1686
MySQLERRORNotableFunctionsHIGH confidence
The initialization vector supplied to aes_encrypt is too short
Production Risk
Medium — encryption calls fail; data is not stored or returned.
What this means
AES_ENCRYPT() or AES_DECRYPT() received an initialization vector (IV) that is shorter than 16 bytes, which is required for CBC, CFB, and OFB block cipher modes.
Why it happens
- 1IV string passed to AES_ENCRYPT/AES_DECRYPT is fewer than 16 characters/bytes.
- 2Using a block cipher mode that requires an IV without providing a full-length IV.
How to reproduce
trigger — this will error
trigger — this will error
SELECT AES_ENCRYPT('secret', 'key', 'short_iv');expected output
ERROR 1686 (HY000): The initialization vector supplied to aes_encrypt is too short. Must be at least 16 bytes long.
Fix
Provide a 16-byte IV
Provide a 16-byte IV
SELECT AES_ENCRYPT('secret', 'mykey_32bytes___', RANDOM_BYTES(16));Why this works
RANDOM_BYTES(16) generates a cryptographically random 16-byte IV of the correct length.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1686 ER_AES_INVALID_IV
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