| Message ID | 20220318182151.100847-4-zohar@linux.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | ima: support fs-verity digests and signatures | expand |
On 3/18/22 14:21, Mimi Zohar wrote: > Permit fsverity's file digest (a hash of struct fsverity_digest) to be > included in the IMA measurement list, based on the new measurement > policy rule 'digest_type=verity' option. > > To differentiate between a regular IMA file hash from an fsverity's > file digest, use the new d-ngv2 format field included in the ima-ngv2 > template. > > The following policy rule requires fsverity file digests and specifies > the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The > policy rule may be constrained, for example based on a fsuuid or LSM > label. > > measure func=FILE_CHECK digest_type=verity template=ima-ngv2 > > Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> > --- > Documentation/ABI/testing/ima_policy | 9 ++++++ > Documentation/security/IMA-templates.rst | 8 +++++ > security/integrity/ima/ima_api.c | 38 +++++++++++++++++++++-- > security/integrity/ima/ima_policy.c | 38 ++++++++++++++++++++++- > security/integrity/ima/ima_template_lib.c | 4 ++- > security/integrity/integrity.h | 3 +- > 6 files changed, 95 insertions(+), 5 deletions(-) > > diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy > index 839fab811b18..2e0c501ce9c8 100644 > --- a/Documentation/ABI/testing/ima_policy > +++ b/Documentation/ABI/testing/ima_policy > @@ -51,6 +51,9 @@ Description: > appraise_flag:= [check_blacklist] > Currently, blacklist check is only for files signed with appended > signature. > + digest_type:= verity > + Require fs-verity's file digest instead of the > + regular IMA file hash. > keyrings:= list of keyrings > (eg, .builtin_trusted_keys|.ima). Only valid > when action is "measure" and func is KEY_CHECK. > @@ -149,3 +152,9 @@ Description: > security.ima xattr of a file: > > appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512 > + > + Example of a 'measure' rule requiring fs-verity's digests > + with indication of type of digest in the measurement list. > + > + measure func=FILE_CHECK digest_type=verity \ > + template=ima-ngv2 > diff --git a/Documentation/security/IMA-templates.rst b/Documentation/security/IMA-templates.rst > index 1a91d92950a7..2d4789dc7750 100644 > --- a/Documentation/security/IMA-templates.rst > +++ b/Documentation/security/IMA-templates.rst > @@ -68,6 +68,9 @@ descriptors by adding their identifier to the format string > - 'd-ng': the digest of the event, calculated with an arbitrary hash > algorithm (field format: [<hash algo>:]digest, where the digest > prefix is shown only if the hash algorithm is not SHA1 or MD5); > + - 'd-ngv2': same as d-ng, but prefixed with the digest type. > + field format: [<digest type>:<hash algo>:]digest, > + where the digest type is either "ima" or "verity". > - 'd-modsig': the digest of the event without the appended modsig; > - 'n-ng': the name of the event, without size limitations; > - 'sig': the file signature, or the EVM portable signature if the file > @@ -106,3 +109,8 @@ currently the following methods are supported: > the ``ima_template=`` parameter; > - register a new template descriptor with custom format through the kernel > command line parameter ``ima_template_fmt=``. > + > + > +References > +========== > +[1] Documentation/filesystems/fsverity.rst > diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c > index c6805af46211..525b13916745 100644 > --- a/security/integrity/ima/ima_api.c > +++ b/security/integrity/ima/ima_api.c > @@ -14,6 +14,7 @@ > #include <linux/xattr.h> > #include <linux/evm.h> > #include <linux/iversion.h> > +#include <linux/fsverity.h> > > #include "ima.h" > > @@ -200,6 +201,23 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode, > allowed_algos); > } > > +static int ima_get_verity_digest(struct integrity_iint_cache *iint, > + struct ima_max_digest_data *hash) > +{ > + u8 verity_digest[FS_VERITY_MAX_DIGEST_SIZE]; > + enum hash_algo verity_alg; > + int ret; > + > + ret = fsverity_get_digest(iint->inode, verity_digest, &verity_alg); > + if (ret) > + return ret; > + if (hash->hdr.algo != verity_alg) > + return -EINVAL; > + hash->hdr.length = hash_digest_size[verity_alg]; > + memcpy(hash->hdr.digest, verity_digest, hash->hdr.length); Could you not pass hash->hdr.digest into fsverity_get_digest() and avoid the copying here? > + return 0; > +} > + > /* > * ima_collect_measurement - collect file measurement > * > @@ -242,14 +260,30 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, > */ > i_version = inode_query_iversion(inode); > hash.hdr.algo = algo; > + hash.hdr.length = hash_digest_size[algo]; > > /* Initialize hash digest to 0's in case of failure */ > memset(&hash.digest, 0, sizeof(hash.digest)); > > - if (buf) > + if (buf) { > result = ima_calc_buffer_hash(buf, size, &hash.hdr); > - else > + } else if (iint->flags & IMA_VERITY_REQUIRED) { > + result = ima_get_verity_digest(iint, &hash); > + switch (result) { > + case 0: > + break; > + case -ENODATA: > + audit_cause = "no-verity-digest"; > + result = -EINVAL; > + break; > + case -EINVAL: > + default: > + audit_cause = "invalid-verity-digest"; > + break; > + } > + } else { > result = ima_calc_file_hash(file, &hash.hdr); > + } > > if (result && result != -EBADF && result != -EINVAL) > goto out; > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index a0f3775cbd82..c6b0454b2e25 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -1024,6 +1024,7 @@ enum policy_opt { > Opt_fowner_gt, Opt_fgroup_gt, > Opt_uid_lt, Opt_euid_lt, Opt_gid_lt, Opt_egid_lt, > Opt_fowner_lt, Opt_fgroup_lt, > + Opt_digest_type, > Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos, > Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, > Opt_label, Opt_err > @@ -1066,6 +1067,7 @@ static const match_table_t policy_tokens = { > {Opt_egid_lt, "egid<%s"}, > {Opt_fowner_lt, "fowner<%s"}, > {Opt_fgroup_lt, "fgroup<%s"}, > + {Opt_digest_type, "digest_type=%s"}, > {Opt_appraise_type, "appraise_type=%s"}, > {Opt_appraise_flag, "appraise_flag=%s"}, > {Opt_appraise_algos, "appraise_algos=%s"}, > @@ -1173,6 +1175,21 @@ static void check_template_modsig(const struct ima_template_desc *template) > #undef MSG > } > > +/* > + * Make sure the policy rule and template format are in sync. If they are not in sync I need to update my policy rule? > + */ > +static void check_template_field(const struct ima_template_desc *template, > + const char *field, const char *msg) > +{ > + int i; > + > + for (i = 0; i < template->num_fields; i++) > + if (!strcmp(template->fields[i]->field_id, field)) > + return; > + > + pr_notice_once("%s", msg) > +} > + > static bool ima_validate_rule(struct ima_rule_entry *entry) > { > /* Ensure that the action is set and is compatible with the flags */ > @@ -1215,7 +1232,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) > IMA_INMASK | IMA_EUID | IMA_PCR | > IMA_FSNAME | IMA_GID | IMA_EGID | > IMA_FGROUP | IMA_DIGSIG_REQUIRED | > - IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS)) > + IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | > + IMA_VERITY_REQUIRED)) > return false; > > break; > @@ -1708,6 +1726,13 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) > LSM_SUBJ_TYPE, > AUDIT_SUBJ_TYPE); > break; > + case Opt_digest_type: > + ima_log_string(ab, "digest_type", args[0].from); > + if ((strcmp(args[0].from, "verity")) == 0) > + entry->flags |= IMA_VERITY_REQUIRED; > + else > + result = -EINVAL; > + break; > case Opt_appraise_type: > ima_log_string(ab, "appraise_type", args[0].from); > if ((strcmp(args[0].from, "imasig")) == 0) > @@ -1798,6 +1823,15 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) > check_template_modsig(template_desc); > } > > + /* d-ngv2 template field recommended for unsigned fs-verity digests */ > + if (!result && entry->action == MEASURE && > + entry->flags & IMA_VERITY_REQUIRED) { > + template_desc = entry->template ? entry->template : > + ima_template_desc_current(); > + check_template_field(template_desc, "d-ngv2", > + "verity rules should include d-ngv2"); > + } > + > audit_log_format(ab, "res=%d", !result); > audit_log_end(ab); > return result; > @@ -2155,6 +2189,8 @@ int ima_policy_show(struct seq_file *m, void *v) > else > seq_puts(m, "appraise_type=imasig "); > } > + if (entry->flags & IMA_VERITY_REQUIRED) > + seq_puts(m, "digest_type=verity "); > if (entry->flags & IMA_CHECK_BLACKLIST) > seq_puts(m, "appraise_flag=check_blacklist "); > if (entry->flags & IMA_PERMIT_DIRECTIO) > diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c > index bd95864a5f6f..0cff6658a4c2 100644 > --- a/security/integrity/ima/ima_template_lib.c > +++ b/security/integrity/ima/ima_template_lib.c > @@ -31,7 +31,7 @@ enum data_formats { > }; > > #define DIGEST_TYPE_MAXLEN 16 /* including NULL */ > -static const char * const digest_type_name[] = {"ima"}; > +static const char * const digest_type_name[] = {"ima", "verity"}; > static int digest_type_size = ARRAY_SIZE(digest_type_name); if this static needs to exist at all, and I dn't think it should, it should probably be called digest_type_array_size. Though I would just use ARRAY_SIZE() where needed. > > static int ima_write_template_field_data(const void *data, const u32 datalen, > @@ -430,6 +430,8 @@ int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, > cur_digestsize = event_data->iint->ima_hash->length; > > hash_algo = event_data->iint->ima_hash->algo; > + if (event_data->iint->flags & IMA_VERITY_REQUIRED) > + digest_type = 1; > out: > return ima_eventdigest_init_common(cur_digest, cur_digestsize, > digest_type, hash_algo, field_data); > diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h > index daf49894fd7d..d42a01903f08 100644 > --- a/security/integrity/integrity.h > +++ b/security/integrity/integrity.h > @@ -32,7 +32,7 @@ > #define IMA_HASHED 0x00000200 > > /* iint policy rule cache flags */ > -#define IMA_NONACTION_FLAGS 0xff000000 > +#define IMA_NONACTION_FLAGS 0xff800000 > #define IMA_DIGSIG_REQUIRED 0x01000000 > #define IMA_PERMIT_DIRECTIO 0x02000000 > #define IMA_NEW_FILE 0x04000000 > @@ -40,6 +40,7 @@ > #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 > #define IMA_MODSIG_ALLOWED 0x20000000 > #define IMA_CHECK_BLACKLIST 0x40000000 > +#define IMA_VERITY_REQUIRED 0x80000000 > > #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ > IMA_HASH | IMA_APPRAISE_SUBMASK)
On Mon, 2022-03-21 at 08:59 -0400, Stefan Berger wrote: > > +/* > > + * Make sure the policy rule and template format are in sync. > If they are not in sync I need to update my policy rule? It doesn't prevent loading the policy, if they're not in sync, but simply issues a warning. > > > + */ > > +static void check_template_field(const struct ima_template_desc *template, > > + const char *field, const char *msg) > > +{ > > + int i; > > + > > + for (i = 0; i < template->num_fields; i++) > > + if (!strcmp(template->fields[i]->field_id, field)) > > + return; > > + > > + pr_notice_once("%s", msg) > > +} > > + > > static bool ima_validate_rule(struct ima_rule_entry *entry) > > { > > /* Ensure that the action is set and is compatible with the flags */ > > @@ -1215,7 +1232,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) > > IMA_INMASK | IMA_EUID | IMA_PCR | > > IMA_FSNAME | IMA_GID | IMA_EGID | > > IMA_FGROUP | IMA_DIGSIG_REQUIRED | > > - IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS)) > > + IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | > > + IMA_VERITY_REQUIRED)) > > return false; > > > > break; > > @@ -1708,6 +1726,13 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) > > LSM_SUBJ_TYPE, > > AUDIT_SUBJ_TYPE); > > break; > > + case Opt_digest_type: > > + ima_log_string(ab, "digest_type", args[0].from); > > + if ((strcmp(args[0].from, "verity")) == 0) > > + entry->flags |= IMA_VERITY_REQUIRED; > > + else > > + result = -EINVAL; > > + break; > > case Opt_appraise_type: > > ima_log_string(ab, "appraise_type", args[0].from); > > if ((strcmp(args[0].from, "imasig")) == 0) > > @@ -1798,6 +1823,15 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) > > check_template_modsig(template_desc); > > } > > > > + /* d-ngv2 template field recommended for unsigned fs-verity digests */ > > + if (!result && entry->action == MEASURE && > > + entry->flags & IMA_VERITY_REQUIRED) { > > + template_desc = entry->template ? entry->template : > > + ima_template_desc_current(); > > + check_template_field(template_desc, "d-ngv2", > > + "verity rules should include d-ngv2"); > > + } > > + > > audit_log_format(ab, "res=%d", !result); > > audit_log_end(ab); > > return result; > > @@ -2155,6 +2189,8 @@ int ima_policy_show(struct seq_file *m, void *v) > > else > > seq_puts(m, "appraise_type=imasig "); > > } > > + if (entry->flags & IMA_VERITY_REQUIRED) > > + seq_puts(m, "digest_type=verity "); > > if (entry->flags & IMA_CHECK_BLACKLIST) > > seq_puts(m, "appraise_flag=check_blacklist "); > > if (entry->flags & IMA_PERMIT_DIRECTIO) > > diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c > > index bd95864a5f6f..0cff6658a4c2 100644 > > --- a/security/integrity/ima/ima_template_lib.c > > +++ b/security/integrity/ima/ima_template_lib.c > > @@ -31,7 +31,7 @@ enum data_formats { > > }; > > > > #define DIGEST_TYPE_MAXLEN 16 /* including NULL */ > > -static const char * const digest_type_name[] = {"ima"}; > > +static const char * const digest_type_name[] = {"ima", "verity"}; > > static int digest_type_size = ARRAY_SIZE(digest_type_name); > > if this static needs to exist at all, and I dn't think it should, it > should probably be called digest_type_array_size. Though I would just > use ARRAY_SIZE() where needed. Ok. thanks, Mimi
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 839fab811b18..2e0c501ce9c8 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -51,6 +51,9 @@ Description: appraise_flag:= [check_blacklist] Currently, blacklist check is only for files signed with appended signature. + digest_type:= verity + Require fs-verity's file digest instead of the + regular IMA file hash. keyrings:= list of keyrings (eg, .builtin_trusted_keys|.ima). Only valid when action is "measure" and func is KEY_CHECK. @@ -149,3 +152,9 @@ Description: security.ima xattr of a file: appraise func=SETXATTR_CHECK appraise_algos=sha256,sha384,sha512 + + Example of a 'measure' rule requiring fs-verity's digests + with indication of type of digest in the measurement list. + + measure func=FILE_CHECK digest_type=verity \ + template=ima-ngv2 diff --git a/Documentation/security/IMA-templates.rst b/Documentation/security/IMA-templates.rst index 1a91d92950a7..2d4789dc7750 100644 --- a/Documentation/security/IMA-templates.rst +++ b/Documentation/security/IMA-templates.rst @@ -68,6 +68,9 @@ descriptors by adding their identifier to the format string - 'd-ng': the digest of the event, calculated with an arbitrary hash algorithm (field format: [<hash algo>:]digest, where the digest prefix is shown only if the hash algorithm is not SHA1 or MD5); + - 'd-ngv2': same as d-ng, but prefixed with the digest type. + field format: [<digest type>:<hash algo>:]digest, + where the digest type is either "ima" or "verity". - 'd-modsig': the digest of the event without the appended modsig; - 'n-ng': the name of the event, without size limitations; - 'sig': the file signature, or the EVM portable signature if the file @@ -106,3 +109,8 @@ currently the following methods are supported: the ``ima_template=`` parameter; - register a new template descriptor with custom format through the kernel command line parameter ``ima_template_fmt=``. + + +References +========== +[1] Documentation/filesystems/fsverity.rst diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index c6805af46211..525b13916745 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -14,6 +14,7 @@ #include <linux/xattr.h> #include <linux/evm.h> #include <linux/iversion.h> +#include <linux/fsverity.h> #include "ima.h" @@ -200,6 +201,23 @@ int ima_get_action(struct user_namespace *mnt_userns, struct inode *inode, allowed_algos); } +static int ima_get_verity_digest(struct integrity_iint_cache *iint, + struct ima_max_digest_data *hash) +{ + u8 verity_digest[FS_VERITY_MAX_DIGEST_SIZE]; + enum hash_algo verity_alg; + int ret; + + ret = fsverity_get_digest(iint->inode, verity_digest, &verity_alg); + if (ret) + return ret; + if (hash->hdr.algo != verity_alg) + return -EINVAL; + hash->hdr.length = hash_digest_size[verity_alg]; + memcpy(hash->hdr.digest, verity_digest, hash->hdr.length); + return 0; +} + /* * ima_collect_measurement - collect file measurement * @@ -242,14 +260,30 @@ int ima_collect_measurement(struct integrity_iint_cache *iint, */ i_version = inode_query_iversion(inode); hash.hdr.algo = algo; + hash.hdr.length = hash_digest_size[algo]; /* Initialize hash digest to 0's in case of failure */ memset(&hash.digest, 0, sizeof(hash.digest)); - if (buf) + if (buf) { result = ima_calc_buffer_hash(buf, size, &hash.hdr); - else + } else if (iint->flags & IMA_VERITY_REQUIRED) { + result = ima_get_verity_digest(iint, &hash); + switch (result) { + case 0: + break; + case -ENODATA: + audit_cause = "no-verity-digest"; + result = -EINVAL; + break; + case -EINVAL: + default: + audit_cause = "invalid-verity-digest"; + break; + } + } else { result = ima_calc_file_hash(file, &hash.hdr); + } if (result && result != -EBADF && result != -EINVAL) goto out; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index a0f3775cbd82..c6b0454b2e25 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -1024,6 +1024,7 @@ enum policy_opt { Opt_fowner_gt, Opt_fgroup_gt, Opt_uid_lt, Opt_euid_lt, Opt_gid_lt, Opt_egid_lt, Opt_fowner_lt, Opt_fgroup_lt, + Opt_digest_type, Opt_appraise_type, Opt_appraise_flag, Opt_appraise_algos, Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, Opt_label, Opt_err @@ -1066,6 +1067,7 @@ static const match_table_t policy_tokens = { {Opt_egid_lt, "egid<%s"}, {Opt_fowner_lt, "fowner<%s"}, {Opt_fgroup_lt, "fgroup<%s"}, + {Opt_digest_type, "digest_type=%s"}, {Opt_appraise_type, "appraise_type=%s"}, {Opt_appraise_flag, "appraise_flag=%s"}, {Opt_appraise_algos, "appraise_algos=%s"}, @@ -1173,6 +1175,21 @@ static void check_template_modsig(const struct ima_template_desc *template) #undef MSG } +/* + * Make sure the policy rule and template format are in sync. + */ +static void check_template_field(const struct ima_template_desc *template, + const char *field, const char *msg) +{ + int i; + + for (i = 0; i < template->num_fields; i++) + if (!strcmp(template->fields[i]->field_id, field)) + return; + + pr_notice_once("%s", msg); +} + static bool ima_validate_rule(struct ima_rule_entry *entry) { /* Ensure that the action is set and is compatible with the flags */ @@ -1215,7 +1232,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) IMA_INMASK | IMA_EUID | IMA_PCR | IMA_FSNAME | IMA_GID | IMA_EGID | IMA_FGROUP | IMA_DIGSIG_REQUIRED | - IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS)) + IMA_PERMIT_DIRECTIO | IMA_VALIDATE_ALGOS | + IMA_VERITY_REQUIRED)) return false; break; @@ -1708,6 +1726,13 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) LSM_SUBJ_TYPE, AUDIT_SUBJ_TYPE); break; + case Opt_digest_type: + ima_log_string(ab, "digest_type", args[0].from); + if ((strcmp(args[0].from, "verity")) == 0) + entry->flags |= IMA_VERITY_REQUIRED; + else + result = -EINVAL; + break; case Opt_appraise_type: ima_log_string(ab, "appraise_type", args[0].from); if ((strcmp(args[0].from, "imasig")) == 0) @@ -1798,6 +1823,15 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) check_template_modsig(template_desc); } + /* d-ngv2 template field recommended for unsigned fs-verity digests */ + if (!result && entry->action == MEASURE && + entry->flags & IMA_VERITY_REQUIRED) { + template_desc = entry->template ? entry->template : + ima_template_desc_current(); + check_template_field(template_desc, "d-ngv2", + "verity rules should include d-ngv2"); + } + audit_log_format(ab, "res=%d", !result); audit_log_end(ab); return result; @@ -2155,6 +2189,8 @@ int ima_policy_show(struct seq_file *m, void *v) else seq_puts(m, "appraise_type=imasig "); } + if (entry->flags & IMA_VERITY_REQUIRED) + seq_puts(m, "digest_type=verity "); if (entry->flags & IMA_CHECK_BLACKLIST) seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index bd95864a5f6f..0cff6658a4c2 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -31,7 +31,7 @@ enum data_formats { }; #define DIGEST_TYPE_MAXLEN 16 /* including NULL */ -static const char * const digest_type_name[] = {"ima"}; +static const char * const digest_type_name[] = {"ima", "verity"}; static int digest_type_size = ARRAY_SIZE(digest_type_name); static int ima_write_template_field_data(const void *data, const u32 datalen, @@ -430,6 +430,8 @@ int ima_eventdigest_ngv2_init(struct ima_event_data *event_data, cur_digestsize = event_data->iint->ima_hash->length; hash_algo = event_data->iint->ima_hash->algo; + if (event_data->iint->flags & IMA_VERITY_REQUIRED) + digest_type = 1; out: return ima_eventdigest_init_common(cur_digest, cur_digestsize, digest_type, hash_algo, field_data); diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index daf49894fd7d..d42a01903f08 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -32,7 +32,7 @@ #define IMA_HASHED 0x00000200 /* iint policy rule cache flags */ -#define IMA_NONACTION_FLAGS 0xff000000 +#define IMA_NONACTION_FLAGS 0xff800000 #define IMA_DIGSIG_REQUIRED 0x01000000 #define IMA_PERMIT_DIRECTIO 0x02000000 #define IMA_NEW_FILE 0x04000000 @@ -40,6 +40,7 @@ #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 #define IMA_MODSIG_ALLOWED 0x20000000 #define IMA_CHECK_BLACKLIST 0x40000000 +#define IMA_VERITY_REQUIRED 0x80000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_HASH | IMA_APPRAISE_SUBMASK)
Permit fsverity's file digest (a hash of struct fsverity_digest) to be included in the IMA measurement list, based on the new measurement policy rule 'digest_type=verity' option. To differentiate between a regular IMA file hash from an fsverity's file digest, use the new d-ngv2 format field included in the ima-ngv2 template. The following policy rule requires fsverity file digests and specifies the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The policy rule may be constrained, for example based on a fsuuid or LSM label. measure func=FILE_CHECK digest_type=verity template=ima-ngv2 Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> --- Documentation/ABI/testing/ima_policy | 9 ++++++ Documentation/security/IMA-templates.rst | 8 +++++ security/integrity/ima/ima_api.c | 38 +++++++++++++++++++++-- security/integrity/ima/ima_policy.c | 38 ++++++++++++++++++++++- security/integrity/ima/ima_template_lib.c | 4 ++- security/integrity/integrity.h | 3 +- 6 files changed, 95 insertions(+), 5 deletions(-)