diff options
Diffstat (limited to 'crypto/aead.c')
-rw-r--r-- | crypto/aead.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/crypto/aead.c b/crypto/aead.c new file mode 100644 index 00000000..6729e8ff --- /dev/null +++ b/crypto/aead.c @@ -0,0 +1,506 @@ +/* + * AEAD: Authenticated Encryption with Associated Data + * + * This file provides API support for AEAD algorithms. + * + * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au> + * + * 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 <crypto/internal/aead.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/rtnetlink.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/seq_file.h> + +#include "internal.h" + +static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key, + unsigned int keylen) +{ + struct aead_alg *aead = crypto_aead_alg(tfm); + unsigned long alignmask = crypto_aead_alignmask(tfm); + int ret; + u8 *buffer, *alignbuffer; + unsigned long absize; + + absize = keylen + alignmask; + buffer = kmalloc(absize, GFP_ATOMIC); + if (!buffer) + return -ENOMEM; + + alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); + memcpy(alignbuffer, key, keylen); + ret = aead->setkey(tfm, alignbuffer, keylen); + memset(alignbuffer, 0, keylen); + kfree(buffer); + return ret; +} + +static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen) +{ + struct aead_alg *aead = crypto_aead_alg(tfm); + unsigned long alignmask = crypto_aead_alignmask(tfm); + + if ((unsigned long)key & alignmask) + return setkey_unaligned(tfm, key, keylen); + + return aead->setkey(tfm, key, keylen); +} + +int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize) +{ + struct aead_tfm *crt = crypto_aead_crt(tfm); + int err; + + if (authsize > crypto_aead_alg(tfm)->maxauthsize) + return -EINVAL; + + if (crypto_aead_alg(tfm)->setauthsize) { + err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize); + if (err) + return err; + } + + crypto_aead_crt(crt->base)->authsize = authsize; + crt->authsize = authsize; + return 0; +} +EXPORT_SYMBOL_GPL(crypto_aead_setauthsize); + +static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type, + u32 mask) +{ + return alg->cra_ctxsize; +} + +static int no_givcrypt(struct aead_givcrypt_request *req) +{ + return -ENOSYS; +} + +static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask) +{ + struct aead_alg *alg = &tfm->__crt_alg->cra_aead; + struct aead_tfm *crt = &tfm->crt_aead; + + if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8) + return -EINVAL; + + crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ? + alg->setkey : setkey; + crt->encrypt = alg->encrypt; + crt->decrypt = alg->decrypt; + crt->givencrypt = alg->givencrypt ?: no_givcrypt; + crt->givdecrypt = alg->givdecrypt ?: no_givcrypt; + crt->base = __crypto_aead_cast(tfm); + crt->ivsize = alg->ivsize; + crt->authsize = alg->maxauthsize; + + return 0; +} + +static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) + __attribute__ ((unused)); +static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg) +{ + struct aead_alg *aead = &alg->cra_aead; + + seq_printf(m, "type : aead\n"); + seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? + "yes" : "no"); + seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); + seq_printf(m, "ivsize : %u\n", aead->ivsize); + seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize); + seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>"); +} + +const struct crypto_type crypto_aead_type = { + .ctxsize = crypto_aead_ctxsize, + .init = crypto_init_aead_ops, +#ifdef CONFIG_PROC_FS + .show = crypto_aead_show, +#endif +}; +EXPORT_SYMBOL_GPL(crypto_aead_type); + +static int aead_null_givencrypt(struct aead_givcrypt_request *req) +{ + return crypto_aead_encrypt(&req->areq); +} + +static int aead_null_givdecrypt(struct aead_givcrypt_request *req) +{ + return crypto_aead_decrypt(&req->areq); +} + +static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask) +{ + struct aead_alg *alg = &tfm->__crt_alg->cra_aead; + struct aead_tfm *crt = &tfm->crt_aead; + + if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8) + return -EINVAL; + + crt->setkey = setkey; + crt->encrypt = alg->encrypt; + crt->decrypt = alg->decrypt; + if (!alg->ivsize) { + crt->givencrypt = aead_null_givencrypt; + crt->givdecrypt = aead_null_givdecrypt; + } + crt->base = __crypto_aead_cast(tfm); + crt->ivsize = alg->ivsize; + crt->authsize = alg->maxauthsize; + + return 0; +} + +static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg) + __attribute__ ((unused)); +static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg) +{ + struct aead_alg *aead = &alg->cra_aead; + + seq_printf(m, "type : nivaead\n"); + seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ? + "yes" : "no"); + seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); + seq_printf(m, "ivsize : %u\n", aead->ivsize); + seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize); + seq_printf(m, "geniv : %s\n", aead->geniv); +} + +const struct crypto_type crypto_nivaead_type = { + .ctxsize = crypto_aead_ctxsize, + .init = crypto_init_nivaead_ops, +#ifdef CONFIG_PROC_FS + .show = crypto_nivaead_show, +#endif +}; +EXPORT_SYMBOL_GPL(crypto_nivaead_type); + +static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn, + const char *name, u32 type, u32 mask) +{ + struct crypto_alg *alg; + int err; + + type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + type |= CRYPTO_ALG_TYPE_AEAD; + mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV; + + alg = crypto_alg_mod_lookup(name, type, mask); + if (IS_ERR(alg)) + return PTR_ERR(alg); + + err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask); + crypto_mod_put(alg); + return err; +} + +struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl, + struct rtattr **tb, u32 type, + u32 mask) +{ + const char *name; + struct crypto_aead_spawn *spawn; + struct crypto_attr_type *algt; + struct crypto_instance *inst; + struct crypto_alg *alg; + int err; + + algt = crypto_get_attr_type(tb); + err = PTR_ERR(algt); + if (IS_ERR(algt)) + return ERR_PTR(err); + + if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) & + algt->mask) + return ERR_PTR(-EINVAL); + + name = crypto_attr_alg_name(tb[1]); + err = PTR_ERR(name); + if (IS_ERR(name)) + return ERR_PTR(err); + + inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); + if (!inst) + return ERR_PTR(-ENOMEM); + + spawn = crypto_instance_ctx(inst); + + /* Ignore async algorithms if necessary. */ + mask |= crypto_requires_sync(algt->type, algt->mask); + + crypto_set_aead_spawn(spawn, inst); + err = crypto_grab_nivaead(spawn, name, type, mask); + if (err) + goto err_free_inst; + + alg = crypto_aead_spawn_alg(spawn); + + err = -EINVAL; + if (!alg->cra_aead.ivsize) + goto err_drop_alg; + + /* + * This is only true if we're constructing an algorithm with its + * default IV generator. For the default generator we elide the + * template name and double-check the IV generator. + */ + if (algt->mask & CRYPTO_ALG_GENIV) { + if (strcmp(tmpl->name, alg->cra_aead.geniv)) + goto err_drop_alg; + + memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); + memcpy(inst->alg.cra_driver_name, alg->cra_driver_name, + CRYPTO_MAX_ALG_NAME); + } else { + err = -ENAMETOOLONG; + if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->cra_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_drop_alg; + if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, + "%s(%s)", tmpl->name, alg->cra_driver_name) >= + CRYPTO_MAX_ALG_NAME) + goto err_drop_alg; + } + + inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV; + inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; + inst->alg.cra_priority = alg->cra_priority; + inst->alg.cra_blocksize = alg->cra_blocksize; + inst->alg.cra_alignmask = alg->cra_alignmask; + inst->alg.cra_type = &crypto_aead_type; + + inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize; + inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize; + inst->alg.cra_aead.geniv = alg->cra_aead.geniv; + + inst->alg.cra_aead.setkey = alg->cra_aead.setkey; + inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize; + inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt; + inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt; + +out: + return inst; + +err_drop_alg: + crypto_drop_aead(spawn); +err_free_inst: + kfree(inst); + inst = ERR_PTR(err); + goto out; +} +EXPORT_SYMBOL_GPL(aead_geniv_alloc); + +void aead_geniv_free(struct crypto_instance *inst) +{ + crypto_drop_aead(crypto_instance_ctx(inst)); + kfree(inst); +} +EXPORT_SYMBOL_GPL(aead_geniv_free); + +int aead_geniv_init(struct crypto_tfm *tfm) +{ + struct crypto_instance *inst = (void *)tfm->__crt_alg; + struct crypto_aead *aead; + + aead = crypto_spawn_aead(crypto_instance_ctx(inst)); + if (IS_ERR(aead)) + return PTR_ERR(aead); + + tfm->crt_aead.base = aead; + tfm->crt_aead.reqsize += crypto_aead_reqsize(aead); + + return 0; +} +EXPORT_SYMBOL_GPL(aead_geniv_init); + +void aead_geniv_exit(struct crypto_tfm *tfm) +{ + crypto_free_aead(tfm->crt_aead.base); +} +EXPORT_SYMBOL_GPL(aead_geniv_exit); + +static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask) +{ + struct rtattr *tb[3]; + struct { + struct rtattr attr; + struct crypto_attr_type data; + } ptype; + struct { + struct rtattr attr; + struct crypto_attr_alg data; + } palg; + struct crypto_template *tmpl; + struct crypto_instance *inst; + struct crypto_alg *larval; + const char *geniv; + int err; + + larval = crypto_larval_lookup(alg->cra_driver_name, + CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV, + CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + err = PTR_ERR(larval); + if (IS_ERR(larval)) + goto out; + + err = -EAGAIN; + if (!crypto_is_larval(larval)) + goto drop_larval; + + ptype.attr.rta_len = sizeof(ptype); + ptype.attr.rta_type = CRYPTOA_TYPE; + ptype.data.type = type | CRYPTO_ALG_GENIV; + /* GENIV tells the template that we're making a default geniv. */ + ptype.data.mask = mask | CRYPTO_ALG_GENIV; + tb[0] = &ptype.attr; + + palg.attr.rta_len = sizeof(palg); + palg.attr.rta_type = CRYPTOA_ALG; + /* Must use the exact name to locate ourselves. */ + memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME); + tb[1] = &palg.attr; + + tb[2] = NULL; + + geniv = alg->cra_aead.geniv; + + tmpl = crypto_lookup_template(geniv); + err = -ENOENT; + if (!tmpl) + goto kill_larval; + + inst = tmpl->alloc(tb); + err = PTR_ERR(inst); + if (IS_ERR(inst)) + goto put_tmpl; + + if ((err = crypto_register_instance(tmpl, inst))) { + tmpl->free(inst); + goto put_tmpl; + } + + /* Redo the lookup to use the instance we just registered. */ + err = -EAGAIN; + +put_tmpl: + crypto_tmpl_put(tmpl); +kill_larval: + crypto_larval_kill(larval); +drop_larval: + crypto_mod_put(larval); +out: + crypto_mod_put(alg); + return err; +} + +static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, + u32 mask) +{ + struct crypto_alg *alg; + + alg = crypto_alg_mod_lookup(name, type, mask); + if (IS_ERR(alg)) + return alg; + + if (alg->cra_type == &crypto_aead_type) + return alg; + + if (!alg->cra_aead.ivsize) + return alg; + + crypto_mod_put(alg); + alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED, + mask & ~CRYPTO_ALG_TESTED); + if (IS_ERR(alg)) + return alg; + + if (alg->cra_type == &crypto_aead_type) { + if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) { + crypto_mod_put(alg); + alg = ERR_PTR(-ENOENT); + } + return alg; + } + + BUG_ON(!alg->cra_aead.ivsize); + + return ERR_PTR(crypto_nivaead_default(alg, type, mask)); +} + +int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name, + u32 type, u32 mask) +{ + struct crypto_alg *alg; + int err; + + type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + type |= CRYPTO_ALG_TYPE_AEAD; + mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + mask |= CRYPTO_ALG_TYPE_MASK; + + alg = crypto_lookup_aead(name, type, mask); + if (IS_ERR(alg)) + return PTR_ERR(alg); + + err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask); + crypto_mod_put(alg); + return err; +} +EXPORT_SYMBOL_GPL(crypto_grab_aead); + +struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask) +{ + struct crypto_tfm *tfm; + int err; + + type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + type |= CRYPTO_ALG_TYPE_AEAD; + mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV); + mask |= CRYPTO_ALG_TYPE_MASK; + + for (;;) { + struct crypto_alg *alg; + + alg = crypto_lookup_aead(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 __crypto_aead_cast(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_aead); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)"); |