commit cba7122d74fce7bc73f457920c818b12009766f6
author Hanno Becker <hanno.becker@arm.com> Wed Sep 11 14:15:10 2019 +0100
committer Hanno Becker <hanno.becker@arm.com> Fri Jan 31 15:37:26 2020 +0000
tree 86d4f40262194f82e0cbf435eb7c2666889969bb
parent 819799cfc68e4c4381673a8a27af19802c8263f2

ASN.1: Add helper macro to detect string types

include/mbedtls/asn1.h

diff --git a/include/mbedtls/asn1.h b/include/mbedtls/asn1.h
index 1c6683f..1cfd414 100644
--- a/include/mbedtls/asn1.h
+++ b/include/mbedtls/asn1.h
@@ -90,6 +90,18 @@
 #define MBEDTLS_ASN1_CONSTRUCTED             0x20
 #define MBEDTLS_ASN1_CONTEXT_SPECIFIC        0x80
 
+/* Slightly smaller way to check if tag is a string tag
+ * compared to canonical implementation. */
+#define MBEDTLS_ASN1_IS_STRING_TAG( tag )                                     \
+    ( ( tag ) < 32u && (                                                      \
+        ( ( 1u << ( tag ) ) & ( ( 1u << MBEDTLS_ASN1_BMP_STRING )       |     \
+                                ( 1u << MBEDTLS_ASN1_UTF8_STRING )      |     \
+                                ( 1u << MBEDTLS_ASN1_T61_STRING )       |     \
+                                ( 1u << MBEDTLS_ASN1_IA5_STRING )       |     \
+                                ( 1u << MBEDTLS_ASN1_UNIVERSAL_STRING ) |     \
+                                ( 1u << MBEDTLS_ASN1_PRINTABLE_STRING ) |     \
+                                ( 1u << MBEDTLS_ASN1_BIT_STRING ) ) ) != 0 ) )
+
 /*
  * Bit masks for each of the components of an ASN.1 tag as specified in
  * ITU X.690 (08/2015), section 8.1 "General rules for encoding",