def test_package_identity(self):
index = 0
message = "Test that pad being 0 is identity"
p_text = chr(0)*len(message)
p_body = chr(0)*(len(message)+ crypto.TAG_LENGTH)
p_tag_key = chr(0) * crypto.TAG_KEY_LENGTH
package = crypto.package(index, message, p_text, p_body, p_tag_key)
# Should be index | message | HMAC(key, index | message)
correctPackage = 6*chr(0)+message+(crypto.hmac_sha256(p_tag_key, 6*chr(0)+message))
self.assertEqual(package, correctPackage)
def test_package_reflexive(self):
message = "Test that packaged and unpackaging returns the same message"
index = 0
p_text = "otuhixnuheotuheouaoecgudoaeuteoahduao',.peaecd'983d uaoeuhu" #pseudo random typing
p_body = ",'cd.ucr,'.gud.,9'ud249 l3uf19842gfpd4gdu r9'7i3pkur84gciudr.g,fi r138uf927 i'e7pduxanw;jk8"
p_tag_key = "N\xbb\xcf\xb0jT\x81\x12X2.\xe5zMi\xee"
self.assertEquals(len(p_body), len(p_text)+crypto.TAG_LENGTH)
package = crypto.package(index, message, p_text, p_body, p_tag_key)
unpackage = crypto.unpackage(package, p_text, p_body, p_tag_key)
self.assertEquals(unpackage, message)
def package(src_uid, dst_uid, message):
"""Encrypt a message from from_uid to to_uid.
Message is plaintext.
Package it up with the index and MAC so the recipient can decode it.
"""
if src_uid == dst_uid:
return {
"success": False,
"error": "Rejecting message to yourself."
}
message = message.encode("utf-8")
if not csc.yn_prompt("Are you sure you want send a\n{} byte message?".format(len(message))):
return {
"success": False,
"error": "User rejected pad read request.",
}
try:
(p_text, index) = read.read_encrypt_pad(src_uid, dst_uid, len(message))
(p_body, _) = read.read_encrypt_pad(src_uid, dst_uid, len(message) + crypto.TAG_LENGTH)
(p_tag_key, _) = read.read_encrypt_pad(src_uid, dst_uid, crypto.TAG_KEY_LENGTH)
except metadata.NoMetadataException:
return {
"success": False,
"error": "Shared pad not found.",
}
except read.PadContainException:
return {
"success": False,
"error": "Pad depleted.",
}
try:
package = crypto.package(index, message, p_text, p_body, p_tag_key, verbose=True)
# Base64 encode the package for transport.
package_b64 = base64.b64encode(package)
return {
"success": True,
"package": package_b64,
}
except crypto.CryptoError:
traceback.print_exc()
return {
"success": False,
"error": "Encryption failed.",
}
