providers/implementations/macs/hmac_prov.c

   1 /*
   2  * Copyright 2018-2020 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  * HMAC low level APIs are deprecated for public use, but still ok for internal
  12  * use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <openssl/core_dispatch.h>
  17 #include <openssl/core_names.h>
  18 #include <openssl/params.h>
  19 #include <openssl/engine.h>
  20 #include <openssl/evp.h>
  21 #include <openssl/hmac.h>
  22
  23 #include "prov/implementations.h"
  24 #include "prov/provider_ctx.h"
  25 #include "prov/provider_util.h"
  26
  27 /*
  28  * Forward declaration of everything implemented here.  This is not strictly
  29  * necessary for the compiler, but provides an assurance that the signatures
  30  * of the functions in the dispatch table are correct.
  31  */
  32 static OSSL_FUNC_mac_newctx_fn hmac_new;
  33 static OSSL_FUNC_mac_dupctx_fn hmac_dup;
  34 static OSSL_FUNC_mac_freectx_fn hmac_free;
  35 static OSSL_FUNC_mac_gettable_ctx_params_fn hmac_gettable_ctx_params;
  36 static OSSL_FUNC_mac_get_ctx_params_fn hmac_get_ctx_params;
  37 static OSSL_FUNC_mac_settable_ctx_params_fn hmac_settable_ctx_params;
  38 static OSSL_FUNC_mac_set_ctx_params_fn hmac_set_ctx_params;
  39 static OSSL_FUNC_mac_init_fn hmac_init;
  40 static OSSL_FUNC_mac_update_fn hmac_update;
  41 static OSSL_FUNC_mac_final_fn hmac_final;
  42
  43 /* local HMAC context structure */
  44
  45 /* typedef EVP_MAC_IMPL */
  46 struct hmac_data_st {
  47     void *provctx;
  48     HMAC_CTX *ctx;               /* HMAC context */
  49     PROV_DIGEST digest;
  50 };
  51
  52 static size_t hmac_size(void *vmacctx);
  53
  54 static void *hmac_new(void *provctx)
  55 {
  56     struct hmac_data_st *macctx;
  57
  58     if ((macctx = OPENSSL_zalloc(sizeof(*macctx))) == NULL
  59         || (macctx->ctx = HMAC_CTX_new()) == NULL) {
  60         OPENSSL_free(macctx);
  61         return NULL;
  62     }
  63     /* TODO(3.0) Should we do something more with that context? */
  64     macctx->provctx = provctx;
  65
  66     return macctx;
  67 }
  68
  69 static void hmac_free(void *vmacctx)
  70 {
  71     struct hmac_data_st *macctx = vmacctx;
  72
  73     if (macctx != NULL) {
  74         HMAC_CTX_free(macctx->ctx);
  75         ossl_prov_digest_reset(&macctx->digest);
  76         OPENSSL_free(macctx);
  77     }
  78 }
  79
  80 static void *hmac_dup(void *vsrc)
  81 {
  82     struct hmac_data_st *src = vsrc;
  83     struct hmac_data_st *dst = hmac_new(src->provctx);
  84
  85     if (dst == NULL)
  86         return NULL;
  87
  88     if (!HMAC_CTX_copy(dst->ctx, src->ctx)
  89         || !ossl_prov_digest_copy(&dst->digest, &src->digest)) {
  90         hmac_free(dst);
  91         return NULL;
  92     }
  93     return dst;
  94 }
  95
  96 static size_t hmac_size(void *vmacctx)
  97 {
  98     struct hmac_data_st *macctx = vmacctx;
  99
 100     return HMAC_size(macctx->ctx);
 101 }
 102
 103 static int hmac_init(void *vmacctx)
 104 {
 105     struct hmac_data_st *macctx = vmacctx;
 106     const EVP_MD *digest = ossl_prov_digest_md(&macctx->digest);
 107     int rv = 1;
 108
 109     /* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */
 110     if (digest != NULL)
 111         rv = HMAC_Init_ex(macctx->ctx, NULL, 0, digest,
 112                           ossl_prov_digest_engine(&macctx->digest));
 113     ossl_prov_digest_reset(&macctx->digest);
 114     return rv;
 115 }
 116
 117 static int hmac_update(void *vmacctx, const unsigned char *data,
 118                        size_t datalen)
 119 {
 120     struct hmac_data_st *macctx = vmacctx;
 121
 122     return HMAC_Update(macctx->ctx, data, datalen);
 123 }
 124
 125 static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl,
 126                       size_t outsize)
 127 {
 128     unsigned int hlen;
 129     struct hmac_data_st *macctx = vmacctx;
 130
 131     if (!HMAC_Final(macctx->ctx, out, &hlen))
 132         return 0;
 133     *outl = hlen;
 134     return 1;
 135 }
 136
 137 static const OSSL_PARAM known_gettable_ctx_params[] = {
 138     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
 139     OSSL_PARAM_END
 140 };
 141 static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *provctx)
 142 {
 143     return known_gettable_ctx_params;
 144 }
 145
 146 static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 147 {
 148     OSSL_PARAM *p;
 149
 150     if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
 151         return OSSL_PARAM_set_size_t(p, hmac_size(vmacctx));
 152
 153     return 1;
 154 }
 155
 156 static const OSSL_PARAM known_settable_ctx_params[] = {
 157     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST, NULL, 0),
 158     OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_PROPERTIES, NULL, 0),
 159     OSSL_PARAM_octet_string(OSSL_MAC_PARAM_KEY, NULL, 0),
 160     OSSL_PARAM_int(OSSL_MAC_PARAM_FLAGS, NULL),
 161     OSSL_PARAM_END
 162 };
 163 static const OSSL_PARAM *hmac_settable_ctx_params(ossl_unused void *provctx)
 164 {
 165     return known_settable_ctx_params;
 166 }
 167
 168 /*
 169  * ALL parameters should be set before init().
 170  */
 171 static int hmac_set_ctx_params(void *vmacctx, const OSSL_PARAM params[])
 172 {
 173     struct hmac_data_st *macctx = vmacctx;
 174     OPENSSL_CTX *ctx = PROV_LIBRARY_CONTEXT_OF(macctx->provctx);
 175     const OSSL_PARAM *p;
 176
 177     if (!ossl_prov_digest_load_from_params(&macctx->digest, params, ctx))
 178         return 0;
 179
 180     /* TODO(3.0) formalize the meaning of "flags", perhaps as other params */
 181     if ((p = OSSL_PARAM_locate_const(params,
 182                                      OSSL_MAC_PARAM_FLAGS)) != NULL) {
 183         int flags = 0;
 184
 185         if (!OSSL_PARAM_get_int(p, &flags))
 186             return 0;
 187         HMAC_CTX_set_flags(macctx->ctx, flags);
 188     }
 189     if ((p = OSSL_PARAM_locate_const(params, OSSL_MAC_PARAM_KEY)) != NULL) {
 190         if (p->data_type != OSSL_PARAM_OCTET_STRING)
 191             return 0;
 192
 193         if (!HMAC_Init_ex(macctx->ctx, p->data, p->data_size,
 194                           ossl_prov_digest_md(&macctx->digest),
 195                           NULL /* ENGINE */))
 196             return 0;
 197
 198         ossl_prov_digest_reset(&macctx->digest);
 199     }
 200     return 1;
 201 }
 202
 203 const OSSL_DISPATCH hmac_functions[] = {
 204     { OSSL_FUNC_MAC_NEWCTX, (void (*)(void))hmac_new },
 205     { OSSL_FUNC_MAC_DUPCTX, (void (*)(void))hmac_dup },
 206     { OSSL_FUNC_MAC_FREECTX, (void (*)(void))hmac_free },
 207     { OSSL_FUNC_MAC_INIT, (void (*)(void))hmac_init },
 208     { OSSL_FUNC_MAC_UPDATE, (void (*)(void))hmac_update },
 209     { OSSL_FUNC_MAC_FINAL, (void (*)(void))hmac_final },
 210     { OSSL_FUNC_MAC_GETTABLE_CTX_PARAMS,
 211       (void (*)(void))hmac_gettable_ctx_params },
 212     { OSSL_FUNC_MAC_GET_CTX_PARAMS, (void (*)(void))hmac_get_ctx_params },
 213     { OSSL_FUNC_MAC_SETTABLE_CTX_PARAMS,
 214       (void (*)(void))hmac_settable_ctx_params },
 215     { OSSL_FUNC_MAC_SET_CTX_PARAMS, (void (*)(void))hmac_set_ctx_params },
 216     { 0, NULL }
 217 };