/* * Copyright (c) 2020 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ #include <IOKit/IOLib.h> #include <kern/debug.h> // for panic() #include <libkern/ptrauth_utils.h> #if __has_feature(ptrauth_calls) /* * ptrauth_utils_sign_blob_generic * * Sign a blob of data with the GA key * */ ptrauth_generic_signature_t ptrauth_utils_sign_blob_generic(void * ptr, size_t len_bytes, uint64_t data, int flags) { ptrauth_generic_signature_t sig = 0; uint64_t rounds = len_bytes / sizeof(uintptr_t); size_t ntrailing = len_bytes % sizeof(uintptr_t); uintptr_t trailing = 0; if (ptr == NULL) { return 0; } /* If address diversification is requested, mix the blob address with the salt */ if (flags & PTRAUTH_ADDR_DIVERSIFY) { data ^= (uint64_t)ptr; } /* First round adds salt */ sig = ptrauth_sign_generic_data(sig, data); /* Calculate an additive signature of the buffer */ for (uint64_t i = 0; i < rounds; i++) { sig = ptrauth_sign_generic_data(*(uintptr_t *)ptr, sig); ptr += sizeof(uintptr_t); } /* ptrauth_sign_generic_data operates on pointer-sized values only, * so we need to handle trailing bytes for the non-pointer-aligned case */ if (ntrailing) { memcpy(&trailing, ptr, ntrailing); sig = ptrauth_sign_generic_data(trailing, sig); } return sig; } /* * ptrauth_utils_auth_blob_generic * * Authenticate signature produced by ptrauth_utils_sign_blob_generic */ void ptrauth_utils_auth_blob_generic(void * ptr, size_t len_bytes, uint64_t data, int flags, ptrauth_generic_signature_t signature) { ptrauth_generic_signature_t calculated_signature = 0; if (ptr == NULL) { if (flags & PTRAUTH_NON_NULL) { panic("ptrauth_utils_auth_blob_generic: ptr must not be NULL"); } else { return; } } if ((calculated_signature = ptrauth_utils_sign_blob_generic(ptr, len_bytes, data, flags)) == signature) { return; } else { panic("signature mismatch for %lu bytes at %p, calculated %lx vs %lx", len_bytes, ptr, calculated_signature, signature); } } #endif //!ptrauth_calls