{"id":70394,"date":"2026-05-15T16:06:18","date_gmt":"2026-05-15T15:06:18","guid":{"rendered":"https:\/\/ekiwi-blog.de\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/"},"modified":"2026-05-15T16:17:56","modified_gmt":"2026-05-15T15:17:56","slug":"openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus","status":"publish","type":"post","link":"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/","title":{"rendered":"OpenSSL DLLs for Windows: A collection for developers (e.g. Lazarus)"},"content":{"rendered":"<p>When developing Windows applications \u2013 for example, using Lazarus (Free Pascal) \u2013 OpenSSL is often required for encrypted network connections. As Windows does not include these libraries by default, the relevant DLL files must be supplied with the application.<\/p>\n<p><!--more--><\/p>\n<p>For my own projects, I have compiled a selection of frequently required OpenSSL files and am making them available for download here.<\/p>\n<hr>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_83 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of content<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#Contents_of_the_package\" >Contents of the package<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#OpenSSL_3x_64-bit\" >OpenSSL 3.x (64-bit)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#OpenSSL_11x_64-bit\" >OpenSSL 1.1.x (64-bit)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#Older_OpenSSL_versions_v10x\" >Older OpenSSL versions (v1.0.x)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#Usage\" >Usage<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/ekiwi-blog.de\/en\/70394\/openssl-dlls-for-windows-a-collection-for-developers-eg-lazarus\/#Security_Note\" >Security Note<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Contents_of_the_package\"><\/span>Contents of the package<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The collection contains files from various OpenSSL branches, as different libraries are required depending on the age of the project or the components used:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"OpenSSL_3x_64-bit\"><\/span>OpenSSL 3.x (64-bit)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>These files are required by many newer 64-bit applications and modern HTTP clients:<\/p>\n<ul>\n<li><b><code>libcrypto-3-x64.dll<\/code><\/b><\/li>\n<li><b><code>libssl-3-x64.dll<\/code><\/b><\/li>\n<li><b><code>libcrypto.dll<\/code><\/b> (is looked for by some frameworks under this generic name)<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"OpenSSL_11x_64-bit\"><\/span>OpenSSL 1.1.x (64-bit)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Used by many applications and components that have not yet transitioned to the newer 3.x branch:<\/p>\n<ul>\n<li><b><code>libcrypto-1_1-x64.dll<\/code><\/b><\/li>\n<li><b><code>libssl-1_1-x64.dll<\/code><\/b><\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Older_OpenSSL_versions_v10x\"><\/span>Older OpenSSL versions (v1.0.x)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>These files are frequently required by older projects or older network components (such as certain versions of Indy or Synapse):<\/p>\n<ul>\n<li><b><code>libeay32.dll<\/code><\/b><\/li>\n<li><b><code>ssleay32.dll<\/code><\/b><\/li>\n<\/ul>\n<hr>\n<h2><span class=\"ez-toc-section\" id=\"Usage\"><\/span>Usage<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>In practice, it is usually safest to copy the required DLL files directly into the directory of the executable application (next to the <code>.exe<\/code>). This ensures that the application remains portable and uses exactly the versions with which it was tested.<\/p>\n<hr>\n<h2><span class=\"ez-toc-section\" id=\"Security_Note\"><\/span>Security Note<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The older files (<code>ssleay32.dll<\/code> and <code>libeay32.dll<\/code>) date from 2018. They no longer meet current security standards and should, where possible, only be used to maintain compatibility with existing legacy systems. For new or security-critical projects, we recommend using the OpenSSL 3.x branch.<\/p>\n<p><a href=\"https:\/\/ekiwi-blog.de\/wp-content\/uploads\/2026\/05\/libssl.zip\">Download the DLL files<\/a><\/p>","protected":false},"excerpt":{"rendered":"<p>When developing Windows applications \u2013 for example, using Lazarus (Free Pascal) \u2013 OpenSSL is often required for encrypted network connections.<\/p>\n","protected":false},"author":1,"featured_media":14619,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1555],"tags":[3942,3943,3384,2068],"class_list":["post-70394","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-software-en","tag-development-en","tag-dll-en","tag-lazarus-en","tag-windows-en-2"],"_links":{"self":[{"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/posts\/70394","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/comments?post=70394"}],"version-history":[{"count":0,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/posts\/70394\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/media\/14619"}],"wp:attachment":[{"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/media?parent=70394"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/categories?post=70394"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ekiwi-blog.de\/en\/wp-json\/wp\/v2\/tags?post=70394"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}