if (message.mic != mdnMIC[0]):

message.status = 'W'

models.Log.objects.create(message=message, status='W', text=_(u'Message Integrity check failed, please validate message content with your partner'))

else:

message.status = 'S'

models.Log.objects.create(message=message, status='S', text=_(u'File Transferred successfully to the partner'))

else:

message.status = 'S'

models.Log.objects.create(message=message, status='S', text=_(u'File Transferred successfully to the partner'))

run_postsend(message)

else:

raise as2utils.as2exception(_(u'Partner failed to process file. MDN status is %s'%mdn.get('Disposition')))

else:

raise as2utils.as2exception(_(u'MDN report not found in the response'))

finally:

''' Execute command after successful send, can be used to notify successfule sends '''

command = message.partner.cmd_send

if command:

models.Log.objects.create(message=message, status='S', text=_(u'Exectute command post successful send'))

command = Template(command)

variables = {'filename':message.payload.name, 'sender':message.organization.as2_name, 'recevier':message.partner.as2_name, 'messageid':message.message_id}

variables.update(dict(HeaderParser().parsestr(message.headers).items()))

''' Execute command after successful receive, can be used to call the edi program for further processing'''

command = message.partner.cmd_receive

if command:

models.Log.objects.create(message=message, status='S', text=_(u'Exectute command post successful receive'))

command = Template(command)

variables = {'filename':message.payload.name, 'fullfilename':fullfilename, 'sender':message.organization.as2_name, 'recevier':message.partner.as2_name, 'messageid':message.message_id}

variables.update(dict(HeaderParser().parsestr(message.headers).items()))