libec manual

Export & Import

Certificates may be exported / imported in either binary or base64-encoded form. Binary is more efficient and should be used by default in most cases - base64 is intended for scenarios where a user may need to interact with the certificate directly (for example, pasting into a web form).

A certificate's secret key will not be exported unless EC_EXPORT_SECRET is set, but will always be imported if available.

API

ec_export_len()

uint16_t ec_export_len(ec_cert_t *c, uint8_t export_flags);

Get the buffer length required to export a certificate with the given flags.

#include <ec.h>
...
unsigned char buf[ec_export_len(c, EC_EXPORT_SECRET)];
...

ec_export_len_64

size_t ec_export_len_64(ec_cert_t *c, uint8_t export_flags);

Identical to ec_export_len(), except returns the buffer length required to export to base64.

ec_export()

size_t ec_export(unsigned char *dest, ec_cert_t *c, uint8_t export_flags);

Export a certificate to the given buffer. Returns the number of bytes written to the buffer, or zero on failure.

#include <ec.h>
...
size_t bytes_written = ec_export(buf, c, EC_EXPORT_SECRET);
if(bytes_written == 0) {
    //failed to export certificate
}
...

ec_export_64()

char *ec_export_64(char *dest, ec_cert_t *c, uint8_t export_flags);

Identical to ec_export(), except that the certificate is base64-encoded and armoured before writing to dest. Returns dest on success, or NULL on failure.

ec_import()

ec_cert_t *ec_import(unsigned char *src, size_t length, size_t *consumed);

Import a certificate from a buffer. Returns a certificate on success, or NULL otherwise.

If consumed is not NULL, then the number of bytes consumed from src will be stored there. On error, this value is considered undefined.

The certificate is tested with EC_CHECK_CERT before returning - if it does not pass, the import is considered to have failed and NULL is returned.

#include <ec.h>
...
ec_cert_t *c = ec_import(buf, buf_size);
if(c != NULL) {
    //imported successfully
}
...

ec_import_64()

ec_cert_t *ec_import_64(char *src, size_t length, size_t *consumed);

Identical to ec_import(), except interprets the buffer as armoured and base64-encoded. The certificate may be present at any offset in the buffer, provided that the envelope is intact.