crypto/cmp/cmp_protect.c

   1 /*
   2  * Copyright 2007-2019 The OpenSSL Project Authors. All Rights Reserved.
   3  * Copyright Nokia 2007-2019
   4  * Copyright Siemens AG 2015-2019
   5  *
   6  * Licensed under the Apache License 2.0 (the "License").  You may not use
   7  * this file except in compliance with the License.  You can obtain a copy
   8  * in the file LICENSE in the source distribution or at
   9  * https://www.openssl.org/source/license.html
  10  */
  11
  12 #include "cmp_local.h"
  13
  14 /* explicit #includes not strictly needed since implied by the above: */
  15 #include <openssl/asn1t.h>
  16 #include <openssl/cmp.h>
  17 #include <openssl/crmf.h>
  18 #include <openssl/err.h>
  19 #include <openssl/x509.h>
  20
  21 /*
  22  * This function is also used for verification from cmp_vfy.
  23  *
  24  * Calculate protection for given PKImessage utilizing the given credentials
  25  * and the algorithm parameters set inside the message header's protectionAlg.
  26  *
  27  * Either secret or pkey must be set, the other must be NULL. Attempts doing
  28  * PBMAC in case 'secret' is set and signature if 'pkey' is set - but will only
  29  * do the protection already marked in msg->header->protectionAlg.
  30  *
  31  * returns ptr to ASN1_BIT_STRING containing protection on success, else NULL
  32  */
  33 ASN1_BIT_STRING *ossl_cmp_calc_protection(const OSSL_CMP_MSG *msg,
  34                                           const ASN1_OCTET_STRING *secret,
  35                                           EVP_PKEY *pkey)
  36 {
  37     ASN1_BIT_STRING *prot = NULL;
  38     CMP_PROTECTEDPART prot_part;
  39     const ASN1_OBJECT *algorOID = NULL;
  40     int len;
  41     size_t prot_part_der_len;
  42     unsigned char *prot_part_der = NULL;
  43     size_t sig_len;
  44     unsigned char *protection = NULL;
  45     const void *ppval = NULL;
  46     int pptype = 0;
  47     OSSL_CRMF_PBMPARAMETER *pbm = NULL;
  48     ASN1_STRING *pbm_str = NULL;
  49     const unsigned char *pbm_str_uc = NULL;
  50     EVP_MD_CTX *evp_ctx = NULL;
  51     int md_NID;
  52     const EVP_MD *md = NULL;
  53
  54     if (!ossl_assert(msg != NULL))
  55         return NULL;
  56
  57     /* construct data to be signed */
  58     prot_part.header = msg->header;
  59     prot_part.body = msg->body;
  60
  61     len = i2d_CMP_PROTECTEDPART(&prot_part, &prot_part_der);
  62     if (len < 0 || prot_part_der == NULL) {
  63         CMPerr(0, CMP_R_ERROR_CALCULATING_PROTECTION);
  64         goto end;
  65     }
  66     prot_part_der_len = (size_t) len;
  67
  68     if (msg->header->protectionAlg == NULL) {
  69         CMPerr(0, CMP_R_UNKNOWN_ALGORITHM_ID);
  70         goto end;
  71     }
  72     X509_ALGOR_get0(&algorOID, &pptype, &ppval, msg->header->protectionAlg);
  73
  74     if (secret != NULL && pkey == NULL) {
  75         if (ppval == NULL) {
  76             CMPerr(0, CMP_R_ERROR_CALCULATING_PROTECTION);
  77             goto end;
  78         }
  79         if (NID_id_PasswordBasedMAC != OBJ_obj2nid(algorOID)) {
  80             CMPerr(0, CMP_R_WRONG_ALGORITHM_OID);
  81             goto end;
  82         }
  83         pbm_str = (ASN1_STRING *)ppval;
  84         pbm_str_uc = pbm_str->data;
  85         pbm = d2i_OSSL_CRMF_PBMPARAMETER(NULL, &pbm_str_uc, pbm_str->length);
  86         if (pbm == NULL) {
  87             CMPerr(0, CMP_R_WRONG_ALGORITHM_OID);
  88             goto end;
  89         }
  90
  91         if (!OSSL_CRMF_pbm_new(pbm, prot_part_der, prot_part_der_len,
  92                                secret->data, secret->length,
  93                                &protection, &sig_len))
  94             goto end;
  95     } else if (secret == NULL && pkey != NULL) {
  96         /* TODO combine this with large parts of CRMF_poposigningkey_init() */
  97         /* EVP_DigestSignInit() checks that pkey type is correct for the alg */
  98
  99         if (!OBJ_find_sigid_algs(OBJ_obj2nid(algorOID), &md_NID, NULL)
 100                 || (md = EVP_get_digestbynid(md_NID)) == NULL
 101                 || (evp_ctx = EVP_MD_CTX_new()) == NULL) {
 102             CMPerr(0, CMP_R_UNKNOWN_ALGORITHM_ID);
 103             goto end;
 104         }
 105         if (EVP_DigestSignInit(evp_ctx, NULL, md, NULL, pkey) <= 0
 106                 || EVP_DigestSignUpdate(evp_ctx, prot_part_der,
 107                                         prot_part_der_len) <= 0
 108                 || EVP_DigestSignFinal(evp_ctx, NULL, &sig_len) <= 0
 109                 || (protection = OPENSSL_malloc(sig_len)) == NULL
 110                 || EVP_DigestSignFinal(evp_ctx, protection, &sig_len) <= 0) {
 111             CMPerr(0, CMP_R_ERROR_CALCULATING_PROTECTION);
 112             goto end;
 113         }
 114     } else {
 115         CMPerr(0, CMP_R_INVALID_ARGS);
 116         goto end;
 117     }
 118
 119     if ((prot = ASN1_BIT_STRING_new()) == NULL)
 120         goto end;
 121     /* OpenSSL defaults all bit strings to be encoded as ASN.1 NamedBitList */
 122     prot->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);
 123     prot->flags |= ASN1_STRING_FLAG_BITS_LEFT;
 124     if (!ASN1_BIT_STRING_set(prot, protection, sig_len)) {
 125         ASN1_BIT_STRING_free(prot);
 126         prot = NULL;
 127     }
 128
 129  end:
 130     OSSL_CRMF_PBMPARAMETER_free(pbm);
 131     EVP_MD_CTX_free(evp_ctx);
 132     OPENSSL_free(protection);
 133     OPENSSL_free(prot_part_der);
 134     return prot;
 135 }
 136
 137 int ossl_cmp_msg_add_extraCerts(OSSL_CMP_CTX *ctx, OSSL_CMP_MSG *msg)
 138 {
 139     if (!ossl_assert(ctx != NULL && msg != NULL))
 140         return 0;
 141
 142     if (msg->extraCerts == NULL
 143             && (msg->extraCerts = sk_X509_new_null()) == NULL)
 144         return 0;
 145
 146     if (ctx->clCert != NULL) {
 147         /* Make sure that our own cert gets sent, in the first position */
 148         if (!X509_up_ref(ctx->clCert))
 149             return 0;
 150         if (!sk_X509_push(msg->extraCerts, ctx->clCert)) {
 151             X509_free(ctx->clCert);
 152             return 0;
 153         }
 154         /* if we have untrusted store, try to add intermediate certs */
 155         if (ctx->untrusted_certs != NULL) {
 156             STACK_OF(X509) *chain =
 157                 ossl_cmp_build_cert_chain(ctx->untrusted_certs, ctx->clCert);
 158             int res = ossl_cmp_sk_X509_add1_certs(msg->extraCerts, chain,
 159                                                   1 /* no self-issued */,
 160                                                   1 /* no duplicates */, 0);
 161             sk_X509_pop_free(chain, X509_free);
 162             if (res == 0)
 163                 return 0;
 164         }
 165     }
 166
 167     /* add any additional certificates from ctx->extraCertsOut */
 168     if (!ossl_cmp_sk_X509_add1_certs(msg->extraCerts, ctx->extraCertsOut, 0,
 169                                      1 /* no duplicates */, 0))
 170         return 0;
 171
 172     /* if none was found avoid empty ASN.1 sequence */
 173     if (sk_X509_num(msg->extraCerts) == 0) {
 174         sk_X509_free(msg->extraCerts);
 175         msg->extraCerts = NULL;
 176     }
 177     return 1;
 178 }
 179
 180 /*
 181  * Create an X509_ALGOR structure for PasswordBasedMAC protection based on
 182  * the pbm settings in the context
 183  * returns pointer to X509_ALGOR on success, NULL on error
 184  */
 185 static X509_ALGOR *create_pbmac_algor(OSSL_CMP_CTX *ctx)
 186 {
 187     X509_ALGOR *alg = NULL;
 188     OSSL_CRMF_PBMPARAMETER *pbm = NULL;
 189     unsigned char *pbm_der = NULL;
 190     int pbm_der_len;
 191     ASN1_STRING *pbm_str = NULL;
 192
 193     if (!ossl_assert(ctx != NULL))
 194         return NULL;
 195
 196     alg = X509_ALGOR_new();
 197     pbm = OSSL_CRMF_pbmp_new(ctx->pbm_slen, ctx->pbm_owf, ctx->pbm_itercnt,
 198                              ctx->pbm_mac);
 199     pbm_str = ASN1_STRING_new();
 200     if (alg == NULL || pbm == NULL || pbm_str == NULL)
 201         goto err;
 202
 203     if ((pbm_der_len = i2d_OSSL_CRMF_PBMPARAMETER(pbm, &pbm_der)) < 0)
 204         goto err;
 205
 206     if (!ASN1_STRING_set(pbm_str, pbm_der, pbm_der_len))
 207         goto err;
 208     OPENSSL_free(pbm_der);
 209
 210     X509_ALGOR_set0(alg, OBJ_nid2obj(NID_id_PasswordBasedMAC),
 211                     V_ASN1_SEQUENCE, pbm_str);
 212     OSSL_CRMF_PBMPARAMETER_free(pbm);
 213     return alg;
 214
 215  err:
 216     ASN1_STRING_free(pbm_str);
 217     X509_ALGOR_free(alg);
 218     OPENSSL_free(pbm_der);
 219     OSSL_CRMF_PBMPARAMETER_free(pbm);
 220     return NULL;
 221 }
 222
 223 int ossl_cmp_msg_protect(OSSL_CMP_CTX *ctx, OSSL_CMP_MSG *msg)
 224 {
 225     if (!ossl_assert(ctx != NULL && msg != NULL))
 226         return 0;
 227
 228     if (ctx->unprotectedSend)
 229         return 1;
 230
 231     /* use PasswordBasedMac according to 5.1.3.1 if secretValue is given */
 232     if (ctx->secretValue != NULL) {
 233         if ((msg->header->protectionAlg = create_pbmac_algor(ctx)) == NULL)
 234             goto err;
 235         if (ctx->referenceValue != NULL
 236                 && !ossl_cmp_hdr_set1_senderKID(msg->header,
 237                                                 ctx->referenceValue))
 238             goto err;
 239
 240         /*
 241          * add any additional certificates from ctx->extraCertsOut
 242          * while not needed to validate the signing cert, the option to do
 243          * this might be handy for certain use cases
 244          */
 245         if (!ossl_cmp_msg_add_extraCerts(ctx, msg))
 246             goto err;
 247
 248         if ((msg->protection =
 249              ossl_cmp_calc_protection(msg, ctx->secretValue, NULL)) == NULL)
 250             goto err;
 251     } else {
 252         /*
 253          * use MSG_SIG_ALG according to 5.1.3.3 if client Certificate and
 254          * private key is given
 255          */
 256         if (ctx->clCert != NULL && ctx->pkey != NULL) {
 257             const ASN1_OCTET_STRING *subjKeyIDStr = NULL;
 258             int algNID = 0;
 259             ASN1_OBJECT *alg = NULL;
 260
 261             /* make sure that key and certificate match */
 262             if (!X509_check_private_key(ctx->clCert, ctx->pkey)) {
 263                 CMPerr(0, CMP_R_CERT_AND_KEY_DO_NOT_MATCH);
 264                 goto err;
 265             }
 266
 267             if (msg->header->protectionAlg == NULL)
 268                 if ((msg->header->protectionAlg = X509_ALGOR_new()) == NULL)
 269                     goto err;
 270
 271             if (!OBJ_find_sigid_by_algs(&algNID, ctx->digest,
 272                                         EVP_PKEY_id(ctx->pkey))) {
 273                 CMPerr(0, CMP_R_UNSUPPORTED_KEY_TYPE);
 274                 goto err;
 275             }
 276             if ((alg = OBJ_nid2obj(algNID)) == NULL)
 277                 goto err;
 278             if (!X509_ALGOR_set0(msg->header->protectionAlg,
 279                                  alg, V_ASN1_UNDEF, NULL)) {
 280                 ASN1_OBJECT_free(alg);
 281                 goto err;
 282             }
 283
 284             /*
 285              * set senderKID to keyIdentifier of the used certificate according
 286              * to section 5.1.1
 287              */
 288             subjKeyIDStr = X509_get0_subject_key_id(ctx->clCert);
 289             if (subjKeyIDStr != NULL
 290                     && !ossl_cmp_hdr_set1_senderKID(msg->header, subjKeyIDStr))
 291                 goto err;
 292
 293             /*
 294              * Add ctx->clCert followed, if possible, by its chain built
 295              * from ctx->untrusted_certs, and then ctx->extraCertsOut
 296              */
 297             if (!ossl_cmp_msg_add_extraCerts(ctx, msg))
 298                 goto err;
 299
 300             if ((msg->protection =
 301                  ossl_cmp_calc_protection(msg, NULL, ctx->pkey)) == NULL)
 302                 goto err;
 303         } else {
 304             CMPerr(0, CMP_R_MISSING_KEY_INPUT_FOR_CREATING_PROTECTION);
 305             goto err;
 306         }
 307     }
 308
 309     return 1;
 310  err:
 311     CMPerr(0, CMP_R_ERROR_PROTECTING_MESSAGE);
 312     return 0;
 313 }