问开始使用使用Python的安全AWS CloudFront流

EN

import boto

#credentials stored in environment AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
s3 = boto.connect_s3()

#bucket name MUST follow dns guidelines
new_bucket_name = "stream.example.com"
bucket = s3.create_bucket(new_bucket_name)

object_name = "video.mp4"
key = bucket.new_key(object_name)
key.set_contents_from_filename(object_name)

import boto

#credentials stored in environment AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
cf = boto.connect_cloudfront()

oai = cf.create_origin_access_identity(comment='New identity for secure videos')

#We need the following two values for later steps:
print("Origin Access Identity ID: %s" % oai.id)
print("Origin Access Identity S3CanonicalUserId: %s" % oai.s3_user_id)

import boto

#credentials stored in environment AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY
s3 = boto.connect_s3()

bucket_name = "stream.example.com"
bucket = s3.get_bucket(bucket_name)

object_name = "video.mp4"
key = bucket.get_key(object_name)

#Now add read permission to our new s3 account
s3_canonical_user_id = "<your S3CanonicalUserID from above>"
key.add_user_grant("READ", s3_canonical_user_id)

import boto
from boto.cloudfront.distribution import DistributionConfig
from boto.cloudfront.exception import CloudFrontServerError

import re

def get_domain_from_xml(xml):
    results = re.findall("<DomainName>([^<]+)</DomainName>", xml)
    return results[0]

#custom class to hack this until boto v2.0 is released
class HackedStreamingDistributionConfig(DistributionConfig):

    def __init__(self, connection=None, origin='', enabled=False,
                 caller_reference='', cnames=None, comment='',
                 trusted_signers=None):
        DistributionConfig.__init__(self, connection=connection,
                                    origin=origin, enabled=enabled,
                                    caller_reference=caller_reference,
                                    cnames=cnames, comment=comment,
                                    trusted_signers=trusted_signers)

    #override the to_xml() function
    def to_xml(self):
        s = '<?xml version="1.0" encoding="UTF-8"?>\n'
        s += '<StreamingDistributionConfig xmlns="http://cloudfront.amazonaws.com/doc/2010-07-15/">\n'

        s += '  <S3Origin>\n'
        s += '    <DNSName>%s</DNSName>\n' % self.origin
        if self.origin_access_identity:
            val = self.origin_access_identity
            s += '    <OriginAccessIdentity>origin-access-identity/cloudfront/%s</OriginAccessIdentity>\n' % val
        s += '  </S3Origin>\n'


        s += '  <CallerReference>%s</CallerReference>\n' % self.caller_reference
        for cname in self.cnames:
            s += '  <CNAME>%s</CNAME>\n' % cname
        if self.comment:
            s += '  <Comment>%s</Comment>\n' % self.comment
        s += '  <Enabled>'
        if self.enabled:
            s += 'true'
        else:
            s += 'false'
        s += '</Enabled>\n'
        if self.trusted_signers:
            s += '<TrustedSigners>\n'
            for signer in self.trusted_signers:
                if signer == 'Self':
                    s += '  <Self/>\n'
                else:
                    s += '  <AwsAccountNumber>%s</AwsAccountNumber>\n' % signer
            s += '</TrustedSigners>\n'
        if self.logging:
            s += '<Logging>\n'
            s += '  <Bucket>%s</Bucket>\n' % self.logging.bucket
            s += '  <Prefix>%s</Prefix>\n' % self.logging.prefix
            s += '</Logging>\n'
        s += '</StreamingDistributionConfig>\n'

        return s

    def create(self):
        response = self.connection.make_request('POST',
            '/%s/%s' % ("2010-11-01", "streaming-distribution"),
            {'Content-Type' : 'text/xml'},
            data=self.to_xml())

        body = response.read()
        if response.status == 201:
            return body
        else:
            raise CloudFrontServerError(response.status, response.reason, body)


cf = boto.connect_cloudfront()

s3_dns_name = "stream.example.com.s3.amazonaws.com"
comment = "example streaming distribution"
oai = "<OAI ID from step 2 above like E23KRHS6GDUF5L>"

#Create a distribution that does NOT need signed URLS
hsd = HackedStreamingDistributionConfig(connection=cf, origin=s3_dns_name, comment=comment, enabled=True)
hsd.origin_access_identity = oai
basic_dist = hsd.create()
print("Distribution with basic URLs: %s" % get_domain_from_xml(basic_dist))

#Create a distribution that DOES need signed URLS
hsd = HackedStreamingDistributionConfig(connection=cf, origin=s3_dns_name, comment=comment, enabled=True)
hsd.origin_access_identity = oai
#Add some required signers (Self means your own account)
hsd.trusted_signers = ['Self']
signed_dist = hsd.create()
print("Distribution with signed URLs: %s" % get_domain_from_xml(signed_dist))

from M2Crypto import EVP
import base64
import time

def aws_url_base64_encode(msg):
    msg_base64 = base64.b64encode(msg)
    msg_base64 = msg_base64.replace('+', '-')
    msg_base64 = msg_base64.replace('=', '_')
    msg_base64 = msg_base64.replace('/', '~')
    return msg_base64

def sign_string(message, priv_key_string):
    key = EVP.load_key_string(priv_key_string)
    key.reset_context(md='sha1')
    key.sign_init()
    key.sign_update(str(message))
    signature = key.sign_final()
    return signature

def create_url(url, encoded_signature, key_pair_id, expires):
    signed_url = "%(url)s?Expires=%(expires)s&Signature=%(encoded_signature)s&Key-Pair-Id=%(key_pair_id)s" % {
            'url':url,
            'expires':expires,
            'encoded_signature':encoded_signature,
            'key_pair_id':key_pair_id,
            }
    return signed_url

def get_canned_policy_url(url, priv_key_string, key_pair_id, expires):
    #we manually construct this policy string to ensure formatting matches signature
    canned_policy = '{"Statement":[{"Resource":"%(url)s","Condition":{"DateLessThan":{"AWS:EpochTime":%(expires)s}}}]}' % {'url':url, 'expires':expires}

    #now base64 encode it (must be URL safe)
    encoded_policy = aws_url_base64_encode(canned_policy)
    #sign the non-encoded policy
    signature = sign_string(canned_policy, priv_key_string)
    #now base64 encode the signature (URL safe as well)
    encoded_signature = aws_url_base64_encode(signature)

    #combine these into a full url
    signed_url = create_url(url, encoded_signature, key_pair_id, expires);

    return signed_url

def encode_query_param(resource):
    enc = resource
    enc = enc.replace('?', '%3F')
    enc = enc.replace('=', '%3D')
    enc = enc.replace('&', '%26')
    return enc


#Set parameters for URL
key_pair_id = "APKAIAZCZRKVIO4BQ" #from the AWS accounts page
priv_key_file = "cloudfront-pk.pem" #your private keypair file
resource = 'video.mp4' #your resource (just object name for streaming videos)
expires = int(time.time()) + 300 #5 min

#Create the signed URL
priv_key_string = open(priv_key_file).read()
signed_url = get_canned_policy_url(resource, priv_key_string, key_pair_id, expires)

#Flash player doesn't like query params so encode them
enc_url = encode_query_param(signed_url)
print(enc_url)

video.mp4%3FExpires%3D1309979985%26Signature%3DMUNF7pw1689FhMeSN6JzQmWNVxcaIE9mk1x~KOudJky7anTuX0oAgL~1GW-ON6Zh5NFLBoocX3fUhmC9FusAHtJUzWyJVZLzYT9iLyoyfWMsm2ylCDBqpy5IynFbi8CUajd~CjYdxZBWpxTsPO3yIFNJI~R2AFpWx8qp3fs38Yw_%26Key-Pair-Id%3DAPKAIAZRKVIO4BQ

var so_canned = new SWFObject('http://location.domname.com/~jvngkhow/player.swf','mpl','640','360','9');
    so_canned.addParam('allowfullscreen','true');
    so_canned.addParam('allowscriptaccess','always');
    so_canned.addParam('wmode','opaque');
    so_canned.addVariable('file','video.mp4%3FExpires%3D1309979985%26Signature%3DMUNF7pw1689FhMeSN6JzQmWNVxcaIE9mk1x~KOudJky7anTuX0oAgL~1GW-ON6Zh5NFLBoocX3fUhmC9FusAHtJUzWyJVZLzYT9iLyoyfWMsm2ylCDBqpy5IynFbi8CUajd~CjYdxZBWpxTsPO3yIFNJI~R2AFpWx8qp3fs38Yw_%26Key-Pair-Id%3DAPKAIAZRKVIO4BQ');
    so_canned.addVariable('streamer','rtmp://s3nzpoyjpct.cloudfront.net/cfx/st');
    so_canned.write('canned');