1// Copyright 2024 The BoringSSL Authors 2// 3// Permission to use, copy, modify, and/or distribute this software for any 4// purpose with or without fee is hereby granted, provided that the above 5// copyright notice and this permission notice appear in all copies. 6// 7// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 8// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 9// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 10// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 11// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION 12// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 13// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 14 15//go:build ignore 16 17// This trivial program is used to corrupt the FIPS module. This is done as 18// part of FIPS testing to show that the integrity check is effective. 19// 20// It finds the (sole) occurance of a given hex pattern in a file and flips the 21// first bit. The hex pattern is intended to be the output of running 22// `BORINGSSL_FIPS_SHOW_HASH=1 ninja bcm.o`, i.e. the integrity hash value of 23// the module. By flipping the first bit we ensure that the check will 24// mismatch. 25// 26// This is a simplier version of `break-hash.go` for when we're building with 27// BORINGSSL_FIPS_SHOW_HASH. (But we don't do that in all cases.) 28 29package main 30 31import ( 32 "bytes" 33 "encoding/hex" 34 "fmt" 35 "io/ioutil" 36 "os" 37) 38 39func main() { 40 if len(os.Args) != 3 { 41 fmt.Fprintln(os.Stderr, "Usage: program <hex_string> <file_path>") 42 os.Exit(1) 43 } 44 45 hexString := os.Args[1] 46 filePath := os.Args[2] 47 48 // Decode hex string 49 searchBytes, err := hex.DecodeString(hexString) 50 if err != nil { 51 fmt.Fprintln(os.Stderr, "Error decoding hex string:", err) 52 os.Exit(1) 53 } 54 55 // Read file contents 56 content, err := ioutil.ReadFile(filePath) 57 if err != nil { 58 fmt.Fprintln(os.Stderr, "Error reading file:", err) 59 os.Exit(1) 60 } 61 62 // Search for the occurrence of the hex string 63 index := bytes.Index(content, searchBytes) 64 if index == -1 { 65 fmt.Fprintln(os.Stderr, "Hex string not found in the file") 66 os.Exit(1) 67 } 68 69 // Check for other occurrences 70 if bytes.Index(content[index+len(searchBytes):], searchBytes) != -1 { 71 fmt.Fprintln(os.Stderr, "Multiple occurrences of the hex string found") 72 os.Exit(1) 73 } 74 75 // Flip the first bit 76 content[index] ^= 0x80 77 78 // Write updated contents to stdout 79 os.Stdout.Write(content) 80} 81