Add new function mbedtls_asn1_write_named_bitstring()
Add a new function mbedtls_asn1_write_named_bitstring() that removes
trailing 0s at the end of DER encoded bitstrings. The function is
implemented according to Hanno Becker's suggestions.
This commit also changes the functions x509write_crt_set_ns_cert_type
and crt_set_key_usage to call the new function as the use named
bitstrings instead of the regular bitstrings.
diff --git a/library/x509write_csr.c b/library/x509write_csr.c
index 777a632..8dc39e7 100644
--- a/library/x509write_csr.c
+++ b/library/x509write_csr.c
@@ -94,12 +94,13 @@
c = buf + 4;
- if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
+ ret = mbedtls_asn1_write_named_bitstring( &c, buf, &key_usage, 8 );
+ if( ret < 3 || ret > 4 )
return( ret );
ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
- buf, 4 );
+ c, (size_t)ret );
if( ret != 0 )
return( ret );
@@ -115,12 +116,13 @@
c = buf + 4;
- if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
+ ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
+ if( ret < 3 || ret > 4 )
return( ret );
ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
- buf, 4 );
+ c, (size_t)ret );
if( ret != 0 )
return( ret );