providers/common/macs/hmac_prov.c

   1 /*
   2  * Copyright 2018 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 <openssl/core_numbers.h>
  11 #include <openssl/core_names.h>
  12 #include <openssl/params.h>
  13 #include <openssl/engine.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/hmac.h>
  16
  17 #include "internal/provider_algs.h"
  18 #include "internal/provider_ctx.h"
  19
  20 /*
  21  * Forward declaration of everything implemented here.  This is not strictly
  22  * necessary for the compiler, but provides an assurance that the signatures
  23  * of the functions in the dispatch table are correct.
  24  */
  25 static OSSL_OP_mac_newctx_fn hmac_new;
  26 static OSSL_OP_mac_dupctx_fn hmac_dup;
  27 static OSSL_OP_mac_freectx_fn hmac_free;
  28 static OSSL_OP_mac_gettable_ctx_params_fn hmac_gettable_ctx_params;
  29 static OSSL_OP_mac_get_ctx_params_fn hmac_get_ctx_params;
  30 static OSSL_OP_mac_settable_ctx_params_fn hmac_settable_ctx_params;
  31 static OSSL_OP_mac_set_ctx_params_fn hmac_set_ctx_params;
  32 static OSSL_OP_mac_init_fn hmac_init;
  33 static OSSL_OP_mac_update_fn hmac_update;
  34 static OSSL_OP_mac_final_fn hmac_final;
  35
  36 /* local HMAC context structure */
  37
  38 /* typedef EVP_MAC_IMPL */
  39 struct hmac_data_st {
  40     void *provctx;
  41     HMAC_CTX *ctx;               /* HMAC context */
  42
  43     /*
  44      * References to the underlying digest implementation.  tmpmd caches
  45      * the md, always.  alloc_md only holds a reference to an explicitly
  46      * fetched digest.
  47      * tmpmd is cleared after a CMAC_Init call.
  48      */
  49     const EVP_MD *tmpmd;         /* HMAC digest */
  50     EVP_MD *alloc_md;            /* fetched digest */
  51
  52     /*
  53      * Conditions for legacy EVP_MD uses.
  54      * tmpengine is cleared after a CMAC_Init call.
  55      */
  56     ENGINE *tmpengine;           /* HMAC digest engine */
  57 };
  58
  59 static size_t hmac_size(void *vmacctx);
  60
  61 static void *hmac_new(void *provctx)
  62 {
  63     struct hmac_data_st *macctx;
  64
  65     if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
  66         || (macctx->ctx = HMAC_CTX_new()) == NULL) {
  67         OPENSSL_free(macctx);
  68         return NULL;
  69     }
  70     /* TODO(3.0) Should we do something more with that context? */
  71     macctx->provctx = provctx;
  72
  73     return macctx;
  74 }
  75
  76 static void hmac_free(void *vmacctx)
  77 {
  78     struct hmac_data_st *macctx = vmacctx;
  79
  80     if (macctx != NULL) {
  81         HMAC_CTX_free(macctx->ctx);
  82         EVP_MD_free(macctx->alloc_md);
  83         OPENSSL_free(macctx);
  84     }
  85 }
  86
  87 static void *hmac_dup(void *vsrc)
  88 {
  89     struct hmac_data_st *src = vsrc;
  90     struct hmac_data_st *dst = hmac_new(src->provctx);
  91
  92     if (dst == NULL)
  93         return NULL;
  94
  95     if (!HMAC_CTX_copy(dst->ctx, src->ctx)) {
  96         hmac_free(dst);
  97         return NULL;
  98     }
  99
 100     if (src->alloc_md != NULL && !EVP_MD_up_ref(src->alloc_md)) {
 101         hmac_free(dst);
 102         return NULL;
 103     }
 104
 105     dst->tmpengine = src->tmpengine;
 106     dst->tmpmd = src->tmpmd;
 107     dst->alloc_md = src->alloc_md;
 108     return dst;
 109 }
 110
 111 static size_t hmac_size(void *vmacctx)
 112 {
 113     struct hmac_data_st *macctx = vmacctx;
 114
 115     return HMAC_size(macctx->ctx);
 116 }
 117
 118 static int hmac_init(void *vmacctx)
 119 {
 120     struct hmac_data_st *macctx = vmacctx;
 121     int rv = 1;
 122
 123     /* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */
 124     if (macctx->tmpmd != NULL)
 125         rv = HMAC_Init_ex(macctx->ctx, NULL, 0, macctx->tmpmd,
 126                           (ENGINE * )macctx->tmpengine);
 127     macctx->tmpengine = NULL;
 128     macctx->tmpmd = NULL;
 129     return rv;
 130 }
 131
 132 static int hmac_update(void *vmacctx, const unsigned char *data,
 133                        size_t datalen)
 134 {
 135     struct hmac_data_st *macctx = vmacctx;
 136
 137     return HMAC_Update(macctx->ctx, data, datalen);
 138 }
 139
 140 static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl,
 141                       size_t outsize)
 142 {
 143     unsigned int hlen;
 144     struct hmac_data_st *macctx = vmacctx;
 145
 146     if (!HMAC_Final(macctx->ctx, out, &hlen))
 147         return 0;
 148     if (outl != NULL)
 149         *outl = hlen;
 150     return 1;
 151 }
 152
 153 static const OSSL_PARAM known_gettable_ctx_params[] = {
 154     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
 155     OSSL_PARAM_END
 156 };
 157 static const OSSL_PARAM *hmac_gettable_ctx_params(void)
 158 {
 159     return known_gettable_ctx_params;
 160 }
 161
 162 static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 163 {
 164     OSSL_PARAM *p;
 165
 166     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
 167         return OSSL_PARAM_set_size_t(p, hmac_size(vmacctx));
 168
 169     return 1;
 170 }
 171
 172 static const OSSL_PARAM known_settable_ctx_params[] = {
 173     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, NULL, 0),
 174     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_ENGINE, NULL, 0),
 175     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
 176     OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
 177     OSSL_PARAM_int(OSSL_MAC_PARAM_FLAGS, NULL),
 178     OSSL_PARAM_END
 179 };
 180 static const OSSL_PARAM *hmac_settable_ctx_params(void)
 181 {
 182     return known_settable_ctx_params;
 183 }
 184
 185 /*
 186  * ALL parameters should be set before init().
 187  */
 188 static int hmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
 189 {
 190     struct hmac_data_st *macctx = vmacctx;
 191     const OSSL_PARAM *p;
 192
 193     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_DIGEST)) != NULL) {
 194         if (p->data_type != OSSL_PARAM_UTF8_STRING)
 195             return 0;
 196
 197         {
 198             const char *algoname = p->data;
 199             const char *propquery = NULL;
 200
 201 /* Inside the FIPS module, we don't support engines */
 202 #if !defined(FIPS_MODE) && !defined(OPENSSL_NO_ENGINE)
 203             ENGINE_finish(macctx->tmpengine);
 204             macctx->tmpengine = NULL;
 205
 206             if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_ENGINE))
 207                 != NULL) {
 208                 if (p->data_type != OSSL_PARAM_UTF8_STRING)
 209                     return 0;
 210
 211                 macctx->tmpengine = ENGINE_by_id(p->data);
 212                 if (macctx->tmpengine == NULL)
 213                     return 0;
 214             }
 215 #endif
 216             if ((p = OSSL_PARAM_locate_const(params,
 217                                              OSSL_MAC_PARAM_PROPERTIES))
 218                 != NULL) {
 219                 if (p->data_type != OSSL_PARAM_UTF8_STRING)
 220                     return 0;
 221
 222                 propquery = p->data;
 223             }
 224
 225             EVP_MD_free(macctx->alloc_md);
 226
 227             macctx->tmpmd = macctx->alloc_md =
 228                 EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(macctx->provctx),
 229                              algoname, propquery);
 230
 231 #ifndef FIPS_MODE /* Inside the FIPS module, we don't support legacy digests */
 232             /* TODO(3.0) BEGIN legacy stuff, to be removed */
 233             if (macctx->tmpmd == NULL)
 234                 macctx->tmpmd = EVP_get_digestbyname(algoname);
 235             /* TODO(3.0) END of legacy stuff */
 236 #endif
 237
 238             if (macctx->tmpmd == NULL)
 239                     return 0;
 240         }
 241     }
 242     /* TODO(3.0) formalize the meaning of "flags", perhaps as other params */
 243     if ((p = OSSL_PARAM_locate_const(params,
 244                                      OSSL_MAC_PARAM_FLAGS)) != NULL) {
 245         int flags = 0;
 246
 247         if (!OSSL_PARAM_get_int(p, &flags))
 248             return 0;
 249         HMAC_CTX_set_flags(macctx->ctx, flags);
 250     }
 251     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
 252         if (p->data_type != OSSL_PARAM_OCTET_STRING)
 253             return 0;
 254
 255         if (!HMAC_Init_ex(macctx->ctx, p->data, p->data_size,
 256                           macctx->tmpmd, NULL /* ENGINE */))
 257             return 0;
 258
 259         macctx->tmpmd = NULL;
 260         macctx->tmpengine = NULL;
 261     }
 262     return 1;
 263 }
 264
 265 const OSSL_DISPATCH hmac_functions[] = {
 266     { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_new },
 267     { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup },
 268     { OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free },
 269     { OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init },
 270     { OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update },
 271     { OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final },
 272     { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
 273       (void (*)(void))hmac_gettable_ctx_params },
 274     { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params },
 275     { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
 276       (void (*)(void))hmac_settable_ctx_params },
 277     { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params },
 278     { 0, NULL }
 279 };