From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- crypto/algif_aead.c | 593 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 593 insertions(+) create mode 100644 crypto/algif_aead.c (limited to 'crypto/algif_aead.c') diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c new file mode 100644 index 0000000000..7d58cbbce4 --- /dev/null +++ b/crypto/algif_aead.c @@ -0,0 +1,593 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * algif_aead: User-space interface for AEAD algorithms + * + * Copyright (C) 2014, Stephan Mueller + * + * This file provides the user-space API for AEAD ciphers. + * + * 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 sendmsg (maybe with + * MSG_SPLICE_PAGES). 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct aead_tfm { + struct crypto_aead *aead; + struct crypto_sync_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_sync_skcipher *null_tfm, + struct scatterlist *src, + struct scatterlist *dst, unsigned int len) +{ + SYNC_SKCIPHER_REQUEST_ON_STACK(skreq, null_tfm); + + skcipher_request_set_sync_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_sync_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->init || ctx->more) { + err = af_alg_wait_for_data(sk, flags, 0); + if (err) + return err; + } + + /* + * Data length provided by caller via sendmsg that has not yet been + * processed. + */ + used = ctx->used; + + /* + * Make sure sufficient data is present -- note, the same check is also + * present in sendmsg. The checks in 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 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.sgt.sgl; + + 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.sgt.sgl, + 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.sgt.sgl, + 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; + struct scatterlist *sg = sgl_prev->sgt.sgl; + + sg_unmark_end(sg + sgl_prev->sgt.nents - 1); + sg_chain(sg, sgl_prev->sgt.nents + 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.sgt.sgl, 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, + .mmap = sock_no_mmap, + .bind = sock_no_bind, + .accept = sock_no_accept, + + .release = af_alg_release, + .sendmsg = aead_sendmsg, + .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 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, + .mmap = sock_no_mmap, + .bind = sock_no_bind, + .accept = sock_no_accept, + + .release = af_alg_release, + .sendmsg = aead_sendmsg_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_sync_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; + 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 "); +MODULE_DESCRIPTION("AEAD kernel crypto API user space interface"); -- cgit v1.2.3