Merge branch 'next-integrity.fsverity-v9' into next-integrity

Support for including fs-verity file digests and signatures in the IMA
measurement list as well as verifying the fs-verity file digest based
signatures.

Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

9 files changed, 342 insertions, 35 deletions

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index c8c8a4a4e7a0..8a82a6c7f48a 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -75,7 +75,8 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 		/* v1 API expect signature without xattr type */
 		return digsig_verify(keyring, sig + 1, siglen - 1, digest,
 				     digestlen);
-	case 2:
+	case 2: /* regular file data hash based signature */
+	case 3: /* struct ima_file_id data based signature */
 		return asymmetric_verify(keyring, sig, siglen, digest,
 					 digestlen);
 	}
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index c6805af46211..c1e76282b5ee 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 +201,32 @@ 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)
+{
+	enum hash_algo verity_alg;
+	int ret;
+
+	/*
+	 * On failure, 'measure' policy rules will result in a file data
+	 * hash containing 0's.
+	 */
+	ret = fsverity_get_digest(iint->inode, hash->digest, &verity_alg);
+	if (ret)
+		return ret;
+
+	/*
+	 * Unlike in the case of actually calculating the file hash, in
+	 * the fsverity case regardless of the hash algorithm, return
+	 * the verity digest to be included in the measurement list. A
+	 * mismatch between the verity algorithm and the xattr signature
+	 * algorithm, if one exists, will be detected later.
+	 */
+	hash->hdr.algo = verity_alg;
+	hash->hdr.length = hash_digest_size[verity_alg];
+	return 0;
+}
+
 /*
  * ima_collect_measurement - collect file measurement
  *
@@ -242,16 +269,30 @@ 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 (iint->flags & IMA_VERITY_REQUIRED) {
+		result = ima_get_verity_digest(iint, &hash);
+		switch (result) {
+		case 0:
+			break;
+		case -ENODATA:
+			audit_cause = "no-verity-digest";
+			break;
+		default:
+			audit_cause = "invalid-verity-digest";
+			break;
+		}
+	} else if (buf) {
 		result = ima_calc_buffer_hash(buf, size, &hash.hdr);
-	else
+	} else {
 		result = ima_calc_file_hash(file, &hash.hdr);
+	}
 
-	if (result && result != -EBADF && result != -EINVAL)
+	if (result == -ENOMEM)
 		goto out;
 
 	length = sizeof(hash.hdr) + hash.hdr.length;
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 17232bbfb9f9..cdb84dccd24e 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -13,7 +13,9 @@
 #include <linux/magic.h>
 #include <linux/ima.h>
 #include <linux/evm.h>
+#include <linux/fsverity.h>
 #include <keys/system_keyring.h>
+#include <uapi/linux/fsverity.h>
 
 #include "ima.h"
 
@@ -183,13 +185,18 @@ enum hash_algo ima_get_hash_algo(const struct evm_ima_xattr_data *xattr_value,
 		return ima_hash_algo;
 
 	switch (xattr_value->type) {
+	case IMA_VERITY_DIGSIG:
+		sig = (typeof(sig))xattr_value;
+		if (sig->version != 3 || xattr_len <= sizeof(*sig) ||
+		    sig->hash_algo >= HASH_ALGO__LAST)
+			return ima_hash_algo;
+		return sig->hash_algo;
 	case EVM_IMA_XATTR_DIGSIG:
 		sig = (typeof(sig))xattr_value;
 		if (sig->version != 2 || xattr_len <= sizeof(*sig)
 		    || sig->hash_algo >= HASH_ALGO__LAST)
 			return ima_hash_algo;
 		return sig->hash_algo;
-		break;
 	case IMA_XATTR_DIGEST_NG:
 		/* first byte contains algorithm id */
 		ret = xattr_value->data[0];
@@ -226,6 +233,40 @@ int ima_read_xattr(struct dentry *dentry,
 }
 
 /*
+ * calc_file_id_hash - calculate the hash of the ima_file_id struct data
+ * @type: xattr type [enum evm_ima_xattr_type]
+ * @algo: hash algorithm [enum hash_algo]
+ * @digest: pointer to the digest to be hashed
+ * @hash: (out) pointer to the hash
+ *
+ * IMA signature version 3 disambiguates the data that is signed by
+ * indirectly signing the hash of the ima_file_id structure data.
+ *
+ * Signing the ima_file_id struct is currently only supported for
+ * IMA_VERITY_DIGSIG type xattrs.
+ *
+ * Return 0 on success, error code otherwise.
+ */
+static int calc_file_id_hash(enum evm_ima_xattr_type type,
+			     enum hash_algo algo, const u8 *digest,
+			     struct ima_digest_data *hash)
+{
+	struct ima_file_id file_id = {
+		.hash_type = IMA_VERITY_DIGSIG, .hash_algorithm = algo};
+	unsigned int unused = HASH_MAX_DIGESTSIZE - hash_digest_size[algo];
+
+	if (type != IMA_VERITY_DIGSIG)
+		return -EINVAL;
+
+	memcpy(file_id.hash, digest, hash_digest_size[algo]);
+
+	hash->algo = algo;
+	hash->length = hash_digest_size[algo];
+
+	return ima_calc_buffer_hash(&file_id, sizeof(file_id) - unused, hash);
+}
+
+/*
  * xattr_verify - verify xattr digest or signature
  *
  * Verify whether the hash or signature matches the file contents.
@@ -236,7 +277,10 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
 			struct evm_ima_xattr_data *xattr_value, int xattr_len,
 			enum integrity_status *status, const char **cause)
 {
+	struct ima_max_digest_data hash;
+	struct signature_v2_hdr *sig;
 	int rc = -EINVAL, hash_start = 0;
+	int mask;
 
 	switch (xattr_value->type) {
 	case IMA_XATTR_DIGEST_NG:
@@ -246,7 +290,10 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
 	case IMA_XATTR_DIGEST:
 		if (*status != INTEGRITY_PASS_IMMUTABLE) {
 			if (iint->flags & IMA_DIGSIG_REQUIRED) {
-				*cause = "IMA-signature-required";
+				if (iint->flags & IMA_VERITY_REQUIRED)
+					*cause = "verity-signature-required";
+				else
+					*cause = "IMA-signature-required";
 				*status = INTEGRITY_FAIL;
 				break;
 			}
@@ -274,6 +321,20 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
 		break;
 	case EVM_IMA_XATTR_DIGSIG:
 		set_bit(IMA_DIGSIG, &iint->atomic_flags);
+
+		mask = IMA_DIGSIG_REQUIRED | IMA_VERITY_REQUIRED;
+		if ((iint->flags & mask) == mask) {
+			*cause = "verity-signature-required";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
+
+		sig = (typeof(sig))xattr_value;
+		if (sig->version >= 3) {
+			*cause = "invalid-signature-version";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
 		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
 					     (const char *)xattr_value,
 					     xattr_len,
@@ -297,6 +358,44 @@ static int xattr_verify(enum ima_hooks func, struct integrity_iint_cache *iint,
 			*status = INTEGRITY_PASS;
 		}
 		break;
+	case IMA_VERITY_DIGSIG:
+		set_bit(IMA_DIGSIG, &iint->atomic_flags);
+
+		if (iint->flags & IMA_DIGSIG_REQUIRED) {
+			if (!(iint->flags & IMA_VERITY_REQUIRED)) {
+				*cause = "IMA-signature-required";
+				*status = INTEGRITY_FAIL;
+				break;
+			}
+		}
+
+		sig = (typeof(sig))xattr_value;
+		if (sig->version != 3) {
+			*cause = "invalid-signature-version";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
+
+		rc = calc_file_id_hash(IMA_VERITY_DIGSIG, iint->ima_hash->algo,
+				       iint->ima_hash->digest, &hash.hdr);
+		if (rc) {
+			*cause = "sigv3-hashing-error";
+			*status = INTEGRITY_FAIL;
+			break;
+		}
+
+		rc = integrity_digsig_verify(INTEGRITY_KEYRING_IMA,
+					     (const char *)xattr_value,
+					     xattr_len, hash.digest,
+					     hash.hdr.length);
+		if (rc) {
+			*cause = "invalid-verity-signature";
+			*status = INTEGRITY_FAIL;
+		} else {
+			*status = INTEGRITY_PASS;
+		}
+
+		break;
 	default:
 		*status = INTEGRITY_UNKNOWN;
 		*cause = "unknown-ima-data";
@@ -396,8 +495,15 @@ int ima_appraise_measurement(enum ima_hooks func,
 		if (rc && rc != -ENODATA)
 			goto out;
 
-		cause = iint->flags & IMA_DIGSIG_REQUIRED ?
-				"IMA-signature-required" : "missing-hash";
+		if (iint->flags & IMA_DIGSIG_REQUIRED) {
+			if (iint->flags & IMA_VERITY_REQUIRED)
+				cause = "verity-signature-required";
+			else
+				cause = "IMA-signature-required";
+		} else {
+			cause = "missing-hash";
+		}
+
 		status = INTEGRITY_NOLABEL;
 		if (file->f_mode & FMODE_CREATED)
 			iint->flags |= IMA_NEW_FILE;
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 1aebf63ad7a6..040b03ddc1c7 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -335,7 +335,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
 	hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
 
 	rc = ima_collect_measurement(iint, file, buf, size, hash_algo, modsig);
-	if (rc != 0 && rc != -EBADF && rc != -EINVAL)
+	if (rc == -ENOMEM)
 		goto out_locked;
 
 	if (!pathbuf)	/* ima_rdwr_violation possibly pre-fetched */
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index eea6e92500b8..73917413365b 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -1023,6 +1023,7 @@ 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
@@ -1065,6 +1066,7 @@ 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"},
@@ -1172,6 +1174,21 @@ static void check_template_modsig(const struct ima_template_desc *template)
 #undef MSG
 }
 
+/*
+ * Warn if the template does not contain the given field.
+ */
+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 */
@@ -1214,7 +1231,8 @@ 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;
@@ -1292,6 +1310,18 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
 	    !(entry->flags & IMA_MODSIG_ALLOWED))
 		return false;
 
+	/*
+	 * Unlike for regular IMA 'appraise' policy rules where security.ima
+	 * xattr may contain either a file hash or signature, the security.ima
+	 * xattr for fsverity must contain a file signature (sigv3).  Ensure
+	 * that 'appraise' rules for fsverity require file signatures by
+	 * checking the IMA_DIGSIG_REQUIRED flag is set.
+	 */
+	if (entry->action == APPRAISE &&
+	    (entry->flags & IMA_VERITY_REQUIRED) &&
+	    !(entry->flags & IMA_DIGSIG_REQUIRED))
+		return false;
+
 	return true;
 }
 
@@ -1707,16 +1737,39 @@ 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 (entry->flags & IMA_DIGSIG_REQUIRED)
+				result = -EINVAL;
+			else 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)
-				entry->flags |= IMA_DIGSIG_REQUIRED;
-			else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) &&
-				 strcmp(args[0].from, "imasig|modsig") == 0)
-				entry->flags |= IMA_DIGSIG_REQUIRED |
+
+			if ((strcmp(args[0].from, "imasig")) == 0) {
+				if (entry->flags & IMA_VERITY_REQUIRED)
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_DIGSIG_REQUIRED;
+			} else if (strcmp(args[0].from, "sigv3") == 0) {
+				/* Only fsverity supports sigv3 for now */
+				if (entry->flags & IMA_VERITY_REQUIRED)
+					entry->flags |= IMA_DIGSIG_REQUIRED;
+				else
+					result = -EINVAL;
+			} else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) &&
+				 strcmp(args[0].from, "imasig|modsig") == 0) {
+				if (entry->flags & IMA_VERITY_REQUIRED)
+					result = -EINVAL;
+				else
+					entry->flags |= IMA_DIGSIG_REQUIRED |
 						IMA_MODSIG_ALLOWED;
-			else
+			} else {
 				result = -EINVAL;
+			}
 			break;
 		case Opt_appraise_flag:
 			ima_log_string(ab, "appraise_flag", args[0].from);
@@ -1797,6 +1850,15 @@ 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;
@@ -2149,11 +2211,15 @@ int ima_policy_show(struct seq_file *m, void *v)
 	if (entry->template)
 		seq_printf(m, "template=%s ", entry->template->name);
 	if (entry->flags & IMA_DIGSIG_REQUIRED) {
-		if (entry->flags & IMA_MODSIG_ALLOWED)
+		if (entry->flags & IMA_VERITY_REQUIRED)
+			seq_puts(m, "appraise_type=sigv3 ");
+		else if (entry->flags & IMA_MODSIG_ALLOWED)
 			seq_puts(m, "appraise_type=imasig|modsig ");
 		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.c b/security/integrity/ima/ima_template.c
index db1ad6d7a57f..c25079faa208 100644
--- a/security/integrity/ima/ima_template.c
+++ b/security/integrity/ima/ima_template.c
@@ -20,6 +20,8 @@ static struct ima_template_desc builtin_templates[] = {
 	{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
 	{.name = "ima-ng", .fmt = "d-ng|n-ng"},
 	{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
+	{.name = "ima-ngv2", .fmt = "d-ngv2|n-ng"},
+	{.name = "ima-sigv2", .fmt = "d-ngv2|n-ng|sig"},
 	{.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
 	{.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"},
 	{.name = "evm-sig",
@@ -38,6 +40,8 @@ static const struct ima_template_field supported_fields[] = {
 	 .field_show = ima_show_template_string},
 	{.field_id = "d-ng", .field_init = ima_eventdigest_ng_init,
 	 .field_show = ima_show_template_digest_ng},
+	{.field_id = "d-ngv2", .field_init = ima_eventdigest_ngv2_init,
+	 .field_show = ima_show_template_digest_ngv2},
 	{.field_id = "n-ng", .field_init = ima_eventname_ng_init,
 	 .field_show = ima_show_template_string},
 	{.field_id = "sig", .field_init = ima_eventsig_init,
diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c
index 7155d17a3b75..c877f01a5471 100644
--- a/security/integrity/ima/ima_template_lib.c
+++ b/security/integrity/ima/ima_template_lib.c
@@ -24,11 +24,24 @@ static bool ima_template_hash_algo_allowed(u8 algo)
 enum data_formats {
 	DATA_FMT_DIGEST = 0,
 	DATA_FMT_DIGEST_WITH_ALGO,
+	DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO,
 	DATA_FMT_STRING,
 	DATA_FMT_HEX,
 	DATA_FMT_UINT
 };
 
+enum digest_type {
+	DIGEST_TYPE_IMA,
+	DIGEST_TYPE_VERITY,
+	DIGEST_TYPE__LAST
+};
+
+#define DIGEST_TYPE_NAME_LEN_MAX 7	/* including NUL */
+static const char * const digest_type_name[DIGEST_TYPE__LAST] = {
+	[DIGEST_TYPE_IMA] = "ima",
+	[DIGEST_TYPE_VERITY] = "verity"
+};
+
 static int ima_write_template_field_data(const void *data, const u32 datalen,
 					 enum data_formats datafmt,
 					 struct ima_field_data *field_data)
@@ -72,8 +85,9 @@ static void ima_show_template_data_ascii(struct seq_file *m,
 	u32 buflen = field_data->len;
 
 	switch (datafmt) {
+	case DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO:
 	case DATA_FMT_DIGEST_WITH_ALGO:
-		buf_ptr = strnchr(field_data->data, buflen, ':');
+		buf_ptr = strrchr(field_data->data, ':');
 		if (buf_ptr != field_data->data)
 			seq_printf(m, "%s", field_data->data);
 
@@ -178,6 +192,14 @@ void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
 				     field_data);
 }
 
+void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show,
+				   struct ima_field_data *field_data)
+{
+	ima_show_template_field_data(m, show,
+				     DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO,
+				     field_data);
+}
+
 void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
 			      struct ima_field_data *field_data)
 {
@@ -265,26 +287,35 @@ int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
 }
 
 static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
-				       u8 hash_algo,
+				       u8 digest_type, u8 hash_algo,
 				       struct ima_field_data *field_data)
 {
 	/*
 	 * digest formats:
 	 *  - DATA_FMT_DIGEST: digest
-	 *  - DATA_FMT_DIGEST_WITH_ALGO: [<hash algo>] + ':' + '\0' + digest,
-	 *    where <hash algo> is provided if the hash algorithm is not
-	 *    SHA1 or MD5
+	 *  - DATA_FMT_DIGEST_WITH_ALGO: <hash algo> + ':' + '\0' + digest,
+	 *  - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO:
+	 *	<digest type> + ':' + <hash algo> + ':' + '\0' + digest,
+	 *
+	 *    where 'DATA_FMT_DIGEST' is the original digest format ('d')
+	 *      with a hash size limitation of 20 bytes,
+	 *    where <digest type> is either "ima" or "verity",
+	 *    where <hash algo> is the hash_algo_name[] string.
 	 */
-	u8 buffer[CRYPTO_MAX_ALG_NAME + 2 + IMA_MAX_DIGEST_SIZE] = { 0 };
+	u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 +
+		IMA_MAX_DIGEST_SIZE] = { 0 };
 	enum data_formats fmt = DATA_FMT_DIGEST;
 	u32 offset = 0;
 
-	if (hash_algo < HASH_ALGO__LAST) {
+	if (digest_type < DIGEST_TYPE__LAST && hash_algo < HASH_ALGO__LAST) {
+		fmt = DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO;
+		offset += 1 + sprintf(buffer, "%s:%s:",
+				      digest_type_name[digest_type],
+				      hash_algo_name[hash_algo]);
+	} else if (hash_algo < HASH_ALGO__LAST) {
 		fmt = DATA_FMT_DIGEST_WITH_ALGO;
-		offset += snprintf(buffer, CRYPTO_MAX_ALG_NAME + 1, "%s",
-				   hash_algo_name[hash_algo]);
-		buffer[offset] = ':';
-		offset += 2;
+		offset += 1 + sprintf(buffer, "%s:",
+				      hash_algo_name[hash_algo]);
 	}
 
 	if (digest)
@@ -359,7 +390,8 @@ int ima_eventdigest_init(struct ima_event_data *event_data,
 	cur_digestsize = hash.hdr.length;
 out:
 	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
-					   HASH_ALGO__LAST, field_data);
+					   DIGEST_TYPE__LAST, HASH_ALGO__LAST,
+					   field_data);
 }
 
 /*
@@ -368,8 +400,32 @@ out:
 int ima_eventdigest_ng_init(struct ima_event_data *event_data,
 			    struct ima_field_data *field_data)
 {
-	u8 *cur_digest = NULL, hash_algo = HASH_ALGO_SHA1;
+	u8 *cur_digest = NULL, hash_algo = ima_hash_algo;
+	u32 cur_digestsize = 0;
+
+	if (event_data->violation)	/* recording a violation. */
+		goto out;
+
+	cur_digest = event_data->iint->ima_hash->digest;
+	cur_digestsize = event_data->iint->ima_hash->length;
+
+	hash_algo = event_data->iint->ima_hash->algo;
+out:
+	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
+					   DIGEST_TYPE__LAST, hash_algo,
+					   field_data);
+}
+
+/*
+ * This function writes the digest of an event (without size limit),
+ * prefixed with both the digest type and hash algorithm.
+ */
+int ima_eventdigest_ngv2_init(struct ima_event_data *event_data,
+			      struct ima_field_data *field_data)
+{
+	u8 *cur_digest = NULL, hash_algo = ima_hash_algo;
 	u32 cur_digestsize = 0;
+	u8 digest_type = DIGEST_TYPE_IMA;
 
 	if (event_data->violation)	/* recording a violation. */
 		goto out;
@@ -378,9 +434,12 @@ int ima_eventdigest_ng_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 = DIGEST_TYPE_VERITY;
 out:
 	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
-					   hash_algo, field_data);
+					   digest_type, hash_algo,
+					   field_data);
 }
 
 /*
@@ -415,7 +474,8 @@ int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
 	}
 
 	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
-					   hash_algo, field_data);
+					   DIGEST_TYPE__LAST, hash_algo,
+					   field_data);
 }
 
 static int ima_eventname_init_common(struct ima_event_data *event_data,
@@ -475,7 +535,9 @@ int ima_eventsig_init(struct ima_event_data *event_data,
 {
 	struct evm_ima_xattr_data *xattr_value = event_data->xattr_value;
 
-	if ((!xattr_value) || (xattr_value->type != EVM_IMA_XATTR_DIGSIG))
+	if (!xattr_value ||
+	    (xattr_value->type != EVM_IMA_XATTR_DIGSIG &&
+	     xattr_value->type != IMA_VERITY_DIGSIG))
 		return ima_eventevmsig_init(event_data, field_data);
 
 	return ima_write_template_field_data(xattr_value, event_data->xattr_len,
diff --git a/security/integrity/ima/ima_template_lib.h b/security/integrity/ima/ima_template_lib.h
index c71f1de95753..9f7c335f304f 100644
--- a/security/integrity/ima/ima_template_lib.h
+++ b/security/integrity/ima/ima_template_lib.h
@@ -21,6 +21,8 @@ void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
 			      struct ima_field_data *field_data);
 void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
 				 struct ima_field_data *field_data);
+void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show,
+				   struct ima_field_data *field_data);
 void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
 			      struct ima_field_data *field_data);
 void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
@@ -38,6 +40,8 @@ int ima_eventname_init(struct ima_event_data *event_data,
 		       struct ima_field_data *field_data);
 int ima_eventdigest_ng_init(struct ima_event_data *event_data,
 			    struct ima_field_data *field_data);
+int ima_eventdigest_ngv2_init(struct ima_event_data *event_data,
+			      struct ima_field_data *field_data);
 int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
 				struct ima_field_data *field_data);
 int ima_eventname_ng_init(struct ima_event_data *event_data,
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 3510e413ea17..7167a6e99bdc 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -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)
@@ -78,6 +79,7 @@ enum evm_ima_xattr_type {
 	EVM_IMA_XATTR_DIGSIG,
 	IMA_XATTR_DIGEST_NG,
 	EVM_XATTR_PORTABLE_DIGSIG,
+	IMA_VERITY_DIGSIG,
 	IMA_XATTR_LAST
 };
 
@@ -92,7 +94,7 @@ struct evm_xattr {
 	u8 digest[SHA1_DIGEST_SIZE];
 } __packed;
 
-#define IMA_MAX_DIGEST_SIZE	64
+#define IMA_MAX_DIGEST_SIZE	HASH_MAX_DIGESTSIZE
 
 struct ima_digest_data {
 	u8 algo;
@@ -121,7 +123,14 @@ struct ima_max_digest_data {
 } __packed;
 
 /*
- * signature format v2 - for using with asymmetric keys
+ * signature header format v2 - for using with asymmetric keys
+ *
+ * The signature_v2_hdr struct includes a signature format version
+ * to simplify defining new signature formats.
+ *
+ * signature format:
+ * version 2: regular file data hash based signature
+ * version 3: struct ima_file_id data based signature
  */
 struct signature_v2_hdr {
 	uint8_t type;		/* xattr type */
@@ -132,6 +141,20 @@ struct signature_v2_hdr {
 	uint8_t sig[];		/* signature payload */
 } __packed;
 
+/*
+ * IMA signature version 3 disambiguates the data that is signed, by
+ * indirectly signing the hash of the ima_file_id structure data,
+ * containing either the fsverity_descriptor struct digest or, in the
+ * future, the regular IMA file hash.
+ *
+ * (The hash of the ima_file_id structure is only of the portion used.)
+ */
+struct ima_file_id {
+	__u8 hash_type;		/* xattr type [enum evm_ima_xattr_type] */
+	__u8 hash_algorithm;	/* Digest algorithm [enum hash_algo] */
+	__u8 hash[HASH_MAX_DIGESTSIZE];
+} __packed;
+
 /* integrity data associated with an inode */
 struct integrity_iint_cache {
 	struct rb_node rb_node;	/* rooted in integrity_iint_tree */