SMS-confirmation library

Wraps Nexmo.com sms service

First you have to register at nexmo.com, or modify code to use other provider. Finally you should obtain two hex numbers: 8-hex-digit API_KEY and 16-hex-digit API_SECRET.

Usage:

0. Add ossrh SHAPSHOT repository and dependency to yous pom.xml file:

     <repositories>
         ...
         <repository>
             <id>ossrh</id>
             <url>
                 https://oss.sonatype.org/content/repositories/snapshots/
             </url>
         </repository>
     </repositories>
     ...

1. Add dependency:

      <dependency>
        <groupId>io.github.ac2epsilon</groupId>
        <artifactId>sms-confirmation</artifactId>
        <version>1.0-SNAPSHOT</version>
      </dependency>

2. Import package

import io.github.ac2epsilon

3. Create new confirmation object:

    SmsConfirmation sms = new SmsConfirmation("MyCompany", API_KEY, API_SECRET);

First parameter company used as "namespace", so you can serve several projects/companies/parties. API_KEY and API_SECRET are values, provided by Nexmo.com during your registration.

4. Call send method:

    String code = sms.send("380639003365");

This will generate random 4-digit number and send it to given phone. Sole parameter is phone, which have to be in international format, starting with country code, and consist of numbers (see Nexmo API documentation for further information).

SMS body will be like "Your confirmation code: 9304" and From: will consist of company, set in constructor. If you wish to change this there is overloaded version of method:

    String code = sms.send("380639003365","Enter this code: ~");

Tilda ~ denotes place, where code have to be. If provided message contains no tilda character, IllegalArgumentException exception will be thrown.

Return value will be generated code, anything else but 4-digit string should be treated as error (actually code returns "fail" in such event). You can, of course, keep this code. However our lib either persist this code along with phone number during 24h, so you can simplify your life just keeping track of phone.

We use phone number as primary key. This means that it is unique, so no duplications allowed. If new request arrives before code confirmation, new code will overwrite old one.

5. Call check method:

    String hash = sms.check(phone, code);

As soon as user get code on his/her phone and enters it into confirmation dialogue, you can compare it against stored one. You provide two parameters, phone and code. Be careful, as code valid during 24h period of time. If provided code matches with sent and stored one result of call will be SHA-1 hash as function of phone+code+datetime-of-confirmation. So you can back track confirmation.

Once confirmation complete record will persist in DB forever and stay immutable. Further valid conformations will not affect date of confirmation, so resulting hash will be unchanged.

6. You may retrieve data about confirmation calling method reHash:

    String re = sms.reHash(hash);

Returning string will contain phone number, 4-digit code and date/time as formatted string, all separated by minus sign. SHA-1 of this string will yield given hash code.