1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <modes/modes.h> 28 #include <sys/crypto/common.h> 29 #include <sys/crypto/impl.h> 30 31 /* 32 * Initialize by setting iov_or_mp to point to the current iovec or mp, 33 * and by setting current_offset to an offset within the current iovec or mp. 34 */ 35 void 36 crypto_init_ptrs(crypto_data_t *out, void **iov_or_mp, offset_t *current_offset) 37 { 38 offset_t offset; 39 40 switch (out->cd_format) { 41 case CRYPTO_DATA_RAW: 42 *current_offset = out->cd_offset; 43 break; 44 45 case CRYPTO_DATA_UIO: { 46 zfs_uio_t *uiop = out->cd_uio; 47 uint_t vec_idx; 48 49 offset = out->cd_offset; 50 offset = zfs_uio_index_at_offset(uiop, offset, &vec_idx); 51 52 *current_offset = offset; 53 *iov_or_mp = (void *)(uintptr_t)vec_idx; 54 break; 55 } 56 } /* end switch */ 57 } 58 59 /* 60 * Get pointers for where in the output to copy a block of encrypted or 61 * decrypted data. The iov_or_mp argument stores a pointer to the current 62 * iovec or mp, and offset stores an offset into the current iovec or mp. 63 */ 64 void 65 crypto_get_ptrs(crypto_data_t *out, void **iov_or_mp, offset_t *current_offset, 66 uint8_t **out_data_1, size_t *out_data_1_len, uint8_t **out_data_2, 67 size_t amt) 68 { 69 offset_t offset; 70 71 switch (out->cd_format) { 72 case CRYPTO_DATA_RAW: { 73 iovec_t *iov; 74 75 offset = *current_offset; 76 iov = &out->cd_raw; 77 if ((offset + amt) <= iov->iov_len) { 78 /* one block fits */ 79 *out_data_1 = (uint8_t *)iov->iov_base + offset; 80 *out_data_1_len = amt; 81 *out_data_2 = NULL; 82 *current_offset = offset + amt; 83 } 84 break; 85 } 86 87 case CRYPTO_DATA_UIO: { 88 zfs_uio_t *uio = out->cd_uio; 89 offset_t offset; 90 uint_t vec_idx; 91 uint8_t *p; 92 uint64_t iov_len; 93 void *iov_base; 94 95 offset = *current_offset; 96 vec_idx = (uintptr_t)(*iov_or_mp); 97 zfs_uio_iov_at_index(uio, vec_idx, &iov_base, &iov_len); 98 p = (uint8_t *)iov_base + offset; 99 *out_data_1 = p; 100 101 if (offset + amt <= iov_len) { 102 /* can fit one block into this iov */ 103 *out_data_1_len = amt; 104 *out_data_2 = NULL; 105 *current_offset = offset + amt; 106 } else { 107 /* one block spans two iovecs */ 108 *out_data_1_len = iov_len - offset; 109 if (vec_idx == zfs_uio_iovcnt(uio)) { 110 *out_data_2 = NULL; 111 return; 112 } 113 vec_idx++; 114 zfs_uio_iov_at_index(uio, vec_idx, &iov_base, &iov_len); 115 *out_data_2 = (uint8_t *)iov_base; 116 *current_offset = amt - *out_data_1_len; 117 } 118 *iov_or_mp = (void *)(uintptr_t)vec_idx; 119 break; 120 } 121 } /* end switch */ 122 } 123 124 void 125 crypto_free_mode_ctx(void *ctx) 126 { 127 common_ctx_t *common_ctx = (common_ctx_t *)ctx; 128 129 switch (common_ctx->cc_flags & (CCM_MODE|GCM_MODE)) { 130 case CCM_MODE: 131 if (((ccm_ctx_t *)ctx)->ccm_pt_buf != NULL) 132 vmem_free(((ccm_ctx_t *)ctx)->ccm_pt_buf, 133 ((ccm_ctx_t *)ctx)->ccm_data_len); 134 135 kmem_free(ctx, sizeof (ccm_ctx_t)); 136 break; 137 138 case GCM_MODE: 139 gcm_clear_ctx((gcm_ctx_t *)ctx); 140 kmem_free(ctx, sizeof (gcm_ctx_t)); 141 break; 142 143 default: 144 __builtin_unreachable(); 145 } 146 } 147 148 static void * 149 explicit_memset(void *s, int c, size_t n) 150 { 151 memset(s, c, n); 152 __asm__ __volatile__("" :: "r"(s) : "memory"); 153 return (s); 154 } 155 156 /* 157 * Clear sensitive data in the context and free allocated memory. 158 * 159 * ctx->gcm_remainder may contain a plaintext remainder. ctx->gcm_H and 160 * ctx->gcm_Htable contain the hash sub key which protects authentication. 161 * ctx->gcm_pt_buf contains the plaintext result of decryption. 162 * 163 * Although extremely unlikely, ctx->gcm_J0 and ctx->gcm_tmp could be used for 164 * a known plaintext attack, they consist of the IV and the first and last 165 * counter respectively. If they should be cleared is debatable. 166 */ 167 void 168 gcm_clear_ctx(gcm_ctx_t *ctx) 169 { 170 explicit_memset(ctx->gcm_remainder, 0, sizeof (ctx->gcm_remainder)); 171 explicit_memset(ctx->gcm_H, 0, sizeof (ctx->gcm_H)); 172 #if defined(CAN_USE_GCM_ASM) 173 if (ctx->gcm_use_avx == B_TRUE) { 174 ASSERT3P(ctx->gcm_Htable, !=, NULL); 175 memset(ctx->gcm_Htable, 0, ctx->gcm_htab_len); 176 kmem_free(ctx->gcm_Htable, ctx->gcm_htab_len); 177 } 178 #endif 179 if (ctx->gcm_pt_buf != NULL) { 180 memset(ctx->gcm_pt_buf, 0, ctx->gcm_pt_buf_len); 181 vmem_free(ctx->gcm_pt_buf, ctx->gcm_pt_buf_len); 182 } 183 /* Optional */ 184 explicit_memset(ctx->gcm_J0, 0, sizeof (ctx->gcm_J0)); 185 explicit_memset(ctx->gcm_tmp, 0, sizeof (ctx->gcm_tmp)); 186 } 187