I am working on EMV technology and trying to decrypt ISSUER PUBLIC KEY CERTIFICATE. As per my understanding about CA Certificate, certificate contain Issuer Public key inside it. CA authority keep data along with public key and encrypt this all with its PRIVATE KEY.
EMV BOOK 2 Table 6: Format of Data Recovered from Issuer Public Key Certificate,
This above table Define certificate format. it means if I will decrypt the certificate from CA public key, we could get the data in the format specified in table -6.
On the internet I found BP-TOOL which doing this kind of activity and very similar what I want to get. sharing here BP-Tool example:- DDA: Issuer Public Key Recovery
CA PK Modulus:
BE9E1FA5E9A803852999C4AB432DB28600DCD9DAB76DFAAA47355A0FE37B1508AC6BF38860D3C6C2E5B12A3CAAF2A7005A7241EBAA7771112C74CF9A0634652FBCA0E5980C54A64761EA101A114E0F0B5572ADD57D010B7C9C887E104CA4EE1272DA66D997B9A90B5A6D624AB6C57E73C8F919000EB5F684898EF8C3DBEFB330C62660BED88EA78E909AFF05F6DA627B
Issuer's Public Key Certificate:
7F4C6034C33BF35BAFFF53F51C0F8A2B32C8FDE1D033DDB69DCA85C5B4797BD2F55BE970C026B75B76E9C17E8564111FDEB97B26E350F59F6C63C30B0BD80E33123DF73CF8F87B28D54D28E4D6284F44E6E61AD95826474EBF6C28796B9B222DF14194A539E92DB185D86D8EDDD8AA01ECBE93E0EC3F87383D879534FE0BD397D7D59FC6E37012258B894400EE715338
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Recovered Data: 6A02457896FF12170314EF01019001E04E4FC478A42241068E2C9CFDEE9D7450F48F812FA66CEFB8ECBE31DD3C26C3B8A3891B77C1AA2A5A7448B869B7213D36C341E9B71302ADF478F67537032C080186C44034B1801D7644B6EEFAEA566D7336A8C83F42B7992F28BF5EA6B9D14C05870AD4DBD8CDAB8771F65F83D800B353B11E1805C7E4529F261C16A38DE756BC
Data Header: 6A
Data Format: 02
Issuer Identifier: 457896FF
Certificate Expiration Date: 1217
Certificate Serial Number: 0314EF
Hash Algorithm Indicator: 01
Issuer Public Key Algorithm Indicator: 01
Issuer Public Key Length: 90
Issuer Public Key Exponent Length: 01
Issuer Public Key: E04E4FC478A42241068E2C9CFDEE9D7450F48F812FA66CEFB8ECBE31DD3C26C3B8A3891B77C1AA2A5A7448B869B7213D36C341E9B71302ADF478F67537032C080186C44034B1801D7644B6EEFAEA566D7336A8C83F42B7992F28BF5EA6B9D14C05870AD4DBD8CDAB8771F65F
Hash Result: 83D800B353B11E1805C7E4529F261C16A38DE756
Data Trailer: BC
I think here RSA decyption is took place, could anybody tell me algorithm/concept used in this above example. Is this a simple decryption where certificate is decrypting using modulus???? Is there any online tool which is good for this kind of calculation.
Actually i am facing problem to import certificate in my HSM, I want to check the data is coming from CA is correct or not, it is as per standard (table -6 ) or not.
Any suggestion would a lot for me..
Thanks in advance...