providers/common/ciphers/aes.c

   1 /*
   2  * Copyright 2019 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 #include <string.h>
  11 #include <openssl/crypto.h>
  12 #include <openssl/core_numbers.h>
  13 #include <openssl/core_names.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/params.h>
  16 #include "internal/cryptlib.h"
  17 #include "ciphers_locl.h"
  18
  19 static void PROV_AES_KEY_generic_init(PROV_AES_KEY *ctx,
  20                                       const unsigned char *iv,
  21                                       int enc)
  22 {
  23     if (iv != NULL)
  24         memcpy(ctx->iv, iv, AES_BLOCK_SIZE);
  25     ctx->enc = enc;
  26 }
  27
  28 static int aes_einit(void *vctx, const unsigned char *key,
  29                            const unsigned char *iv)
  30 {
  31     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
  32
  33     PROV_AES_KEY_generic_init(ctx, iv, 1);
  34     if (key != NULL)
  35         return ctx->ciph->init(ctx, key, ctx->keylen);
  36
  37     return 1;
  38 }
  39
  40 static int aes_dinit(void *vctx, const unsigned char *key,
  41                      const unsigned char *iv)
  42 {
  43     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
  44
  45     PROV_AES_KEY_generic_init(ctx, iv, 0);
  46     if (key != NULL)
  47         return ctx->ciph->init(ctx, key, ctx->keylen);
  48
  49     return 1;
  50 }
  51
  52 static int aes_update(void *vctx, unsigned char *out, size_t *outl,
  53                       const unsigned char *in, size_t inl)
  54 {
  55     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
  56     size_t nextblocks = fillblock(ctx->buf, &ctx->bufsz, AES_BLOCK_SIZE, &in,
  57                                   &inl);
  58     size_t outlint = 0;
  59
  60     /*
  61      * If we're decrypting and we end an update on a block boundary we hold
  62      * the last block back in case this is the last update call and the last
  63      * block is padded.
  64      */
  65     if (ctx->bufsz == AES_BLOCK_SIZE
  66             && (ctx->enc || inl > 0 || !ctx->pad)) {
  67         if (!ctx->ciph->cipher(ctx, out, ctx->buf, AES_BLOCK_SIZE))
  68             return 0;
  69         ctx->bufsz = 0;
  70         outlint = AES_BLOCK_SIZE;
  71         out += AES_BLOCK_SIZE;
  72     }
  73     if (nextblocks > 0) {
  74         if (!ctx->enc && ctx->pad && nextblocks == inl) {
  75             if (!ossl_assert(inl >= AES_BLOCK_SIZE))
  76                 return 0;
  77             nextblocks -= AES_BLOCK_SIZE;
  78         }
  79         if (!ctx->ciph->cipher(ctx, out, in, nextblocks))
  80             return 0;
  81         in += nextblocks;
  82         inl -= nextblocks;
  83         outlint += nextblocks;
  84     }
  85     if (!trailingdata(ctx->buf, &ctx->bufsz, AES_BLOCK_SIZE, &in, &inl))
  86         return 0;
  87
  88     *outl = outlint;
  89     return inl == 0;
  90 }
  91
  92 static int aes_final(void *vctx, unsigned char *out, size_t *outl)
  93 {
  94     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
  95
  96     if (ctx->enc) {
  97         if (ctx->pad) {
  98             padblock(ctx->buf, &ctx->bufsz, AES_BLOCK_SIZE);
  99         } else if (ctx->bufsz == 0) {
 100             *outl = 0;
 101             return 1;
 102         } else if (ctx->bufsz != AES_BLOCK_SIZE) {
 103             /* TODO(3.0): What is the correct error code here? */
 104             return 0;
 105         }
 106
 107         if (!ctx->ciph->cipher(ctx, out, ctx->buf, AES_BLOCK_SIZE))
 108             return 0;
 109         ctx->bufsz = 0;
 110         *outl = AES_BLOCK_SIZE;
 111         return 1;
 112     }
 113
 114     /* Decrypting */
 115     /* TODO(3.0): What's the correct error here */
 116     if (ctx->bufsz != AES_BLOCK_SIZE) {
 117         if (ctx->bufsz == 0 && !ctx->pad) {
 118             *outl = 0;
 119             return 1;
 120         }
 121         return 0;
 122     }
 123
 124     if (!ctx->ciph->cipher(ctx, ctx->buf, ctx->buf, AES_BLOCK_SIZE))
 125         return 0;
 126
 127     /* TODO(3.0): What is the correct error here */
 128     if (ctx->pad && !unpadblock(ctx->buf, &ctx->bufsz, AES_BLOCK_SIZE))
 129         return 0;
 130
 131     memcpy(out, ctx->buf, ctx->bufsz);
 132     *outl = ctx->bufsz;
 133     ctx->bufsz = 0;
 134     return 1;
 135 }
 136
 137 static void *aes_256_ecb_newctx(void)
 138 {
 139     PROV_AES_KEY *ctx = OPENSSL_zalloc(sizeof(*ctx));
 140
 141     ctx->pad = 1;
 142     ctx->keylen = 256 / 8;
 143     ctx->ciph = PROV_AES_CIPHER_ecb();
 144     ctx->mode = EVP_CIPH_ECB_MODE;
 145     return ctx;
 146 }
 147
 148 static void aes_freectx(void *vctx)
 149 {
 150     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
 151
 152     OPENSSL_clear_free(ctx,  sizeof(*ctx));
 153 }
 154
 155 static void *aes_dupctx(void *ctx)
 156 {
 157     PROV_AES_KEY *in = (PROV_AES_KEY *)ctx;
 158     PROV_AES_KEY *ret = OPENSSL_malloc(sizeof(*ret));
 159
 160     *ret = *in;
 161
 162     return ret;
 163 }
 164
 165 static size_t key_length_256(void)
 166 {
 167     return 256 / 8;
 168 }
 169
 170 static int aes_get_params(void *vctx, const OSSL_PARAM params[])
 171 {
 172     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
 173     const OSSL_PARAM *p;
 174
 175     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_PADDING);
 176     if (p != NULL && !OSSL_PARAM_set_uint(p, ctx->pad))
 177         return 0;
 178
 179     return 1;
 180 }
 181
 182 static int aes_set_params(void *vctx, const OSSL_PARAM params[])
 183 {
 184     PROV_AES_KEY *ctx = (PROV_AES_KEY *)vctx;
 185     const OSSL_PARAM *p;
 186
 187     p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_PADDING);
 188     if (p != NULL) {
 189         int pad;
 190
 191         if (!OSSL_PARAM_get_int(p, &pad))
 192             return 0;
 193         ctx->pad = pad ? 1 : 0;
 194     }
 195     return 1;
 196 }
 197
 198 extern const OSSL_DISPATCH aes256ecb_functions[];
 199 const OSSL_DISPATCH aes256ecb_functions[] = {
 200     { OSSL_FUNC_CIPHER_NEWCTX, (void (*)(void))aes_256_ecb_newctx },
 201     { OSSL_FUNC_CIPHER_ENCRYPT_INIT, (void (*)(void))aes_einit },
 202     { OSSL_FUNC_CIPHER_DECRYPT_INIT, (void (*)(void))aes_dinit },
 203     { OSSL_FUNC_CIPHER_UPDATE, (void (*)(void))aes_update },
 204     { OSSL_FUNC_CIPHER_FINAL, (void (*)(void))aes_final },
 205     { OSSL_FUNC_CIPHER_FREECTX, (void (*)(void))aes_freectx },
 206     { OSSL_FUNC_CIPHER_DUPCTX, (void (*)(void))aes_dupctx },
 207     { OSSL_FUNC_CIPHER_KEY_LENGTH, (void (*)(void))key_length_256 },
 208     { OSSL_FUNC_CIPHER_GET_PARAMS, (void (*)(void))aes_get_params },
 209     { OSSL_FUNC_CIPHER_SET_PARAMS, (void (*)(void))aes_set_params },
 210     { 0, NULL }
 211 };