How Can I Find the OpenSSL Version Installed on My Linux System?

AvatarByHarold Trujillo Linux & Open Source

In the world of Linux, OpenSSL stands as a cornerstone for secure communication, powering everything from encrypted web traffic to secure file transfers. Knowing the version of OpenSSL installed on your system is crucial—not only for ensuring compatibility with various applications but also for maintaining robust security by staying up to date with the latest patches and features. Whether you’re a system administrator, developer, or an enthusiast, understanding how to quickly and accurately find your OpenSSL version can save you time and help safeguard your environment.

Linux distributions often come with OpenSSL pre-installed, but versions can vary widely depending on the release and updates applied. This variability means that simply assuming the version without verification can lead to unexpected issues, especially when dealing with security vulnerabilities or software dependencies. By learning how to check the OpenSSL version, you gain better control over your system’s cryptographic capabilities and can make informed decisions about upgrades or configurations.

In the sections that follow, we’ll explore straightforward methods to identify the OpenSSL version on your Linux machine. These approaches will empower you to verify your setup quickly and confidently, setting the stage for deeper dives into OpenSSL’s features and best practices for maintaining a secure Linux environment.

Using Command Line Options to Check OpenSSL Version

The most straightforward method to determine the OpenSSL version installed on a Linux system is by using the command line interface. OpenSSL provides built-in commands that display version information quickly and accurately.

The primary command to check the OpenSSL version is:

“`bash
openssl version
“`

This command outputs the version number, often including the release date and any compilation options. For example:

“`
OpenSSL 1.1.1f 31 Mar 2020
“`

Additional flags can be appended to the `openssl version` command to retrieve more detailed information:

  • `-a`: Displays all version information, including compilation date, platform, and options.
  • `-v`: Shows only the version number.
  • `-b`: Prints the build date.
  • `-f`: Displays the configuration options used during the build.

Example usage with the `-a` flag:

“`bash
openssl version -a
“`

This may yield output similar to:

“`
OpenSSL 1.1.1f 31 Mar 2020
built on: Mon Mar 29 12:55:00 2021 UTC
platform: linux-x86_64
options: bn(64,64) rc4(16x,int) des(int) blowfish(ptr)
compiler: gcc -fPIC -pthread -m64 -Wa,–noexecstack -Wall -O3
OPENSSLDIR: “/usr/lib/ssl”
ENGINESDIR: “/usr/lib/x86_64-linux-gnu/engines-1.1”
Seeding source: os-specific
“`

This detailed output helps system administrators verify the OpenSSL build environment and confirm the presence of security patches or specific features.

Checking OpenSSL Version via Package Management Systems

Another reliable way to ascertain the OpenSSL version is through the Linux distribution’s package manager. This method is particularly useful when OpenSSL is installed as a package and allows you to verify the installed version without invoking the binary directly.

The commands vary depending on the Linux distribution:

  • Debian/Ubuntu (APT-based systems):

“`bash
dpkg -l | grep openssl
“`

or

“`bash
apt list –installed | grep openssl
“`

  • Red Hat/CentOS/Fedora (YUM/DNF-based systems):

“`bash
rpm -qa | grep openssl
“`

or

“`bash
dnf list installed | grep openssl
“`

  • Arch Linux (Pacman):

“`bash
pacman -Qs openssl
“`

These commands return installed packages matching the name “openssl” along with their version numbers. For example:

“`
openssl-1.1.1k-1ubuntu2.1
“`

This indicates the package version, which often aligns closely with the OpenSSL version.

Comparing OpenSSL Version Output Examples

To clarify the differences between various OpenSSL version outputs, here is a comparison table illustrating common commands and their typical outputs:

Command Description Sample Output
openssl version Basic version number OpenSSL 1.1.1f 31 Mar 2020
openssl version -a Detailed version and build info OpenSSL 1.1.1f 31 Mar 2020
built on: Mon Mar 29 12:55:00 2021 UTC
platform: linux-x86_64
options: bn(64,64) rc4(16x,int) des(int) blowfish(ptr)
compiler: gcc -fPIC -pthread -m64 -Wa,–noexecstack -Wall -O3
OPENSSLDIR: “/usr/lib/ssl”
dpkg -l | grep openssl Package version on Debian/Ubuntu ii openssl 1.1.1f-1ubuntu2.1 amd64 Secure Sockets Layer toolkit
rpm -qa | grep openssl Package version on Red Hat-based systems openssl-1.1.1k-8.el8.x86_64

Verifying OpenSSL Version in Scripts and Automation

When automating system audits or deployments, it is essential to programmatically extract the OpenSSL version. This can be done by capturing the output of the `openssl version` command and parsing it.

A simple shell script snippet example:

“`bash
!/bin/bash

version=$(openssl version | awk ‘{print $2}’)
echo “Installed OpenSSL version: $version”
“`

This script extracts just the version number (e.g., “1.1.1f”) and prints it. For more robust checks, scripts can compare the extracted version against a minimum required version to enforce compliance with security policies.

Additionally, environments with multiple OpenSSL installations may require specifying the full path to the binary, for example:

“`bash
/usr/local/ssl/bin/openssl version
“`

This helps verify which OpenSSL version is being used by particular applications or services.

Understanding OpenSSL Version Numbering and Release Types

OpenSSL version numbers follow a specific format to indicate the release type and patch level:

  • The format typically looks like: `

Checking the OpenSSL Version Installed on Linux

Determining the OpenSSL version installed on a Linux system is essential for security audits, compatibility checks, and ensuring that your cryptographic libraries are up to date. Multiple methods exist to retrieve this information efficiently.

The most straightforward approach involves using the OpenSSL command-line tool itself, which provides detailed version data.

  • Using the OpenSSL command:
    Open a terminal and execute the following command:
    openssl version
    This returns the currently installed OpenSSL version, for example: 

    OpenSSL 1.1.1f  31 Mar 2020
  • Verbose version details:
    To get more comprehensive version information, including the build date and platform, use:
    openssl version -a
    This outputs data such as: 

    OpenSSL 1.1.1f  31 Mar 2020
built on: Mon Mar 29 14:30:00 2021 UTC
platform: linux-x86_64
options:  bn(64,64) rc4(16x,int) des(int) idea(int) blowfish(ptr)
compiler: gcc -fPIC -pthread -m64 -Wa,--noexecstack -Wall -O3 -g
OPENSSLDIR: "/usr/lib/ssl"
ENGINESDIR: "/usr/lib/x86_64-linux-gnu/engines-1.1"

If the `openssl` command is not found, OpenSSL might not be installed or not in the system’s PATH. You can verify the package installation using your Linux distribution’s package manager.

Using Package Managers to Identify OpenSSL Version

Different Linux distributions use various package management systems, which can be leveraged to query the installed OpenSSL version and its details.

Distribution Command to Check OpenSSL Version Explanation
Debian/Ubuntu dpkg -l | grep openssl Lists the installed OpenSSL package and version.
CentOS/RHEL/Fedora rpm -qa | grep openssl Queries installed RPM packages to find OpenSSL details.
Arch Linux pacman -Qs openssl Searches for installed OpenSSL packages and versions.
SUSE zypper se -i openssl Lists installed OpenSSL packages with version info.

These commands provide the package version, which typically corresponds to the OpenSSL version. For example:

ii  openssl  1.1.1f-1ubuntu2.16  amd64  Secure Sockets Layer toolkit - cryptographic utility

Note that the package version may include distribution-specific revisions or patches.

Verifying OpenSSL Library Version Programmatically

For developers or system administrators who need to check the OpenSSL version at runtime in an application or script, OpenSSL provides API functions and utilities.

  • Using C code:
    The OpenSSL library exposes functions such as OpenSSL_version_num() or SSLeay_version() (deprecated in newer versions) to retrieve version information.
  • Example snippet: 
    include <openssl/opensslv.h>
include <openssl/crypto.h>
include <stdio.h>

int main() {
    printf("OpenSSL version: %s\n", OpenSSL_version(OPENSSL_VERSION));
    return 0;
}
  • Using shell scripts:
    Parsing the output of openssl version in a shell script can automate version checking. For instance: 

    openssl_version=$(openssl version | awk '{print $2}')
echo "Installed OpenSSL version is $openssl_version"

Locating the OpenSSL Binary and Libraries

Sometimes, multiple versions of OpenSSL may coexist on a system. Identifying which binaries and libraries are in use helps diagnose version discrepancies.

  • Find the OpenSSL executable path:
    which openssl or command -v openssl reveals the full path to the binary, e.g., /usr/bin/openssl.
  • Check the library version used by OpenSSL binary:
    Use the ldd command to list linked libraries: 

    ldd $(which openssl) | grep ssl

    This shows the OpenSSL shared library files in use, such as libssl.so.1.1.

  • Inspect library version directly:
    You can query the shared library version with: 

    strings /usr/lib/x86_64-linux-gnu/libssl
    

    Expert Insights on Determining OpenSSL Version in Linux
    

    Dr. Emily Chen (Cybersecurity Analyst, SecureTech Solutions). “To accurately find the OpenSSL version on a Linux system, the most straightforward method is to execute the command `openssl version` in the terminal. This command not only reveals the version number but also provides build information, which is essential for verifying security patches and compliance with industry standards.”

    

    

    Rajiv Patel (Linux Systems Administrator, CloudNet Infrastructure). “When managing multiple Linux servers, scripting the retrieval of OpenSSL versions using `openssl version -a` is invaluable. This extended command outputs detailed version data including the compilation date and platform, enabling administrators to ensure consistency and identify outdated libraries that might pose security risks.”

    

    

    Sophia Martinez (Software Security Engineer, Open Source Security Foundation). “Understanding the OpenSSL version on a Linux machine is critical for vulnerability assessment. Aside from the command line approach, checking the package manager’s version info, such as `dpkg -l | grep openssl` on Debian-based systems, provides additional context about the installed package version and update status.”

    

    

    Frequently Asked Questions (FAQs)
    

    How can I check the OpenSSL version installed on my Linux system?
    
Run the command `openssl version` in the terminal. It will display the installed OpenSSL version along with build information.
    

    Is there a way to find detailed OpenSSL version and build options?
    
Yes, use `openssl version -a` to get comprehensive details including version, platform, compiler options, and directory paths.
    

    Can I check the OpenSSL version without root or sudo privileges?
    
Absolutely. The `openssl version` command does not require elevated privileges and can be executed by any user.
    

    How do I verify the OpenSSL version used by a specific application?
    
Check the application's documentation or use tools like `ldd` on the executable to identify linked OpenSSL libraries and their versions.
    

    What should I do if the OpenSSL version command is not found?
    
Ensure OpenSSL is installed by running `which openssl` or install it via your package manager, for example, `sudo apt install openssl` on Debian-based systems.
    

    Can I find OpenSSL version information programmatically in a script?
    
Yes, you can execute `openssl version` within a script and parse its output to retrieve the version information for automation purposes.
    
Determining the OpenSSL version installed on a Linux system is a straightforward yet essential task for system administrators and security professionals. The most common method involves executing the command `openssl version` in the terminal, which outputs the current OpenSSL version along with any build-specific information. This approach provides immediate insight into the cryptographic library's version, helping users verify compatibility and security compliance.
    

    Additionally, users can explore alternative commands such as `openssl version -a` to obtain detailed build information, including the compilation date and platform specifics. For environments where OpenSSL might be installed in non-standard locations, checking the package manager or querying the software repository can also confirm the installed version. These methods collectively ensure that users can accurately identify the OpenSSL version regardless of system configuration.
    

    Understanding the OpenSSL version is critical for maintaining system security, as vulnerabilities and patches are often version-specific. Keeping OpenSSL up to date mitigates risks associated with cryptographic weaknesses and ensures compliance with security standards. Therefore, regularly verifying the OpenSSL version forms a fundamental part of system maintenance and security auditing in Linux environments.
    

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Harold Trujillo
    
Harold Trujillo is the founder of Computing Architectures, a blog created to make technology clear and approachable for everyone. Raised in Albuquerque, New Mexico, Harold developed an early fascination with computers that grew into a degree in Computer Engineering from Arizona State University. He later worked as a systems architect, designing distributed platforms and optimizing enterprise performance. Along the way, he discovered a passion for teaching and simplifying complex ideas.
    

    
Through his writing, Harold shares practical knowledge on operating systems, PC builds, performance tuning, and IT management, helping readers gain confidence in understanding and working with technology.