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 #include <sys/types.h> 27 #include <sys/systm.h> 28 #include <sys/param.h> 29 #include <sys/endian.h> 30 #include <opencrypto/cbc_mac.h> 31 #include <opencrypto/xform_auth.h> 32 33 /* 34 * Given two CCM_CBC_BLOCK_LEN blocks, xor 35 * them into dst, and then encrypt dst. 36 */ 37 static void 38 xor_and_encrypt(struct aes_cbc_mac_ctx *ctx, 39 const uint8_t *src, uint8_t *dst) 40 { 41 #define NWORDS (CCM_CBC_BLOCK_LEN / sizeof(uint64_t)) 42 uint64_t b1[NWORDS], b2[NWORDS], temp[NWORDS]; 43 44 memcpy(b1, src, CCM_CBC_BLOCK_LEN); 45 memcpy(b2, dst, CCM_CBC_BLOCK_LEN); 46 47 for (size_t count = 0; count < NWORDS; count++) 48 temp[count] = b1[count] ^ b2[count]; 49 rijndaelEncrypt(ctx->keysched, ctx->rounds, (void *)temp, dst); 50 #undef NWORDS 51 } 52 53 void 54 AES_CBC_MAC_Init(void *vctx) 55 { 56 struct aes_cbc_mac_ctx *ctx; 57 58 ctx = vctx; 59 bzero(ctx, sizeof(*ctx)); 60 } 61 62 void 63 AES_CBC_MAC_Setkey(void *vctx, const uint8_t *key, u_int klen) 64 { 65 struct aes_cbc_mac_ctx *ctx; 66 67 ctx = vctx; 68 ctx->rounds = rijndaelKeySetupEnc(ctx->keysched, key, klen * 8); 69 } 70 71 /* 72 * This is called to set the nonce, aka IV. 73 * 74 * Note that the caller is responsible for constructing b0 as well 75 * as the length and padding around the AAD and passing that data 76 * to _Update. 77 */ 78 void 79 AES_CBC_MAC_Reinit(void *vctx, const uint8_t *nonce, u_int nonceLen) 80 { 81 struct aes_cbc_mac_ctx *ctx = vctx; 82 83 ctx->nonce = nonce; 84 ctx->nonceLength = nonceLen; 85 86 ctx->blockIndex = 0; 87 88 /* XOR b0 with all 0's on first call to _Update. */ 89 memset(ctx->block, 0, CCM_CBC_BLOCK_LEN); 90 } 91 92 int 93 AES_CBC_MAC_Update(void *vctx, const void *vdata, u_int length) 94 { 95 struct aes_cbc_mac_ctx *ctx; 96 const uint8_t *data; 97 size_t copy_amt; 98 99 ctx = vctx; 100 data = vdata; 101 102 /* 103 * _Update can be called with non-aligned update lengths. Use 104 * the staging block when necessary. 105 */ 106 while (length != 0) { 107 uint8_t *ptr; 108 109 /* 110 * If there is no partial block and the length is at 111 * least a full block, encrypt the full block without 112 * copying to the staging block. 113 */ 114 if (ctx->blockIndex == 0 && length >= CCM_CBC_BLOCK_LEN) { 115 xor_and_encrypt(ctx, data, ctx->block); 116 length -= CCM_CBC_BLOCK_LEN; 117 data += CCM_CBC_BLOCK_LEN; 118 continue; 119 } 120 121 copy_amt = MIN(sizeof(ctx->staging_block) - ctx->blockIndex, 122 length); 123 ptr = ctx->staging_block + ctx->blockIndex; 124 bcopy(data, ptr, copy_amt); 125 data += copy_amt; 126 ctx->blockIndex += copy_amt; 127 length -= copy_amt; 128 if (ctx->blockIndex == sizeof(ctx->staging_block)) { 129 /* We've got a full block */ 130 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 131 ctx->blockIndex = 0; 132 } 133 } 134 return (0); 135 } 136 137 void 138 AES_CBC_MAC_Final(uint8_t *buf, void *vctx) 139 { 140 struct aes_cbc_mac_ctx *ctx; 141 uint8_t s0[CCM_CBC_BLOCK_LEN]; 142 143 ctx = vctx; 144 145 /* 146 * We first need to check to see if we've got any data 147 * left over to encrypt. 148 */ 149 if (ctx->blockIndex != 0) { 150 memset(ctx->staging_block + ctx->blockIndex, 0, 151 CCM_CBC_BLOCK_LEN - ctx->blockIndex); 152 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 153 } 154 explicit_bzero(ctx->staging_block, sizeof(ctx->staging_block)); 155 156 bzero(s0, sizeof(s0)); 157 s0[0] = (15 - ctx->nonceLength) - 1; 158 bcopy(ctx->nonce, s0 + 1, ctx->nonceLength); 159 rijndaelEncrypt(ctx->keysched, ctx->rounds, s0, s0); 160 for (size_t indx = 0; indx < AES_CBC_MAC_HASH_LEN; indx++) 161 buf[indx] = ctx->block[indx] ^ s0[indx]; 162 explicit_bzero(s0, sizeof(s0)); 163 } 164