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![Herbert Xu](/assets/img/avatar_default.png)
This patch allows spawns of specific types (e.g., cipher) to be allocated. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
265 lines
6.6 KiB
C
265 lines
6.6 KiB
C
/*
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* Cryptographic API.
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*
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* HMAC: Keyed-Hashing for Message Authentication (RFC2104).
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
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*
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* The HMAC implementation is derived from USAGI.
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* Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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*/
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#include <crypto/algapi.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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struct hmac_ctx {
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struct crypto_hash *child;
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};
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static inline void *align_ptr(void *p, unsigned int align)
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{
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return (void *)ALIGN((unsigned long)p, align);
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}
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static inline struct hmac_ctx *hmac_ctx(struct crypto_hash *tfm)
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{
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return align_ptr(crypto_hash_ctx_aligned(tfm) +
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crypto_hash_blocksize(tfm) * 2 +
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crypto_hash_digestsize(tfm), sizeof(void *));
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}
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static int hmac_setkey(struct crypto_hash *parent,
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const u8 *inkey, unsigned int keylen)
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{
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int bs = crypto_hash_blocksize(parent);
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int ds = crypto_hash_digestsize(parent);
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char *ipad = crypto_hash_ctx_aligned(parent);
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char *opad = ipad + bs;
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char *digest = opad + bs;
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struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
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struct crypto_hash *tfm = ctx->child;
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unsigned int i;
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if (keylen > bs) {
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struct hash_desc desc;
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struct scatterlist tmp;
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int err;
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desc.tfm = tfm;
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desc.flags = crypto_hash_get_flags(parent);
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desc.flags &= CRYPTO_TFM_REQ_MAY_SLEEP;
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sg_set_buf(&tmp, inkey, keylen);
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err = crypto_hash_digest(&desc, &tmp, keylen, digest);
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if (err)
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return err;
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inkey = digest;
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keylen = ds;
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}
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memcpy(ipad, inkey, keylen);
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memset(ipad + keylen, 0, bs - keylen);
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memcpy(opad, ipad, bs);
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for (i = 0; i < bs; i++) {
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ipad[i] ^= 0x36;
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opad[i] ^= 0x5c;
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}
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return 0;
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}
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static int hmac_init(struct hash_desc *pdesc)
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{
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struct crypto_hash *parent = pdesc->tfm;
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int bs = crypto_hash_blocksize(parent);
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int ds = crypto_hash_digestsize(parent);
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char *ipad = crypto_hash_ctx_aligned(parent);
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struct hmac_ctx *ctx = align_ptr(ipad + bs * 2 + ds, sizeof(void *));
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struct hash_desc desc;
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struct scatterlist tmp;
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int err;
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desc.tfm = ctx->child;
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desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
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sg_set_buf(&tmp, ipad, bs);
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err = crypto_hash_init(&desc);
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if (unlikely(err))
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return err;
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return crypto_hash_update(&desc, &tmp, bs);
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}
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static int hmac_update(struct hash_desc *pdesc,
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struct scatterlist *sg, unsigned int nbytes)
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{
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struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
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struct hash_desc desc;
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desc.tfm = ctx->child;
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desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
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return crypto_hash_update(&desc, sg, nbytes);
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}
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static int hmac_final(struct hash_desc *pdesc, u8 *out)
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{
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struct crypto_hash *parent = pdesc->tfm;
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int bs = crypto_hash_blocksize(parent);
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int ds = crypto_hash_digestsize(parent);
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char *opad = crypto_hash_ctx_aligned(parent) + bs;
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char *digest = opad + bs;
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struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
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struct hash_desc desc;
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struct scatterlist tmp;
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int err;
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desc.tfm = ctx->child;
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desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
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sg_set_buf(&tmp, opad, bs + ds);
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err = crypto_hash_final(&desc, digest);
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if (unlikely(err))
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return err;
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return crypto_hash_digest(&desc, &tmp, bs + ds, out);
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}
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static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,
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unsigned int nbytes, u8 *out)
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{
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struct crypto_hash *parent = pdesc->tfm;
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int bs = crypto_hash_blocksize(parent);
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int ds = crypto_hash_digestsize(parent);
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char *ipad = crypto_hash_ctx_aligned(parent);
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char *opad = ipad + bs;
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char *digest = opad + bs;
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struct hmac_ctx *ctx = align_ptr(digest + ds, sizeof(void *));
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struct hash_desc desc;
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struct scatterlist sg1[2];
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struct scatterlist sg2[1];
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int err;
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desc.tfm = ctx->child;
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desc.flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
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sg_set_buf(sg1, ipad, bs);
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sg1[1].page = (void *)sg;
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sg1[1].length = 0;
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sg_set_buf(sg2, opad, bs + ds);
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err = crypto_hash_digest(&desc, sg1, nbytes + bs, digest);
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if (unlikely(err))
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return err;
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return crypto_hash_digest(&desc, sg2, bs + ds, out);
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}
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static int hmac_init_tfm(struct crypto_tfm *tfm)
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{
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struct crypto_hash *hash;
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struct crypto_instance *inst = (void *)tfm->__crt_alg;
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struct crypto_spawn *spawn = crypto_instance_ctx(inst);
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struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
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hash = crypto_spawn_hash(spawn);
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if (IS_ERR(hash))
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return PTR_ERR(hash);
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ctx->child = hash;
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return 0;
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}
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static void hmac_exit_tfm(struct crypto_tfm *tfm)
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{
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struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
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crypto_free_hash(ctx->child);
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}
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static void hmac_free(struct crypto_instance *inst)
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{
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crypto_drop_spawn(crypto_instance_ctx(inst));
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kfree(inst);
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}
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static struct crypto_instance *hmac_alloc(void *param, unsigned int len)
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{
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struct crypto_instance *inst;
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struct crypto_alg *alg;
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alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_HASH,
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CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC);
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if (IS_ERR(alg))
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return ERR_PTR(PTR_ERR(alg));
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inst = crypto_alloc_instance("hmac", alg);
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if (IS_ERR(inst))
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goto out_put_alg;
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inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
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inst->alg.cra_priority = alg->cra_priority;
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inst->alg.cra_blocksize = alg->cra_blocksize;
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inst->alg.cra_alignmask = alg->cra_alignmask;
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inst->alg.cra_type = &crypto_hash_type;
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inst->alg.cra_hash.digestsize =
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(alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
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CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
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alg->cra_digest.dia_digestsize;
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inst->alg.cra_ctxsize = sizeof(struct hmac_ctx) +
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ALIGN(inst->alg.cra_blocksize * 2 +
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inst->alg.cra_hash.digestsize,
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sizeof(void *));
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inst->alg.cra_init = hmac_init_tfm;
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inst->alg.cra_exit = hmac_exit_tfm;
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inst->alg.cra_hash.init = hmac_init;
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inst->alg.cra_hash.update = hmac_update;
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inst->alg.cra_hash.final = hmac_final;
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inst->alg.cra_hash.digest = hmac_digest;
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inst->alg.cra_hash.setkey = hmac_setkey;
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out_put_alg:
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crypto_mod_put(alg);
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return inst;
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}
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static struct crypto_template hmac_tmpl = {
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.name = "hmac",
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.alloc = hmac_alloc,
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.free = hmac_free,
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.module = THIS_MODULE,
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};
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static int __init hmac_module_init(void)
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{
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return crypto_register_template(&hmac_tmpl);
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}
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static void __exit hmac_module_exit(void)
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{
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crypto_unregister_template(&hmac_tmpl);
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}
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module_init(hmac_module_init);
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module_exit(hmac_module_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("HMAC hash algorithm");
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