1238384Sjkim/* crypto/cmac/cmac.c */ 2280304Sjkim/* 3280304Sjkim * 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 14280304Sjkim * 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 62280304Sjkim# include <openssl/fips.h> 63238384Sjkim#endif 64238384Sjkim 65280304Sjkimstruct CMAC_CTX_st { 66280304Sjkim /* Cipher context to use */ 67280304Sjkim EVP_CIPHER_CTX cctx; 68280304Sjkim /* Keys k1 and k2 */ 69280304Sjkim unsigned char k1[EVP_MAX_BLOCK_LENGTH]; 70280304Sjkim unsigned char k2[EVP_MAX_BLOCK_LENGTH]; 71280304Sjkim /* Temporary block */ 72280304Sjkim unsigned char tbl[EVP_MAX_BLOCK_LENGTH]; 73280304Sjkim /* Last (possibly partial) block */ 74280304Sjkim unsigned char last_block[EVP_MAX_BLOCK_LENGTH]; 75280304Sjkim /* Number of bytes in last block: -1 means context not initialised */ 76280304Sjkim int nlast_block; 77280304Sjkim}; 78238384Sjkim 79238384Sjkim/* Make temporary keys K1 and K2 */ 80238384Sjkim 81238384Sjkimstatic void make_kn(unsigned char *k1, unsigned char *l, int bl) 82280304Sjkim{ 83280304Sjkim int i; 84280304Sjkim /* Shift block to left, including carry */ 85280304Sjkim for (i = 0; i < bl; i++) { 86280304Sjkim k1[i] = l[i] << 1; 87280304Sjkim if (i < bl - 1 && l[i + 1] & 0x80) 88280304Sjkim k1[i] |= 1; 89280304Sjkim } 90280304Sjkim /* If MSB set fixup with R */ 91280304Sjkim if (l[0] & 0x80) 92280304Sjkim k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b; 93280304Sjkim} 94238384Sjkim 95238384SjkimCMAC_CTX *CMAC_CTX_new(void) 96280304Sjkim{ 97280304Sjkim CMAC_CTX *ctx; 98280304Sjkim ctx = OPENSSL_malloc(sizeof(CMAC_CTX)); 99280304Sjkim if (!ctx) 100280304Sjkim return NULL; 101280304Sjkim EVP_CIPHER_CTX_init(&ctx->cctx); 102280304Sjkim ctx->nlast_block = -1; 103280304Sjkim return ctx; 104280304Sjkim} 105238384Sjkim 106238384Sjkimvoid CMAC_CTX_cleanup(CMAC_CTX *ctx) 107280304Sjkim{ 108238384Sjkim#ifdef OPENSSL_FIPS 109280304Sjkim if (FIPS_mode() && !ctx->cctx.engine) { 110280304Sjkim FIPS_cmac_ctx_cleanup(ctx); 111280304Sjkim return; 112280304Sjkim } 113238384Sjkim#endif 114280304Sjkim EVP_CIPHER_CTX_cleanup(&ctx->cctx); 115280304Sjkim OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH); 116280304Sjkim OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH); 117280304Sjkim OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH); 118280304Sjkim OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH); 119280304Sjkim ctx->nlast_block = -1; 120280304Sjkim} 121238384Sjkim 122238384SjkimEVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx) 123280304Sjkim{ 124280304Sjkim return &ctx->cctx; 125280304Sjkim} 126238384Sjkim 127238384Sjkimvoid CMAC_CTX_free(CMAC_CTX *ctx) 128280304Sjkim{ 129284285Sjkim if (!ctx) 130284285Sjkim return; 131280304Sjkim CMAC_CTX_cleanup(ctx); 132280304Sjkim OPENSSL_free(ctx); 133280304Sjkim} 134238384Sjkim 135238384Sjkimint CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in) 136280304Sjkim{ 137280304Sjkim int bl; 138280304Sjkim if (in->nlast_block == -1) 139280304Sjkim return 0; 140280304Sjkim if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx)) 141280304Sjkim return 0; 142280304Sjkim bl = EVP_CIPHER_CTX_block_size(&in->cctx); 143280304Sjkim memcpy(out->k1, in->k1, bl); 144280304Sjkim memcpy(out->k2, in->k2, bl); 145280304Sjkim memcpy(out->tbl, in->tbl, bl); 146280304Sjkim memcpy(out->last_block, in->last_block, bl); 147280304Sjkim out->nlast_block = in->nlast_block; 148280304Sjkim return 1; 149280304Sjkim} 150238384Sjkim 151280304Sjkimint CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, 152280304Sjkim const EVP_CIPHER *cipher, ENGINE *impl) 153280304Sjkim{ 154280304Sjkim static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH]; 155238384Sjkim#ifdef OPENSSL_FIPS 156280304Sjkim if (FIPS_mode()) { 157280304Sjkim /* If we have an ENGINE need to allow non FIPS */ 158280304Sjkim if ((impl || ctx->cctx.engine) 159280304Sjkim && !(ctx->cctx.flags & EVP_CIPH_FLAG_NON_FIPS_ALLOW)) { 160280304Sjkim EVPerr(EVP_F_CMAC_INIT, EVP_R_DISABLED_FOR_FIPS); 161280304Sjkim return 0; 162280304Sjkim } 163280304Sjkim /* 164280304Sjkim * Other algorithm blocking will be done in FIPS_cmac_init, via 165280304Sjkim * FIPS_cipherinit(). 166280304Sjkim */ 167280304Sjkim if (!impl && !ctx->cctx.engine) 168280304Sjkim return FIPS_cmac_init(ctx, key, keylen, cipher, NULL); 169280304Sjkim } 170238384Sjkim#endif 171280304Sjkim /* All zeros means restart */ 172280304Sjkim if (!key && !cipher && !impl && keylen == 0) { 173280304Sjkim /* Not initialised */ 174280304Sjkim if (ctx->nlast_block == -1) 175280304Sjkim return 0; 176280304Sjkim if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) 177280304Sjkim return 0; 178280304Sjkim memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx)); 179280304Sjkim ctx->nlast_block = 0; 180280304Sjkim return 1; 181280304Sjkim } 182280304Sjkim /* Initialiase context */ 183280304Sjkim if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL)) 184280304Sjkim return 0; 185280304Sjkim /* Non-NULL key means initialisation complete */ 186280304Sjkim if (key) { 187280304Sjkim int bl; 188280304Sjkim if (!EVP_CIPHER_CTX_cipher(&ctx->cctx)) 189280304Sjkim return 0; 190280304Sjkim if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen)) 191280304Sjkim return 0; 192280304Sjkim if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv)) 193280304Sjkim return 0; 194280304Sjkim bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 195280304Sjkim if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl)) 196280304Sjkim return 0; 197280304Sjkim make_kn(ctx->k1, ctx->tbl, bl); 198280304Sjkim make_kn(ctx->k2, ctx->k1, bl); 199280304Sjkim OPENSSL_cleanse(ctx->tbl, bl); 200280304Sjkim /* Reset context again ready for first data block */ 201280304Sjkim if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) 202280304Sjkim return 0; 203280304Sjkim /* Zero tbl so resume works */ 204280304Sjkim memset(ctx->tbl, 0, bl); 205280304Sjkim ctx->nlast_block = 0; 206280304Sjkim } 207280304Sjkim return 1; 208280304Sjkim} 209238384Sjkim 210238384Sjkimint CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) 211280304Sjkim{ 212280304Sjkim const unsigned char *data = in; 213280304Sjkim size_t bl; 214238384Sjkim#ifdef OPENSSL_FIPS 215280304Sjkim if (FIPS_mode() && !ctx->cctx.engine) 216280304Sjkim return FIPS_cmac_update(ctx, in, dlen); 217238384Sjkim#endif 218280304Sjkim if (ctx->nlast_block == -1) 219280304Sjkim return 0; 220280304Sjkim if (dlen == 0) 221280304Sjkim return 1; 222280304Sjkim bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 223280304Sjkim /* Copy into partial block if we need to */ 224280304Sjkim if (ctx->nlast_block > 0) { 225280304Sjkim size_t nleft; 226280304Sjkim nleft = bl - ctx->nlast_block; 227280304Sjkim if (dlen < nleft) 228280304Sjkim nleft = dlen; 229280304Sjkim memcpy(ctx->last_block + ctx->nlast_block, data, nleft); 230280304Sjkim dlen -= nleft; 231280304Sjkim ctx->nlast_block += nleft; 232280304Sjkim /* If no more to process return */ 233280304Sjkim if (dlen == 0) 234280304Sjkim return 1; 235280304Sjkim data += nleft; 236280304Sjkim /* Else not final block so encrypt it */ 237280304Sjkim if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl)) 238280304Sjkim return 0; 239280304Sjkim } 240280304Sjkim /* Encrypt all but one of the complete blocks left */ 241280304Sjkim while (dlen > bl) { 242280304Sjkim if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl)) 243280304Sjkim return 0; 244280304Sjkim dlen -= bl; 245280304Sjkim data += bl; 246280304Sjkim } 247280304Sjkim /* Copy any data left to last block buffer */ 248280304Sjkim memcpy(ctx->last_block, data, dlen); 249280304Sjkim ctx->nlast_block = dlen; 250280304Sjkim return 1; 251238384Sjkim 252280304Sjkim} 253238384Sjkim 254238384Sjkimint CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen) 255280304Sjkim{ 256280304Sjkim int i, bl, lb; 257238384Sjkim#ifdef OPENSSL_FIPS 258280304Sjkim if (FIPS_mode() && !ctx->cctx.engine) 259280304Sjkim return FIPS_cmac_final(ctx, out, poutlen); 260238384Sjkim#endif 261280304Sjkim if (ctx->nlast_block == -1) 262280304Sjkim return 0; 263280304Sjkim bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); 264280304Sjkim *poutlen = (size_t)bl; 265280304Sjkim if (!out) 266280304Sjkim return 1; 267280304Sjkim lb = ctx->nlast_block; 268280304Sjkim /* Is last block complete? */ 269280304Sjkim if (lb == bl) { 270280304Sjkim for (i = 0; i < bl; i++) 271280304Sjkim out[i] = ctx->last_block[i] ^ ctx->k1[i]; 272280304Sjkim } else { 273280304Sjkim ctx->last_block[lb] = 0x80; 274280304Sjkim if (bl - lb > 1) 275280304Sjkim memset(ctx->last_block + lb + 1, 0, bl - lb - 1); 276280304Sjkim for (i = 0; i < bl; i++) 277280304Sjkim out[i] = ctx->last_block[i] ^ ctx->k2[i]; 278280304Sjkim } 279280304Sjkim if (!EVP_Cipher(&ctx->cctx, out, out, bl)) { 280280304Sjkim OPENSSL_cleanse(out, bl); 281280304Sjkim return 0; 282280304Sjkim } 283280304Sjkim return 1; 284280304Sjkim} 285238384Sjkim 286238384Sjkimint CMAC_resume(CMAC_CTX *ctx) 287280304Sjkim{ 288280304Sjkim if (ctx->nlast_block == -1) 289280304Sjkim return 0; 290280304Sjkim /* 291280304Sjkim * The buffer "tbl" containes the last fully encrypted block which is the 292280304Sjkim * last IV (or all zeroes if no last encrypted block). The last block has 293280304Sjkim * not been modified since CMAC_final(). So reinitliasing using the last 294280304Sjkim * decrypted block will allow CMAC to continue after calling 295280304Sjkim * CMAC_Final(). 296280304Sjkim */ 297280304Sjkim return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl); 298280304Sjkim} 299