Add X.509 CRT verification API using trusted CA callbacks
@@ -501,6 +501,70 @@ int mbedtls_x509_crt_verify_restartable( mbedtls_x509_crt *crt,
void *p_vrfy,
mbedtls_x509_crt_restart_ctx *rs_ctx );
+#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
+/**
+ * \brief The type of trusted certificate callbacks.
+ *
+ * Callbacks of this type are passed to and used by the CRT
+ * verification routine mbedtls_x509_crt_verify_with_cb()
+ * when looking for trusted signers of a given certificate.
+ *
+ * On success, the callback returns a list of trusted
+ * certificates to be considered as potential signers
+ * for the input certificate.
+ *
+ * \param p_ctx An opaque context passed to the callback.
+ * \param child The certificate for which to search a potential signer.
+ * This must point to a readable certificate.
+ * \param candidate_cas The address at which to store the address of the first
+ * entry in the generated linked list of candidate signers.
+ * This must not be \c NULL.
+ *
+ * \note The callback must only return a non-zero value on a
+ * fatal error. If, in contrast, the search for a potential
+ * signer completes without a single candidate, the
+ * callback must return \c 0 and get \c *candidate_cas
+ * to \c NULL.
+ *
+ * \return \c 0 on success. In this case, \c *candidate_cas points
+ * to a heap-allocated linked list of instances of
+ * ::mbedtls_x509_crt, and ownership of this list is passed
+ * to the caller.
+ * \return A negative error code on failure.
+ */
+typedef int (*mbedtls_x509_crt_ca_cb_t)( void *p_ctx,
+ mbedtls_x509_crt const *child,
+ mbedtls_x509_crt **candidate_cas );
+/**
+ * \brief Version of \c mbedtls_x509_crt_verify_with_profile() which
+ * uses a callback to acquire the list of trusted CA
+ * certificates.
+ *
+ * \param crt The certificate chain to be verified.
+ * \param f_ca_cb The callback to be used to query for potential signers
+ * of a given child certificate. See the documentation of
+ * ::mbedtls_x509_crt_ca_cb_t for more information.
+ * \param p_ca_cb The opaque context to be passed to \p f_ca_cb.
+ * \param profile The security profile for the verification.
+ * \param cn The expected Common Name. This may be \c NULL if the
+ * CN need not be verified.
+ * \param flags The address at which to store the result of the verification.
+ * \param f_vrfy The verification callback to use. See the documentation
+ * of mbedtls_x509_crt_verify() for more information.
+ * \param p_vrfy The context to be passed to \p f_vrfy.
+ *
+ * \return See \c mbedtls_crt_verify_with_profile().
+ */
+int mbedtls_x509_crt_verify_with_cb( mbedtls_x509_crt *crt,
+ mbedtls_x509_crt_ca_cb_t f_ca_cb,
+ void *p_ca_cb,
+ const mbedtls_x509_crt_profile *profile,
+ const char *cn, uint32_t *flags,
+ int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
+ void *p_vrfy );
+
+#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
+
#if defined(MBEDTLS_X509_CHECK_KEY_USAGE)
/**
* \brief Check usage of certificate against keyUsage extension.
