module_signing.c 1.1 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445
  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /* Module signature checker
  3. *
  4. * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  5. * Written by David Howells (dhowells@redhat.com)
  6. */
  7. #include <linux/kernel.h>
  8. #include <linux/errno.h>
  9. #include <linux/module.h>
  10. #include <linux/module_signature.h>
  11. #include <linux/string.h>
  12. #include <linux/verification.h>
  13. #include <crypto/public_key.h>
  14. #include "module-internal.h"
  15. /*
  16. * Verify the signature on a module.
  17. */
  18. int mod_verify_sig(const void *mod, struct load_info *info)
  19. {
  20. struct module_signature ms;
  21. size_t sig_len, modlen = info->len;
  22. int ret;
  23. pr_devel("==>%s(,%zu)\n", __func__, modlen);
  24. if (modlen <= sizeof(ms))
  25. return -EBADMSG;
  26. memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
  27. ret = mod_check_sig(&ms, modlen, "module");
  28. if (ret)
  29. return ret;
  30. sig_len = be32_to_cpu(ms.sig_len);
  31. modlen -= sig_len + sizeof(ms);
  32. info->len = modlen;
  33. return verify_pkcs7_signature(mod, modlen, mod + modlen, sig_len,
  34. VERIFY_USE_SECONDARY_KEYRING,
  35. VERIFYING_MODULE_SIGNATURE,
  36. NULL, NULL);
  37. }