Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 428 insertions, 0 deletions

diff --git a/security/keys/dh.c b/security/keys/dh.c
new file mode 100644
index 000000000..711e89d8c
--- /dev/null
+++ b/security/keys/dh.c
@@ -0,0 +1,428 @@
+/* Crypto operations using stored keys
+ *
+ * Copyright (c) 2016, Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#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"
+
+static ssize_t dh_data_from_key(key_serial_t keyid, void **data)
+{
+	struct key *key;
+	key_ref_t key_ref;
+	long status;
+	ssize_t ret;
+
+	key_ref = lookup_user_key(keyid, 0, KEY_NEED_READ);
+	if (IS_ERR(key_ref)) {
+		ret = -ENOKEY;
+		goto error;
+	}
+
+	key = key_ref_to_ptr(key_ref);
+
+	ret = -EOPNOTSUPP;
+	if (key->type == &key_type_user) {
+		down_read(&key->sem);
+		status = key_validate(key);
+		if (status == 0) {
+			const struct user_key_payload *payload;
+			uint8_t *duplicate;
+
+			payload = user_key_payload_locked(key);
+
+			duplicate = kmemdup(payload->data, payload->datalen,
+					    GFP_KERNEL);
+			if (duplicate) {
+				*data = duplicate;
+				ret = payload->datalen;
+			} else {
+				ret = -ENOMEM;
+			}
+		}
+		up_read(&key->sem);
+	}
+
+	key_put(key);
+error:
+	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[];
+};
+
+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);
+	if (IS_ERR(tfm)) {
+		pr_info("could not allocate digest TFM handle %s\n", 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;
+	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)
+{
+	if (!sdesc)
+		return;
+
+	if (sdesc->shash.tfm)
+		crypto_free_shash(sdesc->shash.tfm);
+
+	kzfree(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;
+}
+
+static int keyctl_dh_compute_kdf(struct kdf_sdesc *sdesc,
+				 char __user *buffer, size_t buflen,
+				 uint8_t *kbuf, size_t kbuflen, size_t lzero)
+{
+	uint8_t *outbuf = NULL;
+	int ret;
+	size_t outbuf_len = roundup(buflen,
+				    crypto_shash_digestsize(sdesc->shash.tfm));
+
+	outbuf = kmalloc(outbuf_len, GFP_KERNEL);
+	if (!outbuf) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ret = kdf_ctr(sdesc, kbuf, kbuflen, outbuf, outbuf_len, lzero);
+	if (ret)
+		goto err;
+
+	ret = buflen;
+	if (copy_to_user(buffer, outbuf, buflen) != 0)
+		ret = -EFAULT;
+
+err:
+	kzfree(outbuf);
+	return ret;
+}
+
+long __keyctl_dh_compute(struct keyctl_dh_params __user *params,
+			 char __user *buffer, size_t buflen,
+			 struct keyctl_kdf_params *kdfcopy)
+{
+	long ret;
+	ssize_t dlen;
+	int secretlen;
+	int outlen;
+	struct keyctl_dh_params pcopy;
+	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 out1;
+	}
+	if (copy_from_user(&pcopy, params, sizeof(pcopy)) != 0) {
+		ret = -EFAULT;
+		goto out1;
+	}
+
+	if (kdfcopy) {
+		char *hashname;
+
+		if (memchr_inv(kdfcopy->__spare, 0, sizeof(kdfcopy->__spare))) {
+			ret = -EINVAL;
+			goto out1;
+		}
+
+		if (buflen > KEYCTL_KDF_MAX_OUTPUT_LEN ||
+		    kdfcopy->otherinfolen > KEYCTL_KDF_MAX_OI_LEN) {
+			ret = -EMSGSIZE;
+			goto out1;
+		}
+
+		/* get KDF name string */
+		hashname = strndup_user(kdfcopy->hashname, CRYPTO_MAX_ALG_NAME);
+		if (IS_ERR(hashname)) {
+			ret = PTR_ERR(hashname);
+			goto out1;
+		}
+
+		/* allocate KDF from the kernel crypto API */
+		ret = kdf_alloc(&sdesc, hashname);
+		kfree(hashname);
+		if (ret)
+			goto out1;
+	}
+
+	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;
+
+	dlen = dh_data_from_key(pcopy.base, &dh_inputs.g);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.g_size = dlen;
+
+	dlen = dh_data_from_key(pcopy.private, &dh_inputs.key);
+	if (dlen < 0) {
+		ret = dlen;
+		goto out2;
+	}
+	dh_inputs.key_size = dlen;
+
+	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", 0, 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;
+		}
+	}
+
+	outbuf = kzalloc(kdfcopy ? (outlen + kdfcopy->otherinfolen) : outlen,
+			 GFP_KERNEL);
+	if (!outbuf) {
+		ret = -ENOMEM;
+		goto out4;
+	}
+
+	sg_init_one(&outsg, outbuf, outlen);
+
+	req = kpp_request_alloc(tfm, GFP_KERNEL);
+	if (!req) {
+		ret = -ENOMEM;
+		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);
+
+	/*
+	 * For DH, generate_public_key and generate_shared_secret are
+	 * the same calculation
+	 */
+	ret = crypto_kpp_generate_public_key(req);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&compl.completion);
+		ret = compl.err;
+		if (ret)
+			goto out6;
+	}
+
+	if (kdfcopy) {
+		/*
+		 * 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;
+	}
+
+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;
+}
+
+long keyctl_dh_compute(struct keyctl_dh_params __user *params,
+		       char __user *buffer, size_t buflen,
+		       struct keyctl_kdf_params __user *kdf)
+{
+	struct keyctl_kdf_params kdfcopy;
+
+	if (!kdf)
+		return __keyctl_dh_compute(params, buffer, buflen, NULL);
+
+	if (copy_from_user(&kdfcopy, kdf, sizeof(kdfcopy)) != 0)
+		return -EFAULT;
+
+	return __keyctl_dh_compute(params, buffer, buflen, &kdfcopy);
+}