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-rw-r--r--security/keys/Kconfig2
-rw-r--r--security/keys/dh.c130
2 files changed, 21 insertions, 111 deletions
diff --git a/security/keys/Kconfig b/security/keys/Kconfig
index 64b81abd087e..969122c7b92f 100644
--- a/security/keys/Kconfig
+++ b/security/keys/Kconfig
@@ -109,7 +109,7 @@ config KEY_DH_OPERATIONS
bool "Diffie-Hellman operations on retained keys"
depends on KEYS
select CRYPTO
- select CRYPTO_HASH
+ select CRYPTO_KDF800108_CTR
select CRYPTO_DH
help
This option provides support for calculating Diffie-Hellman
diff --git a/security/keys/dh.c b/security/keys/dh.c
index 1abfa70ed6e1..4573fc15617d 100644
--- a/security/keys/dh.c
+++ b/security/keys/dh.c
@@ -11,6 +11,7 @@
#include <crypto/hash.h>
#include <crypto/kpp.h>
#include <crypto/dh.h>
+#include <crypto/kdf_sp800108.h>
#include <keys/user-type.h>
#include "internal.h"
@@ -79,17 +80,9 @@ static void dh_crypto_done(struct crypto_async_request *req, int err)
complete(&compl->completion);
}
-struct kdf_sdesc {
- struct shash_desc shash;
- char ctx[];
-};
-
-static int kdf_alloc(struct kdf_sdesc **sdesc_ret, char *hashname)
+static int kdf_alloc(struct crypto_shash **hash, char *hashname)
{
struct crypto_shash *tfm;
- struct kdf_sdesc *sdesc;
- int size;
- int err;
/* allocate synchronous hash */
tfm = crypto_alloc_shash(hashname, 0, 0);
@@ -98,112 +91,30 @@ 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)
- goto out_free_tfm;
- sdesc->shash.tfm = tfm;
+ if (crypto_shash_digestsize(tfm) == 0) {
+ crypto_free_shash(tfm);
+ return -EINVAL;
+ }
- *sdesc_ret = sdesc;
+ *hash = tfm;
return 0;
-
-out_free_tfm:
- crypto_free_shash(tfm);
- return err;
}
-static void kdf_dealloc(struct kdf_sdesc *sdesc)
+static void kdf_dealloc(struct crypto_shash *hash)
{
- if (!sdesc)
- return;
-
- if (sdesc->shash.tfm)
- crypto_free_shash(sdesc->shash.tfm);
-
- kfree_sensitive(sdesc);
-}
-
-/*
- * 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).
- *
- * SP800-56A:
- * The src pointer is defined as Z || other info where Z is the shared secret
- * from DH and other info is an arbitrary string (see SP800-56A section
- * 5.8.1.2).
- *
- * 'dlen' must be a multiple of the digest size.
- */
-static int kdf_ctr(struct kdf_sdesc *sdesc, const u8 *src, unsigned int slen,
- u8 *dst, unsigned int dlen, unsigned int zlen)
-{
- struct shash_desc *desc = &sdesc->shash;
- unsigned int h = crypto_shash_digestsize(desc->tfm);
- int err = 0;
- u8 *dst_orig = dst;
- __be32 counter = cpu_to_be32(1);
-
- while (dlen) {
- err = crypto_shash_init(desc);
- if (err)
- goto err;
-
- err = crypto_shash_update(desc, (u8 *)&counter, sizeof(__be32));
- if (err)
- goto err;
-
- if (zlen && h) {
- u8 tmpbuffer[32];
- size_t chunk = min_t(size_t, zlen, sizeof(tmpbuffer));
- memset(tmpbuffer, 0, chunk);
-
- do {
- err = crypto_shash_update(desc, tmpbuffer,
- chunk);
- if (err)
- goto err;
-
- zlen -= chunk;
- chunk = min_t(size_t, zlen, sizeof(tmpbuffer));
- } while (zlen);
- }
-
- if (src && slen) {
- err = crypto_shash_update(desc, src, slen);
- if (err)
- goto err;
- }
-
- err = crypto_shash_final(desc, dst);
- if (err)
- goto err;
-
- dlen -= h;
- dst += h;
- counter = cpu_to_be32(be32_to_cpu(counter) + 1);
- }
-
- return 0;
-
-err:
- memzero_explicit(dst_orig, dlen);
- return err;
+ if (hash)
+ crypto_free_shash(hash);
}
-static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
+static int keyctl_dh_compute_kdf(struct crypto_shash *hash,
char __user *buffer, size_t buflen,
- uint8_t *kbuf, size_t kbuflen, size_t lzero)
+ uint8_t *kbuf, size_t kbuflen)
{
+ struct kvec kbuf_iov = { .iov_base = kbuf, .iov_len = kbuflen };
uint8_t *outbuf = NULL;
int ret;
- size_t outbuf_len = roundup(buflen,
- crypto_shash_digestsize(sdesc->shash.tfm));
+ size_t outbuf_len = roundup(buflen, crypto_shash_digestsize(hash));
outbuf = kmalloc(outbuf_len, GFP_KERNEL);
if (!outbuf) {
@@ -211,7 +122,7 @@ static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
goto err;
}
- ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, outbuf_len, lzero);
+ ret = crypto_kdf108_ctr_generate(hash, &kbuf_iov, 1, outbuf, outbuf_len);
if (ret)
goto err;
@@ -240,7 +151,7 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
struct kpp_request *req;
uint8_t *secret;
uint8_t *outbuf;
- struct kdf_sdesc *sdesc = NULL;
+ struct crypto_shash *hash = NULL;
if (!params || (!buffer && buflen)) {
ret = -EINVAL;
@@ -273,7 +184,7 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
}
/* allocate KDF from the kernel crypto API */
- ret = kdf_alloc(&sdesc, hashname);
+ ret = kdf_alloc(&hash, hashname);
kfree(hashname);
if (ret)
goto out1;
@@ -383,9 +294,8 @@ long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
goto out6;
}
- ret = keyctl_dh_compute_kdf(sdesc, buffer, buflen, outbuf,
- req->dst_len + kdfcopy->otherinfolen,
- outlen - req->dst_len);
+ ret = keyctl_dh_compute_kdf(hash, buffer, buflen, outbuf,
+ req->dst_len + kdfcopy->otherinfolen);
} else if (copy_to_user(buffer, outbuf, req->dst_len) == 0) {
ret = req->dst_len;
} else {
@@ -403,7 +313,7 @@ out3:
out2:
dh_free_data(&dh_inputs);
out1:
- kdf_dealloc(sdesc);
+ kdf_dealloc(hash);
return ret;
}