Here’s a structured approach to diagnosing and fixing the problem.
. Modern OpenSSL DLLs (v1.0.2, v1.1.x, or v3.x) are generally not compatible with Indy 9. Stack Overflow 1. Identify the Correct DLLs
Add runtime logging in Delphi to check the loaded OpenSSL version: Delphi 7 Indy 9 Could Not Load Ssl Library
Many modern servers have completely disabled SSL v2, SSL v3, and TLS 1.0/1.1 due to security vulnerabilities, requiring TLS 1.2 or TLS 1.3 instead. Because Indy 9 and OpenSSL 0.9.6/0.9.7 do not support TLS 1.2 natively, the handshake will fail. If the server rejects the old protocol, Indy sometimes misinterprets this connection drop as a failure to load the library. The Ultimate Solution: Upgrade to Indy 10
Here is the critical detail that most developers miss: It cannot use OpenSSL 1.1.x or 3.x. Modern operating systems (Windows 10, Windows 11, Windows Server 2016/2019/2022) do not ship with these outdated, vulnerable versions. Even if you manually place newer OpenSSL DLLs in your app folder, Indy 9 will refuse to load them because the internal API functions (like SSL_library_init or OpenSSL_add_all_algorithms ) have changed or been removed. Here’s a structured approach to diagnosing and fixing
file. This is the first place Windows looks for dependencies. Avoid System Folders : Do not place them in C:\Windows\System32 , as this can conflict with other applications and the OS. Stack Overflow 3. Debugging the Load Failure
IdHTTP.IOHandler := IdSSLIOHandler; IdHTTP.SSLIOHandler.SSLOptions.Method := sslvTLSv1_2; IdHTTP.SSLIOHandler.SSLOptions.Mode := sslmClient; Stack Overflow 1
: Select your TIdHTTP component (or TIdSMTP , etc.) and set its IOHandler property to the TIdSSLIOHandlerSocket component you just added. This tells Indy to use SSL for the connection.
A: For newer Delphi versions (Delphi 2007 and later) and Indy 10, you should use standard OpenSSL 1.0.2u libraries, which can be obtained from https://indy.fulgan.com/SSL/ . If you encounter issues even with these, try using the WhichFailedToLoad() function to identify the specific problem. Newer versions of Indy 10 generally support OpenSSL 1.0.x and 1.1.x, and OpenSSL 1.1.x is recommended for better security.
Indy 9 requires the or OpenSSL 0.9.7 branch. It is highly recommended to use OpenSSL 0.9.6m or 0.9.7i , as these are the exact versions Indy 9's source code expects. The two essential files you need are: ssleay32.dll libeay32.dll
You are using 64-bit DLLs. Delphi 7 compiles strictly 32-bit applications, meaning it requires 32-bit DLLs. Step-by-Step Fixes 1. Download the Correct OpenSSL DLLs