1 /* 2 * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 /* 11 * This file uses the low level AES functions (which are deprecated for 12 * non-internal use) in order to implement provider AES ciphers. 13 */ 14 #include "internal/deprecated.h" 15 16 #include <openssl/proverr.h> 17 #include "cipher_aes.h" 18 #include "prov/providercommon.h" 19 #include "prov/implementations.h" 20 21 /* AES wrap with padding has IV length of 4, without padding 8 */ 22 #define AES_WRAP_PAD_IVLEN 4 23 #define AES_WRAP_NOPAD_IVLEN 8 24 25 #define WRAP_FLAGS (PROV_CIPHER_FLAG_CUSTOM_IV) 26 #define WRAP_FLAGS_INV (WRAP_FLAGS | PROV_CIPHER_FLAG_INVERSE_CIPHER) 27 28 typedef size_t (*aeswrap_fn)(void *key, const unsigned char *iv, 29 unsigned char *out, const unsigned char *in, 30 size_t inlen, block128_f block); 31 32 static OSSL_FUNC_cipher_encrypt_init_fn aes_wrap_einit; 33 static OSSL_FUNC_cipher_decrypt_init_fn aes_wrap_dinit; 34 static OSSL_FUNC_cipher_update_fn aes_wrap_cipher; 35 static OSSL_FUNC_cipher_final_fn aes_wrap_final; 36 static OSSL_FUNC_cipher_freectx_fn aes_wrap_freectx; 37 static OSSL_FUNC_cipher_set_ctx_params_fn aes_wrap_set_ctx_params; 38 39 typedef struct prov_aes_wrap_ctx_st { 40 PROV_CIPHER_CTX base; 41 union { 42 OSSL_UNION_ALIGN; 43 AES_KEY ks; 44 } ks; 45 aeswrap_fn wrapfn; 46 47 } PROV_AES_WRAP_CTX; 48 49 50 static void *aes_wrap_newctx(size_t kbits, size_t blkbits, 51 size_t ivbits, unsigned int mode, uint64_t flags) 52 { 53 PROV_AES_WRAP_CTX *wctx; 54 PROV_CIPHER_CTX *ctx; 55 56 if (!ossl_prov_is_running()) 57 return NULL; 58 59 wctx = OPENSSL_zalloc(sizeof(*wctx)); 60 ctx = (PROV_CIPHER_CTX *)wctx; 61 if (ctx != NULL) { 62 ossl_cipher_generic_initkey(ctx, kbits, blkbits, ivbits, mode, flags, 63 NULL, NULL); 64 ctx->pad = (ctx->ivlen == AES_WRAP_PAD_IVLEN); 65 } 66 return wctx; 67 } 68 69 static void aes_wrap_freectx(void *vctx) 70 { 71 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx; 72 73 ossl_cipher_generic_reset_ctx((PROV_CIPHER_CTX *)vctx); 74 OPENSSL_clear_free(wctx, sizeof(*wctx)); 75 } 76 77 static int aes_wrap_init(void *vctx, const unsigned char *key, 78 size_t keylen, const unsigned char *iv, 79 size_t ivlen, const OSSL_PARAM params[], int enc) 80 { 81 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx; 82 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx; 83 84 if (!ossl_prov_is_running()) 85 return 0; 86 87 ctx->enc = enc; 88 if (ctx->pad) 89 wctx->wrapfn = enc ? CRYPTO_128_wrap_pad : CRYPTO_128_unwrap_pad; 90 else 91 wctx->wrapfn = enc ? CRYPTO_128_wrap : CRYPTO_128_unwrap; 92 93 if (iv != NULL) { 94 if (!ossl_cipher_generic_initiv(ctx, iv, ivlen)) 95 return 0; 96 } 97 if (key != NULL) { 98 int use_forward_transform; 99 100 if (keylen != ctx->keylen) { 101 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH); 102 return 0; 103 } 104 /* 105 * See SP800-38F : Section 5.1 106 * The forward and inverse transformations for the AES block 107 * cipher—called “cipher” and “inverse cipher” are informally known as 108 * the AES encryption and AES decryption functions, respectively. 109 * If the designated cipher function for a key-wrap algorithm is chosen 110 * to be the AES decryption function, then CIPH-1K will be the AES 111 * encryption function. 112 */ 113 if (ctx->inverse_cipher == 0) 114 use_forward_transform = ctx->enc; 115 else 116 use_forward_transform = !ctx->enc; 117 if (use_forward_transform) { 118 AES_set_encrypt_key(key, keylen * 8, &wctx->ks.ks); 119 ctx->block = (block128_f)AES_encrypt; 120 } else { 121 AES_set_decrypt_key(key, keylen * 8, &wctx->ks.ks); 122 ctx->block = (block128_f)AES_decrypt; 123 } 124 } 125 return aes_wrap_set_ctx_params(ctx, params); 126 } 127 128 static int aes_wrap_einit(void *ctx, const unsigned char *key, size_t keylen, 129 const unsigned char *iv, size_t ivlen, 130 const OSSL_PARAM params[]) 131 { 132 return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 1); 133 } 134 135 static int aes_wrap_dinit(void *ctx, const unsigned char *key, size_t keylen, 136 const unsigned char *iv, size_t ivlen, 137 const OSSL_PARAM params[]) 138 { 139 return aes_wrap_init(ctx, key, keylen, iv, ivlen, params, 0); 140 } 141 142 static int aes_wrap_cipher_internal(void *vctx, unsigned char *out, 143 const unsigned char *in, size_t inlen) 144 { 145 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx; 146 PROV_AES_WRAP_CTX *wctx = (PROV_AES_WRAP_CTX *)vctx; 147 size_t rv; 148 int pad = ctx->pad; 149 150 /* No final operation so always return zero length */ 151 if (in == NULL) 152 return 0; 153 154 /* Input length must always be non-zero */ 155 if (inlen == 0) { 156 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH); 157 return -1; 158 } 159 160 /* If decrypting need at least 16 bytes and multiple of 8 */ 161 if (!ctx->enc && (inlen < 16 || inlen & 0x7)) { 162 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH); 163 return -1; 164 } 165 166 /* If not padding input must be multiple of 8 */ 167 if (!pad && inlen & 0x7) { 168 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_INPUT_LENGTH); 169 return -1; 170 } 171 172 if (out == NULL) { 173 if (ctx->enc) { 174 /* If padding round up to multiple of 8 */ 175 if (pad) 176 inlen = (inlen + 7) / 8 * 8; 177 /* 8 byte prefix */ 178 return inlen + 8; 179 } else { 180 /* 181 * If not padding output will be exactly 8 bytes smaller than 182 * input. If padding it will be at least 8 bytes smaller but we 183 * don't know how much. 184 */ 185 return inlen - 8; 186 } 187 } 188 189 rv = wctx->wrapfn(&wctx->ks.ks, ctx->iv_set ? ctx->iv : NULL, out, in, 190 inlen, ctx->block); 191 if (!rv) { 192 ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED); 193 return -1; 194 } 195 if (rv > INT_MAX) { 196 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_OUTPUT_LENGTH); 197 return -1; 198 } 199 return (int)rv; 200 } 201 202 static int aes_wrap_final(void *vctx, unsigned char *out, size_t *outl, 203 size_t outsize) 204 { 205 if (!ossl_prov_is_running()) 206 return 0; 207 208 *outl = 0; 209 return 1; 210 } 211 212 static int aes_wrap_cipher(void *vctx, 213 unsigned char *out, size_t *outl, size_t outsize, 214 const unsigned char *in, size_t inl) 215 { 216 PROV_AES_WRAP_CTX *ctx = (PROV_AES_WRAP_CTX *)vctx; 217 size_t len; 218 219 if (!ossl_prov_is_running()) 220 return 0; 221 222 if (inl == 0) { 223 *outl = 0; 224 return 1; 225 } 226 227 if (outsize < inl) { 228 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL); 229 return 0; 230 } 231 232 len = aes_wrap_cipher_internal(ctx, out, in, inl); 233 if (len <= 0) 234 return 0; 235 236 *outl = len; 237 return 1; 238 } 239 240 static int aes_wrap_set_ctx_params(void *vctx, const OSSL_PARAM params[]) 241 { 242 PROV_CIPHER_CTX *ctx = (PROV_CIPHER_CTX *)vctx; 243 const OSSL_PARAM *p; 244 size_t keylen = 0; 245 246 if (params == NULL) 247 return 1; 248 249 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN); 250 if (p != NULL) { 251 if (!OSSL_PARAM_get_size_t(p, &keylen)) { 252 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); 253 return 0; 254 } 255 if (ctx->keylen != keylen) { 256 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH); 257 return 0; 258 } 259 } 260 return 1; 261 } 262 263 #define IMPLEMENT_cipher(mode, fname, UCMODE, flags, kbits, blkbits, ivbits) \ 264 static OSSL_FUNC_cipher_get_params_fn aes_##kbits##_##fname##_get_params; \ 265 static int aes_##kbits##_##fname##_get_params(OSSL_PARAM params[]) \ 266 { \ 267 return ossl_cipher_generic_get_params(params, EVP_CIPH_##UCMODE##_MODE,\ 268 flags, kbits, blkbits, ivbits); \ 269 } \ 270 static OSSL_FUNC_cipher_newctx_fn aes_##kbits##fname##_newctx; \ 271 static void *aes_##kbits##fname##_newctx(void *provctx) \ 272 { \ 273 return aes_##mode##_newctx(kbits, blkbits, ivbits, \ 274 EVP_CIPH_##UCMODE##_MODE, flags); \ 275 } \ 276 const OSSL_DISPATCH ossl_##aes##kbits##fname##_functions[] = { \ 277 { OSSL_FUNC_CIPHER_NEWCTX, \ 278 (void (*)(void))aes_##kbits##fname##_newctx }, \ 279 { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))aes_##mode##_einit }, \ 280 { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))aes_##mode##_dinit }, \ 281 { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))aes_##mode##_cipher }, \ 282 { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))aes_##mode##_final }, \ 283 { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))aes_##mode##_freectx }, \ 284 { OSSL_FUNC_CIPHER_GET_PARAMS, \ 285 (void (*)(void))aes_##kbits##_##fname##_get_params }, \ 286 { OSSL_FUNC_CIPHER_GETTABLE_PARAMS, \ 287 (void (*)(void))ossl_cipher_generic_gettable_params }, \ 288 { OSSL_FUNC_CIPHER_GET_CTX_PARAMS, \ 289 (void (*)(void))ossl_cipher_generic_get_ctx_params }, \ 290 { OSSL_FUNC_CIPHER_SET_CTX_PARAMS, \ 291 (void (*)(void))aes_wrap_set_ctx_params }, \ 292 { OSSL_FUNC_CIPHER_GETTABLE_CTX_PARAMS, \ 293 (void (*)(void))ossl_cipher_generic_gettable_ctx_params }, \ 294 { OSSL_FUNC_CIPHER_SETTABLE_CTX_PARAMS, \ 295 (void (*)(void))ossl_cipher_generic_settable_ctx_params }, \ 296 { 0, NULL } \ 297 } 298 299 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_NOPAD_IVLEN * 8); 300 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_NOPAD_IVLEN * 8); 301 IMPLEMENT_cipher(wrap, wrap, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_NOPAD_IVLEN * 8); 302 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 256, 64, AES_WRAP_PAD_IVLEN * 8); 303 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 192, 64, AES_WRAP_PAD_IVLEN * 8); 304 IMPLEMENT_cipher(wrap, wrappad, WRAP, WRAP_FLAGS, 128, 64, AES_WRAP_PAD_IVLEN * 8); 305 306 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_NOPAD_IVLEN * 8); 307 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_NOPAD_IVLEN * 8); 308 IMPLEMENT_cipher(wrap, wrapinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_NOPAD_IVLEN * 8); 309 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 256, 64, AES_WRAP_PAD_IVLEN * 8); 310 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 192, 64, AES_WRAP_PAD_IVLEN * 8); 311 IMPLEMENT_cipher(wrap, wrappadinv, WRAP, WRAP_FLAGS_INV, 128, 64, AES_WRAP_PAD_IVLEN * 8); 312