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/* ------------------------------------------------------------ *
* file: certserial.c *
* purpose: Example code for OpenSSL certificate serials *
* author: 06/12/2012 Frank4DD *
* *
* gcc -o certserial certserial.c -lssl -lcrypto *
* ------------------------------------------------------------ */
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#include <openssl/x509.h>
int main() {
const char cert_filestr[] = "./cert-file.pem";
ASN1_INTEGER *asn1_serial = NULL;
BIO *certbio = NULL;
BIO *outbio = NULL;
X509 *cert = NULL;
const char *neg;
int ret, i;
long l;
/* ---------------------------------------------------------- *
* These function calls initialize openssl for correct work. *
* ---------------------------------------------------------- */
OpenSSL_add_all_algorithms();
ERR_load_BIO_strings();
ERR_load_crypto_strings();
/* ---------------------------------------------------------- *
* Create the Input/Output BIO's. *
* ---------------------------------------------------------- */
certbio = BIO_new(BIO_s_file());
outbio = BIO_new_fp(stdout, BIO_NOCLOSE);
/* ---------------------------------------------------------- *
* Load the certificate from file (PEM). *
* ---------------------------------------------------------- */
ret = BIO_read_filename(certbio, cert_filestr);
if (! (cert = PEM_read_bio_X509(certbio, NULL, 0, NULL))) {
BIO_printf(outbio, "Error loading cert into memory\n");
exit(-1);
}
/* ---------------------------------------------------------- *
* Extract the certificate's serial number. *
* ---------------------------------------------------------- */
asn1_serial = X509_get_serialNumber(cert);
if (asn1_serial == NULL)
BIO_printf(outbio, "Error getting serial number from certificate");
/* ---------------------------------------------------------- *
* Print the serial number value, openssl x509 -serial style *
* ---------------------------------------------------------- */
BIO_puts(outbio,"serial (openssl x509 -serial style): ");
i2a_ASN1_INTEGER(outbio, asn1_serial);
BIO_puts(outbio,"\n");
/* ---------------------------------------------------------- *
* Print the serial number value, openssl x509 -text style *
* ---------------------------------------------------------- */
if (asn1_serial->length <= (int)sizeof(long)) {
l=ASN1_INTEGER_get(asn1_serial);
if (asn1_serial->type == V_ASN1_NEG_INTEGER) {
l= -l;
neg="-";
}
else neg="";
if (BIO_printf(outbio," %s%lu (%s0x%lx)\n",neg,l,neg,l) <= 0)
BIO_printf(outbio, "Error during printing the serial.\n");
} else {
neg=(asn1_serial->type == V_ASN1_NEG_INTEGER)?" (Negative)":"";
//if (BIO_printf(outbio,"\n%12s%s","",neg) <= 0)
if (BIO_printf(outbio,"serial (openssl x509 -text style): %s","",neg) <= 0)
BIO_printf(outbio, "Error during printing the serial.\n");
for (i=0; i<asn1_serial->length; i++) {
if (BIO_printf(outbio,"%02x%c",asn1_serial->data[i],
((i+1 == asn1_serial-<length)?'\n':':')) <= 0)
BIO_printf(outbio, "Error during printing the serial.\n");
}
}
X509_free(cert);
BIO_free_all(certbio);
BIO_free_all(outbio);
exit(0);
}