OPENSSL_VERSION_NUMBER(3) | Library Functions Manual | OPENSSL_VERSION_NUMBER(3)

# NAME

`OPENSSL_VERSION_NUMBER`, `LIBRESSL_VERSION_NUMBER`, `LIBRESSL_VERSION_TEXT`, `OPENSSL_VERSION_TEXT`, `OpenSSL_version_num`, `OpenSSL_version`, `SSLeay`, `SSLeay_version` — get OpenSSL version number

# SYNOPSIS

library “libcrypto”
`#include <openssl/opensslv.h>`

`#define OPENSSL_VERSION_NUMBER 0x020000000L`
`#define LIBRESSL_VERSION_NUMBER 0x02nnnn00fL`
`#define LIBRESSL_VERSION_TEXT "LibreSSL 2.n.n"`
`#define OPENSSL_VERSION_TEXT LIBRESSL_VERSION_TEXT`

`#include <openssl/crypto.h>`

unsigned long
`OpenSSL_version_num`(void);

const char *
`OpenSSL_version`(int t);

long
`SSLeay`(void);

const char *
`SSLeay_version`(int t);

# DESCRIPTION

`OPENSSL_VERSION_NUMBER` and `LIBRESSL_VERSION_NUMBER` are numeric release version identifiers. The first two digits contain the major release number, the third and fourth digits the minor release number, and the fifth and sixth digits the fix release number. For OpenSSL, the seventh and eight digits contain the patch release number and the final digit is 0 for development, 1 to e for betas 1 to 14, or f for release. For LibreSSL, `OPENSSL_VERSION_NUMBER` is always 0x020000000, and `LIBRESSL_VERSION_NUMBER` always ends with 00f.

For example:

    OPENSSL_VERSION_NUMBER:
    0x000906000 == 0.9.6 dev
    0x000906023 == 0.9.6b beta 3
    0x00090605f == 0.9.6e release
    0x020000000 == 2.0.0 for any version of LibreSSL

    LIBRESSL_VERSION_NUMBER:
    0x02070000f == LibreSSL 2.7.0

OpenSSL versions prior to 0.9.3 had identifiers < 0x0930. For versions between 0.9.3 and 0.9.5, the seventh digit was 1 for release and 0 otherwise, and the eighth and ninth digits were the patch release number.

For example:

    0x000904100 == 0.9.4 release
    0x000905000 == 0.9.5 dev

OpenSSL version 0.9.5a had an interim interpretation that is like the current one, except the patch level got the highest bit set, to keep continuity. The number was therefore 0x0090581f.

`OpenSSL_version_num`() returns `OPENSSL_VERSION_NUMBER`.

`OpenSSL_version`() returns different strings depending on t:

`OPENSSL_VERSION`
  The text variant of the version number, `OPENSSL_VERSION_TEXT`. For OpenSSL, it includes the release date, for example "OpenSSL 0.9.5a 1 Apr 2000". For LibreSSL, `LIBRESSL_VERSION_TEXT` is returned.
`OPENSSL_CFLAGS`
  The compiler flags set for the compilation process in the form "compiler: ..." if available or "compiler: information not available" otherwise. LibreSSL never provides compiler information.
`OPENSSL_BUILT_ON`
  The date of the build process in the form "built on: ..." if available or "built on: date not available" otherwise. LibreSSL never provides information on the build date.
`OPENSSL_PLATFORM`
  The Configure target of the library build in the form "platform: ..." if available or "platform: information not available" otherwise. LibreSSL never provides platform information.
`OPENSSL_DIR`
  The `OPENSSLDIR` setting of the library build in the form "OPENSSLDIR: "..."" if available or "OPENSSLDIR: N/A" otherwise. For LibreSSL, the default is "OPENSSLDIR: "/etc/ssl"".
`OPENSSL_ENGINES_DIR`
  The `ENGINESDIR` setting of the library build in the form "ENGINESDIR: "..."" if available or "ENGINESDIR: N/A" otherwise. LibreSSL never provides or uses an `ENGINESDIR`.

For an unknown t, the text "not available" is returned.

For backward compatibility, `SSLEAY_VERSION_NUMBER` is an alias for `OPENSSL_VERSION_NUMBER` and `SSLeay`() for `OpenSSL_version_num`(). The legacy function `SSLeay_version`() is similar to `OpenSSL_version`() except that it takes arguments `SSLEAY_VERSION`, `SSLEAY_CFLAGS`, `SSLEAY_BUILT_ON`, `SSLEAY_PLATFORM`, and `SSLEAY_DIR` which expand to other numerical values than the corresponding `OPENSSL_*` macros.

# RETURN VALUES

`OpenSSL_version_num`() and `SSLeay`() return a constant version number.

`OpenSSL_version`() and `SSLeay_version`() return pointers to static strings.

# SEE ALSO

crypto(3), OPENSSL_config(3)

# HISTORY

`SSLeay`(), `SSLeay_version`(), and `SSLEAY_VERSION_NUMBER` first appeared in SSLeay 0.6.0 and have been available since OpenBSD 2.4.

`OPENSSL_VERSION_NUMBER` first appeared in the first OpenSSL release, OpenSSL 0.9.1c, and has been available since OpenBSD 2.6.

`SSLEAY_DIR` first appeared in OpenSSL 0.9.7 and have been available since OpenBSD 3.2.

`LIBRESSL_VERSION_NUMBER` first appeared in LibreSSL 2.0.0 and OpenBSD 5.6 and got its final format in LibreSSL 2.3.2 and OpenBSD 5.9. `LIBRESSL_VERSION_TEXT` first appeared in LibreSSL 2.2.2 and OpenBSD 5.8.

`OpenSSL_version_num`() and `OpenSSL_version`() first appeared in OpenSSL 1.1.0 and have been available since LibreSSL 2.7.1 and OpenBSD 6.3.

June 8, 2025 | Debian