Annex 1: Bank Link technical specifications - LHV Pank

2/2- VK_MAC 700 Verification code, i.e. signature3.3 Response query 3002The user’s ID and the date and time of package generation are submitted tothe Merchant. The VK_INFO field contains the name/value pairs, separatedwith semicolons: "NAME:value" (e.g. "PERSON:37508166516;NAME:JAANSAAR"). For security reasons, the Merchant must check the time of thepackage submission (VK_DATE and VK_TIME).NO FIELD DIGITS DESCRIPTION1 VK_SERVICE 4 Service number (3002)2 VK_VERSION 3 Crypto algorithm used (008)3 VK_USER 16 N/A4 VK_DATE 10 Date of package generation(DD.MM.YYYY)5 VK_TIME 8 Time of package generation(HH24:MM:SS)6 VK_SND_ID 15 Query submitter’s ID (Bank’s ID)7 VK_INFO 300 Field containing user’s personaldata- VK_CHARSET 12 ISO-8859-1 (default), UTF-8 orWINDOWS-1257- VK_MAC 700 Verification code, i.e. signature3.4 Authentication query 4002The package submitted by Merchant for the user’s identification, with randomnonss.NO FIELD DIGITS DESCRIPTION1 VK_SERVICE 4 Service number (4002)2 VK_VERSION 3 Crypto algorithm used (008)3 VK_SND_ID 15 Query submitter’s ID (Merchant’sID)4 VK_REC_ID 15 Query submitter’s ID (Bank’s ID)5 VK_NONCE 50 Random nonss generated byquery submitter6 VK_RETURN 60 URL for transaction responsequery- VK_CHARSET 12 ISO-8859-1 (default), UTF-8 orWINDOWS-1257- VK_MAC 700 Verification code, i.e. signature4. PUBLIC KEYS4.1 LHV accepts certificate queries or self-signed certificates. Public keys areexchanged upon conclusion of the agreement. We apply X.509-compliant.PEM-format keys/certificates – i.e. the content is in BASE64 encoding and fitbetween ––BEGIN… –– and ––END… –– tags. The private key generated bythe Customer must be at least 1,024 bits.4.2 The keys can be generated via the openssl utility. We recommendadhering to the following:(i)(ii)(iii)Signature algorithm - sha1RSAPublic key – RSA (1024 Bits)Validity: not more than 10 years5. FINDING THE VERIFICATION CODE VK_MAC5.1 VK_MAC, the electronic signature used in the queries, is calculated basedon a previously agreed algorithm. The algorithm version is determined by thequery parameter VK_VERSION. Only version 008 is currently applied. Thesignature VK_MAC is sent in BASE64 encoding, VK_MAC(MAC008) iscalculated by using the public key algorithm and the secure hashing algorithmSHA-1. MAC008(x1,x2,…,xn) := RSA( SHA-1(p(x1)|| x1|| p(x2)|| x2 || … ||p(xn )||xn), d, n)(i)(ii)(iii)(iv)(v)x1, x2, …, xn are the query parametersp is a function of the length of the parameter in bytes. The length is formattedto a three-digit string. Thus, length 1 ' "001". Empty fields have a length of"000".d is the RSA secret exponentn on RSA modulus|| - adding-up of stringsAS LHV PANKTARTU MNT 2, 10145 TALLINN 6 800 400 INFO@LHV.EE