Directory Services 7.4.2

Data encryption

DS directory servers can encrypt directory data in backend files on disk. This keeps the data confidential until it is accessed by a directory client.

Encrypting stored directory data does not prevent it from being sent over the network in the clear.

Use secure connections to protect data sent over the network.

Advantages Trade-offs

Confidentiality and integrity

Encrypted directory data is confidential, remaining private until decrypted with a proper key.

Encryption ensures data integrity at the moment it is accessed. The DS directory service cannot decrypt corrupted data.

Equality indexes limited to equality matching

When an equality index is configured without confidentiality, the server maintains values in sorted order. It can then use the cleartext equality index can for searches that require ordering or match initial substrings.

An example of a search that requires ordering is a search with a filter "(cn<=App)". The filter matches entries with commonName up to those starting with App (case-insensitive) in alphabetical order.

An example of a search that matches an initial substring is a search with a filter "(cn=A*)". The filter matches entries having a commonName that starts with a (case-insensitive).

In an equality index with confidentiality enabled, the server can no longer sort the values. As a result, you must either add indexes or accept that ordering and initial substring searches are unindexed.

Protection on shared infrastructure

When you share the infrastructure, you relinquish full and sole control of directory data. For example, if the DS directory server runs in the cloud, or in a data center with shared disks, the file system and disk management are not under your control.

With encrypted data, other users cannot read the files unless they also have the decryption keys.

Performance impact

Encryption and decryption requires more processing than handling plaintext values.

Encrypted values also take up more space than plaintext values.

To check what a system user with read access to backend database files can access, use the backendstat dump-raw-db command. The backendstat subcommands list-raw-dbs and dump-raw-db let you list and view the low-level databases within a backend. Unlike the output of other subcommands, the output of the dump-raw-db subcommand is neither decrypted nor formatted for readability. Instead, you can observe values as they are stored in the backend file.

In a backend database, the id2entry index holds LDIF for directory entries. For a database that is not encrypted, the corresponding low-level database shows the cleartext strings:

Show details
$ stop-ds

$ backendstat list-raw-dbs --backendId dsEvaluation
...
/dc=com,dc=example/id2entry

$ backendstat \
 dump-raw-db \
 --backendId dsEvaluation \
 --dbName /dc=com,dc=example/id2entry
...
Key (len 8):
 00 00 00 00 00 00 00 1E                          ........
 Value (len 437):
 02 00 81 B1 03 01 06 27 75 69 64 3D 62 6A 65 6E  .......'uid=bjen
 73 65 6E 2C 6F 75 3D 50 65 6F 70 6C 65 2C 64 63  sen,ou=People,dc
 3D 65 78 61 6D 70 6C 65 2C 64 63 3D 63 6F 6D 01  =example,dc=com.
 06 11 01 08 01 13 62 6A 65 6E 73 65 6E 40 65 78  ......bjensen@ex
 61 6D 70 6C 65 2E 63 6F 6D 01 09 01 04 30 32 30  ample.com....020
 39 01 16 01 0C 65 6E 2C 20 6B 6F 3B 71 3D 30 2E  9....en, ko;q=0.
 38 01 10 01 29 75 69 64 3D 74 72 69 67 64 65 6E  8...)uid=trigden
 2C 20 6F 75 3D 50 65 6F 70 6C 65 2C 20 64 63 3D  , ou=People, dc=
 65 78 61 6D 70 6C 65 2C 64 63 3D 63 6F 6D 01 04  example,dc=com..
 02 13 50 72 6F 64 75 63 74 20 44 65 76 65 6C 6F  ..Product Develo
 70 6D 65 6E 74 06 50 65 6F 70 6C 65 01 0B 01 07  pment.People....
 42 61 72 62 61 72 61 01 0C 01 0F 2B 31 20 34 30  Barbara....+1 40
 38 20 35 35 35 20 31 38 36 32 01 0D 01 06 4A 65  8 555 1862....Je
 6E 73 65 6E 01 07 02 0E 42 61 72 62 61 72 61 20  nsen....Barbara
 4A 65 6E 73 65 6E 0B 42 61 62 73 20 4A 65 6E 73  Jensen.Babs Jens
 65 6E 01 0E 01 0D 2F 68 6F 6D 65 2F 62 6A 65 6E  en..../home/bjen
 73 65 6E 01 0F 01 0F 2B 31 20 34 30 38 20 35 35  sen....+1 408 55
 35 20 31 39 39 32 01 11 01 04 31 30 30 30 01 12  5 1992....1000..
 01 2E 7B 53 53 48 41 7D 33 45 66 54 62 33 70 37  ..{SSHA}3EfTb3p7
 71 75 6F 75 73 4B 35 34 2B 41 4F 34 71 44 57 6C  quousK54+AO4qDWl
 56 33 4F 39 54 58 48 57 49 4A 49 32 4E 41 3D 3D  V3O9TXHWIJI2NA==
 01 13 01 04 31 30 37 36 01 05 01 14 4F 72 69 67  ....1076....Orig
 69 6E 61 6C 20 64 65 73 63 72 69 70 74 69 6F 6E  inal description
 01 14 01 07 62 6A 65 6E 73 65 6E 01 15 01 0D 53  ....bjensen....S
 61 6E 20 46 72 61 6E 63 69 73 63 6F 01 01 02 01  an Francisco....
 24 38 38 37 37 33 32 65 38 2D 33 64 62 32 2D 33  $887732e8-3db2-3
 31 62 62 2D 62 33 32 39 2D 32 30 63 64 36 66 63  1bb-b329-20cd6fc
 65 63 63 30 35                                   ecc05

Enable confidentiality to encrypt database backends. When confidentiality is enabled, the server encrypts entries before storing them in the backend. The following command enables backend confidentiality with the default encryption settings:

$ dsconfig \
 set-backend-prop \
 --hostname localhost \
 --port 4444 \
 --bindDn uid=admin \
 --bindPassword password \
 --backend-name dsEvaluation \
 --set confidentiality-enabled:true \
 --no-prompt \
 --usePkcs12TrustStore /path/to/opendj/config/keystore \
 --trustStorePassword:file /path/to/opendj/config/keystore.pin

After confidentiality is enabled, the server encrypts entries only when it next writes them. The server does not automatically rewrite all entries in encrypted form. Instead, it encrypts each entry the next time it is updated, or when you re-import data from LDIF.

To observe the impact of backend encryption, import the data and view the results, as in the following example:

Show details
$ stop-ds

$ export-ldif \
 --offline \
 --backendId dsEvaluation \
 --includeBranch dc=example,dc=com \
 --ldifFile backup.ldif

$ import-ldif \
 --offline \
 --backendId dsEvaluation \
 --includeBranch dc=example,dc=com \
 --ldifFile backup.ldif

$ backendstat \
 dump-raw-db \
 --backendId dsEvaluation \
 --dbName /dc=com,dc=example/id2entry
...
Key (len 8):
 00 00 00 00 00 00 00 C2                          ........
 Value (len 437):
 02 02 81 82 01 C4 95 87 5B A5 2E 47 97 80 23 F4  ........[..G..#.
 CE 5D 93 25 97 D4 13 F9 0A A3 A8 31 9A D9 7A 70  .].%.......1..zp
 FE 3E AC 9D 64 41 EB 7B D5 7F 7E B8 B7 74 52 B8  .>..dA.{.^?~..tR.
 C7 7F C8 79 19 46 7D C5 5D 5B 83 9C 5B 9F 85 28  .^?.y.F}.][..[..(
 83 A2 5F A0 C1 B1 09 FC 2F E3 D8 82 4A AA 8B D9  .._...../...J...
 78 43 34 50 AE A1 52 88 5B 70 97 D2 E1 EA 87 CA  xC4P..R.[p......
 3B 4D 07 DC F9 F8 30 BB D2 76 51 C8 75 FF FA 80  ;M....0..vQ.u...
 77 E1 6A 8B 5B 8F DA A4 F4 0B B5 20 56 B3 19 19  w.j.[...... V...
 22 D8 9D 38 04 E3 4D 94 A7 99 4B 81 16 AD 88 46  "..8..M...K....F
 FC 3F 7E 78 66 B8 D1 E9 86 A0 F3 AC B6 68 0D A9  .?~xf........h..
 9A A7 3C 30 40 37 97 4E 90 DD 63 16 8E 11 0F 5E  ..<0@7.N..c....^
 9D 5B 86 90 AF 4E E2 1F 9E 70 73 14 0A 11 5C DB  .[...N...ps...\.
 B7 BC B8 A9 31 3F 74 8D 0A 9F F4 6C E1 B0 36 78  ....1?t....l..6x
 F0 5A 5E CD 7C B3 A2 36 66 8E 88 86 A0 8B 9A 77  .Z^.|..6f......w
 D5 CD 7E 9C 4E 62 20 0E D0 DB AD E7 7E 99 46 4F  ..~.Nb .....~.FO
 67 C7 A6 7E 2C 24 82 50 51 9F A7 B2 02 44 5B 30  g..~,$.PQ....D[0
 74 41 99 D9 83 69 EF AE 2E C0 FF C4 E6 4F F2 2F  tA...i.......O./
 95 FB 93 65 30 2A 2D 8D 20 88 83 B5 DE 35 B6 20  ...e0*-. ....5.
 47 17 30 25 60 FD E3 43 B9 D6 A4 F7 47 B6 6C 9F  G.0%`..C....G.l.
 47 FD 63 8E 7F A5 00 CE 6C 3E BC 95 23 69 ED D0  G.c.^?...l>..#i..
 69 4F BE 61 BD 30 C2 40 66 F6 F9 C3 3E C1 D7 8C  iO.a.0.@f...>...
 B0 C8 4A 2E 27 BE 13 6C 40 88 B0 13 A3 12 F4 50  ..J.'..l@......P
 CA 92 D8 EB 4A E5 3F E2 64 A3 76 C7 5C 2B D8 89  ....J.?.d.v.+..
 A3 6E C1 F7 0A C2 37 7A BD AF 14 4B 52 04 6B F2  .n....7z...KR.k.
 8F 4F C3 F8 00 90 BA 0F EC 6D B1 2D A8 18 0C A6  .O.......m.-....
 29 96 82 3B 5C BC D0 F4 2B BE 9C C5 8B 18 7A DE  )..;\...+.....z.
 C7 B5 10 2D 45 50 4F 77 ED F7 23 34 95 AF C3 2E  ...-EPOw..#4....
 B0 9B FA E9 DF                                   .....

The settings for data confidentiality depend on the encryption capabilities of the JVM. Refer to the explanations in javax.crypto.Cipher. You can accept the default settings, or choose to specify the following:

  • The cipher algorithm defining how the plaintext is encrypted and decrypted.

  • The cipher mode of operation defining how a block cipher algorithm transforms data larger than a single block.

  • The cipher padding defining how to pad the plaintext to reach appropriate size for the algorithm.

  • The cipher key length, where longer key lengths strengthen encryption at the cost of lower performance.

The default settings for confidentiality are cipher-transformation: AES/GCM/NoPadding, and cipher-key-length: 128. This means the algorithm is the Advanced Encryption Standard (AES), and the cipher mode is Galois/Counter Mode (GCM). The syntax for the cipher-transformation is algorithm/mode/padding. You must specify the algorithm, mode, and padding. When the algorithm does not require a mode, use NONE. When the algorithm does not require padding, use NoPadding.

DS servers encrypt data using symmetric keys. Servers generate symmetric keys when needed and store them, encrypted with the shared master key, with the data they encrypt. As long as servers have the same shared master key, any server can recover symmetric keys needed to decrypt data.

Symmetric keys for (deprecated) reversible password storage schemes are the exception to this rule. When you configure a reversible password storage scheme, enable the adminRoot backend, and configure a replication domain for cn=admin data.

You can enable confidentiality by backend index, as long as confidentiality is enabled for the backend itself. Confidentiality hashes keys for equality type indexes using SHA-1. It encrypts the list of entries matching a substring key for substring indexes. The following example shows how to enable confidentiality for the mail index:

$ dsconfig \
 set-backend-index-prop \
 --hostname localhost \
 --port 4444 \
 --bindDn uid=admin \
 --bindPassword password \
 --backend-name dsEvaluation \
 --index-name mail \
 --set confidentiality-enabled:true \
 --no-prompt \
 --usePkcs12TrustStore /path/to/opendj/config/keystore \
 --trustStorePassword:file /path/to/opendj/config/keystore.pin

After changing the index configuration, rebuild the index to enforce confidentiality immediately.

Confidentiality cannot be enabled for VLV indexes. Avoid using sensitive attributes in VLV indexes.

When reading files for an encrypted backend database, be aware that although user data is kept confidential, the following are not encrypted on disk:

  • Existing backend database files.

    The server encrypts backend database content only when it is next written. If you must make sure that all relevant data are encrypted, export the data to LDIF and then import the data again.

  • The dn2id index and its keys.

  • Substring index keys.

    Substring index values are encrypted.

Encrypting and decrypting data require cryptographic processing that reduces throughput, and extra space for larger encrypted values. Tests with default settings show that the cost of enabling confidentiality can be quite modest. Your results can vary based on the host system hardware, the JVM, and the settings for cipher-transformation and cipher-key-length. Make sure you test your deployment to qualify the impact of confidentiality before changing settings in production.