xref: /OK3568_Linux_fs/kernel/drivers/crypto/rockchip/cryptodev_linux/authenc.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)

/*
 * Driver for /dev/crypto device (aka CryptoDev)
 *
 * Copyright (c) 2011, 2012 OpenSSL Software Foundation, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of linux cryptodev.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

/*
 * This file handles the AEAD part of /dev/crypto.
 *
 */

#include <crypto/hash.h>
#include <linux/crypto.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/ioctl.h>
#include <linux/random.h>
#include <linux/syscalls.h>
#include <linux/pagemap.h>
#include <linux/poll.h>
#include <linux/uaccess.h>
#include <crypto/scatterwalk.h>
#include <linux/scatterlist.h>
#include "cryptodev.h"
#include "zc.h"
#include "util.h"
#include "cryptlib.h"
#include "version.h"


/* make caop->dst available in scatterlist.
 * (caop->src is assumed to be equal to caop->dst)
 */
static int get_userbuf_tls(struct csession *ses, struct kernel_crypt_auth_op *kcaop,
			struct scatterlist **dst_sg)
{
	int pagecount = 0;
	struct crypt_auth_op *caop = &kcaop->caop;
	int rc;

	if (caop->dst == NULL)
		return -EINVAL;

	if (ses->alignmask) {
		if (!IS_ALIGNED((unsigned long)caop->dst, ses->alignmask + 1))
			dwarning(2, "careful - source address %p is not %d byte aligned",
					caop->dst, ses->alignmask + 1);
	}

	if (kcaop->dst_len == 0) {
		dwarning(1, "Destination length cannot be zero");
		return -EINVAL;
	}

	pagecount = PAGECOUNT(caop->dst, kcaop->dst_len);

	ses->used_pages = pagecount;
	ses->readonly_pages = 0;

	rc = cryptodev_adjust_sg_array(ses, pagecount);
	if (rc)
		return rc;

	rc = __cryptodev_get_userbuf(caop->dst, kcaop->dst_len, 1, pagecount,
	                   ses->pages, ses->sg, kcaop->task, kcaop->mm);
	if (unlikely(rc)) {
		derr(1, "failed to get user pages for data input");
		return -EINVAL;
	}

	(*dst_sg) = ses->sg;

	return 0;
}


#define MAX_SRTP_AUTH_DATA_DIFF 256

/* Makes caop->auth_src available as scatterlist.
 * It also provides a pointer to caop->dst, which however,
 * is assumed to be within the caop->auth_src buffer. If not
 * (if their difference exceeds MAX_SRTP_AUTH_DATA_DIFF) it
 * returns error.
 */
static int get_userbuf_srtp(struct csession *ses, struct kernel_crypt_auth_op *kcaop,
			struct scatterlist **auth_sg, struct scatterlist **dst_sg)
{
	int pagecount, diff;
	int auth_pagecount = 0;
	struct crypt_auth_op *caop = &kcaop->caop;
	int rc;

	if (caop->dst == NULL && caop->auth_src == NULL) {
		derr(1, "dst and auth_src cannot be both null");
		return -EINVAL;
	}

	if (ses->alignmask) {
		if (!IS_ALIGNED((unsigned long)caop->dst, ses->alignmask + 1))
			dwarning(2, "careful - source address %p is not %d byte aligned",
					caop->dst, ses->alignmask + 1);
		if (!IS_ALIGNED((unsigned long)caop->auth_src, ses->alignmask + 1))
			dwarning(2, "careful - source address %p is not %d byte aligned",
					caop->auth_src, ses->alignmask + 1);
	}

	if (unlikely(kcaop->dst_len == 0 || caop->auth_len == 0)) {
		dwarning(1, "Destination length cannot be zero");
		return -EINVAL;
	}

	/* Note that in SRTP auth data overlap with data to be encrypted (dst)
         */

	auth_pagecount = PAGECOUNT(caop->auth_src, caop->auth_len);
	diff = (int)(caop->src - caop->auth_src);
	if (diff > MAX_SRTP_AUTH_DATA_DIFF || diff < 0) {
		dwarning(1, "auth_src must overlap with src (diff: %d).", diff);
		return -EINVAL;
	}

	pagecount = auth_pagecount;

	rc = cryptodev_adjust_sg_array(ses, pagecount*2); /* double pages to have pages for dst(=auth_src) */
	if (rc) {
		derr(1, "cannot adjust sg array");
		return rc;
	}

	rc = __cryptodev_get_userbuf(caop->auth_src, caop->auth_len, 1, auth_pagecount,
			   ses->pages, ses->sg, kcaop->task, kcaop->mm);
	if (unlikely(rc)) {
		derr(1, "failed to get user pages for data input");
		return -EINVAL;
	}

	ses->used_pages = pagecount;
	ses->readonly_pages = 0;

	(*auth_sg) = ses->sg;

	(*dst_sg) = ses->sg + auth_pagecount;
	sg_init_table(*dst_sg, auth_pagecount);
	cryptodev_sg_copy(ses->sg, (*dst_sg), caop->auth_len);
	(*dst_sg) = cryptodev_sg_advance(*dst_sg, diff);
	if (*dst_sg == NULL) {
		cryptodev_release_user_pages(ses);
		derr(1, "failed to get enough pages for auth data");
		return -EINVAL;
	}

	return 0;
}

/*
 * Return tag (digest) length for authenticated encryption
 * If the cipher and digest are separate, hdata.init is set - just return
 * digest length. Otherwise return digest length for aead ciphers
 */
static int cryptodev_get_tag_len(struct csession *ses_ptr)
{
	if (ses_ptr->hdata.init)
		return ses_ptr->hdata.digestsize;
	else
		return cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
}

/*
 * Calculate destination buffer length for authenticated encryption. The
 * expectation is that user-space code allocates exactly the same space for
 * destination buffer before calling cryptodev. The result is cipher-dependent.
 */
static int cryptodev_get_dst_len(struct crypt_auth_op *caop, struct csession *ses_ptr)
{
	int dst_len = caop->len;
	if (caop->op == COP_DECRYPT)
		return dst_len;

	if (caop->flags & COP_FLAG_AEAD_RK_TYPE)
		return dst_len;

	dst_len += caop->tag_len;

	/* for TLS always add some padding so the total length is rounded to
	 * cipher block size */
	if (caop->flags & COP_FLAG_AEAD_TLS_TYPE) {
		int bs = ses_ptr->cdata.blocksize;
		dst_len += bs - (dst_len % bs);
	}

	return dst_len;
}

static int fill_kcaop_from_caop(struct kernel_crypt_auth_op *kcaop, struct fcrypt *fcr)
{
	struct crypt_auth_op *caop = &kcaop->caop;
	struct csession *ses_ptr;
	int ret;

	/* this also enters ses_ptr->sem */
	ses_ptr = crypto_get_session_by_sid(fcr, caop->ses);
	if (unlikely(!ses_ptr)) {
		derr(1, "invalid session ID=0x%08X", caop->ses);
		return -EINVAL;
	}

	if (caop->flags & COP_FLAG_AEAD_TLS_TYPE || caop->flags & COP_FLAG_AEAD_SRTP_TYPE) {
		if (caop->src != caop->dst) {
			derr(1, "Non-inplace encryption and decryption is not efficient and not implemented");
			ret = -EINVAL;
			goto out_unlock;
		}
	}

	if (caop->tag_len == 0)
		caop->tag_len = cryptodev_get_tag_len(ses_ptr);

	kcaop->ivlen = caop->iv ? ses_ptr->cdata.ivsize : 0;
	kcaop->dst_len = cryptodev_get_dst_len(caop, ses_ptr);
	kcaop->task = current;
	kcaop->mm = current->mm;

	if (caop->iv) {
		ret = copy_from_user(kcaop->iv, caop->iv, kcaop->ivlen);
		if (unlikely(ret)) {
			derr(1, "error copying IV (%d bytes), copy_from_user returned %d for address %p",
					kcaop->ivlen, ret, caop->iv);
			ret = -EFAULT;
			goto out_unlock;
		}
	}

	ret = 0;

out_unlock:
	crypto_put_session(ses_ptr);
	return ret;

}

static int fill_caop_from_kcaop(struct kernel_crypt_auth_op *kcaop, struct fcrypt *fcr)
{
	int ret;

	kcaop->caop.len = kcaop->dst_len;

	if (kcaop->ivlen && kcaop->caop.flags & COP_FLAG_WRITE_IV) {
		ret = copy_to_user(kcaop->caop.iv,
				kcaop->iv, kcaop->ivlen);
		if (unlikely(ret)) {
			derr(1, "Error in copying to userspace");
			return -EFAULT;
		}
	}
	return 0;
}


int cryptodev_kcaop_from_user(struct kernel_crypt_auth_op *kcaop,
			struct fcrypt *fcr, void __user *arg)
{
	if (unlikely(copy_from_user(&kcaop->caop, arg, sizeof(kcaop->caop)))) {
		derr(1, "Error in copying from userspace");
		return -EFAULT;
	}

	return fill_kcaop_from_caop(kcaop, fcr);
}

int cryptodev_kcaop_to_user(struct kernel_crypt_auth_op *kcaop,
		struct fcrypt *fcr, void __user *arg)
{
	int ret;

	ret = fill_caop_from_kcaop(kcaop, fcr);
	if (unlikely(ret)) {
		derr(1, "fill_caop_from_kcaop");
		return ret;
	}

	if (unlikely(copy_to_user(arg, &kcaop->caop, sizeof(kcaop->caop)))) {
		derr(1, "Error in copying to userspace");
		return -EFAULT;
	}
	return 0;
}

/* compatibility code for 32bit userlands */
#ifdef CONFIG_COMPAT

static inline void
compat_to_crypt_auth_op(struct compat_crypt_auth_op *compat, struct crypt_auth_op *caop)
{
	caop->ses      = compat->ses;
	caop->op       = compat->op;
	caop->flags    = compat->flags;
	caop->len      = compat->len;
	caop->auth_len = compat->auth_len;
	caop->tag_len  = compat->tag_len;
	caop->iv_len   = compat->iv_len;

	caop->auth_src = compat_ptr(compat->auth_src);
	caop->src      = compat_ptr(compat->src);
	caop->dst      = compat_ptr(compat->dst);
	caop->tag      = compat_ptr(compat->tag);
	caop->iv       = compat_ptr(compat->iv);
}

static inline void
crypt_auth_op_to_compat(struct crypt_auth_op *caop, struct compat_crypt_auth_op *compat)
{
	compat->ses      = caop->ses;
	compat->op       = caop->op;
	compat->flags    = caop->flags;
	compat->len      = caop->len;
	compat->auth_len = caop->auth_len;
	compat->tag_len  = caop->tag_len;
	compat->iv_len   = caop->iv_len;

	compat->auth_src = ptr_to_compat(caop->auth_src);
	compat->src      = ptr_to_compat(caop->src);
	compat->dst      = ptr_to_compat(caop->dst);
	compat->tag      = ptr_to_compat(caop->tag);
	compat->iv       = ptr_to_compat(caop->iv);
}

int compat_kcaop_from_user(struct kernel_crypt_auth_op *kcaop,
			   struct fcrypt *fcr, void __user *arg)
{
	int ret;
	struct compat_crypt_auth_op compat_auth_cop;

	ret = copy_from_user(&compat_auth_cop, arg, sizeof(compat_auth_cop));
	if (unlikely(ret)) {
		derr(1, "Error in copying from userspace");
		return -EFAULT;
	}

	compat_to_crypt_auth_op(&compat_auth_cop, &kcaop->caop);

	return fill_kcaop_from_caop(kcaop, fcr);
}

int compat_kcaop_to_user(struct kernel_crypt_auth_op *kcaop,
			 struct fcrypt *fcr, void __user *arg)
{
	int ret;
	struct compat_crypt_auth_op compat_auth_cop;

	ret = fill_caop_from_kcaop(kcaop, fcr);
	if (unlikely(ret)) {
		derr(1, "fill_caop_from_kcaop");
		return ret;
	}

	crypt_auth_op_to_compat(&kcaop->caop, &compat_auth_cop);

	if (unlikely(copy_to_user(arg, &compat_auth_cop, sizeof(compat_auth_cop)))) {
		derr(1, "Error in copying to userspace");
		return -EFAULT;
	}
	return 0;
}

#endif /* CONFIG_COMPAT */

static void copy_tls_hash(struct scatterlist *dst_sg, int len, void *hash, int hash_len)
{
	scatterwalk_map_and_copy(hash, dst_sg, len, hash_len, 1);
}

static void read_tls_hash(struct scatterlist *dst_sg, int len, void *hash, int hash_len)
{
	scatterwalk_map_and_copy(hash, dst_sg, len - hash_len, hash_len, 0);
}

#define TLS_MAX_PADDING_SIZE 256
static int pad_record(struct scatterlist *dst_sg, int len, int block_size)
{
	uint8_t pad[TLS_MAX_PADDING_SIZE];
	int pad_size = block_size - (len % block_size);

	memset(pad, pad_size - 1, pad_size);

	scatterwalk_map_and_copy(pad, dst_sg, len, pad_size, 1);

	return pad_size;
}

static int verify_tls_record_pad(struct scatterlist *dst_sg, int len, int block_size)
{
	uint8_t pad[TLS_MAX_PADDING_SIZE];
	uint8_t pad_size;
	int i;

	scatterwalk_map_and_copy(&pad_size, dst_sg, len - 1, 1, 0);

	if (pad_size + 1 > len) {
		derr(1, "Pad size: %d", pad_size);
		return -EBADMSG;
	}

	scatterwalk_map_and_copy(pad, dst_sg, len - pad_size - 1, pad_size + 1, 0);

	for (i = 0; i < pad_size; i++)
		if (pad[i] != pad_size) {
			derr(1, "Pad size: %u, pad: %d", pad_size, pad[i]);
			return -EBADMSG;
		}

	return pad_size + 1;
}

/* Authenticate and encrypt the TLS way (also perform padding).
 * During decryption it verifies the pad and tag and returns -EBADMSG on error.
 */
static int
tls_auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
		 struct scatterlist *auth_sg, uint32_t auth_len,
		 struct scatterlist *dst_sg, uint32_t len)
{
	int ret, fail = 0;
	struct crypt_auth_op *caop = &kcaop->caop;
	uint8_t vhash[AALG_MAX_RESULT_LEN];
	uint8_t hash_output[AALG_MAX_RESULT_LEN];

	/* TLS authenticates the plaintext except for the padding.
	 */
	if (caop->op == COP_ENCRYPT) {
		if (ses_ptr->hdata.init != 0) {
			if (auth_len > 0) {
				ret = cryptodev_hash_update(&ses_ptr->hdata,
								auth_sg, auth_len);
				if (unlikely(ret)) {
					derr(0, "cryptodev_hash_update: %d", ret);
					return ret;
				}
			}

			if (len > 0) {
				ret = cryptodev_hash_update(&ses_ptr->hdata,
								dst_sg, len);
				if (unlikely(ret)) {
					derr(0, "cryptodev_hash_update: %d", ret);
					return ret;
				}
			}

			ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
			if (unlikely(ret)) {
				derr(0, "cryptodev_hash_final: %d", ret);
				return ret;
			}

			copy_tls_hash(dst_sg, len, hash_output, caop->tag_len);
			len += caop->tag_len;
		}

		if (ses_ptr->cdata.init != 0) {
			if (ses_ptr->cdata.blocksize > 1) {
				ret = pad_record(dst_sg, len, ses_ptr->cdata.blocksize);
				len += ret;
			}

			ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
							dst_sg, dst_sg, len);
			if (unlikely(ret)) {
				derr(0, "cryptodev_cipher_encrypt: %d", ret);
				return ret;
			}
		}
	} else {
		if (ses_ptr->cdata.init != 0) {
			ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
							dst_sg, dst_sg, len);

			if (unlikely(ret)) {
				derr(0, "cryptodev_cipher_decrypt: %d", ret);
				return ret;
			}

			if (ses_ptr->cdata.blocksize > 1) {
				ret = verify_tls_record_pad(dst_sg, len, ses_ptr->cdata.blocksize);
				if (unlikely(ret < 0)) {
					derr(2, "verify_record_pad: %d", ret);
					fail = 1;
				} else {
					len -= ret;
				}
			}
		}

		if (ses_ptr->hdata.init != 0) {
			if (unlikely(caop->tag_len > sizeof(vhash) || caop->tag_len > len)) {
				derr(1, "Illegal tag len size");
				return -EINVAL;
			}

			read_tls_hash(dst_sg, len, vhash, caop->tag_len);
			len -= caop->tag_len;

			if (auth_len > 0) {
				ret = cryptodev_hash_update(&ses_ptr->hdata,
								auth_sg, auth_len);
				if (unlikely(ret)) {
					derr(0, "cryptodev_hash_update: %d", ret);
					return ret;
				}
			}

			if (len > 0) {
				ret = cryptodev_hash_update(&ses_ptr->hdata,
									dst_sg, len);
				if (unlikely(ret)) {
					derr(0, "cryptodev_hash_update: %d", ret);
					return ret;
				}
			}

			ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
			if (unlikely(ret)) {
				derr(0, "cryptodev_hash_final: %d", ret);
				return ret;
			}

			if (memcmp(vhash, hash_output, caop->tag_len) != 0 || fail != 0) {
				derr(2, "MAC verification failed (tag_len: %d)", caop->tag_len);
				return -EBADMSG;
			}
		}
	}
	kcaop->dst_len = len;
	return 0;
}

/* Authenticate and encrypt the SRTP way. During decryption
 * it verifies the tag and returns -EBADMSG on error.
 */
static int
srtp_auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
		  struct scatterlist *auth_sg, uint32_t auth_len,
		  struct scatterlist *dst_sg, uint32_t len)
{
	int ret, fail = 0;
	struct crypt_auth_op *caop = &kcaop->caop;
	uint8_t vhash[AALG_MAX_RESULT_LEN];
	uint8_t hash_output[AALG_MAX_RESULT_LEN];

	/* SRTP authenticates the encrypted data.
	 */
	if (caop->op == COP_ENCRYPT) {
		if (ses_ptr->cdata.init != 0) {
			ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
							dst_sg, dst_sg, len);
			if (unlikely(ret)) {
				derr(0, "cryptodev_cipher_encrypt: %d", ret);
				return ret;
			}
		}

		if (ses_ptr->hdata.init != 0) {
			if (auth_len > 0) {
				ret = cryptodev_hash_update(&ses_ptr->hdata,
								auth_sg, auth_len);
				if (unlikely(ret)) {
					derr(0, "cryptodev_hash_update: %d", ret);
					return ret;
				}
			}

			ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
			if (unlikely(ret)) {
				derr(0, "cryptodev_hash_final: %d", ret);
				return ret;
			}

			if (unlikely(copy_to_user(caop->tag, hash_output, caop->tag_len)))
				return -EFAULT;
		}

	} else {
		if (ses_ptr->hdata.init != 0) {
			if (unlikely(caop->tag_len > sizeof(vhash) || caop->tag_len > len)) {
				derr(1, "Illegal tag len size");
				return -EINVAL;
			}

			if (unlikely(copy_from_user(vhash, caop->tag, caop->tag_len)))
				return -EFAULT;

			ret = cryptodev_hash_update(&ses_ptr->hdata,
							auth_sg, auth_len);
			if (unlikely(ret)) {
				derr(0, "cryptodev_hash_update: %d", ret);
				return ret;
			}

			ret = cryptodev_hash_final(&ses_ptr->hdata, hash_output);
			if (unlikely(ret)) {
				derr(0, "cryptodev_hash_final: %d", ret);
				return ret;
			}

			if (memcmp(vhash, hash_output, caop->tag_len) != 0 || fail != 0) {
				derr(2, "MAC verification failed");
				return -EBADMSG;
			}
		}

		if (ses_ptr->cdata.init != 0) {
			ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
							dst_sg, dst_sg, len);

			if (unlikely(ret)) {
				derr(0, "cryptodev_cipher_decrypt: %d", ret);
				return ret;
			}
		}

	}
	kcaop->dst_len = len;
	return 0;
}

static int rk_auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
			   struct scatterlist *auth_sg, uint32_t auth_len,
			   struct scatterlist *src_sg,
			   struct scatterlist *dst_sg, uint32_t len)
{
	int ret;
	struct crypt_auth_op *caop = &kcaop->caop;
	int max_tag_len;

	max_tag_len = cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
	if (unlikely(caop->tag_len > max_tag_len)) {
		derr(0, "Illegal tag length: %d", caop->tag_len);
		return -EINVAL;
	}

	if (caop->tag_len)
		cryptodev_cipher_set_tag_size(&ses_ptr->cdata, caop->tag_len);
	else
		caop->tag_len = max_tag_len;

	cryptodev_cipher_auth(&ses_ptr->cdata, auth_sg, auth_len);

	if (caop->op == COP_ENCRYPT) {
		ret = cryptodev_cipher_encrypt(&ses_ptr->cdata, src_sg, dst_sg, len);
		if (unlikely(ret)) {
			derr(0, "cryptodev_cipher_encrypt: %d", ret);
			return ret;
		}
	} else {
		ret = cryptodev_cipher_decrypt(&ses_ptr->cdata, src_sg, dst_sg, len);
		if (unlikely(ret)) {
			derr(0, "cryptodev_cipher_decrypt: %d", ret);
			return ret;
		}
	}

	return 0;
}

/* Typical AEAD (i.e. GCM) encryption/decryption.
 * During decryption the tag is verified.
 */
static int
auth_n_crypt(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop,
		  struct scatterlist *auth_sg, uint32_t auth_len,
		  struct scatterlist *src_sg,
		  struct scatterlist *dst_sg, uint32_t len)
{
	int ret;
	struct crypt_auth_op *caop = &kcaop->caop;
	int max_tag_len;

	max_tag_len = cryptodev_cipher_get_tag_size(&ses_ptr->cdata);
	if (unlikely(caop->tag_len > max_tag_len)) {
		derr(0, "Illegal tag length: %d", caop->tag_len);
		return -EINVAL;
	}

	if (caop->tag_len)
		cryptodev_cipher_set_tag_size(&ses_ptr->cdata, caop->tag_len);
	else
		caop->tag_len = max_tag_len;

	cryptodev_cipher_auth(&ses_ptr->cdata, auth_sg, auth_len);

	if (caop->op == COP_ENCRYPT) {
		ret = cryptodev_cipher_encrypt(&ses_ptr->cdata,
						src_sg, dst_sg, len);
		if (unlikely(ret)) {
			derr(0, "cryptodev_cipher_encrypt: %d", ret);
			return ret;
		}
		kcaop->dst_len = len + caop->tag_len;
		caop->tag = caop->dst + len;
	} else {
		ret = cryptodev_cipher_decrypt(&ses_ptr->cdata,
						src_sg, dst_sg, len);

		if (unlikely(ret)) {
			derr(0, "cryptodev_cipher_decrypt: %d", ret);
			return ret;
		}
		kcaop->dst_len = len - caop->tag_len;
		caop->tag = caop->dst + len - caop->tag_len;
	}

	return 0;
}

static int crypto_auth_zc_srtp(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
{
	struct scatterlist *dst_sg, *auth_sg;
	struct crypt_auth_op *caop = &kcaop->caop;
	int ret;

	if (unlikely(ses_ptr->cdata.init != 0 &&
		(ses_ptr->cdata.stream == 0 || ses_ptr->cdata.aead != 0))) {
		derr(0, "Only stream modes are allowed in SRTP mode (but not AEAD)");
		return -EINVAL;
	}

	ret = get_userbuf_srtp(ses_ptr, kcaop, &auth_sg, &dst_sg);
	if (unlikely(ret)) {
		derr(1, "get_userbuf_srtp(): Error getting user pages.");
		return ret;
	}

	ret = srtp_auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
			dst_sg, caop->len);

	cryptodev_release_user_pages(ses_ptr);

	return ret;
}

static int crypto_auth_zc_tls(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
{
	struct crypt_auth_op *caop = &kcaop->caop;
	struct scatterlist *dst_sg, *auth_sg;
	unsigned char *auth_buf = NULL;
	struct scatterlist tmp;
	int ret;

	if (unlikely(caop->auth_len > PAGE_SIZE)) {
		derr(1, "auth data len is excessive.");
		return -EINVAL;
	}

	auth_buf = (char *)__get_free_page(GFP_KERNEL);
	if (unlikely(!auth_buf)) {
		derr(1, "unable to get a free page.");
		return -ENOMEM;
	}

	if (caop->auth_src && caop->auth_len > 0) {
		if (unlikely(copy_from_user(auth_buf, caop->auth_src, caop->auth_len))) {
			derr(1, "unable to copy auth data from userspace.");
			ret = -EFAULT;
			goto free_auth_buf;
		}

		sg_init_one(&tmp, auth_buf, caop->auth_len);
		auth_sg = &tmp;
	} else {
		auth_sg = NULL;
	}

	ret = get_userbuf_tls(ses_ptr, kcaop, &dst_sg);
	if (unlikely(ret)) {
		derr(1, "get_userbuf_tls(): Error getting user pages.");
		goto free_auth_buf;
	}

	ret = tls_auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
			dst_sg, caop->len);
	cryptodev_release_user_pages(ses_ptr);

free_auth_buf:
	free_page((unsigned long)auth_buf);
	return ret;
}

static int crypto_auth_zc_aead(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
{
	struct scatterlist *dst_sg;
	struct scatterlist *src_sg;
	struct crypt_auth_op *caop = &kcaop->caop;
	unsigned char *auth_buf = NULL;
	int ret;

#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0))
	struct scatterlist tmp;
	struct scatterlist *auth_sg;
#else
	struct scatterlist auth1[2];
	struct scatterlist auth2[2];
#endif

	if (unlikely(ses_ptr->cdata.init == 0 ||
		(ses_ptr->cdata.stream == 0 && ses_ptr->cdata.aead == 0))) {
		derr(0, "Only stream and AEAD ciphers are allowed for authenc");
		return -EINVAL;
	}

	if (unlikely(caop->auth_len > PAGE_SIZE)) {
		derr(1, "auth data len is excessive.");
		return -EINVAL;
	}

	auth_buf = (char *)__get_free_page(GFP_KERNEL);
	if (unlikely(!auth_buf)) {
		derr(1, "unable to get a free page.");
		return -ENOMEM;
	}

	ret = cryptodev_get_userbuf(ses_ptr, caop->src, caop->len, caop->dst, kcaop->dst_len,
			kcaop->task, kcaop->mm, &src_sg, &dst_sg);
	if (unlikely(ret)) {
		derr(1, "get_userbuf(): Error getting user pages.");
		goto free_auth_buf;
	}

#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 2, 0))
	if (caop->auth_src && caop->auth_len > 0) {
		if (unlikely(copy_from_user(auth_buf, caop->auth_src, caop->auth_len))) {
			derr(1, "unable to copy auth data from userspace.");
			ret = -EFAULT;
			goto free_pages;
		}

		sg_init_one(&tmp, auth_buf, caop->auth_len);
		auth_sg = &tmp;
	} else {
		auth_sg = NULL;
	}

	ret = auth_n_crypt(ses_ptr, kcaop, auth_sg, caop->auth_len,
			src_sg, dst_sg, caop->len);
#else
	if (caop->auth_src && caop->auth_len > 0) {
		if (unlikely(copy_from_user(auth_buf, caop->auth_src, caop->auth_len))) {
			derr(1, "unable to copy auth data from userspace.");
			ret = -EFAULT;
			goto free_pages;
		}

		sg_init_table(auth1, 2);
		sg_set_buf(auth1, auth_buf, caop->auth_len);
		sg_chain(auth1, 2, src_sg);

		if (src_sg == dst_sg) {
			src_sg = auth1;
			dst_sg = auth1;
		} else {
			sg_init_table(auth2, 2);
			sg_set_buf(auth2, auth_buf, caop->auth_len);
			sg_chain(auth2, 2, dst_sg);
			src_sg = auth1;
			dst_sg = auth2;
		}
	}

	ret = auth_n_crypt(ses_ptr, kcaop, NULL, caop->auth_len,
			src_sg, dst_sg, caop->len);
#endif

free_pages:
	cryptodev_release_user_pages(ses_ptr);

free_auth_buf:
	free_page((unsigned long)auth_buf);

	return ret;
}

/* Chain two sglists together. It will keep the last nent of priv
 * and invalidate the first nent of sgl
 */
static struct scatterlist *sg_copy_chain(struct scatterlist *prv,
					 unsigned int prv_nents,
					 struct scatterlist *sgl)
{
	struct scatterlist *sg_tmp = sg_last(prv, prv_nents);

	sg_set_page(sgl, sg_page(sg_tmp), sg_tmp->length, sg_tmp->offset);

	if (prv_nents > 1) {
		sg_chain(prv, prv_nents, sgl);
		return prv;
	} else {
		return sgl;
	}
}

static int crypto_auth_zc_rk(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
{
	struct scatterlist *dst;
	struct scatterlist *src;
	struct scatterlist *dst_sg;
	struct scatterlist *src_sg;
	struct crypt_auth_op *caop = &kcaop->caop;
	unsigned char *auth_buf = NULL, *tag_buf = NULL;
	struct scatterlist auth_src[2], auth_dst[2], tag[3];
	int ret;

	if (unlikely(ses_ptr->cdata.init == 0 ||
	    (ses_ptr->cdata.stream == 0 && ses_ptr->cdata.aead == 0))) {
		derr(0, "Only stream and AEAD ciphers are allowed for authenc");
		return -EINVAL;
	}

	if (unlikely(caop->auth_len > PAGE_SIZE)) {
		derr(1, "auth data len is excessive.");
		return -EINVAL;
	}

	ret = cryptodev_get_userbuf(ses_ptr, caop->src, caop->len,
				    caop->dst, kcaop->dst_len,
				    kcaop->task, kcaop->mm, &src_sg, &dst_sg);
	if (unlikely(ret)) {
		derr(1, "get_userbuf(): Error getting user pages.");
		ret = -EFAULT;
		goto exit;
	}

	dst = dst_sg;
	src = src_sg;

	/* chain tag */
	if (caop->tag && caop->tag_len > 0) {
		tag_buf = kcalloc(caop->tag_len, sizeof(*tag_buf), GFP_KERNEL);
		if (unlikely(!tag_buf)) {
			derr(1, "unable to kcalloc %d.", caop->tag_len);
			ret = -EFAULT;
			goto free_pages;
		}

		if (unlikely(copy_from_user(tag_buf, caop->tag, caop->tag_len))) {
			derr(1, "unable to copy tag data from userspace.");
			ret = -EFAULT;
			goto free_pages;
		}

		sg_init_table(tag, ARRAY_SIZE(tag));
		sg_set_buf(&tag[1], tag_buf, caop->tag_len);

		/* Since the sg_chain() requires the last sg in the list is empty and
		 * used for link information, we can not directly link src/dst_sg to tags
		 */
		if (caop->op == COP_ENCRYPT)
			dst = sg_copy_chain(dst_sg, sg_nents(dst_sg), tag);
		else
			src = sg_copy_chain(src_sg, sg_nents(src_sg), tag);
	}

	/* chain auth */
	auth_buf = (char *)__get_free_page(GFP_KERNEL);
	if (unlikely(!auth_buf)) {
		derr(1, "unable to get a free page.");
		ret = -EFAULT;
		goto free_pages;
	}

	if (caop->auth_src && caop->auth_len > 0) {
		if (unlikely(copy_from_user(auth_buf, caop->auth_src, caop->auth_len))) {
			derr(1, "unable to copy auth data from userspace.");
			ret = -EFAULT;
			goto free_pages;
		}

		sg_init_table(auth_src, ARRAY_SIZE(auth_src));
		sg_set_buf(auth_src, auth_buf, caop->auth_len);
		sg_init_table(auth_dst, ARRAY_SIZE(auth_dst));
		sg_set_buf(auth_dst, auth_buf, caop->auth_len);

		sg_chain(auth_src, 2, src);
		sg_chain(auth_dst, 2, dst);
		src = auth_src;
		dst = auth_dst;
	}

	if (caop->op == COP_ENCRYPT)
		ret = rk_auth_n_crypt(ses_ptr, kcaop, NULL, caop->auth_len,
				      src, dst, caop->len);
	else
		ret = rk_auth_n_crypt(ses_ptr, kcaop, NULL, caop->auth_len,
				      src, dst, caop->len + caop->tag_len);

	if (!ret && caop->op == COP_ENCRYPT) {
		if (unlikely(copy_to_user(kcaop->caop.tag, tag_buf, caop->tag_len))) {
			derr(1, "Error in copying to userspace");
			ret = -EFAULT;
			goto free_pages;
		}
	}

free_pages:
	cryptodev_release_user_pages(ses_ptr);

exit:
	if (auth_buf)
		free_page((unsigned long)auth_buf);

	kfree(tag_buf);

	return ret;
}

static int
__crypto_auth_run_zc(struct csession *ses_ptr, struct kernel_crypt_auth_op *kcaop)
{
	struct crypt_auth_op *caop = &kcaop->caop;
	int ret;

	if (caop->flags & COP_FLAG_AEAD_SRTP_TYPE) {
		ret = crypto_auth_zc_srtp(ses_ptr, kcaop);
	} else if (caop->flags & COP_FLAG_AEAD_TLS_TYPE &&
		   ses_ptr->cdata.aead == 0) {
		ret = crypto_auth_zc_tls(ses_ptr, kcaop);
	} else if (caop->flags & COP_FLAG_AEAD_RK_TYPE &&
		   ses_ptr->cdata.aead) {
		ret = crypto_auth_zc_rk(ses_ptr, kcaop);
	} else if (ses_ptr->cdata.aead) {
		ret = crypto_auth_zc_aead(ses_ptr, kcaop);
	} else {
		ret = -EINVAL;
	}

	return ret;
}


int crypto_auth_run(struct fcrypt *fcr, struct kernel_crypt_auth_op *kcaop)
{
	struct csession *ses_ptr;
	struct crypt_auth_op *caop = &kcaop->caop;
	int ret;

	if (unlikely(caop->op != COP_ENCRYPT && caop->op != COP_DECRYPT)) {
		ddebug(1, "invalid operation op=%u", caop->op);
		return -EINVAL;
	}

	/* this also enters ses_ptr->sem */
	ses_ptr = crypto_get_session_by_sid(fcr, caop->ses);
	if (unlikely(!ses_ptr)) {
		derr(1, "invalid session ID=0x%08X", caop->ses);
		return -EINVAL;
	}

	if (unlikely(ses_ptr->cdata.init == 0)) {
		derr(1, "cipher context not initialized");
		ret = -EINVAL;
		goto out_unlock;
	}

	/* If we have a hash/mac handle reset its state */
	if (ses_ptr->hdata.init != 0) {
		ret = cryptodev_hash_reset(&ses_ptr->hdata);
		if (unlikely(ret)) {
			derr(1, "error in cryptodev_hash_reset()");
			goto out_unlock;
		}
	}

	cryptodev_cipher_set_iv(&ses_ptr->cdata, kcaop->iv,
				min(ses_ptr->cdata.ivsize, kcaop->ivlen));

	ret = __crypto_auth_run_zc(ses_ptr, kcaop);
	if (unlikely(ret)) {
		derr(1, "error in __crypto_auth_run_zc()");
		goto out_unlock;
	}

	ret = 0;

	cryptodev_cipher_get_iv(&ses_ptr->cdata, kcaop->iv,
				min(ses_ptr->cdata.ivsize, kcaop->ivlen));

out_unlock:
	crypto_put_session(ses_ptr);
	return ret;
}