From a71dc65d30a472409f05d247f4eab91b14acf2f5 Mon Sep 17 00:00:00 2001 From: Roberto Sassu Date: Fri, 7 Jun 2013 12:16:33 +0200 Subject: ima: switch to new template management mechanism This patch performs the switch to the new template mechanism by modifying the functions ima_alloc_init_template(), ima_measurements_show() and ima_ascii_measurements_show(). The old function ima_template_show() was removed as it is no longer needed. Also, if the template descriptor used to generate a measurement entry is not 'ima', the whole length of field data stored for an entry is provided before the data itself through the binary_runtime_measurement interface. Changelog: - unnecessary to use strncmp() (Mimi Zohar) - create new variable 'field' in ima_alloc_init_template() (Roberto Sassu) - use GFP_NOFS flag in ima_alloc_init_template() (Roberto Sassu) - new variable 'num_fields' in ima_store_template() (Roberto Sassu, proposed by Mimi Zohar) - rename ima_calc_buffer_hash/template_hash() to ima_calc_field_array_hash(), something more generic (Mimi, requested by Dmitry) - sparse error fix - Fengguang Wu - fix lindent warnings - always include the field length in the template data length - include the template field length variable size in the template data length - include both the template field data and field length in the template digest calculation. Simplifies verifying the template digest. (Mimi) Signed-off-by: Roberto Sassu Signed-off-by: Mimi Zohar --- security/integrity/ima/ima.h | 19 ++++----- security/integrity/ima/ima_api.c | 75 ++++++++++++----------------------- security/integrity/ima/ima_crypto.c | 34 ++++++++++++---- security/integrity/ima/ima_fs.c | 54 ++++++++++++------------- security/integrity/ima/ima_template.c | 22 ++++++++++ 5 files changed, 107 insertions(+), 97 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e1f081d65dbf..72d013e190b1 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -72,17 +72,11 @@ struct ima_template_desc { struct ima_template_field **fields; }; -/* IMA inode template definition */ -struct ima_template_data { - u8 digest[IMA_DIGEST_SIZE]; /* sha1/md5 measurement hash */ - char file_name[IMA_EVENT_NAME_LEN_MAX + 1]; /* name + \0 */ -}; - struct ima_template_entry { u8 digest[TPM_DIGEST_SIZE]; /* sha1 or md5 measurement hash */ - const char *template_name; - int template_len; - struct ima_template_data template; + struct ima_template_desc *template_desc; /* template descriptor */ + u32 template_data_len; + struct ima_field_data template_data[0]; /* template related data */ }; struct ima_queue_entry { @@ -102,14 +96,16 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation, const char *op, struct inode *inode, const unsigned char *filename); int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash); -int ima_calc_buffer_hash(const void *data, int len, - struct ima_digest_data *hash); +int ima_calc_field_array_hash(struct ima_field_data *field_data, int num_fields, + struct ima_digest_data *hash); int __init ima_calc_boot_aggregate(struct ima_digest_data *hash); void ima_add_violation(struct file *file, const unsigned char *filename, const char *op, const char *cause); int ima_init_crypto(void); void ima_putc(struct seq_file *m, void *data, int datalen); void ima_print_digest(struct seq_file *m, u8 *digest, int size); +struct ima_template_desc *ima_template_desc_current(void); +int ima_init_template(void); int ima_init_template(void); @@ -146,7 +142,6 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint, struct ima_template_entry **entry); int ima_store_template(struct ima_template_entry *entry, int violation, struct inode *inode, const unsigned char *filename); -void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show); const char *ima_d_path(struct path *path, char **pathbuf); /* rbtree tree calls to lookup, insert, delete diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 29dd43de823a..baa348179527 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -21,8 +21,6 @@ #include #include "ima.h" -static const char *IMA_TEMPLATE_NAME = "ima"; - /* * ima_alloc_init_template - create and initialize a new template entry */ @@ -30,52 +28,32 @@ int ima_alloc_init_template(struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, struct ima_template_entry **entry) { - struct ima_template_entry *e; - int result = 0; + struct ima_template_desc *template_desc = ima_template_desc_current(); + int i, result = 0; - e = kzalloc(sizeof(**entry), GFP_NOFS); - if (!e) + *entry = kzalloc(sizeof(**entry) + template_desc->num_fields * + sizeof(struct ima_field_data), GFP_NOFS); + if (!*entry) return -ENOMEM; - memset(&(e)->template, 0, sizeof(e->template)); - if (!iint) /* IMA measurement violation entry */ - goto out; - - if (iint->ima_hash->algo != ima_hash_algo) { - struct inode *inode; - struct { - struct ima_digest_data hdr; - char digest[IMA_MAX_DIGEST_SIZE]; - } hash; + for (i = 0; i < template_desc->num_fields; i++) { + struct ima_template_field *field = template_desc->fields[i]; + u32 len; - if (!file) { - result = -EINVAL; - goto out_free; - } + result = field->field_init(iint, file, filename, + &((*entry)->template_data[i])); + if (result != 0) + goto out; - inode = file_inode(file); - hash.hdr.algo = ima_hash_algo; - hash.hdr.length = SHA1_DIGEST_SIZE; - result = ima_calc_file_hash(file, &hash.hdr); - if (result) { - integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, - filename, "collect_data", - "failed", result, 0); - goto out_free; - } else - memcpy(e->template.digest, hash.hdr.digest, - hash.hdr.length); - } else - memcpy(e->template.digest, iint->ima_hash->digest, - iint->ima_hash->length); -out: - strcpy(e->template.file_name, - (strlen(filename) > IMA_EVENT_NAME_LEN_MAX && file != NULL) ? - file->f_dentry->d_name.name : filename); - *entry = e; + len = (*entry)->template_data[i].len; + (*entry)->template_data_len += sizeof(len); + (*entry)->template_data_len += len; + } + (*entry)->template_desc = template_desc; return 0; -out_free: - kfree(e); +out: + kfree(*entry); + *entry = NULL; return result; } @@ -101,24 +79,23 @@ int ima_store_template(struct ima_template_entry *entry, { const char *op = "add_template_measure"; const char *audit_cause = "hashing_error"; + char *template_name = entry->template_desc->name; int result; struct { struct ima_digest_data hdr; char digest[TPM_DIGEST_SIZE]; } hash; - memset(entry->digest, 0, sizeof(entry->digest)); - entry->template_name = IMA_TEMPLATE_NAME; - entry->template_len = sizeof(entry->template); - if (!violation) { + int num_fields = entry->template_desc->num_fields; + /* this function uses default algo */ hash.hdr.algo = HASH_ALGO_SHA1; - result = ima_calc_buffer_hash(&entry->template, - entry->template_len, &hash.hdr); + result = ima_calc_field_array_hash(&entry->template_data[0], + num_fields, &hash.hdr); if (result < 0) { integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, - entry->template_name, op, + template_name, op, audit_cause, result, 0); return result; } diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 22be23f13b3d..676e0292dfec 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -137,26 +137,46 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) } /* - * Calculate the hash of a given buffer + * Calculate the hash of template data */ -static int ima_calc_buffer_hash_tfm(const void *buf, int len, - struct ima_digest_data *hash, - struct crypto_shash *tfm) +static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, + int num_fields, + struct ima_digest_data *hash, + struct crypto_shash *tfm) { struct { struct shash_desc shash; char ctx[crypto_shash_descsize(tfm)]; } desc; + int rc, i; desc.shash.tfm = tfm; desc.shash.flags = 0; hash->length = crypto_shash_digestsize(tfm); - return crypto_shash_digest(&desc.shash, buf, len, hash->digest); + rc = crypto_shash_init(&desc.shash); + if (rc != 0) + return rc; + + for (i = 0; i < num_fields; i++) { + rc = crypto_shash_update(&desc.shash, + (const u8 *) &field_data[i].len, + sizeof(field_data[i].len)); + rc = crypto_shash_update(&desc.shash, field_data[i].data, + field_data[i].len); + if (rc) + break; + } + + if (!rc) + rc = crypto_shash_final(&desc.shash, hash->digest); + + return rc; } -int ima_calc_buffer_hash(const void *buf, int len, struct ima_digest_data *hash) +int ima_calc_field_array_hash(struct ima_field_data *field_data, int num_fields, + struct ima_digest_data *hash) { struct crypto_shash *tfm; int rc; @@ -165,7 +185,7 @@ int ima_calc_buffer_hash(const void *buf, int len, struct ima_digest_data *hash) if (IS_ERR(tfm)) return PTR_ERR(tfm); - rc = ima_calc_buffer_hash_tfm(buf, len, hash, tfm); + rc = ima_calc_field_array_hash_tfm(field_data, num_fields, hash, tfm); ima_free_tfm(tfm); diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 414862e1904b..d47a7c86a21d 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -110,6 +110,7 @@ void ima_putc(struct seq_file *m, void *data, int datalen) * char[20]=template digest * 32bit-le=template name size * char[n]=template name + * [eventdata length] * eventdata[n]=template specific data */ static int ima_measurements_show(struct seq_file *m, void *v) @@ -119,6 +120,7 @@ static int ima_measurements_show(struct seq_file *m, void *v) struct ima_template_entry *e; int namelen; u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX; + int i; /* get entry */ e = qe->entry; @@ -136,15 +138,22 @@ static int ima_measurements_show(struct seq_file *m, void *v) ima_putc(m, e->digest, TPM_DIGEST_SIZE); /* 3rd: template name size */ - namelen = strlen(e->template_name); + namelen = strlen(e->template_desc->name); ima_putc(m, &namelen, sizeof namelen); /* 4th: template name */ - ima_putc(m, (void *)e->template_name, namelen); + ima_putc(m, e->template_desc->name, namelen); + + /* 5th: template length (except for 'ima' template) */ + if (strcmp(e->template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) + ima_putc(m, &e->template_data_len, + sizeof(e->template_data_len)); - /* 5th: template specific data */ - ima_template_show(m, (struct ima_template_data *)&e->template, - IMA_SHOW_BINARY); + /* 6th: template specific data */ + for (i = 0; i < e->template_desc->num_fields; i++) { + e->template_desc->fields[i]->field_show(m, IMA_SHOW_BINARY, + &e->template_data[i]); + } return 0; } @@ -175,33 +184,13 @@ void ima_print_digest(struct seq_file *m, u8 *digest, int size) seq_printf(m, "%02x", *(digest + i)); } -void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show) -{ - struct ima_template_data *entry = e; - int namelen; - - switch (show) { - case IMA_SHOW_ASCII: - ima_print_digest(m, entry->digest, IMA_DIGEST_SIZE); - seq_printf(m, " %s\n", entry->file_name); - break; - case IMA_SHOW_BINARY: - ima_putc(m, entry->digest, IMA_DIGEST_SIZE); - - namelen = strlen(entry->file_name); - ima_putc(m, &namelen, sizeof namelen); - ima_putc(m, entry->file_name, namelen); - default: - break; - } -} - /* print in ascii */ static int ima_ascii_measurements_show(struct seq_file *m, void *v) { /* the list never shrinks, so we don't need a lock here */ struct ima_queue_entry *qe = v; struct ima_template_entry *e; + int i; /* get entry */ e = qe->entry; @@ -215,11 +204,18 @@ static int ima_ascii_measurements_show(struct seq_file *m, void *v) ima_print_digest(m, e->digest, TPM_DIGEST_SIZE); /* 3th: template name */ - seq_printf(m, " %s ", e->template_name); + seq_printf(m, " %s", e->template_desc->name); /* 4th: template specific data */ - ima_template_show(m, (struct ima_template_data *)&e->template, - IMA_SHOW_ASCII); + for (i = 0; i < e->template_desc->num_fields; i++) { + seq_puts(m, " "); + if (e->template_data[i].len == 0) + continue; + + e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII, + &e->template_data[i]); + } + seq_puts(m, "\n"); return 0; } diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index bf38d1af3cfd..1c4cf194592c 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -31,6 +31,20 @@ static struct ima_template_field supported_fields[] = { .field_show = ima_show_template_string}, }; +static struct ima_template_desc *ima_template; + +static struct ima_template_desc *lookup_template_desc(const char *name) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(defined_templates); i++) { + if (strcmp(defined_templates[i].name, name) == 0) + return defined_templates + i; + } + + return NULL; +} + static struct ima_template_field *lookup_template_field(const char *field_id) { int i; @@ -110,6 +124,14 @@ static int init_defined_templates(void) return result; } +struct ima_template_desc *ima_template_desc_current(void) +{ + if (!ima_template) + ima_template = lookup_template_desc(IMA_TEMPLATE_IMA_NAME); + + return ima_template; +} + int ima_init_template(void) { int result; -- cgit v1.2.3