diff options
Diffstat (limited to 'crypto/api.c')
| -rw-r--r-- | crypto/api.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/crypto/api.c b/crypto/api.c new file mode 100644 index 000000000000..394169a8577d --- /dev/null +++ b/crypto/api.c @@ -0,0 +1,233 @@ +/* + * Scatterlist Cryptographic API. + * + * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> + * Copyright (c) 2002 David S. Miller (davem@redhat.com) + * + * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no> + * 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) + * any later version. + * + */ +#include <linux/init.h> +#include <linux/crypto.h> +#include <linux/errno.h> +#include <linux/rwsem.h> +#include <linux/slab.h> +#include "internal.h" + +LIST_HEAD(crypto_alg_list); +DECLARE_RWSEM(crypto_alg_sem); + +static inline int crypto_alg_get(struct crypto_alg *alg) +{ + return try_module_get(alg->cra_module); +} + +static inline void crypto_alg_put(struct crypto_alg *alg) +{ + module_put(alg->cra_module); +} + +struct crypto_alg *crypto_alg_lookup(const char *name) +{ + struct crypto_alg *q, *alg = NULL; + + if (!name) + return NULL; + + down_read(&crypto_alg_sem); + + list_for_each_entry(q, &crypto_alg_list, cra_list) { + if (!(strcmp(q->cra_name, name))) { + if (crypto_alg_get(q)) + alg = q; + break; + } + } + + up_read(&crypto_alg_sem); + return alg; +} + +static int crypto_init_flags(struct crypto_tfm *tfm, u32 flags) +{ + tfm->crt_flags = 0; + + 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; + } + + BUG(); + return -EINVAL; +} + +static int crypto_init_ops(struct crypto_tfm *tfm) +{ + 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) +{ + 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(); + + } +} + +struct crypto_tfm *crypto_alloc_tfm(const char *name, u32 flags) +{ + struct crypto_tfm *tfm = NULL; + struct crypto_alg *alg; + + alg = crypto_alg_mod_lookup(name); + if (alg == NULL) + goto out; + + tfm = kmalloc(sizeof(*tfm) + alg->cra_ctxsize, GFP_KERNEL); + if (tfm == NULL) + goto out_put; + + memset(tfm, 0, sizeof(*tfm) + alg->cra_ctxsize); + + tfm->__crt_alg = alg; + + if (crypto_init_flags(tfm, flags)) + goto out_free_tfm; + + if (crypto_init_ops(tfm)) { + crypto_exit_ops(tfm); + goto out_free_tfm; + } + + goto out; + +out_free_tfm: + kfree(tfm); + tfm = NULL; +out_put: + crypto_alg_put(alg); +out: + return tfm; +} + +void crypto_free_tfm(struct crypto_tfm *tfm) +{ + struct crypto_alg *alg = tfm->__crt_alg; + int size = sizeof(*tfm) + alg->cra_ctxsize; + + crypto_exit_ops(tfm); + crypto_alg_put(alg); + memset(tfm, 0, size); + kfree(tfm); +} + +int crypto_register_alg(struct crypto_alg *alg) +{ + int ret = 0; + struct crypto_alg *q; + + down_write(&crypto_alg_sem); + + list_for_each_entry(q, &crypto_alg_list, cra_list) { + if (!(strcmp(q->cra_name, alg->cra_name))) { + ret = -EEXIST; + goto out; + } + } + + list_add_tail(&alg->cra_list, &crypto_alg_list); +out: + up_write(&crypto_alg_sem); + return ret; +} + +int crypto_unregister_alg(struct crypto_alg *alg) +{ + 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; +} + +int crypto_alg_available(const char *name, u32 flags) +{ + int ret = 0; + struct crypto_alg *alg = crypto_alg_mod_lookup(name); + + if (alg) { + crypto_alg_put(alg); + ret = 1; + } + + return ret; +} + +static int __init init_crypto(void) +{ + printk(KERN_INFO "Initializing Cryptographic API\n"); + crypto_init_proc(); + return 0; +} + +__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); |