Add macros to ASN.1 module to parse ASN.1 tags

The macros simply extract the component bits of an ASN.1 tag value
This commit is contained in:
Andres Amaya Garcia 2017-08-25 17:12:11 +01:00 committed by Andres Amaya Garcia
parent 6f63db7ed5
commit 7512bf7d63

View file

@ -87,6 +87,22 @@
#define MBEDTLS_ASN1_PRIMITIVE 0x00
#define MBEDTLS_ASN1_CONSTRUCTED 0x20
#define MBEDTLS_ASN1_CONTEXT_SPECIFIC 0x80
/*
* Bit masks for each of the components of an ASN.1 tag as specified in
* Information technnology - ASN.1 encoding rules: Specification of Basic
* Encoding Rules (BER), Canonical Encoding Rules (CER), and Distinguished
* encoding rules (DER) Section 8.1.2.2:
*
* Bit 8 7 6 5 1
* +-------+-----+------------+
* | Class | P/C | Tag number |
* +-------+-----+------------+
*/
#define MBEDTLS_ASN1_TAG_CLASS_MASK ( 0x03 << 6 )
#define MBEDTLS_ASN1_TAG_PC_MASK ( 0x01 << 5 )
#define MBEDTLS_ASN1_TAG_VALUE_MASK ( 0x1F << 0 )
/* \} name */
/* \} addtogroup asn1_module */