X509_get_pubkey.3ssl - Man Page

get or set certificate or certificate request public key


 #include <openssl/x509.h>

 EVP_PKEY *X509_get_pubkey(X509 *x);
 EVP_PKEY *X509_get0_pubkey(const X509 *x);
 int X509_set_pubkey(X509 *x, EVP_PKEY *pkey);
 X509_PUBKEY *X509_get_X509_PUBKEY(X509 *x);

 EVP_PKEY *X509_REQ_get_pubkey(X509_REQ *req);
 EVP_PKEY *X509_REQ_get0_pubkey(X509_REQ *req);
 int X509_REQ_set_pubkey(X509_REQ *x, EVP_PKEY *pkey);
 X509_PUBKEY *X509_REQ_get_X509_PUBKEY(X509_REQ *x);


X509_get_pubkey() attempts to decode the public key for certificate x. If successful it returns the public key as an EVP_PKEY pointer with its reference count incremented: this means the returned key must be freed up after use. X509_get0_pubkey() is similar except it does not increment the reference count of the returned EVP_PKEY so it must not be freed up after use.

X509_get_X509_PUBKEY() returns an internal pointer to the X509_PUBKEY structure which encodes the certificate of x. The returned value must not be freed up after use.

X509_set_pubkey() attempts to set the public key for certificate x to pkey. The key pkey should be freed up after use.

X509_REQ_get_pubkey(), X509_REQ_get0_pubkey(), X509_REQ_set_pubkey() and X509_REQ_get_X509_PUBKEY() are similar but operate on certificate request req.


The first time a public key is decoded the EVP_PKEY structure is cached in the certificate or certificate request itself. Subsequent calls return the cached structure with its reference count incremented to improve performance.

Return Values

X509_get_pubkey(), X509_get0_pubkey(), X509_get_X509_PUBKEY(), X509_REQ_get_pubkey() and X509_REQ_get_X509_PUBKEY() return a public key or NULL if an error occurred.

X509_set_pubkey() and X509_REQ_set_pubkey() return 1 for success and 0 for failure.

See Also

d2i_X509(3), ERR_get_error(3), X509_CRL_get0_by_serial(3), X509_get0_signature(3), X509_get_ext_d2i(3), X509_get_extension_flags(3), X509_get_subject_name(3), X509_get_version(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_sign(3), X509V3_get_d2i(3), X509_verify_cert(3)

Referenced By

i2d_re_X509_tbs.3ssl(3), X509_CRL_get0_by_serial.3ssl(3), X509_get0_notBefore.3ssl(3), X509_get0_signature.3ssl(3), X509_get0_uids.3ssl(3), X509_get_serialNumber.3ssl(3), X509_get_subject_name.3ssl(3), X509_get_version.3ssl(3), X509_new.3ssl(3), X509_PUBKEY_new.3ssl(3), X509_sign.3ssl(3), X509V3_get_d2i.3ssl(3).

The man pages X509_get0_pubkey.3ssl(3), X509_get_X509_PUBKEY.3ssl(3), X509_REQ_get0_pubkey.3ssl(3), X509_REQ_get_pubkey.3ssl(3), X509_REQ_get_X509_PUBKEY.3ssl(3), X509_REQ_set_pubkey.3ssl(3) and X509_set_pubkey.3ssl(3) are aliases of X509_get_pubkey.3ssl(3).

2023-07-20 1.1.1q OpenSSL