Encryption is not a new concept to MongoDB. Encryption may occur in-transit (with TLS) and at-rest (with the encrypted storage engine). But MongoDB 4.2 introduces support for Client Side Encryption, ensuring the most sensitive data is encrypted before ever leaving the client application. Even full access to your MongoDB servers is not enough to decrypt this data. And better yet, Client Side Encryption can be enabled at the "flick of a switch". This session covers using Client Side Encryption in your applications. This includes the necessary setup, how to encrypt data without sacrificing queryability, and what trade-offs to expect.

2. Introducing…

4. db.coll.insert({
_id: 1,
name: "Doris",
ssn: "457-55-5462"
})

6. doc = db.coll.find_one({
ssn: "457-55-5462"
})

8. print (doc)

9. {
_id: 1
name: "Doris",
ssn: "457-55-5462"
}

12. db.coll.insert({
name: "Doris",
ssn: "457-55-5462"
})
{
insert: "coll",
documents: [{
name: "Doris",
ssn: BinData(6, "a10x…")
}]
}
You see: MongoDB sees:
Encrypt before sending

13. {
_id: 1
name: "Doris",
ssn: BinData(6, "a10x…")
}
Driver receives: You see:
{
_id: 1
name: "Doris",
ssn: "457-55-5462"
}
Decrypt after receiving

14. How does this differ from…?
•… encryption in-transit (TLS)
•… encryption at-rest (encrypted storage engine)

15. Attacker
Query
Client
Disk
insert write
MongoDB
Auth
db.coll.insert({ name: "Doris", ssn: "457-55-5462" })

16. Client
Disk
insert write
MongoDB
Attacker
Snoop
TLS
db.coll.insert({ name: "Doris", ssn: "457-55-5462" })

17. Client
Disk
insert write
MongoDB
Attacker
insert
TLS
db.coll.insert({ name: "Doris", ssn: "457-55-5462" })

18. Client
Disk
insert write
MongoDB
Attacker
Steal
ESE
db.coll.insert({ name: "Doris", ssn: "457-55-5462" })

19. Client
Disk
insert write
MongoDB
Attacker
Login
Client Side Encryption
db.coll.insert({ name: "Doris", ssn: "457-55-5462" })

20. Client
Disk
insert write
MongoDB
Boundaries of unencrypted data

21. Client
Disk
insert write
MongoDB
… with Encrypted Storage Engine

22. Client
Disk
insert write
MongoDB
… and TLS

23. Client
Disk
insert write
MongoDB
with Client Side Encryption

25. Client
Disk
insert write
MongoDB
ssn: BinData(6, "a10x…")

26. db.coll.update({}, {
$set: { ssn: "457-55-5462" }
})
{
update: "coll",
updates: [{
q:{},
u: {
$set: { ssn: BinData(6, "a10x…") }
}
}]
}
You see: MongoDB sees:
Update that overwrites value

27. db.coll.aggregate([{
$project: { name_ssn: {$concat: [ "$name", " - ", "$ssn" ] } }
}]
Aggregate acting on the data

28. Find with equality query
* For deterministic encryption
db.coll.find({ssn: "457-55-5462" }) {
find: "coll",
filter: { ssn: BinData(6, "a10x…") }
}
You see: MongoDB sees:

29. Find with equality query
* For deterministic encryption
db.test.find(
{
$and: [
{
$or: [
{ ssn : { $in : [ "457-55-5462", "153-96-2097" ]} },
{ ssn: { $exists: false } }
]
},
{ name: "Doris" }
]
}
)
You see:

30. Find with equality query
* For deterministic encryption
MongoDB sees:
{
find: "coll",
filter: {
$and: [
{
$or: [
{ ssn : { $in : [ BinData(6, "a10x…"), BinData(6, "8dk1…") ]} },
{ ssn: { $exists: false } }
]
},
{ name: "Doris" }
]
}
}

31. MongoDB
Attacker
Login

34. Doris
Private stuff in storage

35. PoliceDoris
Private stuff in storage

36. Vault key
Held only by you
Vault

38. Encrypted Data
MongoDB
Encryption Key

40. { _id: 1, ssn: BinData(0, "A81…"), name: "Kevin" }
{ _id: 2, ssn: BinData(0, "017…"), name: "Eric" }
{ _id: 3, ssn: BinData(0, "5E1…"), name: "Albert" }
…

42. Destroy the key
Provably delete all user data.
GDPR "right-to-be-forgotten"

44. client = MongoClient(
auto_encryption_opts=opts)

45. Not sensitive
{

46. One key for all vaults

47. One key per vault

48. {
name: "Doris"
ssn: "457-55-5462",
email: "Doris@gmail.com",
credit_card: "4690-6950-9373-8791",
comments: [ …. ],
avatar: BinData(0, "0fi8…"),
profile: { likes: {…}, dislikes: {…} }
}

51. Describes JSON
{
bsonType: "object",
properties: {
a: {
bsonType: "int"
maximum: 10
}
b: { bsonType: "string" }
},
required: ["a", "b"]
}
{
a: 5,
b: "hi"
}
{
a: 11,
b: false
}
JSON Schema

52. {
bsonType: "object",
properties: {
ssn: {
encrypt: { … }
}
},
required: ["ssn"]
}
JSON Schema "encrypt"

53. encrypt: {
keyId: <UUID[]> or <string>,
algorithm: <string>
bsonType: <string> or <string[]>
}
bsonType indicates the type of underlying data.
algorithm indicates how to encrypt (Random or Deterministic).
keyId indicates the key used to encrypt.

54. opts = AutoEncryptionOptions(
schema_map = { "db.coll": <schema> }
…)

55. Remote Schema Fallback
db.createCollection("coll", { validator: { $jsonSchema: … } } )
Misconfigured
Client insert "457-55-5462"
error, that should be
encrypted
MongoDB

56. What if
… the server lies about the schema?
Misconfigured
Client insert "457-55-5462"
Evil MongoDB
ok :)

57. schema_map
Sub-options

59. Key vault
Key vault key
Held only by you

62. Stores encrypted keys

63. opts = AutoEncryptionOptions(
schema_map = { "db.coll": <schema> },
key_vault_namespace = "db.keyvault"
…)

64. schema_map
Sub-options
key_vault_namespace

65. What if
… attacker drops key vault collection?

66. Keep at home
opts = AutoEncryptionOptions(
schema_map = { "db.coll": <schema> },
key_vault_namespace = "db.keyvault",
key_vault_client = <client>
…)

67. schema_map
Sub-options
key_vault_namespace
key_vault_client

69. (Key Management Service)

70. Protects keys Stores keys
KMS
Key vault key
Key vault
Key vault
collection

71. Decryption requires

72. opts = AutoEncryptionOptions(
schema_map = { "db.coll": <schema> },
key_vault_namespace = "db.keys",
kms_providers = <creds>
…)

73. schema_map
Sub-options
key_vault_namespace
key_vault_client
kms_providers

75. db.coll.insert({
name: "Doris",
ssn: "457-55-5462"
})
Get encrypted key
Decrypt the key with KMSDecrypt the key with KMS
Encrypt 457-55-5462
Send insert
Compare to JSON schema

78. Authenticated Encryption with Associated Data using the Advance

79. AEAD_AES_256_CBC_HMAC_SHA_512
Provides confidentiality + integrity

80. AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic
AEAD_AES_256_CBC_HMAC_SHA_512-Random

81. coll.insert({ ssn: "457-55-5462" }) { ssn: BinData(6, "a10x…") }
You see: MongoDB stores:
coll.insert({ ssn: "457-55-5462" }) { ssn: BinData(6, "f991…") }
…Random

82. coll.insert({ ssn: "457-55-5462" }) { ssn: BinData(6, "a10x…") }
You see: MongoDB stores:
coll.insert({ ssn: "457-55-5462" }) { ssn: BinData(6, "a10x…") }
…Deterministic

83. Can be queried
doc = db.coll.find({
ssn: "457-55-5642"
})
{
find: "coll",
filter: { ssn: BinData(0, "a10x…") }
}
Driver sends:
{ ssn: BinData(6, "a10x…") }
MongoDB returns:
…Deterministic

84. Only for binary comparable types.
db.coll.find({ a: { b: 1.0 } })
{ a: { b: NumberInt(1) } }
{ a: { b: 1.0 } }
{ a: { b: NumberLong(1) } }
MongoDB returns:
…Deterministic

85. { a: { b: NumberInt(1) } }
{ a: { b: 1.0 } }
{ a: { b: NumberLong(1) } }
{ a: BinData(6, "19d0…") }
{ a: BinData(6, "b515…") }
{ a: BinData(6, "801f…") }
Encrypted as:

86. db.coll.find({ a: { b: 1.0 } })
{ a: { b: 1.0 } }
MongoDB returns:
"a" encrypted

88. { ssn: BinData(6, "AWNkTYTCw89Ss1DPzV3/2pSRDNGNJ9NB" }
New binary subtype
Older drivers and older MongoDB will treat as a black box.

89. byte algorithm
byte[16] key_id
byte original_bson_type
byte* payload
Ciphertext

90. byte algorithm
byte[16] key_id
byte original_bson_type
byte* payload
key_id + algorithm describes how to decrypt.
No JSON Schema necessary!
Ciphertext

91. byte algorithm
byte[16] key_id
byte original_bson_type
byte* payload
Provides extra server-side validation.
But prohibits single-value types (MinKey, MaxKey, Undefined, Null)
Ciphertext

92. byte algorithm
byte[16] key_id
byte original_bson_type
byte* payload
Payload includes encoded IV and padding block, and HMAC.
Ciphertext adds between 66 to 82 bytes of overhead.
Ciphertext

94. opts = ClientEncryptionOptions(…)
ce = ClientEncryption(opts)
opts = DataKeyOpts(kms_provider="aws",
master_key="…")
key_id = ce.create_data_key(opts)
ciphertext = ce.decrypt(ciphertext)
opts = EncryptOpts(algorithm="…", key_id="…")
ciphertext = ce.encrypt("457-55-5462", opts)

96. db.test.find({
$or: [
{ ssn : { $in : [ "457-55-5462", "153-96-2097" ]} },
{ name: "Doris" }
]
})
db.test.find({
$or: [
{ ssn : { $in : [ BinData(6, "a10x…"), BinData(6, "8dk1…") ]} },
{ name: "Doris" }
]
})

97. Limitations
If we cannot parse…
or it is impossible…
we err for safety.

98. { passport_num: "281-301-348", ssn: "457-55-5462" }
{ passport_num: "390-491-482", ssn: "482-38-5899" }
{ passport_num: "104-201-596" }
passport_num and ssn encrypted with different keys

99. db.test.aggregate([
])
{ $project: { identifier: { $ifNull: ["$ssn", "$passport_num" ] } } },
{ $match: { identifier: "457-55-5462" } }
How do we encrypt 457-55-5462?

100. opts = AutoEncryptionOptions(
bypass_auto_encryption = True
…)
client = MongoClient(auto_encryption_opts=opts)
(Decryption still occurs)

101. ce = ClientEncryption(opts)
db.test.aggregate([
])
{ $project: { identifier: { $ifNull: ["$ssn", "$passport_num" ] } } },
{ $match: { identifier: ce.encrypt("457-55-5462", opts) } }

103. {
_id: UUID(…)
keyAltNames: [ "mykey" ],
keyMaterial: BinData(0, "39aJ…"),
… (some metadata) …
}
> db.keyvault.find()
Identify
(Cached locally)

111. encryption = ClientEncryption(…)
id = encryption.create_data_key(…)
print (id)
Script prints: "609"

112. {
_id: 23
email: "Doris@gmail.com",
pwd: "19dg8%"
following: [ 9, 20, 95 ]
}

113. …
"email": {
"encrypt": {
"keyId": 609,
"algorithm": "…Deterministic"
"bsonType": "string",
}
},
"pwd": {
"encrypt": {
"keyId": 609,
"algorithm": "…Random"
"bsonType": "string"
}
}
…

114. client = MongoClient(
auto_encryption_opts=opts)
def register(db, email, pwd):
db.users.insert_one({ "email": email, "pwd": pwd })
def login(db, email, pwd):
user = db.users.find_one({ "email": email })
if user and matches(user["pwd"], pwd):
return True
else:
return False

115. client = MongoClient()
for doc in client.db.users.find():
print doc
{
_id: 23
email: BinData(6, 810f…"),
pwd: BinData(6, "19A0…")
}

117. {
user_id: 123,
date: Date("6/8/2019"),
title: "My first entry",
body: "Dear diary, … "
}
…
"body": {
"encrypt": {
"keyId": 609,
"algorithm": "…Random",
"bsonType": "string"
}
}
…

118. def create_post(db, user_id, title, body):
db.posts.insert_one({
"user_id": user_id,
"date": datetime.now(),
"title": title,
"body": body
})

120. def delete_user_data(db, user_id):
db.posts.delete_many({ "user_id": user_id })

121. delete key

123. encryption = ClientEncryption(…)
def register(encryption, db, email, pwd):
user_id = db.users.insert_one({
"email": email,
"pwd": pwd
}).inserted_id
opts = DataKeyOpts(keyAltNames=[user_id])
encryption.create_data_key("aws", opts)

124. …
"body": {
"encrypt": {
"keyId": 609,
"algorithm": "…Random",
"bsonType": "string"
}
}
…
…
"body": {
"encrypt": {
"keyId": "/user_id",
"algorithm": "…Random",
"bsonType": "string"
}
}
…
{
_id: 584,
user_id: 23,
date: Date("6/8/2019"),
title: "My first entry",
body: "Dear diary, … "
}

125. def delete_user_data(db, user_id):
db.keyvault.delete_one({ "keyAltNames": user_id })

127. def get_follower_posts(db, user):
cursor = db.posts.find_many(
{ "user_id": { "$in": user["followers"] } },
limit = 20,
sort = { "date": DESCENDING }
)
return list(cursor)

128. def list_follower_posts(db, user):
cursor = db.posts.find_many(
{ "user_id": { "$in": user["followers"] } },
limit = 20,
sort = { "date": DESCENDING },
projection = { "body": False }
)
return list(cursor)

130. (used by journalists and teens)

131. EAST
DICTATORLAND
Users
Global Shards

132. EAST
DICTATORLAND

133. EAST
DICTATORLAND
{ _id: 1, body: BinData(6, "A81…") }
{ _id: 2, body: BinData(6, "017…") }
{ _id: 3, body: BinData(6, "5E1…") }
…