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    /* $OpenBSD: cmac.c,v 1.10 2015/09/10 15:56:25 jsing Exp $ */  | 
    
    
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    /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL  | 
    
    
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     * project.  | 
    
    
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     */  | 
    
    
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    /* ====================================================================  | 
    
    
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     * Copyright (c) 2010 The OpenSSL Project.  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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     *  | 
    
    
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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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     *  | 
    
    
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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  | 
    
    
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     *    the documentation and/or other materials provided with the  | 
    
    
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     *    distribution.  | 
    
    
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     *  | 
    
    
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     * 3. All advertising materials mentioning features or use of this  | 
    
    
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     *    software must display the following acknowledgment:  | 
    
    
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     *    "This product includes software developed by the OpenSSL Project  | 
    
    
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     *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"  | 
    
    
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     *  | 
    
    
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     * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to  | 
    
    
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     *    endorse or promote products derived from this software without  | 
    
    
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     *    prior written permission. For written permission, please contact  | 
    
    
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     *    licensing@OpenSSL.org.  | 
    
    
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     *  | 
    
    
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     * 5. Products derived from this software may not be called "OpenSSL"  | 
    
    
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     *    nor may "OpenSSL" appear in their names without prior written  | 
    
    
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     *    permission of the OpenSSL Project.  | 
    
    
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     *  | 
    
    
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     * 6. Redistributions of any form whatsoever must retain the following  | 
    
    
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     *    acknowledgment:  | 
    
    
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     *    "This product includes software developed by the OpenSSL Project  | 
    
    
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     *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"  | 
    
    
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     *  | 
    
    
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     * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY  | 
    
    
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     * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE  | 
    
    
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     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR  | 
    
    
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     * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR  | 
    
    
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     * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,  | 
    
    
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     * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT  | 
    
    
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     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;  | 
    
    
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     * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)  | 
    
    
    47  | 
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     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,  | 
    
    
    48  | 
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     * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)  | 
    
    
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     * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  | 
    
    
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     * OF THE POSSIBILITY OF SUCH DAMAGE.  | 
    
    
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     * ====================================================================  | 
    
    
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     */  | 
    
    
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    #include <stdio.h>  | 
    
    
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    #include <stdlib.h>  | 
    
    
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    #include <string.h>  | 
    
    
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    #include <openssl/cmac.h>  | 
    
    
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    struct CMAC_CTX_st { | 
    
    
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    	/* Cipher context to use */  | 
    
    
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    	EVP_CIPHER_CTX cctx;  | 
    
    
    63  | 
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    	/* Keys k1 and k2 */  | 
    
    
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    	unsigned char k1[EVP_MAX_BLOCK_LENGTH];  | 
    
    
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    	unsigned char k2[EVP_MAX_BLOCK_LENGTH];  | 
    
    
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    	/* Temporary block */  | 
    
    
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    	unsigned char tbl[EVP_MAX_BLOCK_LENGTH];  | 
    
    
    68  | 
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    	/* Last (possibly partial) block */  | 
    
    
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    	unsigned char last_block[EVP_MAX_BLOCK_LENGTH];  | 
    
    
    70  | 
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    	/* Number of bytes in last block: -1 means context not initialised */  | 
    
    
    71  | 
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    	int nlast_block;  | 
    
    
    72  | 
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    };  | 
    
    
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    /* Make temporary keys K1 and K2 */  | 
    
    
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    static void  | 
    
    
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    make_kn(unsigned char *k1, unsigned char *l, int bl)  | 
    
    
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    { | 
    
    
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    	int i;  | 
    
    
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    	/* Shift block to left, including carry */  | 
    
    
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    	for (i = 0; i < bl; i++) { | 
    
    
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    		k1[i] = l[i] << 1;  | 
    
    
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    		if (i < bl - 1 && l[i + 1] & 0x80)  | 
    
    
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    			k1[i] |= 1;  | 
    
    
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    	}  | 
    
    
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    	/* If MSB set fixup with R */  | 
    
    
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    	if (l[0] & 0x80)  | 
    
    
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    		k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;  | 
    
    
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    }  | 
    
    
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    CMAC_CTX *  | 
    
    
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    CMAC_CTX_new(void)  | 
    
    
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    { | 
    
    
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    	CMAC_CTX *ctx;  | 
    
    
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    	ctx = malloc(sizeof(CMAC_CTX));  | 
    
    
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    	if (!ctx)  | 
    
    
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    		return NULL;  | 
    
    
    101  | 
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    	EVP_CIPHER_CTX_init(&ctx->cctx);  | 
    
    
    102  | 
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    	ctx->nlast_block = -1;  | 
    
    
    103  | 
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    	return ctx;  | 
    
    
    104  | 
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    }  | 
    
    
    105  | 
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    106  | 
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    void  | 
    
    
    107  | 
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    CMAC_CTX_cleanup(CMAC_CTX *ctx)  | 
    
    
    108  | 
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    { | 
    
    
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    	EVP_CIPHER_CTX_cleanup(&ctx->cctx);  | 
    
    
    110  | 
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    	explicit_bzero(ctx->tbl, EVP_MAX_BLOCK_LENGTH);  | 
    
    
    111  | 
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    	explicit_bzero(ctx->k1, EVP_MAX_BLOCK_LENGTH);  | 
    
    
    112  | 
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    	explicit_bzero(ctx->k2, EVP_MAX_BLOCK_LENGTH);  | 
    
    
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    	explicit_bzero(ctx->last_block, EVP_MAX_BLOCK_LENGTH);  | 
    
    
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    	ctx->nlast_block = -1;  | 
    
    
    115  | 
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    }  | 
    
    
    116  | 
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    EVP_CIPHER_CTX *  | 
    
    
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    CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx)  | 
    
    
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    { | 
    
    
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    	return &ctx->cctx;  | 
    
    
    121  | 
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    }  | 
    
    
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    void  | 
    
    
    124  | 
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    CMAC_CTX_free(CMAC_CTX *ctx)  | 
    
    
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    { | 
    
    
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    	if (ctx == NULL)  | 
    
    
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    		return;  | 
    
    
    128  | 
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    	CMAC_CTX_cleanup(ctx);  | 
    
    
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    	free(ctx);  | 
    
    
    131  | 
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    }  | 
    
    
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    int  | 
    
    
    134  | 
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    CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in)  | 
    
    
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    { | 
    
    
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    	int bl;  | 
    
    
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    	if (in->nlast_block == -1)  | 
    
    
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    		return 0;  | 
    
    
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    	if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx))  | 
    
    
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    		return 0;  | 
    
    
    142  | 
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    	bl = EVP_CIPHER_CTX_block_size(&in->cctx);  | 
    
    
    143  | 
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    	memcpy(out->k1, in->k1, bl);  | 
    
    
    144  | 
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    	memcpy(out->k2, in->k2, bl);  | 
    
    
    145  | 
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    	memcpy(out->tbl, in->tbl, bl);  | 
    
    
    146  | 
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    	memcpy(out->last_block, in->last_block, bl);  | 
    
    
    147  | 
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    	out->nlast_block = in->nlast_block;  | 
    
    
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    	return 1;  | 
    
    
    149  | 
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    }  | 
    
    
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    int  | 
    
    
    152  | 
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    CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,  | 
    
    
    153  | 
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        const EVP_CIPHER *cipher, ENGINE *impl)  | 
    
    
    154  | 
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    { | 
    
    
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    	static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];  | 
    
    
    156  | 
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    157  | 
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    	/* All zeros means restart */  | 
    
    
    158  | 
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    	if (!key && !cipher && !impl && keylen == 0) { | 
    
    
    159  | 
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    		/* Not initialised */  | 
    
    
    160  | 
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    		if (ctx->nlast_block == -1)  | 
    
    
    161  | 
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    			return 0;  | 
    
    
    162  | 
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    		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))  | 
    
    
    163  | 
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    			return 0;  | 
    
    
    164  | 
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    		memset(ctx->tbl, 0, EVP_CIPHER_CTX_block_size(&ctx->cctx));  | 
    
    
    165  | 
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    		ctx->nlast_block = 0;  | 
    
    
    166  | 
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    		return 1;  | 
    
    
    167  | 
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    	}  | 
    
    
    168  | 
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    	/* Initialiase context */  | 
    
    
    169  | 
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    	if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL))  | 
    
    
    170  | 
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    		return 0;  | 
    
    
    171  | 
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    	/* Non-NULL key means initialisation complete */  | 
    
    
    172  | 
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    	if (key) { | 
    
    
    173  | 
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    		int bl;  | 
    
    
    174  | 
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    175  | 
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    		if (!EVP_CIPHER_CTX_cipher(&ctx->cctx))  | 
    
    
    176  | 
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    			return 0;  | 
    
    
    177  | 
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    		if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen))  | 
    
    
    178  | 
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    			return 0;  | 
    
    
    179  | 
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    		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv))  | 
    
    
    180  | 
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    			return 0;  | 
    
    
    181  | 
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    		bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);  | 
    
    
    182  | 
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    		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl))  | 
    
    
    183  | 
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    			return 0;  | 
    
    
    184  | 
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    		make_kn(ctx->k1, ctx->tbl, bl);  | 
    
    
    185  | 
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    		make_kn(ctx->k2, ctx->k1, bl);  | 
    
    
    186  | 
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    		explicit_bzero(ctx->tbl, bl);  | 
    
    
    187  | 
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    		/* Reset context again ready for first data block */  | 
    
    
    188  | 
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    		if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv))  | 
    
    
    189  | 
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    			return 0;  | 
    
    
    190  | 
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    		/* Zero tbl so resume works */  | 
    
    
    191  | 
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    		memset(ctx->tbl, 0, bl);  | 
    
    
    192  | 
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    		ctx->nlast_block = 0;  | 
    
    
    193  | 
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    	}  | 
    
    
    194  | 
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    	return 1;  | 
    
    
    195  | 
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    }  | 
    
    
    196  | 
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    197  | 
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    int  | 
    
    
    198  | 
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    CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen)  | 
    
    
    199  | 
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    { | 
    
    
    200  | 
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    	const unsigned char *data = in;  | 
    
    
    201  | 
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    	size_t bl;  | 
    
    
    202  | 
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    203  | 
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    	if (ctx->nlast_block == -1)  | 
    
    
    204  | 
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    		return 0;  | 
    
    
    205  | 
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    	if (dlen == 0)  | 
    
    
    206  | 
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    		return 1;  | 
    
    
    207  | 
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    	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);  | 
    
    
    208  | 
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    	/* Copy into partial block if we need to */  | 
    
    
    209  | 
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    	if (ctx->nlast_block > 0) { | 
    
    
    210  | 
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    		size_t nleft;  | 
    
    
    211  | 
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    212  | 
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    		nleft = bl - ctx->nlast_block;  | 
    
    
    213  | 
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    		if (dlen < nleft)  | 
    
    
    214  | 
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    			nleft = dlen;  | 
    
    
    215  | 
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    		memcpy(ctx->last_block + ctx->nlast_block, data, nleft);  | 
    
    
    216  | 
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    		dlen -= nleft;  | 
    
    
    217  | 
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    		ctx->nlast_block += nleft;  | 
    
    
    218  | 
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    		/* If no more to process return */  | 
    
    
    219  | 
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    		if (dlen == 0)  | 
    
    
    220  | 
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    			return 1;  | 
    
    
    221  | 
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    		data += nleft;  | 
    
    
    222  | 
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    		/* Else not final block so encrypt it */  | 
    
    
    223  | 
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    		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block, bl))  | 
    
    
    224  | 
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    			return 0;  | 
    
    
    225  | 
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    	}  | 
    
    
    226  | 
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    	/* Encrypt all but one of the complete blocks left */  | 
    
    
    227  | 
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    	while (dlen > bl) { | 
    
    
    228  | 
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    		if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl))  | 
    
    
    229  | 
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    			return 0;  | 
    
    
    230  | 
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    		dlen -= bl;  | 
    
    
    231  | 
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    		data += bl;  | 
    
    
    232  | 
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    	}  | 
    
    
    233  | 
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    	/* Copy any data left to last block buffer */  | 
    
    
    234  | 
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    	memcpy(ctx->last_block, data, dlen);  | 
    
    
    235  | 
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    	ctx->nlast_block = dlen;  | 
    
    
    236  | 
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    	return 1;  | 
    
    
    237  | 
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    }  | 
    
    
    238  | 
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    239  | 
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    int  | 
    
    
    240  | 
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    CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen)  | 
    
    
    241  | 
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    { | 
    
    
    242  | 
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    	int i, bl, lb;  | 
    
    
    243  | 
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    244  | 
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    	if (ctx->nlast_block == -1)  | 
    
    
    245  | 
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    		return 0;  | 
    
    
    246  | 
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    	bl = EVP_CIPHER_CTX_block_size(&ctx->cctx);  | 
    
    
    247  | 
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    	*poutlen = (size_t)bl;  | 
    
    
    248  | 
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    	if (!out)  | 
    
    
    249  | 
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    		return 1;  | 
    
    
    250  | 
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    	lb = ctx->nlast_block;  | 
    
    
    251  | 
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    	/* Is last block complete? */  | 
    
    
    252  | 
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    	if (lb == bl) { | 
    
    
    253  | 
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    		for (i = 0; i < bl; i++)  | 
    
    
    254  | 
     | 
     | 
    			out[i] = ctx->last_block[i] ^ ctx->k1[i];  | 
    
    
    255  | 
     | 
     | 
    	} else { | 
    
    
    256  | 
     | 
     | 
    		ctx->last_block[lb] = 0x80;  | 
    
    
    257  | 
     | 
     | 
    		if (bl - lb > 1)  | 
    
    
    258  | 
     | 
     | 
    			memset(ctx->last_block + lb + 1, 0, bl - lb - 1);  | 
    
    
    259  | 
     | 
     | 
    		for (i = 0; i < bl; i++)  | 
    
    
    260  | 
     | 
     | 
    			out[i] = ctx->last_block[i] ^ ctx->k2[i];  | 
    
    
    261  | 
     | 
     | 
    	}  | 
    
    
    262  | 
     | 
     | 
    	if (!EVP_Cipher(&ctx->cctx, out, out, bl)) { | 
    
    
    263  | 
     | 
     | 
    		explicit_bzero(out, bl);  | 
    
    
    264  | 
     | 
     | 
    		return 0;  | 
    
    
    265  | 
     | 
     | 
    	}  | 
    
    
    266  | 
     | 
     | 
    	return 1;  | 
    
    
    267  | 
     | 
     | 
    }  | 
    
    
    268  | 
     | 
     | 
     | 
    
    
    269  | 
     | 
     | 
    int  | 
    
    
    270  | 
     | 
     | 
    CMAC_resume(CMAC_CTX *ctx)  | 
    
    
    271  | 
     | 
     | 
    { | 
    
    
    272  | 
     | 
     | 
    	if (ctx->nlast_block == -1)  | 
    
    
    273  | 
     | 
     | 
    		return 0;  | 
    
    
    274  | 
     | 
     | 
    	/* The buffer "tbl" containes the last fully encrypted block  | 
    
    
    275  | 
     | 
     | 
    	 * which is the last IV (or all zeroes if no last encrypted block).  | 
    
    
    276  | 
     | 
     | 
    	 * The last block has not been modified since CMAC_final().  | 
    
    
    277  | 
     | 
     | 
    	 * So reinitialising using the last decrypted block will allow  | 
    
    
    278  | 
     | 
     | 
    	 * CMAC to continue after calling CMAC_Final().  | 
    
    
    279  | 
     | 
     | 
    	 */  | 
    
    
    280  | 
     | 
     | 
    	return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl);  | 
    
    
    281  | 
     | 
     | 
    }  |