EncryptByCert Problem

I posted this message to the wrong group (sqlserver.programming), so I'm
reposting here. Sorry for the repost... it's late... so here goes:

OK, so I'm testing EncryptByCert with some code like the following:

DECLARE @v varchar(8000);
SELECT @v = REPLICATE('A', 117);
SELECT @v;
DECLARE @e varbinary(8000);
SELECT @e = EncryptByCert(Cert_ID(N'TestCertificate'), @v);
SELECT @e;

The function encrypts fine and I'm able to use DecryptByCert to get the
result. Problem is if I change the line SELECT @v = REPLICATE('A', 117) to:

SELECT @v = REPLICATE('A', 118);

The EncryptByCert function returns NULL every time with 118 or higher. BOL
states that the result is returned as a varbinary with a max length of
8,000. I keep getting a varbinary with a max length of 128. Can anyone
else reproduce this, or am I doing something wrong?

Thanks


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