[PATCH 00/23] KEYS: Fixes

@@ -1084,10 +1084,6 @@ config SYSVIPC_COMPAT
 	def_bool y
 	depends on COMPAT && SYSVIPC
 
-config KEYS_COMPAT
-	def_bool y
-	depends on COMPAT && KEYS
-
 endmenu
 
 menu "Power management options"

@@ -1215,11 +1215,6 @@ source "arch/powerpc/Kconfig.debug"
 
 source "security/Kconfig"
 
-config KEYS_COMPAT
-	bool
-	depends on COMPAT && KEYS
-	default y
-
 source "crypto/Kconfig"
 
 config PPC_LIB_RHEAP

@@ -363,9 +363,6 @@ config COMPAT
 config SYSVIPC_COMPAT
 	def_bool y if COMPAT && SYSVIPC
 
-config KEYS_COMPAT
-	def_bool y if COMPAT && KEYS
-
 config SMP
 	def_bool y
 	prompt "Symmetric multi-processing support"

@@ -577,9 +577,6 @@ config SYSVIPC_COMPAT
 	depends on COMPAT && SYSVIPC
 	default y
 
-config KEYS_COMPAT
-	def_bool y if COMPAT && KEYS
-
 endmenu
 
 source "net/Kconfig"

@@ -2776,10 +2776,6 @@ config COMPAT_FOR_U64_ALIGNMENT
 config SYSVIPC_COMPAT
 	def_bool y
 	depends on SYSVIPC
-
-config KEYS_COMPAT
-	def_bool y
-	depends on KEYS
 endif
 
 endmenu

@@ -20,6 +20,10 @@ config KEYS
 
 	  If you are unsure as to whether this is required, answer N.
 
+config KEYS_COMPAT
+	def_bool y
+	depends on COMPAT && KEYS
+
 config PERSISTENT_KEYRINGS
 	bool "Enable register of persistent per-UID keyrings"
 	depends on KEYS

--

@@ -660,14 +660,11 @@ struct key *key_lookup(key_serial_t id)
 	goto error;
 
 found:
-	/* pretend it doesn't exist if it is awaiting deletion */
-	if (refcount_read(&key->usage) == 0)
-		goto not_found;
-
-	/* this races with key_put(), but that doesn't matter since key_put()
-	 * doesn't actually change the key
+	/* A key is allowed to be looked up only if someone still owns a
+	 * reference to it - otherwise it's awaiting the gc.
 	 */
-	__key_get(key);
+	if (!refcount_inc_not_zero(&key->usage))
+		goto not_found;
 
 error:
 	spin_unlock(&key_serial_lock);

--

@@ -385,10 +385,9 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type,
 		derived_buf_len = HASH_SIZE;
 
 	derived_buf = kzalloc(derived_buf_len, GFP_KERNEL);
-	if (!derived_buf) {
-		pr_err("encrypted_key: out of memory\n");
+	if (!derived_buf)
 		return -ENOMEM;
-	}
+
 	if (key_type)
 		strcpy(derived_buf, "AUTH_KEY");
 	else

--

@@ -102,6 +102,7 @@ struct x509_certificate *x509_cert_parse(const void *data, size_t datalen)
 		}
 	}
 
+	ret = -ENOMEM;
 	cert->pub->key = kmemdup(ctx->key, ctx->key_size, GFP_KERNEL);
 	if (!cert->pub->key)
 		goto error_decode;

--

@@ -809,15 +809,14 @@ long join_session_keyring(const char *name)
 		ret = PTR_ERR(keyring);
 		goto error2;
 	} else if (keyring == new->session_keyring) {
-		key_put(keyring);
 		ret = 0;
-		goto error2;
+		goto error3;
 	}
 
 	/* we've got a keyring - now to install it */
 	ret = install_session_keyring_to_cred(new, keyring);
 	if (ret < 0)
-		goto error2;
+		goto error3;
 
 	commit_creds(new);
 	mutex_unlock(&key_session_mutex);

@@ -827,6 +826,8 @@ long join_session_keyring(const char *name)
 okay:
 	return ret;
 
+error3:
+	key_put(keyring);
 error2:
 	mutex_unlock(&key_session_mutex);
 error:

--

@@ -141,23 +141,22 @@ static int valid_ecryptfs_desc(const char *ecryptfs_desc)
  */
 static int valid_master_desc(const char *new_desc, const char *orig_desc)
 {
-	if (!memcmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN)) {
-		if (strlen(new_desc) == KEY_TRUSTED_PREFIX_LEN)
-			goto out;
-		if (orig_desc)
-			if (memcmp(new_desc, orig_desc, KEY_TRUSTED_PREFIX_LEN))
-				goto out;
-	} else if (!memcmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN)) {
-		if (strlen(new_desc) == KEY_USER_PREFIX_LEN)
-			goto out;
-		if (orig_desc)
-			if (memcmp(new_desc, orig_desc, KEY_USER_PREFIX_LEN))
-				goto out;
-	} else
-		goto out;
+	int prefix_len;
+
+	if (!strncmp(new_desc, KEY_TRUSTED_PREFIX, KEY_TRUSTED_PREFIX_LEN))
+		prefix_len = KEY_TRUSTED_PREFIX_LEN;
+	else if (!strncmp(new_desc, KEY_USER_PREFIX, KEY_USER_PREFIX_LEN))
+		prefix_len = KEY_USER_PREFIX_LEN;
+	else
+		return -EINVAL;
+
+	if (!new_desc[prefix_len])
+		return -EINVAL;
+
+	if (orig_desc && strncmp(new_desc, orig_desc, prefix_len))
+		return -EINVAL;
+
 	return 0;
-out:
-	return -EINVAL;
 }
 
 /*

--

@@ -479,12 +479,9 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload,
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
 	u8 iv[AES_BLOCK_SIZE];
-	unsigned int padlen;
-	char pad[16];
 	int ret;
 
 	encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
-	padlen = encrypted_datalen - epayload->decrypted_datalen;
 
 	req = init_skcipher_req(derived_key, derived_keylen);
 	ret = PTR_ERR(req);

@@ -492,11 +489,10 @@ static int derived_key_encrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_decrypted_data(epayload);
 
-	memset(pad, 0, sizeof pad);
 	sg_init_table(sg_in, 2);
 	sg_set_buf(&sg_in[0], epayload->decrypted_data,
 		   epayload->decrypted_datalen);
-	sg_set_buf(&sg_in[1], pad, padlen);
+	sg_set_page(&sg_in[1], ZERO_PAGE(0), AES_BLOCK_SIZE, 0);
 
 	sg_init_table(sg_out, 1);
 	sg_set_buf(sg_out, epayload->encrypted_data, encrypted_datalen);

@@ -583,9 +579,14 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 	struct skcipher_request *req;
 	unsigned int encrypted_datalen;
 	u8 iv[AES_BLOCK_SIZE];
-	char pad[16];
+	u8 *pad;
 	int ret;
 
+	/* Throwaway buffer to hold the unused zero padding at the end */
+	pad = kmalloc(AES_BLOCK_SIZE, GFP_KERNEL);
+	if (!pad)
+		return -ENOMEM;
+
 	encrypted_datalen = roundup(epayload->decrypted_datalen, blksize);
 	req = init_skcipher_req(derived_key, derived_keylen);
 	ret = PTR_ERR(req);

@@ -593,13 +594,12 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_encrypted_data(epayload, encrypted_datalen);
 
-	memset(pad, 0, sizeof pad);
 	sg_init_table(sg_in, 1);
 	sg_init_table(sg_out, 2);
 	sg_set_buf(sg_in, epayload->encrypted_data, encrypted_datalen);
 	sg_set_buf(&sg_out[0], epayload->decrypted_data,
 		   epayload->decrypted_datalen);
-	sg_set_buf(&sg_out[1], pad, sizeof pad);
+	sg_set_buf(&sg_out[1], pad, AES_BLOCK_SIZE);
 
 	memcpy(iv, epayload->iv, sizeof(iv));
 	skcipher_request_set_crypt(req, sg_in, sg_out, encrypted_datalen, iv);

@@ -611,6 +611,7 @@ static int derived_key_decrypt(struct encrypted_key_payload *epayload,
 		goto out;
 	dump_decrypted_data(epayload);
 out:
+	kfree(pad);
 	return ret;
 }
 

--

@@ -30,6 +30,7 @@
 #include <linux/scatterlist.h>
 #include <linux/ctype.h>
 #include <crypto/aes.h>
+#include <crypto/algapi.h>
 #include <crypto/hash.h>
 #include <crypto/sha.h>
 #include <crypto/skcipher.h>

@@ -534,8 +535,8 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
 	ret = calc_hmac(digest, derived_key, sizeof derived_key, p, len);
 	if (ret < 0)
 		goto out;
-	ret = memcmp(digest, epayload->format + epayload->datablob_len,
-		     sizeof digest);
+	ret = crypto_memneq(digest, epayload->format + epayload->datablob_len,
+			    sizeof(digest));
 	if (ret) {
 		ret = -EINVAL;
 		dump_hmac("datablob",

--

@@ -963,12 +963,11 @@ int key_update(key_ref_t key_ref, const void *payload, size_t plen)
 	/* the key must be writable */
 	ret = key_permission(key_ref, KEY_NEED_WRITE);
 	if (ret < 0)
-		goto error;
+		return ret;
 
 	/* attempt to update it if supported */
-	ret = -EOPNOTSUPP;
 	if (!key->type->update)
-		goto error;
+		return -EOPNOTSUPP;
 
 	memset(&prep, 0, sizeof(prep));
 	prep.data = payload;

--

@@ -375,7 +375,7 @@ static int get_derived_key(u8 *derived_key, enum derived_key_type key_type,
 	memcpy(derived_buf + strlen(derived_buf) + 1, master_key,
 	       master_keylen);
 	ret = calc_hash(hash_tfm, derived_key, derived_buf, derived_buf_len);
-	kfree(derived_buf);
+	kzfree(derived_buf);
 	return ret;
 }
 

@@ -507,6 +507,7 @@ static int datablob_hmac_append(struct encrypted_key_payload *epayload,
 	if (!ret)
 		dump_hmac(NULL, digest, HASH_SIZE);
 out:
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 

@@ -545,6 +546,7 @@ static int datablob_hmac_verify(struct encrypted_key_payload *epayload,
 		dump_hmac("calc", digest, HASH_SIZE);
 	}
 out:
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 

@@ -701,6 +703,7 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
 out:
 	up_read(&mkey->sem);
 	key_put(mkey);
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 

@@ -807,13 +810,13 @@ static int encrypted_instantiate(struct key *key,
 	ret = encrypted_init(epayload, key->description, format, master_desc,
 			     decrypted_datalen, hex_encoded_iv);
 	if (ret < 0) {
-		kfree(epayload);
+		kzfree(epayload);
 		goto out;
 	}
 
 	rcu_assign_keypointer(key, epayload);
 out:
-	kfree(datablob);
+	kzfree(datablob);
 	return ret;
 }
 

@@ -822,8 +825,7 @@ static void encrypted_rcu_free(struct rcu_head *rcu)
 	struct encrypted_key_payload *epayload;
 
 	epayload = container_of(rcu, struct encrypted_key_payload, rcu);
-	memset(epayload->decrypted_data, 0, epayload->decrypted_datalen);
-	kfree(epayload);
+	kzfree(epayload);
 }
 
 /*

@@ -881,7 +883,7 @@ static int encrypted_update(struct key *key, struct key_preparsed_payload *prep)
 	rcu_assign_keypointer(key, new_epayload);
 	call_rcu(&epayload->rcu, encrypted_rcu_free);
 out:
-	kfree(buf);
+	kzfree(buf);
 	return ret;
 }
 

@@ -939,33 +941,26 @@ static long encrypted_read(const struct key *key, char __user *buffer,
 
 	up_read(&mkey->sem);
 	key_put(mkey);
+	memzero_explicit(derived_key, sizeof(derived_key));
 
 	if (copy_to_user(buffer, ascii_buf, asciiblob_len) != 0)
 		ret = -EFAULT;
-	kfree(ascii_buf);
+	kzfree(ascii_buf);
 
 	return asciiblob_len;
 out:
 	up_read(&mkey->sem);
 	key_put(mkey);
+	memzero_explicit(derived_key, sizeof(derived_key));
 	return ret;
 }
 
 /*
- * encrypted_destroy - before freeing the key, clear the decrypted data
- *
- * Before freeing the key, clear the memory containing the decrypted
- * key data.
+ * encrypted_destroy - clear and free the key's payload
  */
 static void encrypted_destroy(struct key *key)
 {
-	struct encrypted_key_payload *epayload = key->payload.data[0];
-
-	if (!epayload)
-		return;
-
-	memzero_explicit(epayload->decrypted_data, epayload->decrypted_datalen);
-	kfree(key->payload.data[0]);
+	kzfree(key->payload.data[0]);
 }
 
 struct key_type key_type_encrypted = {

--

@@ -173,7 +173,6 @@ struct key {
 #ifdef KEY_DEBUGGING
 	unsigned		magic;
 #define KEY_DEBUG_MAGIC		0x18273645u
-#define KEY_DEBUG_MAGIC_X	0xf8e9dacbu
 #endif
 
 	unsigned long		flags;		/* status flags (change with bitops) */

@@ -158,9 +158,7 @@ static noinline void key_gc_unused_keys(struct list_head *keys)
 
 		kfree(key->description);
 
-#ifdef KEY_DEBUGGING
-		key->magic = KEY_DEBUG_MAGIC_X;
-#endif
+		memzero_explicit(key, sizeof(*key));
 		kmem_cache_free(key_jar, key);
 	}
 }

--

@@ -89,6 +89,7 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
 	struct crypto_shash *tfm;
 	struct kdf_sdesc *sdesc;
 	int size;
+	int err;
 
 	/* allocate synchronous hash */
 	tfm = crypto_alloc_shash(hashname, 0, 0);

@@ -97,16 +98,25 @@ static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
 		return PTR_ERR(tfm);
 	}
 
+	err = -EINVAL;
+	if (crypto_shash_digestsize(tfm) == 0)
+		goto out_free_tfm;
+
+	err = -ENOMEM;
 	size = sizeof(struct shash_desc) + crypto_shash_descsize(tfm);
 	sdesc = kmalloc(size, GFP_KERNEL);
 	if (!sdesc)
-		return -ENOMEM;
+		goto out_free_tfm;
 	sdesc->shash.tfm = tfm;
 	sdesc->shash.flags = 0x0;
 
 	*sdesc_ret = sdesc;
 
 	return 0;
+
+out_free_tfm:
+	crypto_free_shash(tfm);
+	return err;
 }
 
 static void kdf_dealloc(struct kdf_sdesc *sdesc)

--

@@ -317,7 +317,7 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
 	 * Concatenate SP800-56A otherinfo past DH shared secret -- the
 	 * input to the KDF is (DH shared secret || otherinfo)
 	 */
-	if (kdfcopy && kdfcopy->otherinfo &&
+	if (kdfcopy &&
 	    copy_from_user(kbuf + resultlen, kdfcopy->otherinfo,
 			   kdfcopy->otherinfolen) != 0) {
 		ret = -EFAULT;

--

@@ -130,14 +130,6 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc)
 	kzfree(sdesc);
 }
 
-/* convert 32 bit integer into its string representation */
-static inline void crypto_kw_cpu_to_be32(u32 val, u8 *buf)
-{
-	__be32 *a = (__be32 *)buf;
-
-	*a = cpu_to_be32(val);
-}
-
 /*
  * Implementation of the KDF in counter mode according to SP800-108 section 5.1
  * as well as SP800-56A section 5.8.1 (Single-step KDF).

@@ -154,16 +146,14 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
 	unsigned int h = crypto_shash_digestsize(desc->tfm);
 	int err = 0;
 	u8 *dst_orig = dst;
-	u32 i = 1;
-	u8 iteration[sizeof(u32)];
+	__be32 counter = cpu_to_be32(1);
 
 	while (dlen) {
 		err = crypto_shash_init(desc);
 		if (err)
 			goto err;
 
-		crypto_kw_cpu_to_be32(i, iteration);
-		err = crypto_shash_update(desc, iteration, sizeof(u32));
+		err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32));
 		if (err)
 			goto err;
 

@@ -189,7 +179,7 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
 
 			dlen -= h;
 			dst += h;
-			i++;
+			counter = cpu_to_be32(be32_to_cpu(counter) + 1);
 		}
 	}
 

--

@@ -381,7 +381,7 @@ static int pefile_digest_pe(const void *pebuf, unsigned int pelen,
 	}
 
 error:
-	kfree(desc);
+	kzfree(desc);
 error_no_desc:
 	crypto_free_shash(tfm);
 	kleave(" = %d", ret);

@@ -450,6 +450,6 @@ int verify_pefile_signature(const void *pebuf, unsigned pelen,
 	ret = pefile_digest_pe(pebuf, pelen, &ctx);
 
 error:
-	kfree(ctx.digest);
+	kzfree(ctx.digest);
 	return ret;
 }

--

@@ -70,8 +70,8 @@ struct keyctl_dh_params {
 };
 
 struct keyctl_kdf_params {
-	char *hashname;
-	char *otherinfo;
+	char __user *hashname;
+	char __user *otherinfo;
 	__u32 otherinfolen;
 	__u32 __spare[8];
 };

--

@@ -93,9 +93,9 @@ config ENCRYPTED_KEYS
 config KEY_DH_OPERATIONS
        bool "Diffie-Hellman operations on retained keys"
        depends on KEYS
-       select MPILIB
        select CRYPTO
        select CRYPTO_HASH
+       select CRYPTO_DH
        help
 	 This option provides support for calculating Diffie-Hellman
 	 public keys and shared secrets using values stored as keys

@@ -8,34 +8,17 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/mpi.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/scatterlist.h>
 #include <linux/crypto.h>
 #include <crypto/hash.h>
+#include <crypto/kpp.h>
+#include <crypto/dh.h>
 #include <keys/user-type.h>
 #include "internal.h"
 
-/*
- * Public key or shared secret generation function [RFC2631 sec 2.1.1]
- *
- * ya = g^xa mod p;
- * or
- * ZZ = yb^xa mod p;
- *
- * where xa is the local private key, ya is the local public key, g is
- * the generator, p is the prime, yb is the remote public key, and ZZ
- * is the shared secret.
- *
- * Both are the same calculation, so g or yb are the "base" and ya or
- * ZZ are the "result".
- */
-static int do_dh(MPI result, MPI base, MPI xa, MPI p)
-{
-	return mpi_powm(result, base, xa, p);
-}
-
-static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
+static ssize_t dh_data_from_key(key_serial_t keyid, void **data)
 {
 	struct key *key;
 	key_ref_t key_ref;

@@ -56,19 +39,17 @@ static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
 		status = key_validate(key);
 		if (status == 0) {
 			const struct user_key_payload *payload;
+			uint8_t *duplicate;
 
 			payload = user_key_payload_locked(key);
 
-			if (maxlen == 0) {
-				*mpi = NULL;
+			duplicate = kmemdup(payload->data, payload->datalen,
+					    GFP_KERNEL);
+			if (duplicate) {
+				*data = duplicate;
 				ret = payload->datalen;
-			} else if (payload->datalen <= maxlen) {
-				*mpi = mpi_read_raw_data(payload->data,
-							 payload->datalen);
-				if (*mpi)
-					ret = payload->datalen;
 			} else {
-				ret = -EINVAL;
+				ret = -ENOMEM;
 			}
 		}
 		up_read(&key->sem);

@@ -79,6 +60,29 @@ static ssize_t mpi_from_key(key_serial_t keyid, size_t maxlen, MPI *mpi)
 	return ret;
 }
 
+static void dh_free_data(struct dh *dh)
+{
+	kzfree(dh->key);
+	kzfree(dh->p);
+	kzfree(dh->g);
+}
+
+struct dh_completion {
+	struct completion completion;
+	int err;
+};
+
+static void dh_crypto_done(struct crypto_async_request *req, int err)
+{
+	struct dh_completion *compl = req->data;
+
+	if (err == -EINPROGRESS)
+		return;
+
+	compl->err = err;
+	complete(&compl->completion);
+}
+
 struct kdf_sdesc {
 	struct shash_desc shash;
 	char ctx[];

@@ -140,7 +144,7 @@ static void kdf_dealloc(struct kdf_sdesc *sdesc)
  * 5.8.1.2).
  */
 static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
-		   u8 *dst, unsigned int dlen)
+		   u8 *dst, unsigned int dlen, unsigned int zlen)
 {
 	struct shash_desc *desc = &sdesc->shash;
 	unsigned int h = crypto_shash_digestsize(desc->tfm);

@@ -157,6 +161,22 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
 		if (err)
 			goto err;
 
+		if (zlen && h) {
+			u8 tmpbuffer[h];
+			size_t chunk = min_t(size_t, zlen, h);
+			memset(tmpbuffer, 0, chunk);
+
+			do {
+				err = crypto_shash_update(desc, tmpbuffer,
+							  chunk);
+				if (err)
+					goto err;
+
+				zlen -= chunk;
+				chunk = min_t(size_t, zlen, h);
+			} while (zlen);
+		}
+
 		if (src && slen) {
 			err = crypto_shash_update(desc, src, slen);
 			if (err)

@@ -192,7 +212,7 @@ static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
 
 static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
 				 char __user *buffer, size_t buflen,
-				 uint8_t *kbuf, size_t kbuflen)
+				 uint8_t *kbuf, size_t kbuflen, size_t lzero)
 {
 	uint8_t *outbuf = NULL;
 	int ret;

@@ -203,7 +223,7 @@ static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
 		goto err;
 	}
 
-	ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, buflen);
+	ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, buflen, lzero);
 	if (ret)
 		goto err;
 

@@ -221,21 +241,26 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
 			 struct keyctl_kdf_params *kdfcopy)
 {
 	long ret;
-	MPI base, private, prime, result;
-	unsigned nbytes;
+	ssize_t dlen;
+	int secretlen;
+	int outlen;
 	struct keyctl_dh_params pcopy;
-	uint8_t *kbuf;
-	ssize_t keylen;
-	size_t resultlen;
+	struct dh dh_inputs;
+	struct scatterlist outsg;
+	struct dh_completion compl;
+	struct crypto_kpp *tfm;
+	struct kpp_request *req;
+	uint8_t *secret;
+	uint8_t *outbuf;
 	struct kdf_sdesc *sdesc = NULL;
 
 	if (!params || (!buffer && buflen)) {
 		ret = -EINVAL;
-		goto out;
+		goto out1;
 	}
 	if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
 		ret = -EFAULT;
-		goto out;
+		goto out1;
 	}
 
 	if (kdfcopy) {

@@ -244,104 +269,147 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
 		if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN ||
 		    kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) {
 			ret = -EMSGSIZE;
-			goto out;
+			goto out1;
 		}
 
 		/* get KDF name string */
 		hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME);
 		if (IS_ERR(hashname)) {
 			ret = PTR_ERR(hashname);
-			goto out;
+			goto out1;
 		}
 
 		/* allocate KDF from the kernel crypto API */
 		ret = kdf_alloc(&sdesc, hashname);
 		kfree(hashname);
 		if (ret)
-			goto out;
+			goto out1;
 	}
 
-	/*
-	 * If the caller requests postprocessing with a KDF, allow an
-	 * arbitrary output buffer size since the KDF ensures proper truncation.
-	 */
-	keylen = mpi_from_key(pcopy.prime, kdfcopy ? SIZE_MAX : buflen, &prime);
-	if (keylen < 0 || !prime) {
-		/* buflen == 0 may be used to query the required buffer size,
-		 * which is the prime key length.
-		 */
-		ret = keylen;
-		goto out;
+	memset(&dh_inputs, 0, sizeof(dh_inputs));
+
+	dlen = dh_data_from_key(pcopy.prime, &dh_inputs.p);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out1;
 	}
+	dh_inputs.p_size = dlen;
 
-	/* The result is never longer than the prime */
-	resultlen = keylen;
+	dlen = dh_data_from_key(pcopy.base, &dh_inputs.g);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.g_size = dlen;
 
-	keylen = mpi_from_key(pcopy.base, SIZE_MAX, &base);
-	if (keylen < 0 || !base) {
-		ret = keylen;
-		goto error1;
+	dlen = dh_data_from_key(pcopy.private, &dh_inputs.key);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
 	}
+	dh_inputs.key_size = dlen;
 
-	keylen = mpi_from_key(pcopy.private, SIZE_MAX, &private);
-	if (keylen < 0 || !private) {
-		ret = keylen;
-		goto error2;
+	secretlen = crypto_dh_key_len(&dh_inputs);
+	secret = kmalloc(secretlen, GFP_KERNEL);
+	if (!secret) {
+		ret = -ENOMEM;
+		goto out2;
+	}
+	ret = crypto_dh_encode_key(secret, secretlen, &dh_inputs);
+	if (ret)
+		goto out3;
+
+	tfm = crypto_alloc_kpp("dh", CRYPTO_ALG_TYPE_KPP, 0);
+	if (IS_ERR(tfm)) {
+		ret = PTR_ERR(tfm);
+		goto out3;
+	}
+
+	ret = crypto_kpp_set_secret(tfm, secret, secretlen);
+	if (ret)
+		goto out4;
+
+	outlen = crypto_kpp_maxsize(tfm);
+
+	if (!kdfcopy) {
+		/*
+		 * When not using a KDF, buflen 0 is used to read the
+		 * required buffer length
+		 */
+		if (buflen == 0) {
+			ret = outlen;
+			goto out4;
+		} else if (outlen > buflen) {
+			ret = -EOVERFLOW;
+			goto out4;
+		}
 	}
 
-	result = mpi_alloc(0);
-	if (!result) {
+	outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen,
+			 GFP_KERNEL);
+	if (!outbuf) {
 		ret = -ENOMEM;
-		goto error3;
+		goto out4;
 	}
 
-	/* allocate space for DH shared secret and SP800-56A otherinfo */
-	kbuf = kmalloc(kdfcopy ? (resultlen + kdfcopy->otherinfolen) : resultlen,
-		       GFP_KERNEL);
-	if (!kbuf) {
+	sg_init_one(&outsg, outbuf, outlen);
+
+	req = kpp_request_alloc(tfm, GFP_KERNEL);
+	if (!req) {
 		ret = -ENOMEM;
-		goto error4;
+		goto out5;
 	}
 
+	kpp_request_set_input(req, NULL, 0);
+	kpp_request_set_output(req, &outsg, outlen);
+	init_completion(&compl.completion);
+	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+				 CRYPTO_TFM_REQ_MAY_SLEEP,
+				 dh_crypto_done, &compl);
+
 	/*
-	 * Concatenate SP800-56A otherinfo past DH shared secret -- the
-	 * input to the KDF is (DH shared secret || otherinfo)
+	 * For DH, generate_public_key and generate_shared_secret are
+	 * the same calculation
 	 */
-	if (kdfcopy &&
-	    copy_from_user(kbuf + resultlen, kdfcopy->otherinfo,
-			   kdfcopy->otherinfolen) != 0) {
-		ret = -EFAULT;
-		goto error5;
+	ret = crypto_kpp_generate_public_key(req);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&compl.completion);
+		ret = compl.err;
+		if (ret)
+			goto out6;
 	}
 
-	ret = do_dh(result, base, private, prime);
-	if (ret)
-		goto error5;
-
-	ret = mpi_read_buffer(result, kbuf, resultlen, &nbytes, NULL);
-	if (ret != 0)
-		goto error5;
-
 	if (kdfcopy) {
-		ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, kbuf,
-					    resultlen + kdfcopy->otherinfolen);
-	} else {
-		ret = nbytes;
-		if (copy_to_user(buffer, kbuf, nbytes) != 0)
+		/*
+		 * Concatenate SP800-56A otherinfo past DH shared secret -- the
+		 * input to the KDF is (DH shared secret || otherinfo)
+		 */
+		if (copy_from_user(outbuf + req->dst_len, kdfcopy->otherinfo,
+				   kdfcopy->otherinfolen) != 0) {
 			ret = -EFAULT;
+			goto out6;
+		}
+
+		ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, outbuf,
+					    req->dst_len + kdfcopy->otherinfolen,
+					    outlen - req->dst_len);
+	} else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) {
+		ret = req->dst_len;
+	} else {
+		ret = -EFAULT;
 	}
 
-error5:
-	kzfree(kbuf);
-error4:
-	mpi_free(result);
-error3:
-	mpi_free(private);
-error2:
-	mpi_free(base);
-error1:
-	mpi_free(prime);
-out:
+out6:
+	kpp_request_free(req);
+out5:
+	kzfree(outbuf);
+out4:
+	crypto_free_kpp(tfm);
+out3:
+	kzfree(secret);
+out2:
+	dh_free_data(&dh_inputs);
+out1:
 	kdf_dealloc(sdesc);
 	return ret;
 }

--

@@ -70,7 +70,7 @@ static int TSS_sha1(const unsigned char *data, unsigned int datalen,
 	}
 
 	ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
-	kfree(sdesc);
+	kzfree(sdesc);
 	return ret;
 }
 

@@ -114,7 +114,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
 	if (!ret)
 		ret = crypto_shash_final(&sdesc->shash, digest);
 out:
-	kfree(sdesc);
+	kzfree(sdesc);
 	return ret;
 }
 

@@ -165,7 +165,7 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 				  paramdigest, TPM_NONCE_SIZE, h1,
 				  TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
 out:
-	kfree(sdesc);
+	kzfree(sdesc);
 	return ret;
 }
 

@@ -246,7 +246,7 @@ static int TSS_checkhmac1(unsigned char *buffer,
 	if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
 		ret = -EINVAL;
 out:
-	kfree(sdesc);
+	kzfree(sdesc);
 	return ret;
 }
 

@@ -347,7 +347,7 @@ static int TSS_checkhmac2(unsigned char *buffer,
 	if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
 		ret = -EINVAL;
 out:
-	kfree(sdesc);
+	kzfree(sdesc);
 	return ret;
 }
 

@@ -564,7 +564,7 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 		*bloblen = storedsize;
 	}
 out:
-	kfree(td);
+	kzfree(td);
 	return ret;
 }
 

@@ -678,7 +678,7 @@ static int key_seal(struct trusted_key_payload *p,
 	if (ret < 0)
 		pr_info("trusted_key: srkseal failed (%d)\n", ret);
 
-	kfree(tb);
+	kzfree(tb);
 	return ret;
 }
 

@@ -703,7 +703,7 @@ static int key_unseal(struct trusted_key_payload *p,
 		/* pull migratable flag out of sealed key */
 		p->migratable = p->key[--p->key_len];
 
-	kfree(tb);
+	kzfree(tb);
 	return ret;
 }
 

@@ -1037,12 +1037,12 @@ static int trusted_instantiate(struct key *key,
 	if (!ret && options->pcrlock)
 		ret = pcrlock(options->pcrlock);
 out:
-	kfree(datablob);
-	kfree(options);
+	kzfree(datablob);
+	kzfree(options);
 	if (!ret)
 		rcu_assign_keypointer(key, payload);
 	else
-		kfree(payload);
+		kzfree(payload);
 	return ret;
 }