topic Re: Problem with the sha256() function in New SAS User

Problem with the sha256() function

Charlotte37 — Mon, 21 Oct 2019 09:38:22 GMT

Hello,

Below, my data step :

data test;

length c2 $ 64 c1 $ 64;

format c2 $hex64. c1 $hex64.;

c1=sha256('8811421');

c2=sha256('8811531');

run;

I don't understand why c1 is null while c2 is ok.

C2 = 327B1D31BCEC3EAF555B0FB984ABFBC21C564E7D7B4C21D032DE47E62534BB12

Can you help me ?

Thanks,

Re: Problem with the sha256() function

andreas_lds — Mon, 21 Oct 2019 10:52:50 GMT

There must an error in your code, please check the log. When i execute the data-step you posted (two put-statements added), i get:

c1=005CF1E3EAA9EF7AC87EDA95C3EED5752D273FA165519753A37A855D7DBE8B7E
c2=327B1D31BCEC3EAF555B0FB984ABFBC21C564E7D7B4C21D032DE47E62534BB12

Re: Problem with the sha256() function

Amir — Mon, 21 Oct 2019 11:03:41 GMT

It might be a display issue, as per:

https://communities.sas.com/t5/SAS-Programming/SHA256-does-not-generate-the-same-length-of-encryption/td-p/367265

As can be seen in the response from @andreas_lds to your post, c1 starts with 00, which is also highlighted in the link above.

Try putting the values to the log, rather than viewing the data set and see if that helps, as per the link.

Regards,

Amir.

Re: Problem with the sha256() function

Charlotte37 — Mon, 21 Oct 2019 11:23:51 GMT

Thanks for your feedback. Indeed, with a "Put", I see my hash key

Re: Problem with the sha256() function

Charlotte37 — Mon, 21 Oct 2019 11:26:44 GMT

I use the hash key in 2 tables to compare and find differences between the tables.
How to make the join between the 2 tables on the hash key if sometimes she is empty?

Re: Problem with the sha256() function

Amir — Mon, 21 Oct 2019 11:33:44 GMT

The full hash value should always be there in the table, this is just a display issue.

Comparisons using program code will compare the full hash values held, not the values displayed.

Regards,

Amir.

Re: Problem with the sha256() function

andreas_lds — Mon, 21 Oct 2019 14:16:47 GMT

@Charlotte37 wrote:

I use the hash key in 2 tables to compare and find differences between the tables.
How to make the join between the 2 tables on the hash key if sometimes she is empty?

Just to underline what @Amir already said: the value is the table, and joining/merging etc. work as intended. Can you show as the code not generating the expected result? If the lengths of the variables you use in sha256 are not the same, you will get different results, even if the shown values are the same - in sas all char-variables are padded with blanks. To avoid this, use

hash = sha256(trim(original));

Re: Problem with the sha256() function

Charlotte37 — Mon, 21 Oct 2019 18:35:29 GMT

Thanks