Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 619 insertions, 0 deletions

diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
new file mode 100644
index 000000000..182783801
--- /dev/null
+++ b/crypto/algif_aead.c
@@ -0,0 +1,619 @@
+/*
+ * algif_aead: User-space interface for AEAD algorithms
+ *
+ * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>
+ *
+ * This file provides the user-space API for AEAD ciphers.
+ *
+ * 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.
+ *
+ * The following concept of the memory management is used:
+ *
+ * The kernel maintains two SGLs, the TX SGL and the RX SGL. The TX SGL is
+ * filled by user space with the data submitted via sendpage/sendmsg. Filling
+ * up the TX SGL does not cause a crypto operation -- the data will only be
+ * tracked by the kernel. Upon receipt of one recvmsg call, the caller must
+ * provide a buffer which is tracked with the RX SGL.
+ *
+ * During the processing of the recvmsg operation, the cipher request is
+ * allocated and prepared. As part of the recvmsg operation, the processed
+ * TX buffers are extracted from the TX SGL into a separate SGL.
+ *
+ * After the completion of the crypto operation, the RX SGL and the cipher
+ * request is released. The extracted TX SGL parts are released together with
+ * the RX SGL release.
+ */
+
+#include <crypto/internal/aead.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/if_alg.h>
+#include <crypto/skcipher.h>
+#include <crypto/null.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <net/sock.h>
+
+struct aead_tfm {
+	struct crypto_aead *aead;
+	struct crypto_skcipher *null_tfm;
+};
+
+static inline bool aead_sufficient_data(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct sock *psk = ask->parent;
+	struct alg_sock *pask = alg_sk(psk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct aead_tfm *aeadc = pask->private;
+	struct crypto_aead *tfm = aeadc->aead;
+	unsigned int as = crypto_aead_authsize(tfm);
+
+	/*
+	 * The minimum amount of memory needed for an AEAD cipher is
+	 * the AAD and in case of decryption the tag.
+	 */
+	return ctx->used >= ctx->aead_assoclen + (ctx->enc ? 0 : as);
+}
+
+static int aead_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct sock *psk = ask->parent;
+	struct alg_sock *pask = alg_sk(psk);
+	struct aead_tfm *aeadc = pask->private;
+	struct crypto_aead *tfm = aeadc->aead;
+	unsigned int ivsize = crypto_aead_ivsize(tfm);
+
+	return af_alg_sendmsg(sock, msg, size, ivsize);
+}
+
+static int crypto_aead_copy_sgl(struct crypto_skcipher *null_tfm,
+				struct scatterlist *src,
+				struct scatterlist *dst, unsigned int len)
+{
+	SKCIPHER_REQUEST_ON_STACK(skreq, null_tfm);
+
+	skcipher_request_set_tfm(skreq, null_tfm);
+	skcipher_request_set_callback(skreq, CRYPTO_TFM_REQ_MAY_SLEEP,
+				      NULL, NULL);
+	skcipher_request_set_crypt(skreq, src, dst, len, NULL);
+
+	return crypto_skcipher_encrypt(skreq);
+}
+
+static int _aead_recvmsg(struct socket *sock, struct msghdr *msg,
+			 size_t ignored, int flags)
+{
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+	struct sock *psk = ask->parent;
+	struct alg_sock *pask = alg_sk(psk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct aead_tfm *aeadc = pask->private;
+	struct crypto_aead *tfm = aeadc->aead;
+	struct crypto_skcipher *null_tfm = aeadc->null_tfm;
+	unsigned int i, as = crypto_aead_authsize(tfm);
+	struct af_alg_async_req *areq;
+	struct af_alg_tsgl *tsgl, *tmp;
+	struct scatterlist *rsgl_src, *tsgl_src = NULL;
+	int err = 0;
+	size_t used = 0;		/* [in]  TX bufs to be en/decrypted */
+	size_t outlen = 0;		/* [out] RX bufs produced by kernel */
+	size_t usedpages = 0;		/* [in]  RX bufs to be used from user */
+	size_t processed = 0;		/* [in]  TX bufs to be consumed */
+
+	if (!ctx->used) {
+		err = af_alg_wait_for_data(sk, flags);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Data length provided by caller via sendmsg/sendpage that has not
+	 * yet been processed.
+	 */
+	used = ctx->used;
+
+	/*
+	 * Make sure sufficient data is present -- note, the same check is
+	 * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
+	 * shall provide an information to the data sender that something is
+	 * wrong, but they are irrelevant to maintain the kernel integrity.
+	 * We need this check here too in case user space decides to not honor
+	 * the error message in sendmsg/sendpage and still call recvmsg. This
+	 * check here protects the kernel integrity.
+	 */
+	if (!aead_sufficient_data(sk))
+		return -EINVAL;
+
+	/*
+	 * Calculate the minimum output buffer size holding the result of the
+	 * cipher operation. When encrypting data, the receiving buffer is
+	 * larger by the tag length compared to the input buffer as the
+	 * encryption operation generates the tag. For decryption, the input
+	 * buffer provides the tag which is consumed resulting in only the
+	 * plaintext without a buffer for the tag returned to the caller.
+	 */
+	if (ctx->enc)
+		outlen = used + as;
+	else
+		outlen = used - as;
+
+	/*
+	 * The cipher operation input data is reduced by the associated data
+	 * length as this data is processed separately later on.
+	 */
+	used -= ctx->aead_assoclen;
+
+	/* Allocate cipher request for current operation. */
+	areq = af_alg_alloc_areq(sk, sizeof(struct af_alg_async_req) +
+				     crypto_aead_reqsize(tfm));
+	if (IS_ERR(areq))
+		return PTR_ERR(areq);
+
+	/* convert iovecs of output buffers into RX SGL */
+	err = af_alg_get_rsgl(sk, msg, flags, areq, outlen, &usedpages);
+	if (err)
+		goto free;
+
+	/*
+	 * Ensure output buffer is sufficiently large. If the caller provides
+	 * less buffer space, only use the relative required input size. This
+	 * allows AIO operation where the caller sent all data to be processed
+	 * and the AIO operation performs the operation on the different chunks
+	 * of the input data.
+	 */
+	if (usedpages < outlen) {
+		size_t less = outlen - usedpages;
+
+		if (used < less) {
+			err = -EINVAL;
+			goto free;
+		}
+		used -= less;
+		outlen -= less;
+	}
+
+	processed = used + ctx->aead_assoclen;
+	list_for_each_entry_safe(tsgl, tmp, &ctx->tsgl_list, list) {
+		for (i = 0; i < tsgl->cur; i++) {
+			struct scatterlist *process_sg = tsgl->sg + i;
+
+			if (!(process_sg->length) || !sg_page(process_sg))
+				continue;
+			tsgl_src = process_sg;
+			break;
+		}
+		if (tsgl_src)
+			break;
+	}
+	if (processed && !tsgl_src) {
+		err = -EFAULT;
+		goto free;
+	}
+
+	/*
+	 * Copy of AAD from source to destination
+	 *
+	 * The AAD is copied to the destination buffer without change. Even
+	 * when user space uses an in-place cipher operation, the kernel
+	 * will copy the data as it does not see whether such in-place operation
+	 * is initiated.
+	 *
+	 * To ensure efficiency, the following implementation ensure that the
+	 * ciphers are invoked to perform a crypto operation in-place. This
+	 * is achieved by memory management specified as follows.
+	 */
+
+	/* Use the RX SGL as source (and destination) for crypto op. */
+	rsgl_src = areq->first_rsgl.sgl.sg;
+
+	if (ctx->enc) {
+		/*
+		 * Encryption operation - The in-place cipher operation is
+		 * achieved by the following operation:
+		 *
+		 * TX SGL: AAD || PT
+		 *	    |	   |
+		 *	    | copy |
+		 *	    v	   v
+		 * RX SGL: AAD || PT || Tag
+		 */
+		err = crypto_aead_copy_sgl(null_tfm, tsgl_src,
+					   areq->first_rsgl.sgl.sg, processed);
+		if (err)
+			goto free;
+		af_alg_pull_tsgl(sk, processed, NULL, 0);
+	} else {
+		/*
+		 * Decryption operation - To achieve an in-place cipher
+		 * operation, the following  SGL structure is used:
+		 *
+		 * TX SGL: AAD || CT || Tag
+		 *	    |	   |	 ^
+		 *	    | copy |	 | Create SGL link.
+		 *	    v	   v	 |
+		 * RX SGL: AAD || CT ----+
+		 */
+
+		 /* Copy AAD || CT to RX SGL buffer for in-place operation. */
+		err = crypto_aead_copy_sgl(null_tfm, tsgl_src,
+					   areq->first_rsgl.sgl.sg, outlen);
+		if (err)
+			goto free;
+
+		/* Create TX SGL for tag and chain it to RX SGL. */
+		areq->tsgl_entries = af_alg_count_tsgl(sk, processed,
+						       processed - as);
+		if (!areq->tsgl_entries)
+			areq->tsgl_entries = 1;
+		areq->tsgl = sock_kmalloc(sk, array_size(sizeof(*areq->tsgl),
+							 areq->tsgl_entries),
+					  GFP_KERNEL);
+		if (!areq->tsgl) {
+			err = -ENOMEM;
+			goto free;
+		}
+		sg_init_table(areq->tsgl, areq->tsgl_entries);
+
+		/* Release TX SGL, except for tag data and reassign tag data. */
+		af_alg_pull_tsgl(sk, processed, areq->tsgl, processed - as);
+
+		/* chain the areq TX SGL holding the tag with RX SGL */
+		if (usedpages) {
+			/* RX SGL present */
+			struct af_alg_sgl *sgl_prev = &areq->last_rsgl->sgl;
+
+			sg_unmark_end(sgl_prev->sg + sgl_prev->npages - 1);
+			sg_chain(sgl_prev->sg, sgl_prev->npages + 1,
+				 areq->tsgl);
+		} else
+			/* no RX SGL present (e.g. authentication only) */
+			rsgl_src = areq->tsgl;
+	}
+
+	/* Initialize the crypto operation */
+	aead_request_set_crypt(&areq->cra_u.aead_req, rsgl_src,
+			       areq->first_rsgl.sgl.sg, used, ctx->iv);
+	aead_request_set_ad(&areq->cra_u.aead_req, ctx->aead_assoclen);
+	aead_request_set_tfm(&areq->cra_u.aead_req, tfm);
+
+	if (msg->msg_iocb && !is_sync_kiocb(msg->msg_iocb)) {
+		/* AIO operation */
+		sock_hold(sk);
+		areq->iocb = msg->msg_iocb;
+
+		/* Remember output size that will be generated. */
+		areq->outlen = outlen;
+
+		aead_request_set_callback(&areq->cra_u.aead_req,
+					  CRYPTO_TFM_REQ_MAY_SLEEP,
+					  af_alg_async_cb, areq);
+		err = ctx->enc ? crypto_aead_encrypt(&areq->cra_u.aead_req) :
+				 crypto_aead_decrypt(&areq->cra_u.aead_req);
+
+		/* AIO operation in progress */
+		if (err == -EINPROGRESS)
+			return -EIOCBQUEUED;
+
+		sock_put(sk);
+	} else {
+		/* Synchronous operation */
+		aead_request_set_callback(&areq->cra_u.aead_req,
+					  CRYPTO_TFM_REQ_MAY_SLEEP |
+					  CRYPTO_TFM_REQ_MAY_BACKLOG,
+					  crypto_req_done, &ctx->wait);
+		err = crypto_wait_req(ctx->enc ?
+				crypto_aead_encrypt(&areq->cra_u.aead_req) :
+				crypto_aead_decrypt(&areq->cra_u.aead_req),
+				&ctx->wait);
+	}
+
+
+free:
+	af_alg_free_resources(areq);
+
+	return err ? err : outlen;
+}
+
+static int aead_recvmsg(struct socket *sock, struct msghdr *msg,
+			size_t ignored, int flags)
+{
+	struct sock *sk = sock->sk;
+	int ret = 0;
+
+	lock_sock(sk);
+	while (msg_data_left(msg)) {
+		int err = _aead_recvmsg(sock, msg, ignored, flags);
+
+		/*
+		 * This error covers -EIOCBQUEUED which implies that we can
+		 * only handle one AIO request. If the caller wants to have
+		 * multiple AIO requests in parallel, he must make multiple
+		 * separate AIO calls.
+		 *
+		 * Also return the error if no data has been processed so far.
+		 */
+		if (err <= 0) {
+			if (err == -EIOCBQUEUED || err == -EBADMSG || !ret)
+				ret = err;
+			goto out;
+		}
+
+		ret += err;
+	}
+
+out:
+	af_alg_wmem_wakeup(sk);
+	release_sock(sk);
+	return ret;
+}
+
+static struct proto_ops algif_aead_ops = {
+	.family		=	PF_ALG,
+
+	.connect	=	sock_no_connect,
+	.socketpair	=	sock_no_socketpair,
+	.getname	=	sock_no_getname,
+	.ioctl		=	sock_no_ioctl,
+	.listen		=	sock_no_listen,
+	.shutdown	=	sock_no_shutdown,
+	.getsockopt	=	sock_no_getsockopt,
+	.mmap		=	sock_no_mmap,
+	.bind		=	sock_no_bind,
+	.accept		=	sock_no_accept,
+	.setsockopt	=	sock_no_setsockopt,
+
+	.release	=	af_alg_release,
+	.sendmsg	=	aead_sendmsg,
+	.sendpage	=	af_alg_sendpage,
+	.recvmsg	=	aead_recvmsg,
+	.poll		=	af_alg_poll,
+};
+
+static int aead_check_key(struct socket *sock)
+{
+	int err = 0;
+	struct sock *psk;
+	struct alg_sock *pask;
+	struct aead_tfm *tfm;
+	struct sock *sk = sock->sk;
+	struct alg_sock *ask = alg_sk(sk);
+
+	lock_sock(sk);
+	if (!atomic_read(&ask->nokey_refcnt))
+		goto unlock_child;
+
+	psk = ask->parent;
+	pask = alg_sk(ask->parent);
+	tfm = pask->private;
+
+	err = -ENOKEY;
+	lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
+	if (crypto_aead_get_flags(tfm->aead) & CRYPTO_TFM_NEED_KEY)
+		goto unlock;
+
+	atomic_dec(&pask->nokey_refcnt);
+	atomic_set(&ask->nokey_refcnt, 0);
+
+	err = 0;
+
+unlock:
+	release_sock(psk);
+unlock_child:
+	release_sock(sk);
+
+	return err;
+}
+
+static int aead_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
+				  size_t size)
+{
+	int err;
+
+	err = aead_check_key(sock);
+	if (err)
+		return err;
+
+	return aead_sendmsg(sock, msg, size);
+}
+
+static ssize_t aead_sendpage_nokey(struct socket *sock, struct page *page,
+				       int offset, size_t size, int flags)
+{
+	int err;
+
+	err = aead_check_key(sock);
+	if (err)
+		return err;
+
+	return af_alg_sendpage(sock, page, offset, size, flags);
+}
+
+static int aead_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
+				  size_t ignored, int flags)
+{
+	int err;
+
+	err = aead_check_key(sock);
+	if (err)
+		return err;
+
+	return aead_recvmsg(sock, msg, ignored, flags);
+}
+
+static struct proto_ops algif_aead_ops_nokey = {
+	.family		=	PF_ALG,
+
+	.connect	=	sock_no_connect,
+	.socketpair	=	sock_no_socketpair,
+	.getname	=	sock_no_getname,
+	.ioctl		=	sock_no_ioctl,
+	.listen		=	sock_no_listen,
+	.shutdown	=	sock_no_shutdown,
+	.getsockopt	=	sock_no_getsockopt,
+	.mmap		=	sock_no_mmap,
+	.bind		=	sock_no_bind,
+	.accept		=	sock_no_accept,
+	.setsockopt	=	sock_no_setsockopt,
+
+	.release	=	af_alg_release,
+	.sendmsg	=	aead_sendmsg_nokey,
+	.sendpage	=	aead_sendpage_nokey,
+	.recvmsg	=	aead_recvmsg_nokey,
+	.poll		=	af_alg_poll,
+};
+
+static void *aead_bind(const char *name, u32 type, u32 mask)
+{
+	struct aead_tfm *tfm;
+	struct crypto_aead *aead;
+	struct crypto_skcipher *null_tfm;
+
+	tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
+	if (!tfm)
+		return ERR_PTR(-ENOMEM);
+
+	aead = crypto_alloc_aead(name, type, mask);
+	if (IS_ERR(aead)) {
+		kfree(tfm);
+		return ERR_CAST(aead);
+	}
+
+	null_tfm = crypto_get_default_null_skcipher();
+	if (IS_ERR(null_tfm)) {
+		crypto_free_aead(aead);
+		kfree(tfm);
+		return ERR_CAST(null_tfm);
+	}
+
+	tfm->aead = aead;
+	tfm->null_tfm = null_tfm;
+
+	return tfm;
+}
+
+static void aead_release(void *private)
+{
+	struct aead_tfm *tfm = private;
+
+	crypto_free_aead(tfm->aead);
+	crypto_put_default_null_skcipher();
+	kfree(tfm);
+}
+
+static int aead_setauthsize(void *private, unsigned int authsize)
+{
+	struct aead_tfm *tfm = private;
+
+	return crypto_aead_setauthsize(tfm->aead, authsize);
+}
+
+static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
+{
+	struct aead_tfm *tfm = private;
+
+	return crypto_aead_setkey(tfm->aead, key, keylen);
+}
+
+static void aead_sock_destruct(struct sock *sk)
+{
+	struct alg_sock *ask = alg_sk(sk);
+	struct af_alg_ctx *ctx = ask->private;
+	struct sock *psk = ask->parent;
+	struct alg_sock *pask = alg_sk(psk);
+	struct aead_tfm *aeadc = pask->private;
+	struct crypto_aead *tfm = aeadc->aead;
+	unsigned int ivlen = crypto_aead_ivsize(tfm);
+
+	af_alg_pull_tsgl(sk, ctx->used, NULL, 0);
+	sock_kzfree_s(sk, ctx->iv, ivlen);
+	sock_kfree_s(sk, ctx, ctx->len);
+	af_alg_release_parent(sk);
+}
+
+static int aead_accept_parent_nokey(void *private, struct sock *sk)
+{
+	struct af_alg_ctx *ctx;
+	struct alg_sock *ask = alg_sk(sk);
+	struct aead_tfm *tfm = private;
+	struct crypto_aead *aead = tfm->aead;
+	unsigned int len = sizeof(*ctx);
+	unsigned int ivlen = crypto_aead_ivsize(aead);
+
+	ctx = sock_kmalloc(sk, len, GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+	memset(ctx, 0, len);
+
+	ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL);
+	if (!ctx->iv) {
+		sock_kfree_s(sk, ctx, len);
+		return -ENOMEM;
+	}
+	memset(ctx->iv, 0, ivlen);
+
+	INIT_LIST_HEAD(&ctx->tsgl_list);
+	ctx->len = len;
+	ctx->used = 0;
+	atomic_set(&ctx->rcvused, 0);
+	ctx->more = 0;
+	ctx->merge = 0;
+	ctx->enc = 0;
+	ctx->aead_assoclen = 0;
+	crypto_init_wait(&ctx->wait);
+
+	ask->private = ctx;
+
+	sk->sk_destruct = aead_sock_destruct;
+
+	return 0;
+}
+
+static int aead_accept_parent(void *private, struct sock *sk)
+{
+	struct aead_tfm *tfm = private;
+
+	if (crypto_aead_get_flags(tfm->aead) & CRYPTO_TFM_NEED_KEY)
+		return -ENOKEY;
+
+	return aead_accept_parent_nokey(private, sk);
+}
+
+static const struct af_alg_type algif_type_aead = {
+	.bind		=	aead_bind,
+	.release	=	aead_release,
+	.setkey		=	aead_setkey,
+	.setauthsize	=	aead_setauthsize,
+	.accept		=	aead_accept_parent,
+	.accept_nokey	=	aead_accept_parent_nokey,
+	.ops		=	&algif_aead_ops,
+	.ops_nokey	=	&algif_aead_ops_nokey,
+	.name		=	"aead",
+	.owner		=	THIS_MODULE
+};
+
+static int __init algif_aead_init(void)
+{
+	return af_alg_register_type(&algif_type_aead);
+}
+
+static void __exit algif_aead_exit(void)
+{
+	int err = af_alg_unregister_type(&algif_type_aead);
+	BUG_ON(err);
+}
+
+module_init(algif_aead_init);
+module_exit(algif_aead_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");
+MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");