| Message ID | 20200901165143.10295-1-eric.snowberg@oracle.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [RFC] certs: Add EFI_CERT_X509_GUID support for dbx entries | expand |
On Tue, Sep 01, 2020 at 12:51:43PM -0400, Eric Snowberg wrote: > The Secure Boot Forbidden Signature Database, dbx, contains a list of now > revoked signatures and keys previously approved to boot with UEFI Secure > Boot enabled. The dbx is capable of containing any number of > EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID > entries. > > Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are > skipped. > > This change adds support for EFI_CERT_X509_GUID dbx entries. When a > EFI_CERT_X509_GUID is found, it is added as an asymmetrical key to the > .blacklist keyring. Anytime the .platform keyring is used, the keys in > the .blacklist keyring are referenced, if a matching key is found, the > key will be rejected. > > Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> In the last paragraph, please use imperative form: "Add support for ...". > --- > certs/blacklist.c | 36 +++++++++++++++++++ > certs/system_keyring.c | 6 ++++ > include/keys/system_keyring.h | 11 ++++++ > .../platform_certs/keyring_handler.c | 11 ++++++ > 4 files changed, 64 insertions(+) > > diff --git a/certs/blacklist.c b/certs/blacklist.c > index 6514f9ebc943..17ebf50cf0ae 100644 > --- a/certs/blacklist.c > +++ b/certs/blacklist.c > @@ -15,6 +15,7 @@ > #include <linux/err.h> > #include <linux/seq_file.h> > #include <keys/system_keyring.h> > +#include <crypto/pkcs7.h> > #include "blacklist.h" > > static struct key *blacklist_keyring; > @@ -100,6 +101,41 @@ int mark_hash_blacklisted(const char *hash) > return 0; > } > > +int mark_key_revocationlisted(const char *data, size_t size) > +{ > + key_ref_t key; > + > + key = key_create_or_update(make_key_ref(blacklist_keyring, true), > + "asymmetric", > + NULL, > + data, > + size, > + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | > + KEY_USR_VIEW), > + KEY_ALLOC_NOT_IN_QUOTA | > + KEY_ALLOC_BUILT_IN); > + > + if (IS_ERR(key)) { > + pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key)); > + return PTR_ERR(key); > + } > + > + return 0; > +} > + > +int is_key_revocationlisted(struct pkcs7_message *pkcs7) > +{ > + int ret; > + > + ret = pkcs7_validate_trust(pkcs7, blacklist_keyring); > + > + if (ret == 0) > + return -EKEYREJECTED; > + > + return -ENOKEY; > +} > +EXPORT_SYMBOL_GPL(is_key_revocationlisted); > + > /** > * is_hash_blacklisted - Determine if a hash is blacklisted > * @hash: The hash to be checked as a binary blob > diff --git a/certs/system_keyring.c b/certs/system_keyring.c > index 798291177186..f8ea96219155 100644 > --- a/certs/system_keyring.c > +++ b/certs/system_keyring.c > @@ -241,6 +241,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len, > pr_devel("PKCS#7 platform keyring is not available\n"); > goto error; > } > + > + ret = is_key_revocationlisted(pkcs7); > + if (ret != -ENOKEY) { > + pr_devel("PKCS#7 platform key revocationlisted\n"); > + goto error; > + } > } > ret = pkcs7_validate_trust(pkcs7, trusted_keys); > if (ret < 0) { > diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h > index fb8b07daa9d1..b6991cfe1b6d 100644 > --- a/include/keys/system_keyring.h > +++ b/include/keys/system_keyring.h > @@ -31,11 +31,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted( > #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted > #endif > > +extern struct pkcs7_message *pkcs7; > #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING > extern int mark_hash_blacklisted(const char *hash); > +extern int mark_key_revocationlisted(const char *data, size_t size); > extern int is_hash_blacklisted(const u8 *hash, size_t hash_len, > const char *type); > extern int is_binary_blacklisted(const u8 *hash, size_t hash_len); > +extern int is_key_revocationlisted(struct pkcs7_message *pkcs7); > #else > static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len, > const char *type) > @@ -47,6 +50,14 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len) > { > return 0; > } > +static inline int mark_key_revocationlisted(const char *data, size_t size) > +{ > + return 0; > +} > +static inline int is_key_revocationlisted(struct pkcs7_message *pkcs7) > +{ > + return -ENOKEY; > +} > #endif > > #ifdef CONFIG_IMA_BLACKLIST_KEYRING > diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c > index c5ba695c10e3..cc5a43804bc4 100644 > --- a/security/integrity/platform_certs/keyring_handler.c > +++ b/security/integrity/platform_certs/keyring_handler.c > @@ -55,6 +55,15 @@ static __init void uefi_blacklist_binary(const char *source, > uefi_blacklist_hash(source, data, len, "bin:", 4); > } > > +/* > + * Revocationlist the X509 cert > + */ > +static __init void uefi_revocationlist_x509(const char *source, > + const void *data, size_t len) > +{ > + mark_key_revocationlisted(data, len); > +} > + > /* > * Return the appropriate handler for particular signature list types found in > * the UEFI db and MokListRT tables. > @@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) > return uefi_blacklist_x509_tbs; > if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) > return uefi_blacklist_binary; > + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) > + return uefi_revocationlist_x509; > return 0; > } > -- > 2.18.1 > I did not find anything wrong with the code change. /Jarkko
> On Sep 4, 2020, at 6:59 AM, Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> wrote: > > On Tue, Sep 01, 2020 at 12:51:43PM -0400, Eric Snowberg wrote: >> The Secure Boot Forbidden Signature Database, dbx, contains a list of now >> revoked signatures and keys previously approved to boot with UEFI Secure >> Boot enabled. The dbx is capable of containing any number of >> EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID >> entries. >> >> Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are >> skipped. >> >> This change adds support for EFI_CERT_X509_GUID dbx entries. When a >> EFI_CERT_X509_GUID is found, it is added as an asymmetrical key to the >> .blacklist keyring. Anytime the .platform keyring is used, the keys in >> the .blacklist keyring are referenced, if a matching key is found, the >> key will be rejected. >> >> Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> > > In the last paragraph, please use imperative form: "Add support for …". I will change this in V2. > >> --- >> certs/blacklist.c | 36 +++++++++++++++++++ >> certs/system_keyring.c | 6 ++++ >> include/keys/system_keyring.h | 11 ++++++ >> .../platform_certs/keyring_handler.c | 11 ++++++ >> 4 files changed, 64 insertions(+) >> >> diff --git a/certs/blacklist.c b/certs/blacklist.c >> index 6514f9ebc943..17ebf50cf0ae 100644 >> --- a/certs/blacklist.c >> +++ b/certs/blacklist.c >> @@ -15,6 +15,7 @@ >> #include <linux/err.h> >> #include <linux/seq_file.h> >> #include <keys/system_keyring.h> >> +#include <crypto/pkcs7.h> >> #include "blacklist.h" >> >> static struct key *blacklist_keyring; >> @@ -100,6 +101,41 @@ int mark_hash_blacklisted(const char *hash) >> return 0; >> } >> >> +int mark_key_revocationlisted(const char *data, size_t size) >> +{ >> + key_ref_t key; >> + >> + key = key_create_or_update(make_key_ref(blacklist_keyring, true), >> + "asymmetric", >> + NULL, >> + data, >> + size, >> + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | >> + KEY_USR_VIEW), >> + KEY_ALLOC_NOT_IN_QUOTA | >> + KEY_ALLOC_BUILT_IN); >> + >> + if (IS_ERR(key)) { >> + pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key)); >> + return PTR_ERR(key); >> + } >> + >> + return 0; >> +} >> + >> +int is_key_revocationlisted(struct pkcs7_message *pkcs7) >> +{ >> + int ret; >> + >> + ret = pkcs7_validate_trust(pkcs7, blacklist_keyring); >> + >> + if (ret == 0) >> + return -EKEYREJECTED; >> + >> + return -ENOKEY; >> +} >> +EXPORT_SYMBOL_GPL(is_key_revocationlisted); >> + >> /** >> * is_hash_blacklisted - Determine if a hash is blacklisted >> * @hash: The hash to be checked as a binary blob >> diff --git a/certs/system_keyring.c b/certs/system_keyring.c >> index 798291177186..f8ea96219155 100644 >> --- a/certs/system_keyring.c >> +++ b/certs/system_keyring.c >> @@ -241,6 +241,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len, >> pr_devel("PKCS#7 platform keyring is not available\n"); >> goto error; >> } >> + >> + ret = is_key_revocationlisted(pkcs7); >> + if (ret != -ENOKEY) { >> + pr_devel("PKCS#7 platform key revocationlisted\n"); >> + goto error; >> + } >> } >> ret = pkcs7_validate_trust(pkcs7, trusted_keys); >> if (ret < 0) { >> diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h >> index fb8b07daa9d1..b6991cfe1b6d 100644 >> --- a/include/keys/system_keyring.h >> +++ b/include/keys/system_keyring.h >> @@ -31,11 +31,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted( >> #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted >> #endif >> >> +extern struct pkcs7_message *pkcs7; >> #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING >> extern int mark_hash_blacklisted(const char *hash); >> +extern int mark_key_revocationlisted(const char *data, size_t size); >> extern int is_hash_blacklisted(const u8 *hash, size_t hash_len, >> const char *type); >> extern int is_binary_blacklisted(const u8 *hash, size_t hash_len); >> +extern int is_key_revocationlisted(struct pkcs7_message *pkcs7); >> #else >> static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len, >> const char *type) >> @@ -47,6 +50,14 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len) >> { >> return 0; >> } >> +static inline int mark_key_revocationlisted(const char *data, size_t size) >> +{ >> + return 0; >> +} >> +static inline int is_key_revocationlisted(struct pkcs7_message *pkcs7) >> +{ >> + return -ENOKEY; >> +} >> #endif >> >> #ifdef CONFIG_IMA_BLACKLIST_KEYRING >> diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c >> index c5ba695c10e3..cc5a43804bc4 100644 >> --- a/security/integrity/platform_certs/keyring_handler.c >> +++ b/security/integrity/platform_certs/keyring_handler.c >> @@ -55,6 +55,15 @@ static __init void uefi_blacklist_binary(const char *source, >> uefi_blacklist_hash(source, data, len, "bin:", 4); >> } >> >> +/* >> + * Revocationlist the X509 cert >> + */ >> +static __init void uefi_revocationlist_x509(const char *source, >> + const void *data, size_t len) >> +{ >> + mark_key_revocationlisted(data, len); >> +} >> + >> /* >> * Return the appropriate handler for particular signature list types found in >> * the UEFI db and MokListRT tables. >> @@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) >> return uefi_blacklist_x509_tbs; >> if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) >> return uefi_blacklist_binary; >> + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) >> + return uefi_revocationlist_x509; >> return 0; >> } >> -- >> 2.18.1 >> > > I did not find anything wrong with the code change. Thanks
diff --git a/certs/blacklist.c b/certs/blacklist.c index 6514f9ebc943..17ebf50cf0ae 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -15,6 +15,7 @@ #include <linux/err.h> #include <linux/seq_file.h> #include <keys/system_keyring.h> +#include <crypto/pkcs7.h> #include "blacklist.h" static struct key *blacklist_keyring; @@ -100,6 +101,41 @@ int mark_hash_blacklisted(const char *hash) return 0; } +int mark_key_revocationlisted(const char *data, size_t size) +{ + key_ref_t key; + + key = key_create_or_update(make_key_ref(blacklist_keyring, true), + "asymmetric", + NULL, + data, + size, + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW), + KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_BUILT_IN); + + if (IS_ERR(key)) { + pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key)); + return PTR_ERR(key); + } + + return 0; +} + +int is_key_revocationlisted(struct pkcs7_message *pkcs7) +{ + int ret; + + ret = pkcs7_validate_trust(pkcs7, blacklist_keyring); + + if (ret == 0) + return -EKEYREJECTED; + + return -ENOKEY; +} +EXPORT_SYMBOL_GPL(is_key_revocationlisted); + /** * is_hash_blacklisted - Determine if a hash is blacklisted * @hash: The hash to be checked as a binary blob diff --git a/certs/system_keyring.c b/certs/system_keyring.c index 798291177186..f8ea96219155 100644 --- a/certs/system_keyring.c +++ b/certs/system_keyring.c @@ -241,6 +241,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len, pr_devel("PKCS#7 platform keyring is not available\n"); goto error; } + + ret = is_key_revocationlisted(pkcs7); + if (ret != -ENOKEY) { + pr_devel("PKCS#7 platform key revocationlisted\n"); + goto error; + } } ret = pkcs7_validate_trust(pkcs7, trusted_keys); if (ret < 0) { diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h index fb8b07daa9d1..b6991cfe1b6d 100644 --- a/include/keys/system_keyring.h +++ b/include/keys/system_keyring.h @@ -31,11 +31,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted( #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted #endif +extern struct pkcs7_message *pkcs7; #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING extern int mark_hash_blacklisted(const char *hash); +extern int mark_key_revocationlisted(const char *data, size_t size); extern int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type); extern int is_binary_blacklisted(const u8 *hash, size_t hash_len); +extern int is_key_revocationlisted(struct pkcs7_message *pkcs7); #else static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type) @@ -47,6 +50,14 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len) { return 0; } +static inline int mark_key_revocationlisted(const char *data, size_t size) +{ + return 0; +} +static inline int is_key_revocationlisted(struct pkcs7_message *pkcs7) +{ + return -ENOKEY; +} #endif #ifdef CONFIG_IMA_BLACKLIST_KEYRING diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c index c5ba695c10e3..cc5a43804bc4 100644 --- a/security/integrity/platform_certs/keyring_handler.c +++ b/security/integrity/platform_certs/keyring_handler.c @@ -55,6 +55,15 @@ static __init void uefi_blacklist_binary(const char *source, uefi_blacklist_hash(source, data, len, "bin:", 4); } +/* + * Revocationlist the X509 cert + */ +static __init void uefi_revocationlist_x509(const char *source, + const void *data, size_t len) +{ + mark_key_revocationlisted(data, len); +} + /* * Return the appropriate handler for particular signature list types found in * the UEFI db and MokListRT tables. @@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type) return uefi_blacklist_x509_tbs; if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0) return uefi_blacklist_binary; + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) + return uefi_revocationlist_x509; return 0; }
The Secure Boot Forbidden Signature Database, dbx, contains a list of now revoked signatures and keys previously approved to boot with UEFI Secure Boot enabled. The dbx is capable of containing any number of EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID entries. Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are skipped. This change adds support for EFI_CERT_X509_GUID dbx entries. When a EFI_CERT_X509_GUID is found, it is added as an asymmetrical key to the .blacklist keyring. Anytime the .platform keyring is used, the keys in the .blacklist keyring are referenced, if a matching key is found, the key will be rejected. Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> --- certs/blacklist.c | 36 +++++++++++++++++++ certs/system_keyring.c | 6 ++++ include/keys/system_keyring.h | 11 ++++++ .../platform_certs/keyring_handler.c | 11 ++++++ 4 files changed, 64 insertions(+)