1238384Sjkim/* crypto/cmac/cmac.c */ 2296341Sdelphij/* 3296341Sdelphij * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL 4238384Sjkim * project. 5238384Sjkim */ 6238384Sjkim/* ==================================================================== 7238384Sjkim * Copyright (c) 2010 The OpenSSL Project. All rights reserved. 8238384Sjkim * 9238384Sjkim * Redistribution and use in source and binary forms, with or without 10238384Sjkim * modification, are permitted provided that the following conditions 11238384Sjkim * are met: 12238384Sjkim * 13238384Sjkim * 1. Redistributions of source code must retain the above copyright 14296341Sdelphij * notice, this list of conditions and the following disclaimer. 15238384Sjkim * 16238384Sjkim * 2. Redistributions in binary form must reproduce the above copyright 17238384Sjkim * notice, this list of conditions and the following disclaimer in 18238384Sjkim * the documentation and/or other materials provided with the 19238384Sjkim * distribution. 20238384Sjkim * 21238384Sjkim * 3. All advertising materials mentioning features or use of this 22238384Sjkim * software must display the following acknowledgment: 23238384Sjkim * "This product includes software developed by the OpenSSL Project 24238384Sjkim * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 25238384Sjkim * 26238384Sjkim * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 27238384Sjkim * endorse or promote products derived from this software without 28238384Sjkim * prior written permission. For written permission, please contact 29238384Sjkim * licensing@OpenSSL.org. 30238384Sjkim * 31238384Sjkim * 5. Products derived from this software may not be called "OpenSSL" 32238384Sjkim * nor may "OpenSSL" appear in their names without prior written 33238384Sjkim * permission of the OpenSSL Project. 34238384Sjkim * 35238384Sjkim * 6. Redistributions of any form whatsoever must retain the following 36238384Sjkim * acknowledgment: 37238384Sjkim * "This product includes software developed by the OpenSSL Project 38238384Sjkim * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 39238384Sjkim * 40238384Sjkim * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 41238384Sjkim * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 42238384Sjkim * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 43238384Sjkim * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 44238384Sjkim * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 45238384Sjkim * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 46238384Sjkim * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 47238384Sjkim * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48238384Sjkim * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 49238384Sjkim * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 50238384Sjkim * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 51238384Sjkim * OF THE POSSIBILITY OF SUCH DAMAGE. 52238384Sjkim * ==================================================================== 53238384Sjkim */ 54238384Sjkim 55238384Sjkim#include <stdio.h> 56238384Sjkim#include <stdlib.h> 57238384Sjkim#include <string.h> 58238384Sjkim#include "cryptlib.h" 59238384Sjkim#include <openssl/cmac.h> 60238384Sjkim 61238384Sjkim#ifdef OPENSSL_FIPS 62296341Sdelphij# include <openssl/fips.h> 63238384Sjkim#endif 64238384Sjkim 65296341Sdelphijstruct CMAC_CTX_st { 66296341Sdelphij /* Cipher context to use */ 67296341Sdelphij EVP_CIPHER_CTX cctx; 68296341Sdelphij /* Keys k1 and k2 */ 69296341Sdelphij unsigned char k1[EVP_MAX_BLOCK_LENGTH]; 70296341Sdelphij unsigned char k2[EVP_MAX_BLOCK_LENGTH]; 71296341Sdelphij /* Temporary block */ 72296341Sdelphij unsigned char tbl[EVP_MAX_BLOCK_LENGTH]; 73296341Sdelphij /* Last (possibly partial) block */ 74296341Sdelphij unsigned char last_block[EVP_MAX_BLOCK_LENGTH]; 75296341Sdelphij /* Number of bytes in last block: -1 means context not initialised */ 76296341Sdelphij int nlast_block; 77296341Sdelphij}; 78238384Sjkim 79238384Sjkim/* Make temporary keys K1 and K2 */ 80238384Sjkim 81238384Sjkimstatic void make_kn(unsigned char *k1, unsigned char *l, int bl) 82296341Sdelphij{ 83296341Sdelphij int i; 84296341Sdelphij /* Shift block to left, including carry */ 85296341Sdelphij for (i = 0; i < bl; i++) { 86296341Sdelphij k1[i] = l[i] << 1; 87296341Sdelphij if (i < bl - 1 && l[i + 1] & 0x80) 88296341Sdelphij k1[i] |= 1; 89296341Sdelphij } 90296341Sdelphij /* If MSB set fixup with R */ 91296341Sdelphij if (l[0] & 0x80) 92296341Sdelphij k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b; 93296341Sdelphij} 94238384Sjkim 95238384SjkimCMAC_CTX *CMAC_CTX_new(void) 96296341Sdelphij{ 97296341Sdelphij CMAC_CTX *ctx; 98296341Sdelphij ctx = OPENSSL_malloc(sizeof(CMAC_CTX)); 99296341Sdelphij if (!ctx) 100296341Sdelphij return NULL; 101296341Sdelphij EVP_CIPHER_CTX_init(&ctx->cctx); 102296341Sdelphij ctx->nlast_block = -1; 103296341Sdelphij return ctx; 104296341Sdelphij} 105238384Sjkim 106238384Sjkimvoid CMAC_CTX_cleanup(CMAC_CTX *ctx) 107296341Sdelphij{ 108238384Sjkim#ifdef OPENSSL_FIPS 109296341Sdelphij if (FIPS_mode() && !ctx->cctx.engine) { 110296341Sdelphij FIPS_cmac_ctx_cleanup(ctx); 111296341Sdelphij return; 112296341Sdelphij } 113238384Sjkim#endif 114296341Sdelphij EVP_CIPHER_CTX_cleanup(&ctx->cctx); 115296341Sdelphij OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH); 116296341Sdelphij OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH); 117296341Sdelphij OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH); 118296341Sdelphij OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH); 119296341Sdelphij ctx->nlast_block = -1; 120296341Sdelphij} 121238384Sjkim 122238384SjkimEVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx) 123296341Sdelphij{ 124296341Sdelphij return &ctx->cctx; 125296341Sdelphij} 126238384Sjkim 127238384Sjkimvoid CMAC_CTX_free(CMAC_CTX *ctx) 128296341Sdelphij{ 129296341Sdelphij if (!ctx) 130296341Sdelphij return; 131296341Sdelphij CMAC_CTX_cleanup(ctx); 132296341Sdelphij OPENSSL_free(ctx); 133296341Sdelphij} 134238384Sjkim 135238384Sjkimint CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in) 136296341Sdelphij{ 137296341Sdelphij int bl; 138296341Sdelphij if (in->nlast_block == -1) 139296341Sdelphij return 0; 140296341Sdelphij if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx)) 141296341Sdelphij return 0; 142296341Sdelphij bl = EVP_CIPHER_CTX_block_size(&in->cctx); 143296341Sdelphij memcpy(out->k1, in->k1, bl); 144296341Sdelphij memcpy(out->k2, in->k2, bl); 145296341Sdelphij memcpy(out->tbl, in->tbl, bl); 146296341Sdelphij memcpy(out->last_block, in->last_block, bl); 147296341Sdelphij out->nlast_block = in->nlast_block; 148296341Sdelphij return 1; 149296341Sdelphij} 150238384Sjkim 151296341Sdelphijint CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, 152296341Sdelphij const EVP_CIPHER *cipher, ENGINE *impl) 153296341Sdelphij{ 154296341Sdelphij static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH]; 155238384Sjkim#ifdef OPENSSL_FIPS 156296341Sdelphij if (FIPS_mode()) { 157296341Sdelphij /* If we have an ENGINE need to allow non FIPS */ 158296341Sdelphij if ((impl || ctx->cctx.engine) 159296341Sdelphij && !(ctx->cctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) { 160296341Sdelphij EVPerr(EVP_F_CMAC_INIT, EVP_R_DISABLED_FOR_FIPS); 161296341Sdelphij return 0; 162296341Sdelphij } 163296341Sdelphij /* 164296341Sdelphij * Other algorithm blocking will be done in FIPS_cmac_init, via 165296341Sdelphij * FIPS_cipherinit(). 166296341Sdelphij */ 167296341Sdelphij if (!impl && !ctx->cctx.engine) 168296341Sdelphij return FIPS_cmac_init(ctx, key, keylen, cipher, NULL); 169296341Sdelphij } 170238384Sjkim#endif 171296341Sdelphij /* All zeros means restart */ 172296341Sdelphij if (!key && !cipher && !impl && keylen == 0) { 173296341Sdelphij /* Not initialised */ 174296341Sdelphij if (ctx->nlast_block == -1) 175296341Sdelphij return 0; 176296341Sdelphij if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) 177296341Sdelphij return 0; 178296341Sdelphij memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx)); 179296341Sdelphij ctx->nlast_block = 0; 180296341Sdelphij return 1; 181296341Sdelphij } 182296341Sdelphij /* Initialiase context */ 183296341Sdelphij if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL)) 184296341Sdelphij return 0; 185296341Sdelphij /* Non-NULL key means initialisation complete */ 186296341Sdelphij if (key) { 187296341Sdelphij int bl; 188296341Sdelphij if (!EVP_CIPHER_CTX_cipher(&ctx->cctx)) 189296341Sdelphij return 0; 190296341Sdelphij if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen)) 191296341Sdelphij return 0; 192296341Sdelphij if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv)) 193296341Sdelphij return 0; 194296341Sdelphij bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 195296341Sdelphij if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl)) 196296341Sdelphij return 0; 197296341Sdelphij make_kn(ctx->k1, ctx->tbl, bl); 198296341Sdelphij make_kn(ctx->k2, ctx->k1, bl); 199296341Sdelphij OPENSSL_cleanse(ctx->tbl, bl); 200296341Sdelphij /* Reset context again ready for first data block */ 201296341Sdelphij if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) 202296341Sdelphij return 0; 203296341Sdelphij /* Zero tbl so resume works */ 204296341Sdelphij memset(ctx->tbl, 0, bl); 205296341Sdelphij ctx->nlast_block = 0; 206296341Sdelphij } 207296341Sdelphij return 1; 208296341Sdelphij} 209238384Sjkim 210238384Sjkimint CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) 211296341Sdelphij{ 212296341Sdelphij const unsigned char *data = in; 213296341Sdelphij size_t bl; 214238384Sjkim#ifdef OPENSSL_FIPS 215296341Sdelphij if (FIPS_mode() && !ctx->cctx.engine) 216296341Sdelphij return FIPS_cmac_update(ctx, in, dlen); 217238384Sjkim#endif 218296341Sdelphij if (ctx->nlast_block == -1) 219296341Sdelphij return 0; 220296341Sdelphij if (dlen == 0) 221296341Sdelphij return 1; 222296341Sdelphij bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 223296341Sdelphij /* Copy into partial block if we need to */ 224296341Sdelphij if (ctx->nlast_block > 0) { 225296341Sdelphij size_t nleft; 226296341Sdelphij nleft = bl - ctx->nlast_block; 227296341Sdelphij if (dlen < nleft) 228296341Sdelphij nleft = dlen; 229296341Sdelphij memcpy(ctx->last_block + ctx->nlast_block, data, nleft); 230296341Sdelphij dlen -= nleft; 231296341Sdelphij ctx->nlast_block += nleft; 232296341Sdelphij /* If no more to process return */ 233296341Sdelphij if (dlen == 0) 234296341Sdelphij return 1; 235296341Sdelphij data += nleft; 236296341Sdelphij /* Else not final block so encrypt it */ 237296341Sdelphij if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl)) 238296341Sdelphij return 0; 239296341Sdelphij } 240296341Sdelphij /* Encrypt all but one of the complete blocks left */ 241296341Sdelphij while (dlen > bl) { 242296341Sdelphij if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl)) 243296341Sdelphij return 0; 244296341Sdelphij dlen -= bl; 245296341Sdelphij data += bl; 246296341Sdelphij } 247296341Sdelphij /* Copy any data left to last block buffer */ 248296341Sdelphij memcpy(ctx->last_block, data, dlen); 249296341Sdelphij ctx->nlast_block = dlen; 250296341Sdelphij return 1; 251238384Sjkim 252296341Sdelphij} 253238384Sjkim 254238384Sjkimint CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen) 255296341Sdelphij{ 256296341Sdelphij int i, bl, lb; 257238384Sjkim#ifdef OPENSSL_FIPS 258296341Sdelphij if (FIPS_mode() && !ctx->cctx.engine) 259296341Sdelphij return FIPS_cmac_final(ctx, out, poutlen); 260238384Sjkim#endif 261296341Sdelphij if (ctx->nlast_block == -1) 262296341Sdelphij return 0; 263296341Sdelphij bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 264296341Sdelphij *poutlen = (size_t)bl; 265296341Sdelphij if (!out) 266296341Sdelphij return 1; 267296341Sdelphij lb = ctx->nlast_block; 268296341Sdelphij /* Is last block complete? */ 269296341Sdelphij if (lb == bl) { 270296341Sdelphij for (i = 0; i < bl; i++) 271296341Sdelphij out[i] = ctx->last_block[i] ^ ctx->k1[i]; 272296341Sdelphij } else { 273296341Sdelphij ctx->last_block[lb] = 0x80; 274296341Sdelphij if (bl - lb > 1) 275296341Sdelphij memset(ctx->last_block + lb + 1, 0, bl - lb - 1); 276296341Sdelphij for (i = 0; i < bl; i++) 277296341Sdelphij out[i] = ctx->last_block[i] ^ ctx->k2[i]; 278296341Sdelphij } 279296341Sdelphij if (!EVP_Cipher(&ctx->cctx, out, out, bl)) { 280296341Sdelphij OPENSSL_cleanse(out, bl); 281296341Sdelphij return 0; 282296341Sdelphij } 283296341Sdelphij return 1; 284296341Sdelphij} 285238384Sjkim 286238384Sjkimint CMAC_resume(CMAC_CTX *ctx) 287296341Sdelphij{ 288296341Sdelphij if (ctx->nlast_block == -1) 289296341Sdelphij return 0; 290296341Sdelphij /* 291296341Sdelphij * The buffer "tbl" containes the last fully encrypted block which is the 292296341Sdelphij * last IV (or all zeroes if no last encrypted block). The last block has 293296341Sdelphij * not been modified since CMAC_final(). So reinitliasing using the last 294296341Sdelphij * decrypted block will allow CMAC to continue after calling 295296341Sdelphij * CMAC_Final(). 296296341Sdelphij */ 297296341Sdelphij return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl); 298296341Sdelphij} 299