From a3e407bef759081d9844722ee8e9b72d6881bfaf Mon Sep 17 00:00:00 2001 From: Manorit Chawdhry Date: Fri, 29 Dec 2023 16:16:26 +0530 Subject: [PATCH] binman: ti-secure: Add support for firewalling entities We can now firewall entities while loading them through our secure entity TIFS, the required information should be present in the certificate that is being parsed by TIFS. The following commit adds the support to enable the certificates to be generated if the firewall configurations are present in the binman dtsi nodes. Reviewed-by: Simon Glass Signed-off-by: Manorit Chawdhry --- tools/binman/btool/openssl.py | 16 +++++- tools/binman/etype/ti_secure.py | 95 +++++++++++++++++++++++++++++++++ tools/binman/etype/x509_cert.py | 4 +- 3 files changed, 112 insertions(+), 3 deletions(-) diff --git a/tools/binman/btool/openssl.py b/tools/binman/btool/openssl.py index 7ee2683ab2..fe81a1f51b 100644 --- a/tools/binman/btool/openssl.py +++ b/tools/binman/btool/openssl.py @@ -82,7 +82,7 @@ imageSize = INTEGER:{len(indata)} return self.run_cmd(*args) def x509_cert_sysfw(self, cert_fname, input_fname, key_fname, sw_rev, - config_fname, req_dist_name_dict): + config_fname, req_dist_name_dict, firewall_cert_data): """Create a certificate to be booted by system firmware Args: @@ -94,6 +94,13 @@ imageSize = INTEGER:{len(indata)} req_dist_name_dict (dict): Dictionary containing key-value pairs of req_distinguished_name section extensions, must contain extensions for C, ST, L, O, OU, CN and emailAddress + firewall_cert_data (dict): + - auth_in_place (int): The Priv ID for copying as the + specific host in firewall protected region + - num_firewalls (int): The number of firewalls in the + extended certificate + - certificate (str): Extended firewall certificate with + the information for the firewall configurations. Returns: str: Tool output @@ -121,6 +128,7 @@ basicConstraints = CA:true 1.3.6.1.4.1.294.1.3 = ASN1:SEQUENCE:swrv 1.3.6.1.4.1.294.1.34 = ASN1:SEQUENCE:sysfw_image_integrity 1.3.6.1.4.1.294.1.35 = ASN1:SEQUENCE:sysfw_image_load +1.3.6.1.4.1.294.1.37 = ASN1:SEQUENCE:firewall [ swrv ] swrv = INTEGER:{sw_rev} @@ -132,7 +140,11 @@ imageSize = INTEGER:{len(indata)} [ sysfw_image_load ] destAddr = FORMAT:HEX,OCT:00000000 -authInPlace = INTEGER:2 +authInPlace = INTEGER:{hex(firewall_cert_data['auth_in_place'])} + +[ firewall ] +numFirewallRegions = INTEGER:{firewall_cert_data['num_firewalls']} +{firewall_cert_data['certificate']} ''', file=outf) args = ['req', '-new', '-x509', '-key', key_fname, '-nodes', '-outform', 'DER', '-out', cert_fname, '-config', config_fname, diff --git a/tools/binman/etype/ti_secure.py b/tools/binman/etype/ti_secure.py index d939dce571..704dcf8a38 100644 --- a/tools/binman/etype/ti_secure.py +++ b/tools/binman/etype/ti_secure.py @@ -7,9 +7,44 @@ from binman.entry import EntryArg from binman.etype.x509_cert import Entry_x509_cert +from dataclasses import dataclass from dtoc import fdt_util +@dataclass +class Firewall(): + id: int + region: int + control : int + permissions: list + start_address: str + end_address: str + + def ensure_props(self, etype, name): + missing_props = [] + for key, val in self.__dict__.items(): + if val is None: + missing_props += [key] + + if len(missing_props): + etype.Raise(f"Subnode '{name}' is missing properties: {','.join(missing_props)}") + + def get_certificate(self) -> str: + unique_identifier = f"{self.id}{self.region}" + cert = f""" +firewallID{unique_identifier} = INTEGER:{self.id} +region{unique_identifier} = INTEGER:{self.region} +control{unique_identifier} = INTEGER:{hex(self.control)} +nPermissionRegs{unique_identifier} = INTEGER:{len(self.permissions)} +""" + for index, permission in enumerate(self.permissions): + cert += f"""permissions{unique_identifier}{index} = INTEGER:{hex(permission)} +""" + cert += f"""startAddress{unique_identifier} = FORMAT:HEX,OCT:{self.start_address:02x} +endAddress{unique_identifier} = FORMAT:HEX,OCT:{self.end_address:02x} +""" + return cert + class Entry_ti_secure(Entry_x509_cert): """Entry containing a TI x509 certificate binary @@ -17,6 +52,11 @@ class Entry_ti_secure(Entry_x509_cert): - content: List of phandles to entries to sign - keyfile: Filename of file containing key to sign binary with - sha: Hash function to be used for signing + - auth-in-place: This is an integer field that contains two pieces + of information + Lower Byte - Remains 0x02 as per our use case + ( 0x02: Move the authenticated binary back to the header ) + Upper Byte - The Host ID of the core owning the firewall Output files: - input. - input file passed to openssl @@ -25,6 +65,35 @@ class Entry_ti_secure(Entry_x509_cert): - cert. - output file generated by openssl (which is used as the entry contents) + Depending on auth-in-place information in the inputs, we read the + firewall nodes that describe the configurations of firewall that TIFS + will be doing after reading the certificate. + + The syntax of the firewall nodes are as such: + + firewall-257-0 { + id = <257>; /* The ID of the firewall being configured */ + region = <0>; /* Region number to configure */ + + control = /* The control register */ + <(FWCTRL_EN | FWCTRL_LOCK | FWCTRL_BG | FWCTRL_CACHE)>; + + permissions = /* The permission registers */ + <((FWPRIVID_ALL << FWPRIVID_SHIFT) | + FWPERM_SECURE_PRIV_RWCD | + FWPERM_SECURE_USER_RWCD | + FWPERM_NON_SECURE_PRIV_RWCD | + FWPERM_NON_SECURE_USER_RWCD)>; + + /* More defines can be found in k3-security.h */ + + start_address = /* The Start Address of the firewall */ + <0x0 0x0>; + end_address = /* The End Address of the firewall */ + <0xff 0xffffffff>; + }; + + openssl signs the provided data, using the TI templated config file and writes the signature in this entry. This allows verification that the data is genuine. @@ -32,11 +101,20 @@ class Entry_ti_secure(Entry_x509_cert): def __init__(self, section, etype, node): super().__init__(section, etype, node) self.openssl = None + self.firewall_cert_data: dict = { + 'auth_in_place': 0x02, + 'num_firewalls': 0, + 'certificate': '', + } def ReadNode(self): super().ReadNode() self.key_fname = self.GetEntryArgsOrProps([ EntryArg('keyfile', str)], required=True)[0] + auth_in_place = fdt_util.GetInt(self._node, 'auth-in-place') + if auth_in_place: + self.firewall_cert_data['auth_in_place'] = auth_in_place + self.ReadFirewallNode() self.sha = fdt_util.GetInt(self._node, 'sha', 512) self.req_dist_name = {'C': 'US', 'ST': 'TX', @@ -46,6 +124,23 @@ class Entry_ti_secure(Entry_x509_cert): 'CN': 'TI Support', 'emailAddress': 'support@ti.com'} + def ReadFirewallNode(self): + self.firewall_cert_data['certificate'] = "" + self.firewall_cert_data['num_firewalls'] = 0 + for node in self._node.subnodes: + if 'firewall' in node.name: + firewall = Firewall( + fdt_util.GetInt(node, 'id'), + fdt_util.GetInt(node, 'region'), + fdt_util.GetInt(node, 'control'), + fdt_util.GetPhandleList(node, 'permissions'), + fdt_util.GetInt64(node, 'start_address'), + fdt_util.GetInt64(node, 'end_address'), + ) + firewall.ensure_props(self, node.name) + self.firewall_cert_data['num_firewalls'] += 1 + self.firewall_cert_data['certificate'] += firewall.get_certificate() + def GetCertificate(self, required): """Get the contents of this entry diff --git a/tools/binman/etype/x509_cert.py b/tools/binman/etype/x509_cert.py index fc0bb12278..29630d1b86 100644 --- a/tools/binman/etype/x509_cert.py +++ b/tools/binman/etype/x509_cert.py @@ -51,6 +51,7 @@ class Entry_x509_cert(Entry_collection): self.hashval_sysfw_data = None self.sysfw_inner_cert_ext_boot_block = None self.dm_data_ext_boot_block = None + self.firewall_cert_data = None def ReadNode(self): super().ReadNode() @@ -98,7 +99,8 @@ class Entry_x509_cert(Entry_collection): key_fname=self.key_fname, config_fname=config_fname, sw_rev=self.sw_rev, - req_dist_name_dict=self.req_dist_name) + req_dist_name_dict=self.req_dist_name, + firewall_cert_data=self.firewall_cert_data) elif type == 'rom': stdout = self.openssl.x509_cert_rom( cert_fname=output_fname,