lkml.org 
[lkml]   [2021]   [Feb]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] cert: Add kconfig dependency for validate_trust
    From
    Date

    On 24/02/2021 11:51, David Howells wrote:
    > How about these changes?
    >
    > I've added an extra config option to turn on SYSTEM_REVOCATION_LIST support.
    >
    > I've also added kerneldoc comments and moved the functions so that they're not
    > in the middle of the blacklist-specific stuff.
    >
    > I'm not sure uefi_revocation_list_x509() needs conditionalising as the
    > optimiser should just inline it if SYSTEM_REVOCATION_LIST=n (assuming __init
    > doesn't disable inlining).
    >
    > David
    > ---
    > diff --git a/certs/Kconfig b/certs/Kconfig
    > index c94e93d8bccf..76e469b56a77 100644
    > --- a/certs/Kconfig
    > +++ b/certs/Kconfig
    > @@ -83,4 +83,13 @@ config SYSTEM_BLACKLIST_HASH_LIST
    > wrapper to incorporate the list into the kernel. Each <hash> should
    > be a string of hex digits.
    >
    > +config SYSTEM_REVOCATION_LIST
    > + bool "Provide system-wide ring of revocation certificates"
    > + depends on SYSTEM_BLACKLIST_KEYRING
    > + depends on PKCS7_MESSAGE_PARSER=y

    The function verify_pkcs7_message_sig() (which is patched) is only
    available if CONFIG_SYSTEM_DATA_VERIFICATION is defined. I suggest to
    use the same dependencies as for my dynamic authenticated blacklist
    keyring patchset.


    > + help
    > + If set, this allows revocation certificates to be stored in the
    > + blacklist keyring and implements a hook whereby a PKCS#7 message can
    > + be checked to see if it matches such a certificate.
    > +
    > endmenu
    > diff --git a/certs/blacklist.c b/certs/blacklist.c
    > index e9f5fc632f0d..2b8644123d5f 100644
    > --- a/certs/blacklist.c
    > +++ b/certs/blacklist.c
    > @@ -101,38 +101,6 @@ int mark_hash_blacklisted(const char *hash)
    > return 0;
    > }
    >
    > -int add_key_to_revocation_list(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_on_revocation_list(struct pkcs7_message *pkcs7)
    > -{
    > - int ret;
    > -
    > - ret = validate_trust(pkcs7, blacklist_keyring);
    > -
    > - if (ret == 0)
    > - return -EKEYREJECTED;
    > -
    > - return -ENOKEY;
    > -}
    > -
    > /**
    > * is_hash_blacklisted - Determine if a hash is blacklisted
    > * @hash: The hash to be checked as a binary blob

    Could you please not move those functions? It makes the patch more
    readable and avoids merge conflicts (e.g. with the dynamic authenticated
    blacklist keyring patchset). Thanks.


    > @@ -177,6 +145,49 @@ int is_binary_blacklisted(const u8 *hash, size_t hash_len)
    > }
    > EXPORT_SYMBOL_GPL(is_binary_blacklisted);
    >
    > +#ifdef CONFIG_SYSTEM_REVOCATION_LIST
    > +/**
    > + * add_key_to_revocation_list - Add a revocation certificate to the blacklist
    > + * @data: The data blob containing the certificate
    > + * @size: The size of data blob
    > + */
    > +int add_key_to_revocation_list(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;
    > +}
    > +
    > +/**
    > + * is_key_on_revocation_list - Determine if the key for a PKCS#7 message is revoked
    > + * @pkcs7: The PKCS#7 message to check
    > + */
    > +int is_key_on_revocation_list(struct pkcs7_message *pkcs7)
    > +{
    > + int ret;
    > +
    > + ret = pkcs7_validate_trust(pkcs7, blacklist_keyring);
    > +
    > + if (ret == 0)
    > + return -EKEYREJECTED;
    > +
    > + return -ENOKEY;
    > +}
    > +#endif
    > +
    > /*
    > * Initialise the blacklist
    > */
    > diff --git a/certs/blacklist.h b/certs/blacklist.h
    > index 420bb7c86e07..51b320cf8574 100644
    > --- a/certs/blacklist.h
    > +++ b/certs/blacklist.h
    > @@ -3,13 +3,3 @@
    > #include <crypto/pkcs7.h>
    >
    > extern const char __initconst *const blacklist_hashes[];
    > -
    > -#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
    > -#define validate_trust pkcs7_validate_trust
    > -#else
    > -static inline int validate_trust(struct pkcs7_message *pkcs7,
    > - struct key *trust_keyring)
    > -{
    > - return -ENOKEY;
    > -}
    > -#endif
    > diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
    > index 61f98739e8b1..875e002a4180 100644
    > --- a/include/keys/system_keyring.h
    > +++ b/include/keys/system_keyring.h
    > @@ -34,11 +34,9 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
    > extern struct pkcs7_message *pkcs7;
    > #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING
    > extern int mark_hash_blacklisted(const char *hash);
    > -extern int add_key_to_revocation_list(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_on_revocation_list(struct pkcs7_message *pkcs7);
    > #else
    > static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len,
    > const char *type)
    > @@ -50,6 +48,12 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len)
    > {
    > return 0;
    > }
    > +#endif
    > +
    > +#ifdef CONFIG_SYSTEM_REVOCATION_LIST
    > +extern int add_key_to_revocation_list(const char *data, size_t size);
    > +extern int is_key_on_revocation_list(struct pkcs7_message *pkcs7);
    > +#else
    > static inline int add_key_to_revocation_list(const char *data, size_t size)
    > {
    > return 0;
    >

    \
     
     \ /
      Last update: 2021-02-24 12:58    [W:2.400 / U:0.176 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site