| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Scatterlist Cryptographic API. |
| * |
| * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> |
| * Copyright (c) 2002 David S. Miller (davem@redhat.com) |
| * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au> |
| * |
| * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no> |
| * and Nettle, by Niels Möller. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/kmod.h> |
| #include <linux/module.h> |
| #include <linux/param.h> |
| #include <linux/sched/signal.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| #include <linux/completion.h> |
| #include "internal.h" |
| |
| LIST_HEAD(crypto_alg_list); |
| EXPORT_SYMBOL_GPL(crypto_alg_list); |
| DECLARE_RWSEM(crypto_alg_sem); |
| EXPORT_SYMBOL_GPL(crypto_alg_sem); |
| |
| BLOCKING_NOTIFIER_HEAD(crypto_chain); |
| EXPORT_SYMBOL_GPL(crypto_chain); |
| |
| static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg); |
| |
| struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) |
| { |
| return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL; |
| } |
| EXPORT_SYMBOL_GPL(crypto_mod_get); |
| |
| void crypto_mod_put(struct crypto_alg *alg) |
| { |
| struct module *module = alg->cra_module; |
| |
| crypto_alg_put(alg); |
| module_put(module); |
| } |
| EXPORT_SYMBOL_GPL(crypto_mod_put); |
| |
| static inline int crypto_is_test_larval(struct crypto_larval *larval) |
| { |
| return larval->alg.cra_driver_name[0]; |
| } |
| |
| static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, |
| u32 mask) |
| { |
| struct crypto_alg *q, *alg = NULL; |
| int best = -2; |
| |
| list_for_each_entry(q, &crypto_alg_list, cra_list) { |
| int exact, fuzzy; |
| |
| if (crypto_is_moribund(q)) |
| continue; |
| |
| if ((q->cra_flags ^ type) & mask) |
| continue; |
| |
| if (crypto_is_larval(q) && |
| !crypto_is_test_larval((struct crypto_larval *)q) && |
| ((struct crypto_larval *)q)->mask != mask) |
| continue; |
| |
| exact = !strcmp(q->cra_driver_name, name); |
| fuzzy = !strcmp(q->cra_name, name); |
| if (!exact && !(fuzzy && q->cra_priority > best)) |
| continue; |
| |
| if (unlikely(!crypto_mod_get(q))) |
| continue; |
| |
| best = q->cra_priority; |
| if (alg) |
| crypto_mod_put(alg); |
| alg = q; |
| |
| if (exact) |
| break; |
| } |
| |
| return alg; |
| } |
| |
| static void crypto_larval_destroy(struct crypto_alg *alg) |
| { |
| struct crypto_larval *larval = (void *)alg; |
| |
| BUG_ON(!crypto_is_larval(alg)); |
| if (!IS_ERR_OR_NULL(larval->adult)) |
| crypto_mod_put(larval->adult); |
| kfree(larval); |
| } |
| |
| struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask) |
| { |
| struct crypto_larval *larval; |
| |
| larval = kzalloc(sizeof(*larval), GFP_KERNEL); |
| if (!larval) |
| return ERR_PTR(-ENOMEM); |
| |
| larval->mask = mask; |
| larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type; |
| larval->alg.cra_priority = -1; |
| larval->alg.cra_destroy = crypto_larval_destroy; |
| |
| strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME); |
| init_completion(&larval->completion); |
| |
| return larval; |
| } |
| EXPORT_SYMBOL_GPL(crypto_larval_alloc); |
| |
| static struct crypto_alg *crypto_larval_add(const char *name, u32 type, |
| u32 mask) |
| { |
| struct crypto_alg *alg; |
| struct crypto_larval *larval; |
| |
| larval = crypto_larval_alloc(name, type, mask); |
| if (IS_ERR(larval)) |
| return ERR_CAST(larval); |
| |
| refcount_set(&larval->alg.cra_refcnt, 2); |
| |
| down_write(&crypto_alg_sem); |
| alg = __crypto_alg_lookup(name, type, mask); |
| if (!alg) { |
| alg = &larval->alg; |
| list_add(&alg->cra_list, &crypto_alg_list); |
| } |
| up_write(&crypto_alg_sem); |
| |
| if (alg != &larval->alg) { |
| kfree(larval); |
| if (crypto_is_larval(alg)) |
| alg = crypto_larval_wait(alg); |
| } |
| |
| return alg; |
| } |
| |
| void crypto_larval_kill(struct crypto_alg *alg) |
| { |
| struct crypto_larval *larval = (void *)alg; |
| |
| down_write(&crypto_alg_sem); |
| list_del(&alg->cra_list); |
| up_write(&crypto_alg_sem); |
| complete_all(&larval->completion); |
| crypto_alg_put(alg); |
| } |
| EXPORT_SYMBOL_GPL(crypto_larval_kill); |
| |
| static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg) |
| { |
| struct crypto_larval *larval = (void *)alg; |
| long timeout; |
| |
| timeout = wait_for_completion_killable_timeout( |
| &larval->completion, 60 * HZ); |
| |
| alg = larval->adult; |
| if (timeout < 0) |
| alg = ERR_PTR(-EINTR); |
| else if (!timeout) |
| alg = ERR_PTR(-ETIMEDOUT); |
| else if (!alg) |
| alg = ERR_PTR(-ENOENT); |
| else if (IS_ERR(alg)) |
| ; |
| else if (crypto_is_test_larval(larval) && |
| !(alg->cra_flags & CRYPTO_ALG_TESTED)) |
| alg = ERR_PTR(-EAGAIN); |
| else if (!crypto_mod_get(alg)) |
| alg = ERR_PTR(-EAGAIN); |
| crypto_mod_put(&larval->alg); |
| |
| return alg; |
| } |
| |
| static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, |
| u32 mask) |
| { |
| struct crypto_alg *alg; |
| u32 test = 0; |
| |
| if (!((type | mask) & CRYPTO_ALG_TESTED)) |
| test |= CRYPTO_ALG_TESTED; |
| |
| down_read(&crypto_alg_sem); |
| alg = __crypto_alg_lookup(name, type | test, mask | test); |
| if (!alg && test) { |
| alg = __crypto_alg_lookup(name, type, mask); |
| if (alg && !crypto_is_larval(alg)) { |
| /* Test failed */ |
| crypto_mod_put(alg); |
| alg = ERR_PTR(-ELIBBAD); |
| } |
| } |
| up_read(&crypto_alg_sem); |
| |
| return alg; |
| } |
| |
| static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, |
| u32 mask) |
| { |
| struct crypto_alg *alg; |
| |
| if (!name) |
| return ERR_PTR(-ENOENT); |
| |
| type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); |
| mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); |
| |
| alg = crypto_alg_lookup(name, type, mask); |
| if (!alg && !(mask & CRYPTO_NOLOAD)) { |
| request_module("crypto-%s", name); |
| |
| if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask & |
| CRYPTO_ALG_NEED_FALLBACK)) |
| request_module("crypto-%s-all", name); |
| |
| alg = crypto_alg_lookup(name, type, mask); |
| } |
| |
| if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg)) |
| alg = crypto_larval_wait(alg); |
| else if (!alg) |
| alg = crypto_larval_add(name, type, mask); |
| |
| return alg; |
| } |
| |
| int crypto_probing_notify(unsigned long val, void *v) |
| { |
| int ok; |
| |
| ok = blocking_notifier_call_chain(&crypto_chain, val, v); |
| if (ok == NOTIFY_DONE) { |
| request_module("cryptomgr"); |
| ok = blocking_notifier_call_chain(&crypto_chain, val, v); |
| } |
| |
| return ok; |
| } |
| EXPORT_SYMBOL_GPL(crypto_probing_notify); |
| |
| struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) |
| { |
| struct crypto_alg *alg; |
| struct crypto_alg *larval; |
| int ok; |
| |
| /* |
| * If the internal flag is set for a cipher, require a caller to |
| * to invoke the cipher with the internal flag to use that cipher. |
| * Also, if a caller wants to allocate a cipher that may or may |
| * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and |
| * !(mask & CRYPTO_ALG_INTERNAL). |
| */ |
| if (!((type | mask) & CRYPTO_ALG_INTERNAL)) |
| mask |= CRYPTO_ALG_INTERNAL; |
| |
| larval = crypto_larval_lookup(name, type, mask); |
| if (IS_ERR(larval) || !crypto_is_larval(larval)) |
| return larval; |
| |
| ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval); |
| |
| if (ok == NOTIFY_STOP) |
| alg = crypto_larval_wait(larval); |
| else { |
| crypto_mod_put(larval); |
| alg = ERR_PTR(-ENOENT); |
| } |
| crypto_larval_kill(larval); |
| return alg; |
| } |
| EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup); |
| |
| static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask) |
| { |
| const struct crypto_type *type_obj = tfm->__crt_alg->cra_type; |
| |
| if (type_obj) |
| return type_obj->init(tfm, type, mask); |
| |
| switch (crypto_tfm_alg_type(tfm)) { |
| case CRYPTO_ALG_TYPE_CIPHER: |
| return crypto_init_cipher_ops(tfm); |
| |
| case CRYPTO_ALG_TYPE_COMPRESS: |
| return crypto_init_compress_ops(tfm); |
| |
| default: |
| break; |
| } |
| |
| BUG(); |
| return -EINVAL; |
| } |
| |
| static void crypto_exit_ops(struct crypto_tfm *tfm) |
| { |
| const struct crypto_type *type = tfm->__crt_alg->cra_type; |
| |
| if (type && tfm->exit) |
| tfm->exit(tfm); |
| } |
| |
| static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask) |
| { |
| const struct crypto_type *type_obj = alg->cra_type; |
| unsigned int len; |
| |
| len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1); |
| if (type_obj) |
| return len + type_obj->ctxsize(alg, type, mask); |
| |
| switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) { |
| default: |
| BUG(); |
| |
| case CRYPTO_ALG_TYPE_CIPHER: |
| len += crypto_cipher_ctxsize(alg); |
| break; |
| |
| case CRYPTO_ALG_TYPE_COMPRESS: |
| len += crypto_compress_ctxsize(alg); |
| break; |
| } |
| |
| return len; |
| } |
| |
| static void crypto_shoot_alg(struct crypto_alg *alg) |
| { |
| down_write(&crypto_alg_sem); |
| alg->cra_flags |= CRYPTO_ALG_DYING; |
| up_write(&crypto_alg_sem); |
| } |
| |
| struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, |
| u32 mask) |
| { |
| struct crypto_tfm *tfm = NULL; |
| unsigned int tfm_size; |
| int err = -ENOMEM; |
| |
| tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask); |
| tfm = kzalloc(tfm_size, GFP_KERNEL); |
| if (tfm == NULL) |
| goto out_err; |
| |
| tfm->__crt_alg = alg; |
| |
| err = crypto_init_ops(tfm, type, mask); |
| if (err) |
| goto out_free_tfm; |
| |
| if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) |
| goto cra_init_failed; |
| |
| goto out; |
| |
| cra_init_failed: |
| crypto_exit_ops(tfm); |
| out_free_tfm: |
| if (err == -EAGAIN) |
| crypto_shoot_alg(alg); |
| kfree(tfm); |
| out_err: |
| tfm = ERR_PTR(err); |
| out: |
| return tfm; |
| } |
| EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); |
| |
| /* |
| * crypto_alloc_base - Locate algorithm and allocate transform |
| * @alg_name: Name of algorithm |
| * @type: Type of algorithm |
| * @mask: Mask for type comparison |
| * |
| * This function should not be used by new algorithm types. |
| * Please use crypto_alloc_tfm instead. |
| * |
| * crypto_alloc_base() will first attempt to locate an already loaded |
| * algorithm. If that fails and the kernel supports dynamically loadable |
| * modules, it will then attempt to load a module of the same name or |
| * alias. If that fails it will send a query to any loaded crypto manager |
| * to construct an algorithm on the fly. A refcount is grabbed on the |
| * algorithm which is then associated with the new transform. |
| * |
| * The returned transform is of a non-determinate type. Most people |
| * should use one of the more specific allocation functions such as |
| * crypto_alloc_blkcipher. |
| * |
| * In case of error the return value is an error pointer. |
| */ |
| struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask) |
| { |
| struct crypto_tfm *tfm; |
| int err; |
| |
| for (;;) { |
| struct crypto_alg *alg; |
| |
| alg = crypto_alg_mod_lookup(alg_name, type, mask); |
| if (IS_ERR(alg)) { |
| err = PTR_ERR(alg); |
| goto err; |
| } |
| |
| tfm = __crypto_alloc_tfm(alg, type, mask); |
| if (!IS_ERR(tfm)) |
| return tfm; |
| |
| crypto_mod_put(alg); |
| err = PTR_ERR(tfm); |
| |
| err: |
| if (err != -EAGAIN) |
| break; |
| if (fatal_signal_pending(current)) { |
| err = -EINTR; |
| break; |
| } |
| } |
| |
| return ERR_PTR(err); |
| } |
| EXPORT_SYMBOL_GPL(crypto_alloc_base); |
| |
| void *crypto_create_tfm(struct crypto_alg *alg, |
| const struct crypto_type *frontend) |
| { |
| char *mem; |
| struct crypto_tfm *tfm = NULL; |
| unsigned int tfmsize; |
| unsigned int total; |
| int err = -ENOMEM; |
| |
| tfmsize = frontend->tfmsize; |
| total = tfmsize + sizeof(*tfm) + frontend->extsize(alg); |
| |
| mem = kzalloc(total, GFP_KERNEL); |
| if (mem == NULL) |
| goto out_err; |
| |
| tfm = (struct crypto_tfm *)(mem + tfmsize); |
| tfm->__crt_alg = alg; |
| |
| err = frontend->init_tfm(tfm); |
| if (err) |
| goto out_free_tfm; |
| |
| if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm))) |
| goto cra_init_failed; |
| |
| goto out; |
| |
| cra_init_failed: |
| crypto_exit_ops(tfm); |
| out_free_tfm: |
| if (err == -EAGAIN) |
| crypto_shoot_alg(alg); |
| kfree(mem); |
| out_err: |
| mem = ERR_PTR(err); |
| out: |
| return mem; |
| } |
| EXPORT_SYMBOL_GPL(crypto_create_tfm); |
| |
| struct crypto_alg *crypto_find_alg(const char *alg_name, |
| const struct crypto_type *frontend, |
| u32 type, u32 mask) |
| { |
| if (frontend) { |
| type &= frontend->maskclear; |
| mask &= frontend->maskclear; |
| type |= frontend->type; |
| mask |= frontend->maskset; |
| } |
| |
| return crypto_alg_mod_lookup(alg_name, type, mask); |
| } |
| EXPORT_SYMBOL_GPL(crypto_find_alg); |
| |
| /* |
| * crypto_alloc_tfm - Locate algorithm and allocate transform |
| * @alg_name: Name of algorithm |
| * @frontend: Frontend algorithm type |
| * @type: Type of algorithm |
| * @mask: Mask for type comparison |
| * |
| * crypto_alloc_tfm() will first attempt to locate an already loaded |
| * algorithm. If that fails and the kernel supports dynamically loadable |
| * modules, it will then attempt to load a module of the same name or |
| * alias. If that fails it will send a query to any loaded crypto manager |
| * to construct an algorithm on the fly. A refcount is grabbed on the |
| * algorithm which is then associated with the new transform. |
| * |
| * The returned transform is of a non-determinate type. Most people |
| * should use one of the more specific allocation functions such as |
| * crypto_alloc_blkcipher. |
| * |
| * In case of error the return value is an error pointer. |
| */ |
| void *crypto_alloc_tfm(const char *alg_name, |
| const struct crypto_type *frontend, u32 type, u32 mask) |
| { |
| void *tfm; |
| int err; |
| |
| for (;;) { |
| struct crypto_alg *alg; |
| |
| alg = crypto_find_alg(alg_name, frontend, type, mask); |
| if (IS_ERR(alg)) { |
| err = PTR_ERR(alg); |
| goto err; |
| } |
| |
| tfm = crypto_create_tfm(alg, frontend); |
| if (!IS_ERR(tfm)) |
| return tfm; |
| |
| crypto_mod_put(alg); |
| err = PTR_ERR(tfm); |
| |
| err: |
| if (err != -EAGAIN) |
| break; |
| if (fatal_signal_pending(current)) { |
| err = -EINTR; |
| break; |
| } |
| } |
| |
| return ERR_PTR(err); |
| } |
| EXPORT_SYMBOL_GPL(crypto_alloc_tfm); |
| |
| /* |
| * crypto_destroy_tfm - Free crypto transform |
| * @mem: Start of tfm slab |
| * @tfm: Transform to free |
| * |
| * This function frees up the transform and any associated resources, |
| * then drops the refcount on the associated algorithm. |
| */ |
| void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm) |
| { |
| struct crypto_alg *alg; |
| |
| if (IS_ERR_OR_NULL(mem)) |
| return; |
| |
| alg = tfm->__crt_alg; |
| |
| if (!tfm->exit && alg->cra_exit) |
| alg->cra_exit(tfm); |
| crypto_exit_ops(tfm); |
| crypto_mod_put(alg); |
| kzfree(mem); |
| } |
| EXPORT_SYMBOL_GPL(crypto_destroy_tfm); |
| |
| int crypto_has_alg(const char *name, u32 type, u32 mask) |
| { |
| int ret = 0; |
| struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask); |
| |
| if (!IS_ERR(alg)) { |
| crypto_mod_put(alg); |
| ret = 1; |
| } |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(crypto_has_alg); |
| |
| void crypto_req_done(struct crypto_async_request *req, int err) |
| { |
| struct crypto_wait *wait = req->data; |
| |
| if (err == -EINPROGRESS) |
| return; |
| |
| wait->err = err; |
| complete(&wait->completion); |
| } |
| EXPORT_SYMBOL_GPL(crypto_req_done); |
| |
| MODULE_DESCRIPTION("Cryptographic core API"); |
| MODULE_LICENSE("GPL"); |