SQL & PL/SQL

Hi All,

I am trying to generate a HMAC-Sh256 signature using PLSQL but it's not working and I keep on getting signature mismatch error when I try to use the final generated signature.

Here is the sample code
declare

v_oauth_consumer_key varchar2(200) := 'testKey';
v_oauth_consumer_secret varchar2(200) := 'testSecret';
v_oauth_token varchar2(500);
v_oauth_secret varchar2(500);

v_oauth_signature_method varchar2(50) := urlencode ('HMAC-SHA256');
v_oauth_version varchar2(5) := urlencode ('1.0');

v_oauth_timestamp VARCHAR2 (100);
v_oauth_nonce VARCHAR2 (500);
v_oauth_base_string VARCHAR2 (2000);
-- v_oauth_key VARCHAR2 (500);
v_sig_mac RAW (2000);
v_base64_sig_mac VARCHAR2 (100);

v_random VARCHAR2(15);

v_oauth_header varchar2(4000);

v_token_ws_url varchar2(200) := 'https://account.api.here.com/oauth2/token';

v_clob CLOB;
l_param_names apex_application_global.vc_arr2;
l_param_values apex_application_global.vc_arr2;
begin
-- v_oauth_key := v_oauth_consumer_key || '&' || v_oauth_consumer_secret;

-- random oauth_nonce
select dbms_random.string('A', 15) into v_random from dual;

select urlencode(utl_encode.base64_encode(utl_I18N.string_to_raw(v_random, 'AL32UTF8'))) into v_oauth_nonce from dual;

select urlencode((SYSDATE - TO_DATE ('01-01-1970', 'DD-MM-YYYY')) * 86400) into v_oauth_timestamp from dual;

v_oauth_base_string := 'POST' || '&' || urlencode(v_token_ws_url)
|| '&' || urlencode (
'oauth_consumer_key' || '=' || v_oauth_consumer_key
|| '&' || 'oauth_nonce' || '=' || v_oauth_nonce
|| '&' || 'oauth_signature_method' || '=' || v_oauth_signature_method
|| '&' || 'oauth_timestamp' || '=' || v_oauth_timestamp
|| '&' || 'oauth_version' || '=' || v_oauth_version);

dbms_output.put_line('OAuthBaseString : ' || v_oauth_base_string);

v_sig_mac := DBMS_CRYPTO.mac (src => UTL_I18N.string_to_raw (v_oauth_base_string, 'AL32UTF8'),
typ => DBMS_CRYPTO.HMAC_SH256, 
key => UTL_I18N.string_to_raw (v_oauth_consumer_secret, 'AL32UTF8')
);
dbms_output.put_line('SigMac: ' ||v_sig_mac);

v_base64_sig_mac := UTL_RAW.cast_to_varchar2 (UTL_ENCODE.base64_encode (v_sig_mac));

dbms_output.put_line('Base64Mac: ' ||v_base64_sig_mac);

v_oauth_header := 'OAuth oauth_consumer_key="'||v_oauth_consumer_key||'",'||'oauth_signature_method="'||v_oauth_signature_method||'",'||'oauth_timestamp="'|| v_oauth_timestamp || '",'|| 'oauth_nonce="' || v_oauth_nonce || '",'||'oauth_version="' || v_oauth_version || '",'||'oauth_signature="' || urlencode (v_base64_sig_mac) || '"';

dbms_output.put_line(v_oauth_header);

Can someone suggest what am I doing wrong?

I generated similar signature for twitter api but it has both consumer token secret and token secret, but in case of here maps, I only have consumer key and consumer secret.

Thanks