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/types.h> 26 #include <sys/systm.h> 27 #include <sys/param.h> 28 #include <sys/endian.h> 29 #include <opencrypto/cbc_mac.h> 30 #include <opencrypto/xform_auth.h> 31 32 /* 33 * Given two CCM_CBC_BLOCK_LEN blocks, xor 34 * them into dst, and then encrypt dst. 35 */ 36 static void 37 xor_and_encrypt(struct aes_cbc_mac_ctx *ctx, 38 const uint8_t *src, uint8_t *dst) 39 { 40 #define NWORDS (CCM_CBC_BLOCK_LEN / sizeof(uint64_t)) 41 uint64_t b1[NWORDS], b2[NWORDS], temp[NWORDS]; 42 43 memcpy(b1, src, CCM_CBC_BLOCK_LEN); 44 memcpy(b2, dst, CCM_CBC_BLOCK_LEN); 45 46 for (size_t count = 0; count < NWORDS; count++) 47 temp[count] = b1[count] ^ b2[count]; 48 rijndaelEncrypt(ctx->keysched, ctx->rounds, (void *)temp, dst); 49 #undef NWORDS 50 } 51 52 void 53 AES_CBC_MAC_Init(void *vctx) 54 { 55 struct aes_cbc_mac_ctx *ctx; 56 57 ctx = vctx; 58 bzero(ctx, sizeof(*ctx)); 59 } 60 61 void 62 AES_CBC_MAC_Setkey(void *vctx, const uint8_t *key, u_int klen) 63 { 64 struct aes_cbc_mac_ctx *ctx; 65 66 ctx = vctx; 67 ctx->rounds = rijndaelKeySetupEnc(ctx->keysched, key, klen * 8); 68 } 69 70 /* 71 * This is called to set the nonce, aka IV. 72 * 73 * Note that the caller is responsible for constructing b0 as well 74 * as the length and padding around the AAD and passing that data 75 * to _Update. 76 */ 77 void 78 AES_CBC_MAC_Reinit(void *vctx, const uint8_t *nonce, u_int nonceLen) 79 { 80 struct aes_cbc_mac_ctx *ctx = vctx; 81 82 ctx->nonce = nonce; 83 ctx->nonceLength = nonceLen; 84 85 ctx->blockIndex = 0; 86 87 /* XOR b0 with all 0's on first call to _Update. */ 88 memset(ctx->block, 0, CCM_CBC_BLOCK_LEN); 89 } 90 91 int 92 AES_CBC_MAC_Update(void *vctx, const void *vdata, u_int length) 93 { 94 struct aes_cbc_mac_ctx *ctx; 95 const uint8_t *data; 96 size_t copy_amt; 97 98 ctx = vctx; 99 data = vdata; 100 101 /* 102 * _Update can be called with non-aligned update lengths. Use 103 * the staging block when necessary. 104 */ 105 while (length != 0) { 106 uint8_t *ptr; 107 108 /* 109 * If there is no partial block and the length is at 110 * least a full block, encrypt the full block without 111 * copying to the staging block. 112 */ 113 if (ctx->blockIndex == 0 && length >= CCM_CBC_BLOCK_LEN) { 114 xor_and_encrypt(ctx, data, ctx->block); 115 length -= CCM_CBC_BLOCK_LEN; 116 data += CCM_CBC_BLOCK_LEN; 117 continue; 118 } 119 120 copy_amt = MIN(sizeof(ctx->staging_block) - ctx->blockIndex, 121 length); 122 ptr = ctx->staging_block + ctx->blockIndex; 123 bcopy(data, ptr, copy_amt); 124 data += copy_amt; 125 ctx->blockIndex += copy_amt; 126 length -= copy_amt; 127 if (ctx->blockIndex == sizeof(ctx->staging_block)) { 128 /* We've got a full block */ 129 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 130 ctx->blockIndex = 0; 131 } 132 } 133 return (0); 134 } 135 136 void 137 AES_CBC_MAC_Final(uint8_t *buf, void *vctx) 138 { 139 struct aes_cbc_mac_ctx *ctx; 140 uint8_t s0[CCM_CBC_BLOCK_LEN]; 141 142 ctx = vctx; 143 144 /* 145 * We first need to check to see if we've got any data 146 * left over to encrypt. 147 */ 148 if (ctx->blockIndex != 0) { 149 memset(ctx->staging_block + ctx->blockIndex, 0, 150 CCM_CBC_BLOCK_LEN - ctx->blockIndex); 151 xor_and_encrypt(ctx, ctx->staging_block, ctx->block); 152 } 153 explicit_bzero(ctx->staging_block, sizeof(ctx->staging_block)); 154 155 bzero(s0, sizeof(s0)); 156 s0[0] = (15 - ctx->nonceLength) - 1; 157 bcopy(ctx->nonce, s0 + 1, ctx->nonceLength); 158 rijndaelEncrypt(ctx->keysched, ctx->rounds, s0, s0); 159 for (size_t indx = 0; indx < AES_CBC_MAC_HASH_LEN; indx++) 160 buf[indx] = ctx->block[indx] ^ s0[indx]; 161 explicit_bzero(s0, sizeof(s0)); 162 } 163