crypto/cms/cms_pwri.c

   1 /*
   2  * Copyright 2009-2020 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 #include "internal/cryptlib.h"
  11 #include <openssl/asn1t.h>
  12 #include <openssl/pem.h>
  13 #include <openssl/x509v3.h>
  14 #include <openssl/err.h>
  15 #include <openssl/cms.h>
  16 #include <openssl/rand.h>
  17 #include <openssl/aes.h>
  18 #include "cms_local.h"
  19 #include "crypto/asn1.h"
  20
  21 int CMS_RecipientInfo_set0_password(CMS_RecipientInfo *ri,
  22                                     unsigned char *pass, ossl_ssize_t passlen)
  23 {
  24     CMS_PasswordRecipientInfo *pwri;
  25     if (ri->type != CMS_RECIPINFO_PASS) {
  26         CMSerr(CMS_F_CMS_RECIPIENTINFO_SET0_PASSWORD, CMS_R_NOT_PWRI);
  27         return 0;
  28     }
  29
  30     pwri = ri->d.pwri;
  31     pwri->pass = pass;
  32     if (pass && passlen < 0)
  33         passlen = strlen((char *)pass);
  34     pwri->passlen = passlen;
  35     return 1;
  36 }
  37
  38 CMS_RecipientInfo *CMS_add0_recipient_password(CMS_ContentInfo *cms,
  39                                                int iter, int wrap_nid,
  40                                                int pbe_nid,
  41                                                unsigned char *pass,
  42                                                ossl_ssize_t passlen,
  43                                                const EVP_CIPHER *kekciph)
  44 {
  45     STACK_OF(CMS_RecipientInfo) *ris;
  46     CMS_RecipientInfo *ri = NULL;
  47     CMS_EncryptedContentInfo *ec;
  48     CMS_PasswordRecipientInfo *pwri;
  49     EVP_CIPHER_CTX *ctx = NULL;
  50     X509_ALGOR *encalg = NULL;
  51     unsigned char iv[EVP_MAX_IV_LENGTH];
  52     int ivlen;
  53     const CMS_CTX *cms_ctx = cms_get0_cmsctx(cms);
  54
  55     ec = cms_get0_env_enc_content(cms);
  56     if (ec == NULL)
  57         return NULL;
  58     ris = CMS_get0_RecipientInfos(cms);
  59     if (ris == NULL)
  60         return NULL;
  61
  62     if (wrap_nid <= 0)
  63         wrap_nid = NID_id_alg_PWRI_KEK;
  64
  65     if (pbe_nid <= 0)
  66         pbe_nid = NID_id_pbkdf2;
  67
  68     /* Get from enveloped data */
  69     if (kekciph == NULL)
  70         kekciph = ec->cipher;
  71
  72     if (kekciph == NULL) {
  73         CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD, CMS_R_NO_CIPHER);
  74         return NULL;
  75     }
  76     if (wrap_nid != NID_id_alg_PWRI_KEK) {
  77         CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD,
  78                CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
  79         return NULL;
  80     }
  81
  82     /* Setup algorithm identifier for cipher */
  83     encalg = X509_ALGOR_new();
  84     if (encalg == NULL) {
  85         goto merr;
  86     }
  87     ctx = EVP_CIPHER_CTX_new();
  88
  89     if (EVP_EncryptInit_ex(ctx, kekciph, NULL, NULL, NULL) <= 0) {
  90         CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD, ERR_R_EVP_LIB);
  91         goto err;
  92     }
  93
  94     ivlen = EVP_CIPHER_CTX_iv_length(ctx);
  95
  96     if (ivlen > 0) {
  97         if (RAND_bytes_ex(cms_ctx->libctx, iv, ivlen) <= 0)
  98             goto err;
  99         if (EVP_EncryptInit_ex(ctx, NULL, NULL, NULL, iv) <= 0) {
 100             CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD, ERR_R_EVP_LIB);
 101             goto err;
 102         }
 103         encalg->parameter = ASN1_TYPE_new();
 104         if (!encalg->parameter) {
 105             CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD, ERR_R_MALLOC_FAILURE);
 106             goto err;
 107         }
 108         if (EVP_CIPHER_param_to_asn1(ctx, encalg->parameter) <= 0) {
 109             CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD,
 110                    CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
 111             goto err;
 112         }
 113     }
 114
 115     encalg->algorithm = OBJ_nid2obj(EVP_CIPHER_CTX_type(ctx));
 116
 117     EVP_CIPHER_CTX_free(ctx);
 118     ctx = NULL;
 119
 120     /* Initialize recipient info */
 121     ri = M_ASN1_new_of(CMS_RecipientInfo);
 122     if (ri == NULL)
 123         goto merr;
 124
 125     ri->d.pwri = M_ASN1_new_of(CMS_PasswordRecipientInfo);
 126     if (ri->d.pwri == NULL)
 127         goto merr;
 128     ri->type = CMS_RECIPINFO_PASS;
 129
 130     pwri = ri->d.pwri;
 131     pwri->cms_ctx = cms_ctx;
 132     /* Since this is overwritten, free up empty structure already there */
 133     X509_ALGOR_free(pwri->keyEncryptionAlgorithm);
 134     pwri->keyEncryptionAlgorithm = X509_ALGOR_new();
 135     if (pwri->keyEncryptionAlgorithm == NULL)
 136         goto merr;
 137     pwri->keyEncryptionAlgorithm->algorithm = OBJ_nid2obj(wrap_nid);
 138     pwri->keyEncryptionAlgorithm->parameter = ASN1_TYPE_new();
 139     if (pwri->keyEncryptionAlgorithm->parameter == NULL)
 140         goto merr;
 141
 142     if (!ASN1_item_pack(encalg, ASN1_ITEM_rptr(X509_ALGOR),
 143                         &pwri->keyEncryptionAlgorithm->parameter->
 144                         value.sequence))
 145          goto merr;
 146     pwri->keyEncryptionAlgorithm->parameter->type = V_ASN1_SEQUENCE;
 147
 148     X509_ALGOR_free(encalg);
 149     encalg = NULL;
 150
 151     /* Setup PBE algorithm */
 152
 153     pwri->keyDerivationAlgorithm = PKCS5_pbkdf2_set(iter, NULL, 0, -1, -1);
 154
 155     if (pwri->keyDerivationAlgorithm == NULL)
 156         goto err;
 157
 158     CMS_RecipientInfo_set0_password(ri, pass, passlen);
 159     pwri->version = 0;
 160
 161     if (!sk_CMS_RecipientInfo_push(ris, ri))
 162         goto merr;
 163
 164     return ri;
 165
 166  merr:
 167     CMSerr(CMS_F_CMS_ADD0_RECIPIENT_PASSWORD, ERR_R_MALLOC_FAILURE);
 168  err:
 169     EVP_CIPHER_CTX_free(ctx);
 170     if (ri)
 171         M_ASN1_free_of(ri, CMS_RecipientInfo);
 172     X509_ALGOR_free(encalg);
 173     return NULL;
 174
 175 }
 176
 177 /*
 178  * This is an implementation of the key wrapping mechanism in RFC3211, at
 179  * some point this should go into EVP.
 180  */
 181
 182 static int kek_unwrap_key(unsigned char *out, size_t *outlen,
 183                           const unsigned char *in, size_t inlen,
 184                           EVP_CIPHER_CTX *ctx)
 185 {
 186     size_t blocklen = EVP_CIPHER_CTX_block_size(ctx);
 187     unsigned char *tmp;
 188     int outl, rv = 0;
 189     if (inlen < 2 * blocklen) {
 190         /* too small */
 191         return 0;
 192     }
 193     if (inlen % blocklen) {
 194         /* Invalid size */
 195         return 0;
 196     }
 197     if ((tmp = OPENSSL_malloc(inlen)) == NULL) {
 198         CMSerr(CMS_F_KEK_UNWRAP_KEY, ERR_R_MALLOC_FAILURE);
 199         return 0;
 200     }
 201     /* setup IV by decrypting last two blocks */
 202     if (!EVP_DecryptUpdate(ctx, tmp + inlen - 2 * blocklen, &outl,
 203                            in + inlen - 2 * blocklen, blocklen * 2)
 204         /*
 205          * Do a decrypt of last decrypted block to set IV to correct value
 206          * output it to start of buffer so we don't corrupt decrypted block
 207          * this works because buffer is at least two block lengths long.
 208          */
 209         || !EVP_DecryptUpdate(ctx, tmp, &outl,
 210                               tmp + inlen - blocklen, blocklen)
 211         /* Can now decrypt first n - 1 blocks */
 212         || !EVP_DecryptUpdate(ctx, tmp, &outl, in, inlen - blocklen)
 213
 214         /* Reset IV to original value */
 215         || !EVP_DecryptInit_ex(ctx, NULL, NULL, NULL, NULL)
 216         /* Decrypt again */
 217         || !EVP_DecryptUpdate(ctx, tmp, &outl, tmp, inlen))
 218         goto err;
 219     /* Check check bytes */
 220     if (((tmp[1] ^ tmp[4]) & (tmp[2] ^ tmp[5]) & (tmp[3] ^ tmp[6])) != 0xff) {
 221         /* Check byte failure */
 222         goto err;
 223     }
 224     if (inlen < (size_t)(tmp[0] - 4)) {
 225         /* Invalid length value */
 226         goto err;
 227     }
 228     *outlen = (size_t)tmp[0];
 229     memcpy(out, tmp + 4, *outlen);
 230     rv = 1;
 231  err:
 232     OPENSSL_clear_free(tmp, inlen);
 233     return rv;
 234
 235 }
 236
 237 static int kek_wrap_key(unsigned char *out, size_t *outlen,
 238                         const unsigned char *in, size_t inlen,
 239                         EVP_CIPHER_CTX *ctx, const CMS_CTX *cms_ctx)
 240 {
 241     size_t blocklen = EVP_CIPHER_CTX_block_size(ctx);
 242     size_t olen;
 243     int dummy;
 244     /*
 245      * First decide length of output buffer: need header and round up to
 246      * multiple of block length.
 247      */
 248     olen = (inlen + 4 + blocklen - 1) / blocklen;
 249     olen *= blocklen;
 250     if (olen < 2 * blocklen) {
 251         /* Key too small */
 252         return 0;
 253     }
 254     if (inlen > 0xFF) {
 255         /* Key too large */
 256         return 0;
 257     }
 258     if (out) {
 259         /* Set header */
 260         out[0] = (unsigned char)inlen;
 261         out[1] = in[0] ^ 0xFF;
 262         out[2] = in[1] ^ 0xFF;
 263         out[3] = in[2] ^ 0xFF;
 264         memcpy(out + 4, in, inlen);
 265         /* Add random padding to end */
 266         if (olen > inlen + 4
 267             && RAND_bytes_ex(cms_ctx->libctx, out + 4 + inlen,
 268                              olen - 4 - inlen) <= 0)
 269             return 0;
 270         /* Encrypt twice */
 271         if (!EVP_EncryptUpdate(ctx, out, &dummy, out, olen)
 272             || !EVP_EncryptUpdate(ctx, out, &dummy, out, olen))
 273             return 0;
 274     }
 275
 276     *outlen = olen;
 277
 278     return 1;
 279 }
 280
 281 /* Encrypt/Decrypt content key in PWRI recipient info */
 282
 283 int cms_RecipientInfo_pwri_crypt(const CMS_ContentInfo *cms,
 284                                  CMS_RecipientInfo *ri, int en_de)
 285 {
 286     CMS_EncryptedContentInfo *ec;
 287     CMS_PasswordRecipientInfo *pwri;
 288     int r = 0;
 289     X509_ALGOR *algtmp, *kekalg = NULL;
 290     EVP_CIPHER_CTX *kekctx = NULL;
 291     const char *name;
 292     EVP_CIPHER *kekcipher;
 293     unsigned char *key = NULL;
 294     size_t keylen;
 295     const CMS_CTX *cms_ctx = cms_get0_cmsctx(cms);
 296
 297     ec = cms_get0_env_enc_content(cms);
 298
 299     pwri = ri->d.pwri;
 300
 301     if (pwri->pass == NULL) {
 302         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, CMS_R_NO_PASSWORD);
 303         return 0;
 304     }
 305     algtmp = pwri->keyEncryptionAlgorithm;
 306
 307     if (!algtmp || OBJ_obj2nid(algtmp->algorithm) != NID_id_alg_PWRI_KEK) {
 308         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT,
 309                CMS_R_UNSUPPORTED_KEY_ENCRYPTION_ALGORITHM);
 310         return 0;
 311     }
 312
 313     kekalg = ASN1_TYPE_unpack_sequence(ASN1_ITEM_rptr(X509_ALGOR),
 314                                        algtmp->parameter);
 315
 316     if (kekalg == NULL) {
 317         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT,
 318                CMS_R_INVALID_KEY_ENCRYPTION_PARAMETER);
 319         return 0;
 320     }
 321
 322     name = OBJ_nid2sn(OBJ_obj2nid(kekalg->algorithm));
 323     kekcipher = EVP_CIPHER_fetch(cms_ctx->libctx, name, cms_ctx->propq);
 324
 325     if (kekcipher == NULL) {
 326         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, CMS_R_UNKNOWN_CIPHER);
 327         goto err;
 328     }
 329
 330     kekctx = EVP_CIPHER_CTX_new();
 331     if (kekctx == NULL) {
 332         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, ERR_R_MALLOC_FAILURE);
 333         goto err;
 334     }
 335     /* Fixup cipher based on AlgorithmIdentifier to set IV etc */
 336     if (!EVP_CipherInit_ex(kekctx, kekcipher, NULL, NULL, NULL, en_de))
 337         goto err;
 338     EVP_CIPHER_CTX_set_padding(kekctx, 0);
 339     if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0) {
 340         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT,
 341                CMS_R_CIPHER_PARAMETER_INITIALISATION_ERROR);
 342         goto err;
 343     }
 344
 345     algtmp = pwri->keyDerivationAlgorithm;
 346
 347     /* Finish password based key derivation to setup key in "ctx" */
 348
 349     if (EVP_PBE_CipherInit(algtmp->algorithm,
 350                            (char *)pwri->pass, pwri->passlen,
 351                            algtmp->parameter, kekctx, en_de) < 0) {
 352         CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, ERR_R_EVP_LIB);
 353         goto err;
 354     }
 355
 356     /* Finally wrap/unwrap the key */
 357
 358     if (en_de) {
 359
 360         if (!kek_wrap_key(NULL, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
 361             goto err;
 362
 363         key = OPENSSL_malloc(keylen);
 364
 365         if (key == NULL)
 366             goto err;
 367
 368         if (!kek_wrap_key(key, &keylen, ec->key, ec->keylen, kekctx, cms_ctx))
 369             goto err;
 370         pwri->encryptedKey->data = key;
 371         pwri->encryptedKey->length = keylen;
 372     } else {
 373         key = OPENSSL_malloc(pwri->encryptedKey->length);
 374
 375         if (key == NULL) {
 376             CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, ERR_R_MALLOC_FAILURE);
 377             goto err;
 378         }
 379         if (!kek_unwrap_key(key, &keylen,
 380                             pwri->encryptedKey->data,
 381                             pwri->encryptedKey->length, kekctx)) {
 382             CMSerr(CMS_F_CMS_RECIPIENTINFO_PWRI_CRYPT, CMS_R_UNWRAP_FAILURE);
 383             goto err;
 384         }
 385
 386         OPENSSL_clear_free(ec->key, ec->keylen);
 387         ec->key = key;
 388         ec->keylen = keylen;
 389
 390     }
 391
 392     r = 1;
 393
 394  err:
 395     EVP_CIPHER_free(kekcipher);
 396     EVP_CIPHER_CTX_free(kekctx);
 397
 398     if (!r)
 399         OPENSSL_free(key);
 400     X509_ALGOR_free(kekalg);
 401
 402     return r;
 403
 404 }