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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** NetX Secure Component */
/** */
/** X.509 Digital Certificates */
/** */
/**************************************************************************/
/**************************************************************************/
#define NX_SECURE_SOURCE_CODE
#include "nx_secure_x509.h"
#ifdef NX_SECURE_ENABLE_ECC_CIPHERSUITE
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _nx_secure_x509_ec_private_key_parse PORTABLE C */
/* 6.1.10 */
/* AUTHOR */
/* */
/* Timothy Stapko, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function parses a DER-encoded private EC key for use with */
/* X509 certificates. */
/* */
/* INPUT */
/* */
/* buffer Pointer data to be parsed */
/* length Length of data in buffer */
/* bytes_processed Return bytes processed */
/* ec_key Return EC key structure */
/* */
/* OUTPUT */
/* */
/* status Completion status */
/* */
/* CALLS */
/* */
/* _nx_secure_x509_asn1_tlv_block_parse Parse ASN.1 block */
/* */
/* CALLED BY */
/* */
/* _nx_secure_x509_certificate_initialize */
/* Initialize certificate */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Timothy Stapko Initial Version 6.0 */
/* 09-30-2020 Timothy Stapko Modified comment(s), */
/* resulting in version 6.1 */
/* 04-02-2021 Timothy Stapko Modified comment(s), */
/* removed dependency on TLS, */
/* resulting in version 6.1.6 */
/* 01-31-2022 Timothy Stapko Modified comment(s), */
/* ignored public key in EC */
/* private key, */
/* resulting in version 6.1.10 */
/* */
/**************************************************************************/
UINT _nx_secure_x509_ec_private_key_parse(const UCHAR *buffer, UINT length,
UINT *bytes_processed,
NX_SECURE_EC_PRIVATE_KEY *ec_key)
{
USHORT tlv_type;
USHORT tlv_type_class;
ULONG tlv_length;
ULONG seq_length;
const UCHAR *tlv_data;
ULONG header_length;
UINT status;
USHORT version;
/* Parse an ASN.1 DER-encoded EC private key file. */
/* From RFC 5915. */
/* ECPrivateKey ::= SEQUENCE { */
/* version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1), */
/* privateKey OCTET STRING, */
/* parameters [0] ECParameters {{ NamedCurve }} OPTIONAL, */
/* publicKey [1] BIT STRING OPTIONAL */
/* } */
/* */
/* ECParameters ::= CHOICE { */
/* namedCurve OBJECT IDENTIFIER */
/* -- implicitCurve NULL */
/* -- specifiedCurve SpecifiedECDomain */
/* Parse a TLV block and get information to continue parsing. */
status = _nx_secure_x509_asn1_tlv_block_parse(buffer, (ULONG *)&length, &tlv_type, &tlv_type_class, &tlv_length, &tlv_data, &header_length);
/* Make sure we parsed the block alright. */
if (status != 0)
{
return(status);
}
if (tlv_type != NX_SECURE_ASN_TAG_SEQUENCE || tlv_type_class != NX_SECURE_ASN_TAG_CLASS_UNIVERSAL)
{
return(NX_SECURE_X509_INVALID_CERTIFICATE_SEQUENCE);
}
*bytes_processed = header_length;
length = tlv_length;
/* First item in the EC key sequence is a version field. */
status = _nx_secure_x509_asn1_tlv_block_parse(tlv_data, (ULONG *)&length, &tlv_type, &tlv_type_class, &tlv_length, &tlv_data, &header_length);
/* Make sure we parsed the block alright. */
if (status != 0)
{
return(status);
}
if (tlv_type != NX_SECURE_ASN_TAG_INTEGER || tlv_type_class != NX_SECURE_ASN_TAG_CLASS_UNIVERSAL)
{
return(NX_SECURE_PKCS1_INVALID_PRIVATE_KEY);
}
/* Update byte count. */
*bytes_processed += (header_length + tlv_length);
/* Version shall be one. */
version = tlv_data[0];
if (version != 0x01)
{
return(NX_SECURE_PKCS1_INVALID_PRIVATE_KEY);
}
/* Advance our working pointer past the last field. */
tlv_data = &tlv_data[tlv_length];
/* Parse our next field, the private key. */
status = _nx_secure_x509_asn1_tlv_block_parse(tlv_data, (ULONG *)&length, &tlv_type, &tlv_type_class, &tlv_length, &tlv_data, &header_length);
/* Make sure we parsed the block alright. */
if (status != 0)
{
return(status);
}
if (tlv_type != NX_SECURE_ASN_TAG_OCTET_STRING || tlv_type_class != NX_SECURE_ASN_TAG_CLASS_UNIVERSAL)
{
return(NX_SECURE_PKCS1_INVALID_PRIVATE_KEY);
}
/* Update byte count. */
*bytes_processed += (header_length + tlv_length);
/* The private key is an octet string, so no padding bytes are needed (as with a BITSTRING). */
if (ec_key != NULL)
{
ec_key -> nx_secure_ec_private_key = tlv_data;
ec_key -> nx_secure_ec_private_key_length = (USHORT)tlv_length;
}
/* Advance our working pointer past the last field. */
tlv_data = &tlv_data[tlv_length];
/* Parse our next field, the EC parameter. */
status = _nx_secure_x509_asn1_tlv_block_parse(tlv_data, (ULONG *)&length, &tlv_type, &tlv_type_class, &tlv_length, &tlv_data, &header_length);
/* Make sure we parsed the block alright. */
if (status != 0)
{
return(status);
}
if (tlv_type != 0 || tlv_type_class != NX_SECURE_ASN_TAG_CLASS_CONTEXT)
{
return(NX_SECURE_PKCS1_INVALID_PRIVATE_KEY);
}
/* Update byte count. */
*bytes_processed += header_length;
seq_length = tlv_length;
/* Parse the namedCurve. */
status = _nx_secure_x509_asn1_tlv_block_parse(tlv_data, &seq_length, &tlv_type, &tlv_type_class, &tlv_length, &tlv_data, &header_length);
/* Make sure we parsed the block alright. */
if (status != 0)
{
return(status);
}
if (tlv_type != NX_SECURE_ASN_TAG_OID || tlv_type_class != NX_SECURE_ASN_TAG_CLASS_UNIVERSAL)
{
return(NX_SECURE_PKCS1_INVALID_PRIVATE_KEY);
}
/* Update byte count. */
*bytes_processed += (header_length + tlv_length);
/* The value is an OID. */
if (ec_key != NULL)
{
/* The OID is in the data we extracted. */
_nx_secure_x509_oid_parse(tlv_data, tlv_length, &ec_key -> nx_secure_ec_named_curve);
}
/* The optional public key is ignored. */
return(NX_SECURE_X509_SUCCESS);
}
#endif /* NX_SECURE_ENABLE_ECC_CIPHERSUITE */