Only return VERIFY_FAILED from a single point
Everything else is a fatal error. Also improve documentation about that for
the vrfy callback.
diff --git a/library/error.c b/library/error.c
index 98fba5c..be642ca 100644
--- a/library/error.c
+++ b/library/error.c
@@ -496,6 +496,8 @@
polarssl_snprintf( buf, buflen, "X509 - Allocation of memory failed" );
if( use_ret == -(POLARSSL_ERR_X509_FILE_IO_ERROR) )
polarssl_snprintf( buf, buflen, "X509 - Read/write of file failed" );
+ if( use_ret == -(POLARSSL_ERR_X509_FATAL_ERROR) )
+ polarssl_snprintf( buf, buflen, "X509 - A fatal error occured, eg the chain is too long or the vrfy callback failed" );
#endif /* POLARSSL_X509_USE,X509_CREATE_C */
// END generated code
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 70ad356..fb09253 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -1957,8 +1957,8 @@
/* path_cnt is 0 for the first intermediate CA */
if( 1 + path_cnt > POLARSSL_X509_MAX_INTERMEDIATE_CA )
{
- *flags |= BADCERT_NOT_TRUSTED;
- return( POLARSSL_ERR_X509_CERT_VERIFY_FAILED );
+ /* return immediately as the goal is to avoid unbounded recursion */
+ return( POLARSSL_ERR_X509_FATAL_ERROR );
}
if( x509_time_expired( &child->valid_to ) )
@@ -2174,6 +2174,10 @@
}
exit:
+ /* prevent misuse of the vrfy callback */
+ if( ret == POLARSSL_ERR_X509_CERT_VERIFY_FAILED )
+ ret = POLARSSL_ERR_X509_FATAL_ERROR;
+
if( ret != 0 )
{
*flags = (uint32_t) -1;