X509_GET_VERSION(3) | Library Functions Manual | X509_GET_VERSION(3)

# NAME

`X509_get_version`, `X509_set_version`, `X509_REQ_get_version`, `X509_REQ_set_version`, `X509_CRL_get_version`, `X509_CRL_set_version` — get or set certificate, certificate request, or CRL version

# SYNOPSIS

library “libcrypto”
`#include <openssl/x509.h>`

long
`X509_get_version`(const X509 *x);

int
`X509_set_version`(X509 *x, long version);

long
`X509_REQ_get_version`(const X509_REQ *req);

int
`X509_REQ_set_version`(X509_REQ *x, long version);

long
`X509_CRL_get_version`(const X509_CRL *crl);

int
`X509_CRL_set_version`(X509_CRL *x, long version);

# DESCRIPTION

`X509_get_version`() returns the numerical value of the version field of certificate x. Note: this is defined by standards (X.509 et al.) to be one less than the certificate version. So a version 3 certificate will return 2 and a version 1 certificate will return 0.

`X509_set_version`() sets the numerical value of the version field of certificate x to version.

Similarly `X509_REQ_get_version`(), `X509_REQ_set_version`(), `X509_CRL_get_version`(), and `X509_CRL_set_version`() get and set the version number of certificate requests and CRLs.

The version field of certificates, certificate requests, and CRLs has a DEFAULT value of v1(0) meaning the field should be omitted for version 1. This is handled transparently by these functions.

# RETURN VALUES

`X509_get_version`(), `X509_REQ_get_version`(), and `X509_CRL_get_version`() return the numerical value of the version field.

`X509_set_version`(), `X509_REQ_set_version`(), and `X509_CRL_set_version`() return 1 for success or 0 for failure. In some cases of failure, the reason can be determined with ERR_get_error(3).

# SEE ALSO

d2i_X509(3), X509_CRL_get0_by_serial(3), X509_CRL_new(3), X509_get_pubkey(3), X509_get_subject_name(3), X509_NAME_add_entry_by_txt(3), X509_NAME_ENTRY_get_object(3), X509_NAME_get_index_by_NID(3), X509_NAME_print_ex(3), X509_new(3), X509_REQ_new(3), X509_sign(3), X509_verify_cert(3), X509V3_get_d2i(3)

# HISTORY

`X509_get_version`(), `X509_set_version`(), `X509_REQ_get_version`(), and `X509_REQ_set_version`() first appeared in SSLeay 0.6.5 and have been available since OpenBSD 2.4.

`X509_CRL_get_version`() first appeared in OpenSSL 0.9.2b and has been available since OpenBSD 2.6.

`X509_CRL_set_version`() first appeared in OpenSSL 0.9.7 and has been available since OpenBSD 3.2.

June 8, 2025 | Debian