====== 2.1 Clone GitHub Repository ======

This page explains how to download OpenSSL source code from GitHub.

----

===== What is Git? =====

**Git** is a version control system. It stores:
  * All versions of a project
  * Who changed what and when
  * "Tags" for important versions (e.g. v3.6.0)

**GitHub** is a website that hosts Git repositories.

----

===== Prepare Project Structure =====

First we create a sensible folder structure:

<code powershell>
# Create main folder
mkdir D:\Projects\openssl-3.6.0

# Create subfolders
mkdir D:\Projects\openssl-3.6.0\src   # Source code goes here
mkdir D:\Projects\openssl-3.6.0\bin   # Compiled files go here
</code>

Result:
<code>
D:\Projects\openssl-3.6.0\
├── src\    # OpenSSL source code (from GitHub)
└── bin\    # Target for compiled binaries
</code>

----

===== Clone OpenSSL =====

==== Option A: Only tag v3.6.0 (recommended) ====

<code powershell>
cd D:\Projects\openssl-3.6.0
git clone --depth 1 --branch openssl-3.6.0 https://github.com/openssl/openssl.git src
</code>

**Explanation of parameters:**
| Parameter | Meaning |
|-----------|---------|
| ''--depth 1'' | Only latest version (saves ~500 MB!) |
| ''--branch openssl-3.6.0'' | The tag for version 3.6.0 |
| ''src'' | Target folder |

==== Option B: Complete repository ====

If you want to try different versions:

<code powershell>
cd D:\Projects\openssl-3.6.0
git clone https://github.com/openssl/openssl.git src
cd src
git checkout openssl-3.6.0
</code>

<WRAP info>
The complete repository is about 500 MB. With ''--depth 1'' only ~50 MB.
</WRAP>

----

===== List Available Tags =====

If you need a different version:

<code powershell>
cd D:\Projects\openssl-3.6.0\src

# Show all tags
git tag | Select-String "openssl-3"

# Output (example):
# openssl-3.0.0
# openssl-3.0.1
# ...
# openssl-3.5.0
# openssl-3.6.0
</code>

----

===== Switch to Another Tag =====

<code powershell>
cd D:\Projects\openssl-3.6.0\src

# Switch to another version
git checkout openssl-3.5.0

# Back to 3.6.0
git checkout openssl-3.6.0
</code>

----

===== Verify Version =====

<code powershell>
cd D:\Projects\openssl-3.6.0\src

# Show current tag
git describe --tags
# Expected output: openssl-3.6.0

# Or: Show commit info
git log -1 --oneline
</code>

----

===== Update Source Code =====

If you have the complete repository and want to update:

<code powershell>
cd D:\Projects\openssl-3.6.0\src

# Fetch latest changes
git fetch --all --tags

# Show new tags
git tag | Select-String "openssl-3.6"

# Switch to new tag (e.g. 3.6.1)
git checkout openssl-3.6.1
</code>

----

===== Common Problems =====

==== "git is not recognized" ====

Git is not installed or not in PATH:

<code powershell>
winget install Git.Git
</code>

After installation: Open new terminal.

==== Firewall blocks GitHub ====

If you're behind a corporate firewall:

<code powershell>
# Set proxy (if needed)
git config --global http.proxy http://proxy.company.com:8080
git config --global https.proxy http://proxy.company.com:8080
</code>

==== SSL Certificate Error ====

<code powershell>
# Temporary: Disable SSL verification (not for production!)
git config --global http.sslVerify false
</code>

----

===== Download without Git (Alternative) =====

If Git is not available:

  - Go to [[https://github.com/openssl/openssl/releases]]
  - Select version 3.6.0
  - Download "Source code (zip)"
  - Extract to ''D:\Projects\openssl-3.6.0\src''

<WRAP important>
**Disadvantage:** No easy update possible!
</WRAP>

----

===== Continue to =====

  * [[.:build:start|3. Build - Compile]]
  * [[.:quellen:verzeichnisstruktur|Understand Directory Structure]]

----
//Wolfgang van der Stille @ EMSR DATA d.o.o. - Post-Quantum Cryptography Professional//