X-Git-Url: http://git.alex.org.uk diff --git a/crypto/api.c b/crypto/api.c index 2715afd..033a714 100644 --- a/crypto/api.c +++ b/crypto/api.c @@ -6,320 +6,601 @@ * Copyright (c) 2005 Herbert Xu * * Portions derived from Cryptoapi, by Alexander Kjeldaas - * and Nettle, by Niels Möller. + * and Nettle, by Niels Möller. * * 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) + * Software Foundation; either version 2 of the License, or (at your option) * any later version. * */ -#include -#include -#include +#include #include #include #include -#include +#include +#include +#include #include #include #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); -static inline int crypto_alg_get(struct crypto_alg *alg) +BLOCKING_NOTIFIER_HEAD(crypto_chain); +EXPORT_SYMBOL_GPL(crypto_chain); + +static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg) { - return try_module_get(alg->cra_module); + atomic_inc(&alg->cra_refcnt); + return alg; } -static inline void crypto_alg_put(struct crypto_alg *alg) +struct crypto_alg *crypto_mod_get(struct crypto_alg *alg) { - module_put(alg->cra_module); + 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 struct crypto_alg *crypto_alg_lookup(const char *name) +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 = -1; + int best = -2; - if (!name) - return NULL; - - down_read(&crypto_alg_sem); - 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_alg_get(q))) + if (unlikely(!crypto_mod_get(q))) continue; best = q->cra_priority; if (alg) - crypto_alg_put(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 (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); + + atomic_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); + + 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_interruptible_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 (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; +} + +struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask) +{ + struct crypto_alg *alg; + + down_read(&crypto_alg_sem); + alg = __crypto_alg_lookup(name, type, mask); up_read(&crypto_alg_sem); + return alg; } +EXPORT_SYMBOL_GPL(crypto_alg_lookup); + +struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask) +{ + struct crypto_alg *alg; + + if (!name) + return ERR_PTR(-ENOENT); + + mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD); + type &= mask; + + alg = crypto_alg_lookup(name, type, mask); + if (!alg) { + request_module("%s", name); + + if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask & + CRYPTO_ALG_NEED_FALLBACK)) + request_module("%s-all", name); + + alg = crypto_alg_lookup(name, type, mask); + } + + if (alg) + return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg; + + return crypto_larval_add(name, type, mask); +} +EXPORT_SYMBOL_GPL(crypto_larval_lookup); -/* A far more intelligent version of this is planned. For now, just - * try an exact match on the name of the algorithm. */ -static inline struct crypto_alg *crypto_alg_mod_lookup(const char *name) +int crypto_probing_notify(unsigned long val, void *v) { - return try_then_request_module(crypto_alg_lookup(name), name); + 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); -static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags) +struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask) { - tfm->crt_flags = flags & CRYPTO_TFM_REQ_MASK; - flags &= ~CRYPTO_TFM_REQ_MASK; - - switch (crypto_tfm_alg_type(tfm)) { - case CRYPTO_ALG_TYPE_CIPHER: - return crypto_init_cipher_flags(tfm, flags); - - case CRYPTO_ALG_TYPE_DIGEST: - return crypto_init_digest_flags(tfm, flags); - - case CRYPTO_ALG_TYPE_COMPRESS: - return crypto_init_compress_flags(tfm, flags); - - default: - break; + struct crypto_alg *alg; + struct crypto_alg *larval; + int ok; + + if (!((type | mask) & CRYPTO_ALG_TESTED)) { + type |= CRYPTO_ALG_TESTED; + mask |= CRYPTO_ALG_TESTED; } - - BUG(); - return -EINVAL; + + 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) +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_DIGEST: - return crypto_init_digest_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) { + if (tfm->exit) + tfm->exit(tfm); + return; + } + switch (crypto_tfm_alg_type(tfm)) { case CRYPTO_ALG_TYPE_CIPHER: crypto_exit_cipher_ops(tfm); break; - - case CRYPTO_ALG_TYPE_DIGEST: - crypto_exit_digest_ops(tfm); - break; - + case CRYPTO_ALG_TYPE_COMPRESS: crypto_exit_compress_ops(tfm); break; - + default: BUG(); - } } -static unsigned int crypto_ctxsize(struct crypto_alg *alg, int flags) +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, flags); - break; - - case CRYPTO_ALG_TYPE_DIGEST: - len = crypto_digest_ctxsize(alg, flags); + len += crypto_cipher_ctxsize(alg); break; - + case CRYPTO_ALG_TYPE_COMPRESS: - len = crypto_compress_ctxsize(alg, flags); + len += crypto_compress_ctxsize(alg); break; } - return len + alg->cra_alignmask; + return len; } -struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) +void crypto_shoot_alg(struct crypto_alg *alg) +{ + down_write(&crypto_alg_sem); + alg->cra_flags |= CRYPTO_ALG_DYING; + up_write(&crypto_alg_sem); +} +EXPORT_SYMBOL_GPL(crypto_shoot_alg); + +struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type, + u32 mask) { struct crypto_tfm *tfm = NULL; - struct crypto_alg *alg; unsigned int tfm_size; + int err = -ENOMEM; - alg = crypto_alg_mod_lookup(name); - if (alg == NULL) - goto out; - - tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, flags); - tfm = kmalloc(tfm_size, GFP_KERNEL); + tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask); + tfm = kzalloc(tfm_size, GFP_KERNEL); if (tfm == NULL) - goto out_put; + goto out_err; - memset(tfm, 0, tfm_size); - tfm->__crt_alg = alg; - - if (crypto_init_flags(tfm, flags)) - goto out_free_tfm; - - if (crypto_init_ops(tfm)) { - crypto_exit_ops(tfm); + + 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); - tfm = NULL; -out_put: - crypto_alg_put(alg); +out_err: + tfm = ERR_PTR(err); out: return tfm; } +EXPORT_SYMBOL_GPL(__crypto_alloc_tfm); -void crypto_free_tfm(struct crypto_tfm *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. + * Plesae 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_alg *alg; - int size; + struct crypto_tfm *tfm; + int err; - if (unlikely(!tfm)) - return; + for (;;) { + struct crypto_alg *alg; - alg = tfm->__crt_alg; - size = sizeof(*tfm) + alg->cra_ctxsize; + 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 (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); - crypto_alg_put(alg); - memset(tfm, 0, size); - kfree(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); -static inline int crypto_set_driver_name(struct crypto_alg *alg) +struct crypto_alg *crypto_find_alg(const char *alg_name, + const struct crypto_type *frontend, + u32 type, u32 mask) { - static const char suffix[] = "-generic"; - char *driver_name = (char *)alg->cra_driver_name; - int len; + struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) = + crypto_alg_mod_lookup; - if (*driver_name) - return 0; + if (frontend) { + type &= frontend->maskclear; + mask &= frontend->maskclear; + type |= frontend->type; + mask |= frontend->maskset; - len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); - if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME) - return -ENAMETOOLONG; + if (frontend->lookup) + lookup = frontend->lookup; + } - memcpy(driver_name + len, suffix, sizeof(suffix)); - return 0; + return lookup(alg_name, type, mask); } +EXPORT_SYMBOL_GPL(crypto_find_alg); -int crypto_register_alg(struct crypto_alg *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) { - int ret; - struct crypto_alg *q; + void *tfm; + int err; - if (alg->cra_alignmask & (alg->cra_alignmask + 1)) - return -EINVAL; + for (;;) { + struct crypto_alg *alg; - if (alg->cra_alignmask & alg->cra_blocksize) - return -EINVAL; + alg = crypto_find_alg(alg_name, frontend, type, mask); + if (IS_ERR(alg)) { + err = PTR_ERR(alg); + goto err; + } - if (alg->cra_blocksize > PAGE_SIZE) - return -EINVAL; + tfm = crypto_create_tfm(alg, frontend); + if (!IS_ERR(tfm)) + return tfm; - if (alg->cra_priority < 0) - return -EINVAL; - - ret = crypto_set_driver_name(alg); - if (unlikely(ret)) - return ret; + crypto_mod_put(alg); + err = PTR_ERR(tfm); - down_write(&crypto_alg_sem); - - list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (!strcmp(q->cra_driver_name, alg->cra_driver_name)) { - ret = -EEXIST; - goto out; +err: + if (err != -EAGAIN) + break; + if (signal_pending(current)) { + err = -EINTR; + break; } } - - list_add_tail(&alg->cra_list, &crypto_alg_list); -out: - up_write(&crypto_alg_sem); - return ret; + + return ERR_PTR(err); } +EXPORT_SYMBOL_GPL(crypto_alloc_tfm); -int crypto_unregister_alg(struct crypto_alg *alg) +/* + * 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) { - int ret = -ENOENT; - struct crypto_alg *q; - - BUG_ON(!alg->cra_module); - - down_write(&crypto_alg_sem); - list_for_each_entry(q, &crypto_alg_list, cra_list) { - if (alg == q) { - list_del(&alg->cra_list); - ret = 0; - goto out; - } - } -out: - up_write(&crypto_alg_sem); - return ret; + struct crypto_alg *alg; + + if (unlikely(!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_alg_available(const char *name, u32 flags) +int crypto_has_alg(const char *name, u32 type, u32 mask) { int ret = 0; - struct crypto_alg *alg = crypto_alg_mod_lookup(name); - - if (alg) { - crypto_alg_put(alg); + struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask); + + if (!IS_ERR(alg)) { + crypto_mod_put(alg); ret = 1; } - - return ret; -} -static int __init init_crypto(void) -{ - printk(KERN_INFO "Initializing Cryptographic API\n"); - crypto_init_proc(); - return 0; + return ret; } +EXPORT_SYMBOL_GPL(crypto_has_alg); -__initcall(init_crypto); - -EXPORT_SYMBOL_GPL(crypto_register_alg); -EXPORT_SYMBOL_GPL(crypto_unregister_alg); -EXPORT_SYMBOL_GPL(crypto_alloc_tfm); -EXPORT_SYMBOL_GPL(crypto_free_tfm); -EXPORT_SYMBOL_GPL(crypto_alg_available); +MODULE_DESCRIPTION("Cryptographic core API"); +MODULE_LICENSE("GPL");