c - Extracting client certificate & private key from .p12 file

Question

Can anybody tell me how to use

PKCS12 *d2i_PKCS12_fp(FILE *fp, PKCS12 **p12); 

int PKCS12_parse(PKCS12 *p12, const char *pass, EVP_PKEY **pkey, X509 **cert, STACK_OF(X509) **ca); 

any documenatation reference will also work.

Answer 1

Without error-checking:

FILE *p12_file;
PKCS12 *p12_cert = NULL;
EVP_PKEY *pkey;
X509 *x509_cert;
STACK_OF(X509) *additional_certs = NULL;

p12_file = fopen("foo.p12", "rb");
d2i_PKCS12_fp(p12_file, &p12_cert);
fclose(p12_file);

PKCS12_parse(p12_cert, "password", &pkey, &x509_cert, &additional_certs);

The private key is now in pkey, the certificate in x509_cert and any additional certificates in additional_certs.