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/* $OpenBSD: prf.c,v 1.16 2013/03/21 04:30:14 deraadt Exp $ */ |
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/* $EOM: prf.c,v 1.7 1999/05/02 12:50:29 niklas Exp $ */ |
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/* |
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* Copyright (c) 1998 Niels Provos. All rights reserved. |
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* Copyright (c) 1999 Niklas Hallqvist. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without |
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* modification, are permitted provided that the following conditions |
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* are met: |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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/* |
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* This code was written under funding by Ericsson Radio Systems. |
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*/ |
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#include <stdlib.h> |
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#include <string.h> |
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#include "hash.h" |
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#include "log.h" |
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#include "prf.h" |
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void prf_hash_init(struct prf_hash_ctx *); |
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void prf_hash_update(struct prf_hash_ctx *, unsigned char *, unsigned int); |
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void prf_hash_final(unsigned char *, struct prf_hash_ctx *); |
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/* PRF behaves likes a hash */ |
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void |
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prf_hash_init(struct prf_hash_ctx *ctx) |
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{ |
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memcpy(ctx->hash->ctx, ctx->ctx, ctx->hash->ctxsize); |
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memcpy(ctx->hash->ctx2, ctx->ctx2, ctx->hash->ctxsize); |
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} |
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void |
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prf_hash_update(struct prf_hash_ctx *ctx, unsigned char *data, |
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unsigned int len) |
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{ |
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ctx->hash->Update(ctx->hash->ctx, data, len); |
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} |
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void |
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prf_hash_final(unsigned char *digest, struct prf_hash_ctx *ctx) |
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{ |
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ctx->hash->HMACFinal(digest, ctx->hash); |
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} |
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/* |
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* Obtain a Pseudo-Random Function for us. At the moment this is |
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* the HMAC version of a hash. See RFC-2104 for reference. |
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*/ |
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struct prf * |
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prf_alloc(enum prfs type, int subtype, unsigned char *shared, |
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unsigned int sharedsize) |
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{ |
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struct hash *hash; |
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struct prf *prf; |
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struct prf_hash_ctx *prfctx; |
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switch (type) { |
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case PRF_HMAC: |
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hash = hash_get(subtype); |
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if (!hash) { |
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log_print("prf_alloc: unknown hash type %d", subtype); |
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return 0; |
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} |
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break; |
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default: |
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log_print("prf_alloc: unknown PRF type %d", type); |
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return 0; |
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} |
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prf = malloc(sizeof *prf); |
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if (!prf) { |
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log_error("prf_alloc: malloc (%lu) failed", |
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(unsigned long)sizeof *prf); |
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return 0; |
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} |
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if (type == PRF_HMAC) { |
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/* Obtain needed memory. */ |
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prfctx = malloc(sizeof *prfctx); |
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if (!prfctx) { |
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log_error("prf_alloc: malloc (%lu) failed", |
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(unsigned long)sizeof *prfctx); |
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goto cleanprf; |
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} |
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prf->prfctx = prfctx; |
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prfctx->ctx = malloc(hash->ctxsize); |
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if (!prfctx->ctx) { |
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log_error("prf_alloc: malloc (%d) failed", |
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hash->ctxsize); |
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goto cleanprfctx; |
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} |
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prfctx->ctx2 = malloc(hash->ctxsize); |
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if (!prfctx->ctx2) { |
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log_error("prf_alloc: malloc (%d) failed", |
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hash->ctxsize); |
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free(prfctx->ctx); |
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goto cleanprfctx; |
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} |
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prf->type = PRF_HMAC; |
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prf->blocksize = hash->hashsize; |
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prfctx->hash = hash; |
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/* Use the correct function pointers. */ |
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prf->Init = (void(*)(void *))prf_hash_init; |
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prf->Update = (void(*)(void *, unsigned char *, |
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unsigned int))prf_hash_update; |
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prf->Final = (void(*)(unsigned char *, void *))prf_hash_final; |
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/* Init HMAC contexts. */ |
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hash->HMACInit(hash, shared, sharedsize); |
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/* Save contexts. */ |
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memcpy(prfctx->ctx, hash->ctx, hash->ctxsize); |
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memcpy(prfctx->ctx2, hash->ctx2, hash->ctxsize); |
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} |
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return prf; |
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cleanprfctx: |
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free(prf->prfctx); |
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cleanprf: |
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free(prf); |
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return 0; |
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} |
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/* Deallocate the PRF pointed to by PRF. */ |
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void |
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prf_free(struct prf *prf) |
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{ |
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struct prf_hash_ctx *prfctx = prf->prfctx; |
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if (prf->type == PRF_HMAC) { |
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free(prfctx->ctx2); |
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free(prfctx->ctx); |
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} |
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free(prf->prfctx); |
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free(prf); |
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} |