why the key and iv did't convert to byte array?

[liugt34]

thank u for this nice project! i have some questions,can u explain ，than u very much!

in this code

EntityFrameworkCore.PostgreSQL.ColumnEncryption/AltairCA.EntityFrameworkCore.PostgreSQL.ColumnEncryption/Functions/AltairCAFunctionImplementation.cs

Line 138 in 99acc97

var convertToBytea = _expressionFactory.Convert(value, typeof(byte[]));

this is the pgcrypto function

encrypt_iv(data bytea, key bytea, iv bytea, type text) returns bytea

i find the data is bytea, the key and iv are also bytea, but in the code ,why only convert data to bytea, and the key ,iv is still string