Makefile 5.0 KB

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  1. # SPDX-License-Identifier: GPL-2.0
  2. #
  3. # Makefile for the linux kernel signature checking certificates.
  4. #
  5. obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o common.o
  6. obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o common.o
  7. obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
  8. ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
  9. obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
  10. else
  11. obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
  12. endif
  13. ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
  14. $(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
  15. # GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
  16. $(obj)/system_certificates.o: $(obj)/x509_certificate_list
  17. # Cope with signing_key.x509 existing in $(srctree) not $(objtree)
  18. AFLAGS_system_certificates.o := -I$(srctree)
  19. quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2))
  20. cmd_extract_certs = scripts/extract-cert $(2) $@
  21. targets += x509_certificate_list
  22. $(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
  23. $(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
  24. endif # CONFIG_SYSTEM_TRUSTED_KEYRING
  25. clean-files := x509_certificate_list .x509.list x509_revocation_list
  26. ifeq ($(CONFIG_MODULE_SIG),y)
  27. ###############################################################################
  28. #
  29. # If module signing is requested, say by allyesconfig, but a key has not been
  30. # supplied, then one will need to be generated to make sure the build does not
  31. # fail and that the kernel may be used afterwards.
  32. #
  33. ###############################################################################
  34. ifndef CONFIG_MODULE_SIG_HASH
  35. $(error Could not determine digest type to use from kernel config)
  36. endif
  37. redirect_openssl = 2>&1
  38. quiet_redirect_openssl = 2>&1
  39. silent_redirect_openssl = 2>/dev/null
  40. openssl_available = $(shell openssl help 2>/dev/null && echo yes)
  41. # We do it this way rather than having a boolean option for enabling an
  42. # external private key, because 'make randconfig' might enable such a
  43. # boolean option and we unfortunately can't make it depend on !RANDCONFIG.
  44. ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
  45. ifeq ($(openssl_available),yes)
  46. X509TEXT=$(shell openssl x509 -in "certs/signing_key.pem" -text 2>/dev/null)
  47. $(if $(findstring rsaEncryption,$(X509TEXT)),,$(shell rm -f "certs/signing_key.pem"))
  48. endif
  49. $(obj)/signing_key.pem: $(obj)/x509.genkey
  50. @$(kecho) "###"
  51. @$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
  52. @$(kecho) "###"
  53. @$(kecho) "### If this takes a long time, you might wish to run rngd in the"
  54. @$(kecho) "### background to keep the supply of entropy topped up. It"
  55. @$(kecho) "### needs to be run as root, and uses a hardware random"
  56. @$(kecho) "### number generator if one is available."
  57. @$(kecho) "###"
  58. $(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
  59. -batch -x509 -config $(obj)/x509.genkey \
  60. -outform PEM -out $(obj)/signing_key.pem \
  61. -keyout $(obj)/signing_key.pem \
  62. $($(quiet)redirect_openssl)
  63. @$(kecho) "###"
  64. @$(kecho) "### Key pair generated."
  65. @$(kecho) "###"
  66. $(obj)/x509.genkey:
  67. @$(kecho) Generating X.509 key generation config
  68. @echo >$@ "[ req ]"
  69. @echo >>$@ "default_bits = 4096"
  70. @echo >>$@ "distinguished_name = req_distinguished_name"
  71. @echo >>$@ "prompt = no"
  72. @echo >>$@ "string_mask = utf8only"
  73. @echo >>$@ "x509_extensions = myexts"
  74. @echo >>$@
  75. @echo >>$@ "[ req_distinguished_name ]"
  76. @echo >>$@ "#O = Unspecified company"
  77. @echo >>$@ "CN = Build time autogenerated kernel key"
  78. @echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
  79. @echo >>$@
  80. @echo >>$@ "[ myexts ]"
  81. @echo >>$@ "basicConstraints=critical,CA:FALSE"
  82. @echo >>$@ "keyUsage=digitalSignature"
  83. @echo >>$@ "subjectKeyIdentifier=hash"
  84. @echo >>$@ "authorityKeyIdentifier=keyid"
  85. endif # CONFIG_MODULE_SIG_KEY
  86. $(eval $(call config_filename,MODULE_SIG_KEY))
  87. # If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
  88. ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
  89. X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
  90. endif
  91. # GCC PR#66871 again.
  92. $(obj)/system_certificates.o: $(obj)/signing_key.x509
  93. targets += signing_key.x509
  94. $(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
  95. $(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
  96. endif # CONFIG_MODULE_SIG
  97. ifeq ($(CONFIG_SYSTEM_REVOCATION_LIST),y)
  98. $(eval $(call config_filename,SYSTEM_REVOCATION_KEYS))
  99. $(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
  100. quiet_cmd_extract_certs = EXTRACT_CERTS $(patsubst "%",%,$(2))
  101. cmd_extract_certs = scripts/extract-cert $(2) $@
  102. targets += x509_revocation_list
  103. $(obj)/x509_revocation_list: scripts/extract-cert $(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(SYSTEM_REVOCATION_KEYS_FILENAME) FORCE
  104. $(call if_changed,extract_certs,$(SYSTEM_REVOCATION_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_REVOCATION_KEYS))
  105. endif