Cryptography and SSL/TLS Toolkit



PKCS12_create, PKCS12_create_ex - create a PKCS#12 structure


#include <openssl/pkcs12.h>

PKCS12 *PKCS12_create(const char *pass, const char *name, EVP_PKEY *pkey,
                      X509 *cert, STACK_OF(X509) *ca,
                      int nid_key, int nid_cert, int iter, int mac_iter, int keytype);
PKCS12 *PKCS12_create_ex(const char *pass, const char *name, EVP_PKEY *pkey,
                         X509 *cert, STACK_OF(X509) *ca, int nid_key, int nid_cert,
                         int iter, int mac_iter, int keytype,
                         OSSL_LIB_CTX *ctx, const char *propq);


PKCS12_create() creates a PKCS#12 structure.

pass is the passphrase to use. name is the friendlyName to use for the supplied certificate and key. pkey is the private key to include in the structure and cert its corresponding certificates. ca, if not NULL is an optional set of certificates to also include in the structure.

nid_key and nid_cert are the encryption algorithms that should be used for the key and certificate respectively. The modes GCM, CCM, XTS, and OCB are unsupported. iter is the encryption algorithm iteration count to use and mac_iter is the MAC iteration count to use. keytype is the type of key.

PKCS12_create_ex() is identical to PKCS12_create() but allows for a library context ctx and property query propq to be used to select algorithm implementations.


The parameters nid_key, nid_cert, iter, mac_iter and keytype can all be set to zero and sensible defaults will be used.

These defaults are: AES password based encryption (PBES2 with PBKDF2 and AES-256-CBC) for private keys and certificates, the PBKDF2 and MAC key derivation iteration count of PKCS12_DEFAULT_ITER (currently 2048), and MAC algorithm HMAC with SHA2-256. The MAC key derivation algorithm used for the outer PKCS#12 structure is PKCS12KDF.

The default MAC iteration count is 1 in order to retain compatibility with old software which did not interpret MAC iteration counts. If such compatibility is not required then mac_iter should be set to PKCS12_DEFAULT_ITER.

keytype adds a flag to the store private key. This is a non standard extension that is only currently interpreted by MSIE. If set to zero the flag is omitted, if set to KEY_SIG the key can be used for signing only, if set to KEY_EX it can be used for signing and encryption. This option was useful for old export grade software which could use signing only keys of arbitrary size but had restrictions on the permissible sizes of keys which could be used for encryption.

If name is NULL and cert contains an alias then this will be used for the corresponding friendlyName in the PKCS12 structure instead. Similarly, if pkey is NULL and cert contains a keyid then this will be used for the corresponding localKeyID in the PKCS12 structure instead of the id calculated from the pkey.

For all certificates in ca then if a certificate contains an alias or keyid then this will be used for the corresponding friendlyName or localKeyID in the PKCS12 structure.

Either pkey, cert or both can be NULL to indicate that no key or certificate is required. In previous versions both had to be present or a fatal error is returned.

nid_key or nid_cert can be set to -1 indicating that no encryption should be used.

mac_iter can be set to -1 and the MAC will then be omitted entirely. This can be useful when running with the FIPS provider as the PKCS12KDF is not a FIPS approvable algorithm.

PKCS12_create() makes assumptions regarding the encoding of the given pass phrase. See passphrase-encoding(7) for more information.


PKCS12_create() returns a valid PKCS12 structure or NULL if an error occurred.


IETF RFC 7292 (


EVP_KDF-PKCS12KDF(7), d2i_PKCS12(3), OSSL_PROVIDER-FIPS(7), passphrase-encoding(7)


PKCS12_create_ex() was added in OpenSSL 3.0.

The defaults for encryption algorithms, MAC algorithm, and the MAC key derivation iteration count were changed in OpenSSL 3.0 to more modern standards.

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