diff options
Diffstat (limited to 'crypto/cmac/cmac.c')
-rw-r--r-- | crypto/cmac/cmac.c | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/crypto/cmac/cmac.c b/crypto/cmac/cmac.c new file mode 100644 index 0000000000..0069ae807f --- /dev/null +++ b/crypto/cmac/cmac.c @@ -0,0 +1,271 @@ +/* crypto/cmac/cmac.c */ +/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL + * project. + */ +/* ==================================================================== + * Copyright (c) 2010 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * licensing@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + */ + +#define OPENSSL_FIPSAPI + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "cryptlib.h" +#include <openssl/cmac.h> + +struct CMAC_CTX_st + { + /* Cipher context to use */ + EVP_CIPHER_CTX cctx; + /* Keys k1 and k2 */ + unsigned char k1[EVP_MAX_BLOCK_LENGTH]; + unsigned char k2[EVP_MAX_BLOCK_LENGTH]; + /* Temporary block */ + unsigned char tbl[EVP_MAX_BLOCK_LENGTH]; + /* Last (possibly partial) block */ + unsigned char last_block[EVP_MAX_BLOCK_LENGTH]; + /* Number of bytes in last block: -1 means context not initialised */ + int nlast_block; + }; + + +/* Make temporary keys K1 and K2 */ + +static void make_kn(unsigned char *k1, unsigned char *l, int bl) + { + int i; + /* Shift block to left, including carry */ + for (i = 0; i < bl; i++) + { + k1[i] = l[i] << 1; + if (i < bl - 1 && l[i + 1] & 0x80) + k1[i] |= 1; + } + /* If MSB set fixup with R */ + if (l[0] & 0x80) + k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b; + } + +CMAC_CTX *CMAC_CTX_new(void) + { + CMAC_CTX *ctx; + ctx = OPENSSL_malloc(sizeof(CMAC_CTX)); + if (!ctx) + return NULL; + EVP_CIPHER_CTX_init(&ctx->cctx); + ctx->nlast_block = -1; + return ctx; + } + +void CMAC_CTX_cleanup(CMAC_CTX *ctx) + { + EVP_CIPHER_CTX_cleanup(&ctx->cctx); + OPENSSL_cleanse(ctx->tbl, EVP_MAX_BLOCK_LENGTH); + OPENSSL_cleanse(ctx->k1, EVP_MAX_BLOCK_LENGTH); + OPENSSL_cleanse(ctx->k2, EVP_MAX_BLOCK_LENGTH); + OPENSSL_cleanse(ctx->last_block, EVP_MAX_BLOCK_LENGTH); + ctx->nlast_block = -1; + } + +EVP_CIPHER_CTX *CMAC_CTX_get0_cipher_ctx(CMAC_CTX *ctx) + { + return &ctx->cctx; + } + +void CMAC_CTX_free(CMAC_CTX *ctx) + { + CMAC_CTX_cleanup(ctx); + OPENSSL_free(ctx); + } + +int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in) + { + int bl; + if (in->nlast_block == -1) + return 0; + if (!EVP_CIPHER_CTX_copy(&out->cctx, &in->cctx)) + return 0; + bl = EVP_CIPHER_CTX_block_size(&in->cctx); + memcpy(out->k1, in->k1, bl); + memcpy(out->k2, in->k2, bl); + memcpy(out->tbl, in->tbl, bl); + memcpy(out->last_block, in->last_block, bl); + out->nlast_block = in->nlast_block; + return 1; + } + +int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, + const EVP_CIPHER *cipher, ENGINE *impl) + { + static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH]; + /* All zeros means restart */ + if (!key && !cipher && !impl && keylen == 0) + { + /* Not initialised */ + if (ctx->nlast_block == -1) + return 0; + if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) + return 0; + return 1; + } + /* Initialiase context */ + if (cipher && !EVP_EncryptInit_ex(&ctx->cctx, cipher, impl, NULL, NULL)) + return 0; + /* Non-NULL key means initialisation complete */ + if (key) + { + int bl; + if (!EVP_CIPHER_CTX_cipher(&ctx->cctx)) + return 0; + if (!EVP_CIPHER_CTX_set_key_length(&ctx->cctx, keylen)) + return 0; + if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, key, zero_iv)) + return 0; + bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); + if (!EVP_Cipher(&ctx->cctx, ctx->tbl, zero_iv, bl)) + return 0; + make_kn(ctx->k1, ctx->tbl, bl); + make_kn(ctx->k2, ctx->k1, bl); + OPENSSL_cleanse(ctx->tbl, bl); + /* Reset context again ready for first data block */ + if (!EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, zero_iv)) + return 0; + /* Zero tbl so resume works */ + memset(ctx->tbl, 0, bl); + ctx->nlast_block = 0; + } + return 1; + } + +int CMAC_Update(CMAC_CTX *ctx, const void *in, size_t dlen) + { + const unsigned char *data = in; + size_t bl; + if (ctx->nlast_block == -1) + return 0; + if (dlen == 0) + return 1; + bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); + /* Copy into partial block if we need to */ + if (ctx->nlast_block > 0) + { + size_t nleft; + nleft = bl - ctx->nlast_block; + if (dlen < nleft) + nleft = dlen; + memcpy(ctx->last_block + ctx->nlast_block, data, nleft); + dlen -= nleft; + ctx->nlast_block += nleft; + /* If no more to process return */ + if (dlen == 0) + return 1; + data += nleft; + /* Else not final block so encrypt it */ + if (!EVP_Cipher(&ctx->cctx, ctx->tbl, ctx->last_block,bl)) + return 0; + } + /* Encrypt all but one of the complete blocks left */ + while(dlen > bl) + { + if (!EVP_Cipher(&ctx->cctx, ctx->tbl, data, bl)) + return 0; + dlen -= bl; + data += bl; + } + /* Copy any data left to last block buffer */ + memcpy(ctx->last_block, data, dlen); + ctx->nlast_block = dlen; + return 1; + + } + +int CMAC_Final(CMAC_CTX *ctx, unsigned char *out, size_t *poutlen) + { + int i, bl, lb; + if (ctx->nlast_block == -1) + return 0; + bl = EVP_CIPHER_CTX_block_size(&ctx->cctx); + *poutlen = (size_t)bl; + if (!out) + return 1; + lb = ctx->nlast_block; + /* Is last block complete? */ + if (lb == bl) + { + for (i = 0; i < bl; i++) + out[i] = ctx->last_block[i] ^ ctx->k1[i]; + } + else + { + ctx->last_block[lb] = 0x80; + if (bl - lb > 1) + memset(ctx->last_block + lb + 1, 0, bl - lb - 1); + for (i = 0; i < bl; i++) + out[i] = ctx->last_block[i] ^ ctx->k2[i]; + } + if (!EVP_Cipher(&ctx->cctx, out, out, bl)) + { + OPENSSL_cleanse(out, bl); + return 0; + } + return 1; + } + +int CMAC_resume(CMAC_CTX *ctx) + { + if (ctx->nlast_block == -1) + return 0; + /* The buffer "tbl" containes the last fully encrypted block + * which is the last IV (or all zeroes if no last encrypted block). + * The last block has not been modified since CMAC_final(). + * So reinitliasing using the last decrypted block will allow + * CMAC to continue after calling CMAC_Final(). + */ + return EVP_EncryptInit_ex(&ctx->cctx, NULL, NULL, NULL, ctx->tbl); + } |