1 files changed, 205 insertions, 48 deletions

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 9b3ade7468b..ccd0ac8fa9a 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -10,60 +10,131 @@
  * the Free Software Foundation, version 2 of the License.
  *
  * File: ima_crypto.c
- * 	Calculates md5/sha1 file hash, template hash, boot-aggreate hash
+ *	Calculates md5/sha1 file hash, template hash, boot-aggreate hash
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kernel.h>
 #include <linux/file.h>
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <crypto/hash.h>
+#include <crypto/hash_info.h>
 #include "ima.h"
 
-static int init_desc(struct hash_desc *desc)
+static struct crypto_shash *ima_shash_tfm;
+
+/**
+ * ima_kernel_read - read file content
+ *
+ * This is a function for reading file content instead of kernel_read().
+ * It does not perform locking checks to ensure it cannot be blocked.
+ * It does not perform security checks because it is irrelevant for IMA.
+ *
+ */
+static int ima_kernel_read(struct file *file, loff_t offset,
+			   char *addr, unsigned long count)
 {
-	int rc;
+	mm_segment_t old_fs;
+	char __user *buf = addr;
+	ssize_t ret;
+
+	if (!(file->f_mode & FMODE_READ))
+		return -EBADF;
+	if (!file->f_op->read && !file->f_op->aio_read)
+		return -EINVAL;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	if (file->f_op->read)
+		ret = file->f_op->read(file, buf, count, &offset);
+	else
+		ret = do_sync_read(file, buf, count, &offset);
+	set_fs(old_fs);
+	return ret;
+}
 
-	desc->tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
-	if (IS_ERR(desc->tfm)) {
-		pr_info("IMA: failed to load %s transform: %ld\n",
-			ima_hash, PTR_ERR(desc->tfm));
-		rc = PTR_ERR(desc->tfm);
+int ima_init_crypto(void)
+{
+	long rc;
+
+	ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
+	if (IS_ERR(ima_shash_tfm)) {
+		rc = PTR_ERR(ima_shash_tfm);
+		pr_err("Can not allocate %s (reason: %ld)\n",
+		       hash_algo_name[ima_hash_algo], rc);
 		return rc;
 	}
-	desc->flags = 0;
-	rc = crypto_hash_init(desc);
-	if (rc)
-		crypto_free_hash(desc->tfm);
-	return rc;
+	return 0;
+}
+
+static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
+{
+	struct crypto_shash *tfm = ima_shash_tfm;
+	int rc;
+
+	if (algo != ima_hash_algo && algo < HASH_ALGO__LAST) {
+		tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
+		if (IS_ERR(tfm)) {
+			rc = PTR_ERR(tfm);
+			pr_err("Can not allocate %s (reason: %d)\n",
+			       hash_algo_name[algo], rc);
+		}
+	}
+	return tfm;
+}
+
+static void ima_free_tfm(struct crypto_shash *tfm)
+{
+	if (tfm != ima_shash_tfm)
+		crypto_free_shash(tfm);
 }
 
 /*
  * Calculate the MD5/SHA1 file digest
  */
-int ima_calc_hash(struct file *file, char *digest)
+static int ima_calc_file_hash_tfm(struct file *file,
+				  struct ima_digest_data *hash,
+				  struct crypto_shash *tfm)
 {
-	struct hash_desc desc;
-	struct scatterlist sg[1];
 	loff_t i_size, offset = 0;
 	char *rbuf;
-	int rc;
+	int rc, read = 0;
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(tfm)];
+	} desc;
 
-	rc = init_desc(&desc);
+	desc.shash.tfm = tfm;
+	desc.shash.flags = 0;
+
+	hash->length = crypto_shash_digestsize(tfm);
+
+	rc = crypto_shash_init(&desc.shash);
 	if (rc != 0)
 		return rc;
 
-	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!rbuf) {
-		rc = -ENOMEM;
+	i_size = i_size_read(file_inode(file));
+
+	if (i_size == 0)
 		goto out;
+
+	rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!rbuf)
+		return -ENOMEM;
+
+	if (!(file->f_mode & FMODE_READ)) {
+		file->f_mode |= FMODE_READ;
+		read = 1;
 	}
-	i_size = i_size_read(file->f_dentry->d_inode);
+
 	while (offset < i_size) {
 		int rbuf_len;
 
-		rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
+		rbuf_len = ima_kernel_read(file, offset, rbuf, PAGE_SIZE);
 		if (rbuf_len < 0) {
 			rc = rbuf_len;
 			break;
@@ -71,38 +142,103 @@ int ima_calc_hash(struct file *file, char *digest)
 		if (rbuf_len == 0)
 			break;
 		offset += rbuf_len;
-		sg_init_one(sg, rbuf, rbuf_len);
 
-		rc = crypto_hash_update(&desc, sg, rbuf_len);
+		rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
 		if (rc)
 			break;
 	}
+	if (read)
+		file->f_mode &= ~FMODE_READ;
 	kfree(rbuf);
-	if (!rc)
-		rc = crypto_hash_final(&desc, digest);
 out:
-	crypto_free_hash(desc.tfm);
+	if (!rc)
+		rc = crypto_shash_final(&desc.shash, hash->digest);
+	return rc;
+}
+
+int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
+{
+	struct crypto_shash *tfm;
+	int rc;
+
+	tfm = ima_alloc_tfm(hash->algo);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	rc = ima_calc_file_hash_tfm(file, hash, tfm);
+
+	ima_free_tfm(tfm);
+
 	return rc;
 }
 
 /*
- * Calculate the hash of a given template
+ * Calculate the hash of template data
  */
-int ima_calc_template_hash(int template_len, void *template, char *digest)
+static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
+					 struct ima_template_desc *td,
+					 int num_fields,
+					 struct ima_digest_data *hash,
+					 struct crypto_shash *tfm)
 {
-	struct hash_desc desc;
-	struct scatterlist sg[1];
-	int rc;
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(tfm)];
+	} desc;
+	int rc, i;
+
+	desc.shash.tfm = tfm;
+	desc.shash.flags = 0;
 
-	rc = init_desc(&desc);
+	hash->length = crypto_shash_digestsize(tfm);
+
+	rc = crypto_shash_init(&desc.shash);
 	if (rc != 0)
 		return rc;
 
-	sg_init_one(sg, template, template_len);
-	rc = crypto_hash_update(&desc, sg, template_len);
+	for (i = 0; i < num_fields; i++) {
+		u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
+		u8 *data_to_hash = field_data[i].data;
+		u32 datalen = field_data[i].len;
+
+		if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
+			rc = crypto_shash_update(&desc.shash,
+						(const u8 *) &field_data[i].len,
+						sizeof(field_data[i].len));
+			if (rc)
+				break;
+		} else if (strcmp(td->fields[i]->field_id, "n") == 0) {
+			memcpy(buffer, data_to_hash, datalen);
+			data_to_hash = buffer;
+			datalen = IMA_EVENT_NAME_LEN_MAX + 1;
+		}
+		rc = crypto_shash_update(&desc.shash, data_to_hash, datalen);
+		if (rc)
+			break;
+	}
+
 	if (!rc)
-		rc = crypto_hash_final(&desc, digest);
-	crypto_free_hash(desc.tfm);
+		rc = crypto_shash_final(&desc.shash, hash->digest);
+
+	return rc;
+}
+
+int ima_calc_field_array_hash(struct ima_field_data *field_data,
+			      struct ima_template_desc *desc, int num_fields,
+			      struct ima_digest_data *hash)
+{
+	struct crypto_shash *tfm;
+	int rc;
+
+	tfm = ima_alloc_tfm(hash->algo);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields,
+					   hash, tfm);
+
+	ima_free_tfm(tfm);
+
 	return rc;
 }
 
@@ -112,20 +248,26 @@ static void __init ima_pcrread(int idx, u8 *pcr)
 		return;
 
 	if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
-		pr_err("IMA: Error Communicating to TPM chip\n");
+		pr_err("Error Communicating to TPM chip\n");
 }
 
 /*
  * Calculate the boot aggregate hash
  */
-int __init ima_calc_boot_aggregate(char *digest)
+static int __init ima_calc_boot_aggregate_tfm(char *digest,
+					      struct crypto_shash *tfm)
 {
-	struct hash_desc desc;
-	struct scatterlist sg;
-	u8 pcr_i[IMA_DIGEST_SIZE];
+	u8 pcr_i[TPM_DIGEST_SIZE];
 	int rc, i;
+	struct {
+		struct shash_desc shash;
+		char ctx[crypto_shash_descsize(tfm)];
+	} desc;
+
+	desc.shash.tfm = tfm;
+	desc.shash.flags = 0;
 
-	rc = init_desc(&desc);
+	rc = crypto_shash_init(&desc.shash);
 	if (rc != 0)
 		return rc;
 
@@ -133,11 +275,26 @@ int __init ima_calc_boot_aggregate(char *digest)
 	for (i = TPM_PCR0; i < TPM_PCR8; i++) {
 		ima_pcrread(i, pcr_i);
 		/* now accumulate with current aggregate */
-		sg_init_one(&sg, pcr_i, IMA_DIGEST_SIZE);
-		rc = crypto_hash_update(&desc, &sg, IMA_DIGEST_SIZE);
+		rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE);
 	}
 	if (!rc)
-		crypto_hash_final(&desc, digest);
-	crypto_free_hash(desc.tfm);
+		crypto_shash_final(&desc.shash, digest);
+	return rc;
+}
+
+int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
+{
+	struct crypto_shash *tfm;
+	int rc;
+
+	tfm = ima_alloc_tfm(hash->algo);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	hash->length = crypto_shash_digestsize(tfm);
+	rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);
+
+	ima_free_tfm(tfm);
+
 	return rc;
 }