/* * Cryptographic API. * * Digest operations. * * Copyright (c) 2002 James Morris <jmorris@intercode.com.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/scatterwalk.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/hardirq.h> #include <linux/highmem.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/scatterlist.h> static int init(struct hash_desc *desc) { struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); tfm->__crt_alg->cra_digest.dia_init(tfm); return 0; } static int update2(struct hash_desc *desc, struct scatterlist *sg, unsigned int nbytes) { struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); unsigned int alignmask = crypto_tfm_alg_alignmask(tfm); if (!nbytes) return 0; for (;;) { struct page *pg = sg_page(sg); unsigned int offset = sg->offset; unsigned int l = sg->length; if (unlikely(l > nbytes)) l = nbytes; nbytes -= l; do { unsigned int bytes_from_page = min(l, ((unsigned int) (PAGE_SIZE)) - offset); char *src = crypto_kmap(pg, 0); char *p = src + offset; if (unlikely(offset & alignmask)) { unsigned int bytes = alignmask + 1 - (offset & alignmask); bytes = min(bytes, bytes_from_page); tfm->__crt_alg->cra_digest.dia_update(tfm, p, bytes); p += bytes; bytes_from_page -= bytes; l -= bytes; } tfm->__crt_alg->cra_digest.dia_update(tfm, p, bytes_from_page); crypto_kunmap(src, 0); crypto_yield(desc->flags); offset = 0; pg++; l -= bytes_from_page; } while (l > 0); if (!nbytes) break; sg = scatterwalk_sg_next(sg); } return 0; } static int update(struct hash_desc *desc, struct scatterlist *sg, unsigned int nbytes) { if (WARN_ON_ONCE(in_irq())) return -EDEADLK; return update2(desc, sg, nbytes); } static int final(struct hash_desc *desc, u8 *out) { struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm); unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); struct digest_alg *digest = &tfm->__crt_alg->cra_digest; if (unlikely((unsigned long)out & alignmask)) { unsigned long align = alignmask + 1; unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm); u8 *dst = (u8 *)ALIGN(addr, align) + ALIGN(tfm->__crt_alg->cra_ctxsize, align); digest->dia_final(tfm, dst); memcpy(out, dst, digest->dia_digestsize); } else digest->dia_final(tfm, out); return 0; } static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen) { crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK); return -ENOSYS; } static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen) { struct crypto_tfm *tfm = crypto_hash_tfm(hash); crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK); return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen); } static int digest(struct hash_desc *desc, struct scatterlist *sg, unsigned int nbytes, u8 *out) { if (WARN_ON_ONCE(in_irq())) return -EDEADLK; init(desc); update2(desc, sg, nbytes); return final(desc, out); } int crypto_init_digest_ops(struct crypto_tfm *tfm) { struct hash_tfm *ops = &tfm->crt_hash; struct digest_alg *dalg = &tfm->__crt_alg->cra_digest; if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm)) return -EINVAL; ops->init = init; ops->update = update; ops->final = final; ops->digest = digest; ops->setkey = dalg->dia_setkey ? setkey : nosetkey; ops->digestsize = dalg->dia_digestsize; return 0; } void crypto_exit_digest_ops(struct crypto_tfm *tfm) { }