mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-24 00:22:29 +00:00
405 lines
14 KiB
Markdown
405 lines
14 KiB
Markdown
---
|
||
slug: /en/sql-reference/functions/encryption-functions
|
||
sidebar_position: 67
|
||
sidebar_label: Encryption
|
||
title: "Encryption functions"
|
||
---
|
||
|
||
These functions implement encryption and decryption of data with AES (Advanced Encryption Standard) algorithm.
|
||
|
||
Key length depends on encryption mode. It is 16, 24, and 32 bytes long for `-128-`, `-196-`, and `-256-` modes respectively.
|
||
|
||
Initialization vector length is always 16 bytes (bytes in excess of 16 are ignored).
|
||
|
||
Note that these functions work slowly until ClickHouse 21.1.
|
||
|
||
## encrypt
|
||
|
||
This function encrypts data using these modes:
|
||
|
||
- aes-128-ecb, aes-192-ecb, aes-256-ecb
|
||
- aes-128-cbc, aes-192-cbc, aes-256-cbc
|
||
- aes-128-ofb, aes-192-ofb, aes-256-ofb
|
||
- aes-128-gcm, aes-192-gcm, aes-256-gcm
|
||
- aes-128-ctr, aes-192-ctr, aes-256-ctr
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
encrypt('mode', 'plaintext', 'key' [, iv, aad])
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `mode` — Encryption mode. [String](../../sql-reference/data-types/string.md#string).
|
||
- `plaintext` — Text thats need to be encrypted. [String](../../sql-reference/data-types/string.md#string).
|
||
- `key` — Encryption key. [String](../../sql-reference/data-types/string.md#string).
|
||
- `iv` — Initialization vector. Required for `-gcm` modes, optinal for others. [String](../../sql-reference/data-types/string.md#string).
|
||
- `aad` — Additional authenticated data. It isn't encrypted, but it affects decryption. Works only in `-gcm` modes, for others would throw an exception. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Returned value**
|
||
|
||
- Ciphertext binary string. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Examples**
|
||
|
||
Create this table:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
CREATE TABLE encryption_test
|
||
(
|
||
`comment` String,
|
||
`secret` String
|
||
)
|
||
ENGINE = Memory;
|
||
```
|
||
|
||
Insert some data (please avoid storing the keys/ivs in the database as this undermines the whole concept of encryption), also storing 'hints' is unsafe too and used only for illustrative purposes:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
INSERT INTO encryption_test VALUES('aes-256-ofb no IV', encrypt('aes-256-ofb', 'Secret', '12345678910121314151617181920212')),\
|
||
('aes-256-ofb no IV, different key', encrypt('aes-256-ofb', 'Secret', 'keykeykeykeykeykeykeykeykeykeyke')),\
|
||
('aes-256-ofb with IV', encrypt('aes-256-ofb', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv')),\
|
||
('aes-256-cbc no IV', encrypt('aes-256-cbc', 'Secret', '12345678910121314151617181920212'));
|
||
```
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT comment, hex(secret) FROM encryption_test;
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─comment──────────────────────────┬─hex(secret)──────────────────────┐
|
||
│ aes-256-ofb no IV │ B4972BDC4459 │
|
||
│ aes-256-ofb no IV, different key │ 2FF57C092DC9 │
|
||
│ aes-256-ofb with IV │ 5E6CB398F653 │
|
||
│ aes-256-cbc no IV │ 1BC0629A92450D9E73A00E7D02CF4142 │
|
||
└──────────────────────────────────┴──────────────────────────────────┘
|
||
```
|
||
|
||
Example with `-gcm`:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
INSERT INTO encryption_test VALUES('aes-256-gcm', encrypt('aes-256-gcm', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv')), \
|
||
('aes-256-gcm with AAD', encrypt('aes-256-gcm', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv', 'aad'));
|
||
|
||
SELECT comment, hex(secret) FROM encryption_test WHERE comment LIKE '%gcm%';
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─comment──────────────┬─hex(secret)──────────────────────────────────┐
|
||
│ aes-256-gcm │ A8A3CCBC6426CFEEB60E4EAE03D3E94204C1B09E0254 │
|
||
│ aes-256-gcm with AAD │ A8A3CCBC6426D9A1017A0A932322F1852260A4AD6837 │
|
||
└──────────────────────┴──────────────────────────────────────────────┘
|
||
```
|
||
|
||
## aes_encrypt_mysql
|
||
|
||
Compatible with mysql encryption and resulting ciphertext can be decrypted with [AES_DECRYPT](https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-decrypt) function.
|
||
|
||
Will produce the same ciphertext as `encrypt` on equal inputs. But when `key` or `iv` are longer than they should normally be, `aes_encrypt_mysql` will stick to what MySQL's `aes_encrypt` does: 'fold' `key` and ignore excess bits of `iv`.
|
||
|
||
Supported encryption modes:
|
||
|
||
- aes-128-ecb, aes-192-ecb, aes-256-ecb
|
||
- aes-128-cbc, aes-192-cbc, aes-256-cbc
|
||
- aes-128-ofb, aes-192-ofb, aes-256-ofb
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
aes_encrypt_mysql('mode', 'plaintext', 'key' [, iv])
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `mode` — Encryption mode. [String](../../sql-reference/data-types/string.md#string).
|
||
- `plaintext` — Text that needs to be encrypted. [String](../../sql-reference/data-types/string.md#string).
|
||
- `key` — Encryption key. If key is longer than required by mode, MySQL-specific key folding is performed. [String](../../sql-reference/data-types/string.md#string).
|
||
- `iv` — Initialization vector. Optional, only first 16 bytes are taken into account [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Returned value**
|
||
|
||
- Ciphertext binary string. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Examples**
|
||
|
||
Given equal input `encrypt` and `aes_encrypt_mysql` produce the same ciphertext:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT encrypt('aes-256-ofb', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv') = aes_encrypt_mysql('aes-256-ofb', 'Secret', '12345678910121314151617181920212', 'iviviviviviviviv') AS ciphertexts_equal;
|
||
```
|
||
|
||
Result:
|
||
|
||
```
|
||
┌─ciphertexts_equal─┐
|
||
│ 1 │
|
||
└───────────────────┘
|
||
```
|
||
|
||
But `encrypt` fails when `key` or `iv` is longer than expected:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT encrypt('aes-256-ofb', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123');
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
Received exception from server (version 22.6.1):
|
||
Code: 36. DB::Exception: Received from localhost:9000. DB::Exception: Invalid key size: 33 expected 32: While processing encrypt('aes-256-ofb', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123').
|
||
```
|
||
|
||
While `aes_encrypt_mysql` produces MySQL-compatitalbe output:
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT hex(aes_encrypt_mysql('aes-256-ofb', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123')) AS ciphertext;
|
||
```
|
||
|
||
Result:
|
||
|
||
```text
|
||
┌─ciphertext───┐
|
||
│ 24E9E4966469 │
|
||
└──────────────┘
|
||
```
|
||
|
||
Notice how supplying even longer `IV` produces the same result
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT hex(aes_encrypt_mysql('aes-256-ofb', 'Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456')) AS ciphertext
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─ciphertext───┐
|
||
│ 24E9E4966469 │
|
||
└──────────────┘
|
||
```
|
||
|
||
Which is binary equal to what MySQL produces on same inputs:
|
||
|
||
``` sql
|
||
mysql> SET block_encryption_mode='aes-256-ofb';
|
||
Query OK, 0 rows affected (0.00 sec)
|
||
|
||
mysql> SELECT aes_encrypt('Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456') as ciphertext;
|
||
+------------------------+
|
||
| ciphertext |
|
||
+------------------------+
|
||
| 0x24E9E4966469 |
|
||
+------------------------+
|
||
1 row in set (0.00 sec)
|
||
```
|
||
|
||
## decrypt
|
||
|
||
This function decrypts ciphertext into a plaintext using these modes:
|
||
|
||
- aes-128-ecb, aes-192-ecb, aes-256-ecb
|
||
- aes-128-cbc, aes-192-cbc, aes-256-cbc
|
||
- aes-128-ofb, aes-192-ofb, aes-256-ofb
|
||
- aes-128-gcm, aes-192-gcm, aes-256-gcm
|
||
- aes-128-ctr, aes-192-ctr, aes-256-ctr
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
decrypt('mode', 'ciphertext', 'key' [, iv, aad])
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `mode` — Decryption mode. [String](../../sql-reference/data-types/string.md#string).
|
||
- `ciphertext` — Encrypted text that needs to be decrypted. [String](../../sql-reference/data-types/string.md#string).
|
||
- `key` — Decryption key. [String](../../sql-reference/data-types/string.md#string).
|
||
- `iv` — Initialization vector. Required for `-gcm` modes, optinal for others. [String](../../sql-reference/data-types/string.md#string).
|
||
- `aad` — Additional authenticated data. Won't decrypt if this value is incorrect. Works only in `-gcm` modes, for others would throw an exception. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Returned value**
|
||
|
||
- Decrypted String. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Examples**
|
||
|
||
Re-using table from [encrypt](#encrypt).
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT comment, hex(secret) FROM encryption_test;
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─comment──────────────┬─hex(secret)──────────────────────────────────┐
|
||
│ aes-256-gcm │ A8A3CCBC6426CFEEB60E4EAE03D3E94204C1B09E0254 │
|
||
│ aes-256-gcm with AAD │ A8A3CCBC6426D9A1017A0A932322F1852260A4AD6837 │
|
||
└──────────────────────┴──────────────────────────────────────────────┘
|
||
┌─comment──────────────────────────┬─hex(secret)──────────────────────┐
|
||
│ aes-256-ofb no IV │ B4972BDC4459 │
|
||
│ aes-256-ofb no IV, different key │ 2FF57C092DC9 │
|
||
│ aes-256-ofb with IV │ 5E6CB398F653 │
|
||
│ aes-256-cbc no IV │ 1BC0629A92450D9E73A00E7D02CF4142 │
|
||
└──────────────────────────────────┴──────────────────────────────────┘
|
||
```
|
||
|
||
Now let's try to decrypt all that data.
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT comment, decrypt('aes-256-cfb128', secret, '12345678910121314151617181920212') as plaintext FROM encryption_test
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─comment──────────────┬─plaintext──┐
|
||
│ aes-256-gcm │ OQ<4F>E
|
||
<20>t<EFBFBD>7T<37>\<5C><><EFBFBD>\<5C> │
|
||
│ aes-256-gcm with AAD │ OQ<4F>E
|
||
<20>\<5C><>si<73><69><EFBFBD><EFBFBD>;<3B>o<EFBFBD><6F> │
|
||
└──────────────────────┴────────────┘
|
||
┌─comment──────────────────────────┬─plaintext─┐
|
||
│ aes-256-ofb no IV │ Secret │
|
||
│ aes-256-ofb no IV, different key │ <20>4<EFBFBD>
|
||
<20> │
|
||
│ aes-256-ofb with IV │ <20><><EFBFBD>6<EFBFBD>~ │
|
||
│aes-256-cbc no IV │ <20>2*4<>h3c<33>4w<34><77>@
|
||
└──────────────────────────────────┴───────────┘
|
||
```
|
||
|
||
Notice how only a portion of the data was properly decrypted, and the rest is gibberish since either `mode`, `key`, or `iv` were different upon encryption.
|
||
|
||
## tryDecrypt
|
||
|
||
Similar to `decrypt`, but returns NULL if decryption fails because of using the wrong key.
|
||
|
||
**Examples**
|
||
|
||
Let's create a table where `user_id` is the unique user id, `encrypted` is an encrypted string field, `iv` is an initial vector for decrypt/encrypt. Assume that users know their id and the key to decrypt the encrypted field:
|
||
|
||
```sql
|
||
CREATE TABLE decrypt_null (
|
||
dt DateTime,
|
||
user_id UInt32,
|
||
encrypted String,
|
||
iv String
|
||
) ENGINE = Memory;
|
||
```
|
||
|
||
Insert some data:
|
||
|
||
```sql
|
||
INSERT INTO decrypt_null VALUES
|
||
('2022-08-02 00:00:00', 1, encrypt('aes-256-gcm', 'value1', 'keykeykeykeykeykeykeykeykeykey01', 'iv1'), 'iv1'),
|
||
('2022-09-02 00:00:00', 2, encrypt('aes-256-gcm', 'value2', 'keykeykeykeykeykeykeykeykeykey02', 'iv2'), 'iv2'),
|
||
('2022-09-02 00:00:01', 3, encrypt('aes-256-gcm', 'value3', 'keykeykeykeykeykeykeykeykeykey03', 'iv3'), 'iv3');
|
||
```
|
||
|
||
Query:
|
||
|
||
```sql
|
||
SELECT
|
||
dt,
|
||
user_id,
|
||
tryDecrypt('aes-256-gcm', encrypted, 'keykeykeykeykeykeykeykeykeykey02', iv) AS value
|
||
FROM decrypt_null
|
||
ORDER BY user_id ASC
|
||
```
|
||
|
||
Result:
|
||
|
||
```
|
||
┌──────────────────dt─┬─user_id─┬─value──┐
|
||
│ 2022-08-02 00:00:00 │ 1 │ ᴺᵁᴸᴸ │
|
||
│ 2022-09-02 00:00:00 │ 2 │ value2 │
|
||
│ 2022-09-02 00:00:01 │ 3 │ ᴺᵁᴸᴸ │
|
||
└─────────────────────┴─────────┴────────┘
|
||
```
|
||
|
||
## aes_decrypt_mysql
|
||
|
||
Compatible with mysql encryption and decrypts data encrypted with [AES_ENCRYPT](https://dev.mysql.com/doc/refman/8.0/en/encryption-functions.html#function_aes-encrypt) function.
|
||
|
||
Will produce same plaintext as `decrypt` on equal inputs. But when `key` or `iv` are longer than they should normally be, `aes_decrypt_mysql` will stick to what MySQL's `aes_decrypt` does: 'fold' `key` and ignore excess bits of `IV`.
|
||
|
||
Supported decryption modes:
|
||
|
||
- aes-128-ecb, aes-192-ecb, aes-256-ecb
|
||
- aes-128-cbc, aes-192-cbc, aes-256-cbc
|
||
- aes-128-cfb128
|
||
- aes-128-ofb, aes-192-ofb, aes-256-ofb
|
||
|
||
**Syntax**
|
||
|
||
``` sql
|
||
aes_decrypt_mysql('mode', 'ciphertext', 'key' [, iv])
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `mode` — Decryption mode. [String](../../sql-reference/data-types/string.md#string).
|
||
- `ciphertext` — Encrypted text that needs to be decrypted. [String](../../sql-reference/data-types/string.md#string).
|
||
- `key` — Decryption key. [String](../../sql-reference/data-types/string.md#string).
|
||
- `iv` — Initialization vector. Optinal. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Returned value**
|
||
|
||
- Decrypted String. [String](../../sql-reference/data-types/string.md#string).
|
||
|
||
**Examples**
|
||
|
||
Let's decrypt data we've previously encrypted with MySQL:
|
||
|
||
``` sql
|
||
mysql> SET block_encryption_mode='aes-256-ofb';
|
||
Query OK, 0 rows affected (0.00 sec)
|
||
|
||
mysql> SELECT aes_encrypt('Secret', '123456789101213141516171819202122', 'iviviviviviviviv123456') as ciphertext;
|
||
+------------------------+
|
||
| ciphertext |
|
||
+------------------------+
|
||
| 0x24E9E4966469 |
|
||
+------------------------+
|
||
1 row in set (0.00 sec)
|
||
```
|
||
|
||
Query:
|
||
|
||
``` sql
|
||
SELECT aes_decrypt_mysql('aes-256-ofb', unhex('24E9E4966469'), '123456789101213141516171819202122', 'iviviviviviviviv123456') AS plaintext
|
||
```
|
||
|
||
Result:
|
||
|
||
``` text
|
||
┌─plaintext─┐
|
||
│ Secret │
|
||
└───────────┘
|
||
```
|
||
|