JWT on j2234's log

JWT on j2234's loghttps://log.j2234.cc/tags/jwt/Recent content in JWT on j2234's logHugo -- gohugo.ioen© 2026Tue, 07 Apr 2026 15:22:59 +0000JWT 구조https://log.j2234.cc/posts/velog/035-jwt-%EA%B5%AC%EC%A1%B0/Sun, 30 Jul 2023 21:34:27 +0000https://log.j2234.cc/posts/velog/035-jwt-%EA%B5%AC%EC%A1%B0/<p><a href="JWT-%EB%B0%B0%EA%B2%BD%EC%A7%80%EC%8B%9D" >이전글</a></p> <h2 class="relative group">구조 <div id="구조" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#%ea%b5%ac%ec%a1%b0" aria-label="Anchor">#</a> </span> </h2> <p><code>.</code>으로 구분된 세 부분</p> <ul> <li>Header</li> <li>Payload (정보)</li> <li>Signature (서명)</li> </ul> <h3 class="relative group">Header <div id="header" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#header" aria-label="Anchor">#</a> </span> </h3> <p>서명 알고리즘, 토큰 유형 ex)</p> <div class="highlight-wrapper"><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-json" data-lang="json"><span class="line"><span class="cl"><span class="p">{</span> </span></span><span class="line"><span class="cl"> <span class="nt">"alg"</span><span class="p">:</span> <span class="s2">"HS256"</span><span class="p">,</span> </span></span><span class="line"><span class="cl"> <span class="nt">"typ"</span><span class="p">:</span> <span class="s2">"JWT"</span> </span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre></div></div> <p><strong>Base64Url</strong>로 인코딩됨</p> <h3 class="relative group">Payload <div id="payload" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#payload" aria-label="Anchor">#</a> </span> </h3> <p>클래임 (정보의 단위)</p> <details> <summary>종류</summary> <ul> <li>등록된 클레임 (Registered Claims) : 이미 정해저 있는, JWT에 공통적으로 포함되는 클레임 <strong>필수❌ </strong> </li> <li>공개 클레임 (Public Claims) : 사용저 정의 클레임 </li> <li>비공개 클레임 (Private Claims) : 등록되지 않음, 두 개체가 합의해서 사용</li> </ul> </details> <div class="highlight-wrapper"><div class="highlight"><pre tabindex="0" class="chroma"><code class="language-json" data-lang="json"><span class="line"><span class="cl"><span class="p">{</span> </span></span><span class="line"><span class="cl"> <span class="nt">"sub"</span><span class="p">:</span> <span class="s2">"1234567890"</span><span class="p">,</span> </span></span><span class="line"><span class="cl"> <span class="nt">"name"</span><span class="p">:</span> <span class="s2">"John Doe"</span><span class="p">,</span> </span></span><span class="line"><span class="cl"> <span class="nt">"admin"</span><span class="p">:</span> <span class="kc">true</span> </span></span><span class="line"><span class="cl"><span class="p">}</span></span></span></code></pre></div></div> <p>해더와 같이 <strong>Base64Url</strong>로 인코딩됨</p>JWT 배경지식https://log.j2234.cc/posts/velog/036-jwt-%EB%B0%B0%EA%B2%BD%EC%A7%80%EC%8B%9D/Sun, 30 Jul 2023 21:33:50 +0000https://log.j2234.cc/posts/velog/036-jwt-%EB%B0%B0%EA%B2%BD%EC%A7%80%EC%8B%9D/<blockquote><p>JWT 이해에 필요한 배경지식들 정리</p> </blockquote> <h2 class="relative group">기존 세션 방식의 문제점 <div id="기존-세션-방식의-문제점" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#%ea%b8%b0%ec%a1%b4-%ec%84%b8%ec%85%98-%eb%b0%a9%ec%8b%9d%ec%9d%98-%eb%ac%b8%ec%a0%9c%ec%a0%90" aria-label="Anchor">#</a> </span> </h2> <h4 class="relative group">로드 밸런싱 (여러대의 서버가 나누어 운영)에서, 세션 처리를 어떻게 해야될지 난감 <div id="로드-밸런싱-여러대의-서버가-나누어-운영에서-세션-처리를-어떻게-해야될지-난감" class="anchor"></div> <span class="absolute top-0 w-6 transition-opacity opacity-0 -start-6 not-prose group-hover:opacity-100 select-none"> <a class="text-primary-300 dark:text-neutral-700 !no-underline" href="#%eb%a1%9c%eb%93%9c-%eb%b0%b8%eb%9f%b0%ec%8b%b1-%ec%97%ac%eb%9f%ac%eb%8c%80%ec%9d%98-%ec%84%9c%eb%b2%84%ea%b0%80-%eb%82%98%eb%88%84%ec%96%b4-%ec%9a%b4%ec%98%81%ec%97%90%ec%84%9c-%ec%84%b8%ec%85%98-%ec%b2%98%eb%a6%ac%eb%a5%bc-%ec%96%b4%eb%96%bb%ea%b2%8c-%ed%95%b4%ec%95%bc%eb%90%a0%ec%a7%80-%eb%82%9c%ea%b0%90" aria-label="Anchor">#</a> </span> </h4> <p>EX)</p> <blockquote><ol> <li>A,B,C라는 서버 3대가 요청을 처리중</li> </ol> </blockquote><ol start="2"> <li>사용자가 A서버에 로그인을 처리해서 세션쿠키 발급받음</li> <li>갑자기 A서버에 트래픽이 몰려서, B서버에서 다음 작업을 수행</li> <li>B서버는 사용자에 대한 세션이 없음</li> </ol> <p>또한, 서버의 메모리를 소모하므로, 사용자가 많아지면 ….</p>