Algorithm RSA

Question

Hi,
Since the 1 of January, 2011 all portuguese invoices must be signed up digitally and registered.
We have come up to the following solution:
With the help of OPENSSL generate a private key:
  OPENSSL GENRSA -OUT privatekey.PEM 1024
It must fulfill the following requisites of RSA algorithm:
-> Format = x.509
-> Charset = UTF-8
-> Encoding = Base-64
-> Endianess = Little Endian
-> OAEP Padding = PKCS1 v1.5 padding
-> Length private key = 1024 bytes
-> Mensage Format Hash  = SHA-1
Then on the basis of the private key a public key should be generated:
    OPENSSL RSA -IN privatekey.PEM - OUT publickey.PEM -OUTFORM PEM -PUBOUT
With the help pf the HOST command I create the signatures for the invoice registry:
cmd> echo TEXT.TXT | openssl dgst -sha1 -sign privatekey.pem | openssl enc -base64
where the file TEXT.TXT is: "2010-05-18;2010-05-18T11:22:19;FAC 001/14;3.12;"
It has been an horrible, but efficient solution.
It functions well when you register an invoice, but it gets complicated when you want to verify if the signatures are correct.
Reasons:
- You have to filter all the documents and all the registries must execute the Host command in the background.
  The command will open and create files for each verification.
  When you delete these files it continues in the registry...
What I´m asking is whether there is a better, more efficient way to generate signatures in pl/sql as well as their verification?
Regards
Jomar

Answer 1

Hi Jomar,
correct me if I'm wrong, but from your post it looks like what you are doing is capturing the ouput from an OS command to manipulate within the database. If you search this forum or google for something like "execute OS command from PL/SQL" you will get lots of hits. Also, have you searched to see if there is a java based equivalent to openssl which could be compiled in and called from the Oracle database.
Andre