How to get digital signature for Google Map geocoding V3 in PL/SQL?

Question

Hi, Gurus:
    Could anyone provide me an example about how to generate digital signature for Google Maps service v3 in PL/SQL? We tried to upgrade our program using Google maps service from v2 to v3. We are using PL/SQl on background to send request to Google for geocoding. We found some sample code to register with digital signature, but none of them is based on PL/SQl. Notice I used Google business client ID "gme-XXX" and wallet.
https://developers.google.com/maps/documentation/business/webservices/auth#digital_signatures
Google Maps API - more URL signing samples
Here is my code for V2. I notice in order to get signature, I need to use HMAC-SHA1 algorithm.
procedure Get_Geocoding(P_s_Address in varchar2, P_s_Geocoding out varchar2, P_n_accuracy out number, P_b_success out boolean) is
  l_address varchar2(4000);
  l_url varchar2(32000);
  l_response varchar2(3200);
  n_first_comma number;
  n_second_comma number;
  n_level_length number;
BEGIN
  /* TODO implementation required */
  l_address:=APEX_UTIL.URL_ENCODE(P_s_Address);
  l_address := replace(l_address,' ','+');
  l_url := 'http://maps.google.com/maps/geo?q='||l_address||'&'||'output=csv'||'&'||'client=gme-XXX';
l_response := utl_http.request(l_url, APEX_APPLICATION.G_PROXY_SERVER, '/u02/app/oracle/admin/apexsb/wallet', 'XXXXXXXX');
  n_level_length:=0;
  n_first_comma:=instr(l_response,',',1,1);
  n_second_comma:=instr(l_response,',',1,2);
  n_level_length:=n_second_comma-n_first_comma-1;
  P_n_accuracy:=0;
  if n_level_length>0 then
  P_n_accuracy:=to_number(substr(l_response,n_first_comma+1, n_level_length));
  end if;
  l_response:=substr(l_response,instr(l_response,',',1,2)+1);
  --dbms_output.put_line('In function: l_response ='||l_response);
  P_s_Geocoding:=l_response;
  if (P_s_Geocoding<>'0,0') then
  P_b_success:=true;
  --dbms_output.put_line('true');
  else
  P_b_success:=false;
  --dbms_output.put_line('false');
  end if;
END;
Thanks!

Answer 1

Hi, guys:
    I tried to generate digital signature for Google map service
     Maps for Business: Generating Valid Signatures - YouTube
    Generating an HMAC-SHA-1 Signature Using Only PL/SQL
      OAuth and the PL/SQL | Data Warehouse in the Cloud
   but I got error message from Google:
Unable to authenticate the request. Provided 'signature' is not valid for the provided client ID. Learn more: https://developers.google.com/maps/documentation/business/webservices/auth
   I think there is something wrong with my code to generate signature, as if I remove the part regarding client and signature, it will work, can anyone help me on this problem?
/*Procedure Get_Geocoding is used to get geocoding with accuracy level for V3 business account, you can find Google map digital signature descrirption from
https://developers.google.com/maps/documentation/business/webservices/auth#digital_signatures
if geocoding is 0,0, procedure returns false to indicate failure of get geocoding*/
procedure Get_Geocoding2(P_s_Address in varchar2, P_s_Geocoding out varchar2, P_n_accuracy out number, P_b_success out boolean) is
  --private key for Google business account, this is provided by Google with client name.
  l_private_key_src varchar2(200):='xxxxxxxxxxxxxxxxxxx';
  l_private_key_b64_alter varchar2(200):= translate(l_private_key_src,'-_','+/');
  l_private_key_bin raw(2000);
  l_client_name varchar2(100):='gme-xxx';
  l_signature_mac raw(2000);
  l_signature_b64 varchar2(200);
  l_signature_b64_alter_back varchar2(200);
  l_Google_service_domain varchar2(200):='http://maps.googleapis.com';
  l_address varchar2(4000);
  l_url varchar2(32000);
  l_path varchar2(32000);
  l_response varchar2(32000);
  l_page UTL_HTTP.HTML_PIECES;
  n_actual_length number;
  json_obj json;
  json_tempobj json;
  jl_listOfValues json_list;
  json_geom_obj json;
  json_loc json;
  l_lat  VARCHAR2(40);
  l_lng  VARCHAR2(40);
  l_status VARCHAR2(255);
  json_accuracy json;
  --temp_string varchar2(10000);
  n_first_comma number;
  n_second_comma number;
  n_level_length number;
  BEGIN
/* TODO implementation required */
l_private_key_bin := utl_encode.base64_decode(UTL_I18N.string_to_raw(l_private_key_b64_alter, 'AL32UTF8'));
l_address:=APEX_UTIL.URL_ENCODE(P_s_Address);
--dbms_output.put_line(l_address);
l_address := replace(l_address,' ','+');
l_path := '/maps/api/geocode/json?address='||l_address||'&'||'sensor=true';
dbms_output.put_line(l_path);
l_signature_mac :=DBMS_CRYPTO.mac(UTL_I18N.string_to_raw(l_path, 'AL32UTF8'), DBMS_CRYPTO.hmac_sh1,l_private_key_bin);
l_signature_b64:= UTL_RAW.cast_to_varchar2(UTL_ENCODE.base64_encode(l_signature_mac));
l_signature_b64_alter_back:=translate(l_signature_b64,'+/','-_');
dbms_output.put_line(l_signature_b64_alter_back);
--get response from Google map service
l_url:=l_Google_service_domain||l_path||'&client='||l_client_name||'&signature='||l_signature_b64_alter_back;
--l_url:=l_Google_service_domain||l_path;
dbms_output.put_line(l_url);
l_page:=utl_http.request_pieces( l_url, 99999);
for i in 1..l_page.count loop
l_response:=l_response||l_page(i);
end loop;
n_actual_length:=length(l_response);
dbms_output.put_line(n_actual_length);
dbms_output.put_line(l_response);
--parse JSON result
json_obj:=new json(l_response);
l_status := json_ext.get_string(json_obj, 'status');
IF l_status = 'OK' then
jl_listOfValues := json_list(json_obj.get('results'));
json_tempobj := json(jl_listOfValues.get(1));
json_geom_obj := json(json_tempobj.get(3));
json_loc := json_ext.get_json(json_geom_obj, 'location');
l_lat := to_char(json_ext.get_number(json_loc, 'lat'));
l_lng := to_char(json_ext.get_number(json_loc, 'lng'));
P_s_Geocoding:=l_lat||','||l_lng;
dbms_output.put_line('##########'||P_s_Geocoding);
case json_ext.get_string(json_geom_obj, 'location_type')
when 'ROOFTOP' then P_n_accuracy:=9;
when 'RANGE_INTERPOLATED' then P_n_accuracy:=7;
when 'GEOMETRIC_CENTER' then P_n_accuracy:=5;
else P_n_accuracy:=3;
end case;
P_b_success:=true;
else
P_b_success:=false;
P_n_accuracy:=0;
P_s_Geocoding:='0,0';
end if;
  END;