1 /* 2 * Copyright (c) 2018-2019 iXsystems Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #include <sys/cdefs.h> 26 __FBSDID("$FreeBSD$"); 27 28 #include <sys/types.h> 29 #include <sys/systm.h> 30 #include <sys/param.h> 31 #include <sys/endian.h> 32 #include <opencrypto/cbc_mac.h> 33 #include <opencrypto/xform_auth.h> 34 35 /* 36 * Given two CCM_CBC_BLOCK_LEN blocks, xor 37 * them into dst, and then encrypt dst. 38 */ 39 static void 40 xor_and_encrypt(struct aes_cbc_mac_ctx *ctx, 41 const uint8_t *src, uint8_t *dst) 42 { 43 #define NWORDS (CCM_CBC_BLOCK_LEN / sizeof(uint64_t)) 44 uint64_t b1[NWORDS], b2[NWORDS], temp[NWORDS]; 45 46 memcpy(b1, src, CCM_CBC_BLOCK_LEN); 47 memcpy(b2, dst, CCM_CBC_BLOCK_LEN); 48 49 for (size_t count = 0; count < NWORDS; count++) 50 temp[count] = b1[count] ^ b2[count]; 51 rijndaelEncrypt(ctx->keysched, ctx->rounds, (void *)temp, dst); 52 #undef NWORDS 53 } 54 55 void 56 AES_CBC_MAC_Init(void *vctx) 57 { 58 struct aes_cbc_mac_ctx *ctx; 59 60 ctx = vctx; 61 bzero(ctx, sizeof(*ctx)); 62 } 63 64 void 65 AES_CBC_MAC_Setkey(void *vctx, const uint8_t *key, u_int klen) 66 { 67 struct aes_cbc_mac_ctx *ctx; 68 69 ctx = vctx; 70 ctx->rounds = rijndaelKeySetupEnc(ctx->keysched, key, klen * 8); 71 } 72 73 /* 74 * This is called to set the nonce, aka IV. 75 * 76 * Note that the caller is responsible for constructing b0 as well 77 * as the length and padding around the AAD and passing that data 78 * to _Update. 79 */ 80 void 81 AES_CBC_MAC_Reinit(void *vctx, const uint8_t *nonce, u_int nonceLen) 82 { 83 struct aes_cbc_mac_ctx *ctx = vctx; 84 85 ctx->nonce = nonce; 86 ctx->nonceLength = nonceLen; 87 88 ctx->blockIndex = 0; 89 90 /* XOR b0 with all 0's on first call to _Update. */ 91 memset(ctx->block, 0, CCM_CBC_BLOCK_LEN); 92 } 93 94 int 95 AES_CBC_MAC_Update(void *vctx, const void *vdata, u_int length) 96 { 97 struct aes_cbc_mac_ctx *ctx; 98 const uint8_t *data; 99 size_t copy_amt; 100 101 ctx = vctx; 102 data = vdata; 103 104 /* 105 * _Update can be called with non-aligned update lengths. Use 106 * the staging block when necessary. 107 */ 108 while (length != 0) { 109 uint8_t *ptr; 110 111 /* 112 * If there is no partial block and the length is at 113 * least a full block, encrypt the full block without 114 * copying to the staging block. 115 */ 116 if (ctx->blockIndex == 0 && length >= CCM_CBC_BLOCK_LEN) { 117 xor_and_encrypt(ctx, data, ctx->block); 118 length -= CCM_CBC_BLOCK_LEN; 119 data += CCM_CBC_BLOCK_LEN; 120 continue; 121 } 122 123 copy_amt = MIN(sizeof(ctx->staging_block) - ctx->blockIndex, 124 length); 125 ptr = ctx->staging_block + ctx->blockIndex; 126 bcopy(data, ptr, copy_amt); 127 data += copy_amt; 128 ctx->blockIndex += copy_amt; 129 length -= copy_amt; 130 if (ctx->blockIndex == sizeof(ctx->staging_block)) { 131 /* We've got a full block */ 132 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 133 ctx->blockIndex = 0; 134 } 135 } 136 return (0); 137 } 138 139 void 140 AES_CBC_MAC_Final(uint8_t *buf, void *vctx) 141 { 142 struct aes_cbc_mac_ctx *ctx; 143 uint8_t s0[CCM_CBC_BLOCK_LEN]; 144 145 ctx = vctx; 146 147 /* 148 * We first need to check to see if we've got any data 149 * left over to encrypt. 150 */ 151 if (ctx->blockIndex != 0) { 152 memset(ctx->staging_block + ctx->blockIndex, 0, 153 CCM_CBC_BLOCK_LEN - ctx->blockIndex); 154 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 155 } 156 explicit_bzero(ctx->staging_block, sizeof(ctx->staging_block)); 157 158 bzero(s0, sizeof(s0)); 159 s0[0] = (15 - ctx->nonceLength) - 1; 160 bcopy(ctx->nonce, s0 + 1, ctx->nonceLength); 161 rijndaelEncrypt(ctx->keysched, ctx->rounds, s0, s0); 162 for (size_t indx = 0; indx < AES_CBC_MAC_HASH_LEN; indx++) 163 buf[indx] = ctx->block[indx] ^ s0[indx]; 164 explicit_bzero(s0, sizeof(s0)); 165 } 166