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| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | generate-test-cases | 66 |
2 files changed, 67 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..668df9a --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +aes_keywrap.pyc diff --git a/generate-test-cases b/generate-test-cases new file mode 100644 index 0000000..2e40d5f --- /dev/null +++ b/generate-test-cases @@ -0,0 +1,66 @@ +#!/usr/bin/env python + +""" +Generate test cases for AES Key Wrap, RFC 5649, for all key lengths +rather than just the 192-bit test vectors given in the RFC. +""" + +# Motivation: The test vectors in the RFC happen to be for the one +# size of AES key which our AES core doesn't support (sigh), so +# they're useless for testing our code. An external implementation +# would be ideal, but failing that, generating test vectors with an +# implementation that supports all key lengths and which got the right +# answers for the 192-bit case seems like the best bet. We do this +# using our Python test implementation, because it's easier, but, more +# importantly, because it shares no code (just an author) with the C +# code we want to test. + +from aes_keywrap import (KEK, hex2bin, + block_wrap_key, block_unwrap_key, + array_wrap_key, array_unwrap_key) +from argparse import ArgumentParser, FileType +from textwrap import TextWrapper +from cryptlib_py import * +import sys, os, atexit + +wrapper = TextWrapper(width = 78, initial_indent = " " * 2, subsequent_indent = " " * 2) + +def dump_hex(name, value, comment): + args.output.write("\nstatic const uint8_t %s[] = { /* %s, %d bytes */\n" % (name, comment, len(value))) + args.output.write(wrapper.fill(", ".join("0x%02x" % ord(v) for v in value))) + args.output.write("\n};\n") + +parser = ArgumentParser(description = __doc__) +parser.add_argument("--plaintext", help = "specify plaintext to be encrypted") +parser.add_argument("--kek-128", help = "specify 128-bit KEK to use") +parser.add_argument("--kek-256", help = "specify 256-bit KEK to use") +parser.add_argument("output", nargs = "?", type = FileType("w"), default = sys.stdout, help = "output file") +args = parser.parse_args() + +def generate_and_test(K): + C = array_wrap_key(Q, K) + if block_wrap_key(Q, K) != C: + raise RuntimeError + if array_unwrap_key(C, K) != Q: + raise RuntimeError + if block_unwrap_key(C, K) != Q: + raise RuntimeError + return C + +cryptInit() +atexit.register(cryptEnd) + +Q = args.plaintext or "Hello! My name is Inigo Montoya. You broke my AES key wrapper. Prepare to die." + +K_128 = hex2bin(args.kek_128) if args.kek_128 else os.urandom(128 / 8) +K_256 = hex2bin(args.kek_256) if args.kek_256 else os.urandom(256 / 8) + +C_128 = generate_and_test(KEK(K_128)) +C_256 = generate_and_test(KEK(K_256)) + +args.output.write("/* Automated AES Key Wrap test cases generated by %s */\n" % os.path.basename(sys.argv[0])) +dump_hex("Q", Q, "Plaintext") +dump_hex("K_128", K_128, "128-bit KEK") +dump_hex("K_256", K_256, "256-bit KEK") +dump_hex("C_128", C_128, "Plaintext wrapped by 128-bit KEK") +dump_hex("C_256", C_256, "Plaintext wrapped by 256-bit KEK") |