crypto/pem/pem_pkey.c

   1 /*
   2  * Copyright 1995-2023 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 /* We need to use some deprecated APIs */
  11 #define OPENSSL_SUPPRESS_DEPRECATED
  12
  13 #include <stdio.h>
  14 #include <openssl/buffer.h>
  15 #include <openssl/objects.h>
  16 #include <openssl/evp.h>
  17 #include <openssl/x509.h>
  18 #include <openssl/pkcs12.h>
  19 #include <openssl/pem.h>
  20 #include <openssl/engine.h>
  21 #include <openssl/dh.h>
  22 #include <openssl/decoder.h>
  23 #include <openssl/ui.h>
  24 #include "internal/cryptlib.h"
  25 #include "internal/passphrase.h"
  26 #include "crypto/asn1.h"
  27 #include "crypto/x509.h"
  28 #include "crypto/evp.h"
  29 #include "pem_local.h"
  30
  31 int ossl_pem_check_suffix(const char *pem_str, const char *suffix);
  32
  33 static EVP_PKEY *pem_read_bio_key_decoder(BIO *bp, EVP_PKEY **x,
  34                                           pem_password_cb *cb, void *u,
  35                                           OSSL_LIB_CTX *libctx,
  36                                           const char *propq,
  37                                           int selection)
  38 {
  39     EVP_PKEY *pkey = NULL;
  40     OSSL_DECODER_CTX *dctx = NULL;
  41     int pos, newpos;
  42
  43     if ((pos = BIO_tell(bp)) < 0)
  44         /* We can depend on BIO_tell() thanks to the BIO_f_readbuffer() */
  45         return NULL;
  46
  47     dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "PEM", NULL, NULL,
  48                                          selection, libctx, propq);
  49
  50     if (dctx == NULL)
  51         return NULL;
  52
  53     if (cb == NULL)
  54         cb = PEM_def_callback;
  55
  56     if (!OSSL_DECODER_CTX_set_pem_password_cb(dctx, cb, u))
  57         goto err;
  58
  59     ERR_set_mark();
  60     while (!OSSL_DECODER_from_bio(dctx, bp) || pkey == NULL)
  61         if (BIO_eof(bp) != 0 || (newpos = BIO_tell(bp)) < 0 || newpos <= pos) {
  62             ERR_clear_last_mark();
  63             goto err;
  64         } else {
  65             if (ERR_GET_REASON(ERR_peek_error()) == ERR_R_UNSUPPORTED) {
  66                 /* unsupported PEM data, try again */
  67                 ERR_pop_to_mark();
  68                 ERR_set_mark();
  69             } else {
  70                 /* other error, bail out */
  71                 ERR_clear_last_mark();
  72                 goto err;
  73             }
  74             pos = newpos;
  75         }
  76     ERR_pop_to_mark();
  77
  78     /* if we were asked for private key, the public key is optional */
  79     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
  80         selection = selection & ~OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
  81
  82     if (!evp_keymgmt_util_has(pkey, selection)) {
  83         EVP_PKEY_free(pkey);
  84         pkey = NULL;
  85         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
  86         goto err;
  87     }
  88
  89     if (x != NULL) {
  90         EVP_PKEY_free(*x);
  91         *x = pkey;
  92     }
  93
  94  err:
  95     OSSL_DECODER_CTX_free(dctx);
  96     return pkey;
  97 }
  98
  99 static EVP_PKEY *pem_read_bio_key_legacy(BIO *bp, EVP_PKEY **x,
 100                                          pem_password_cb *cb, void *u,
 101                                          OSSL_LIB_CTX *libctx,
 102                                          const char *propq,
 103                                          int selection)
 104 {
 105     char *nm = NULL;
 106     const unsigned char *p = NULL;
 107     unsigned char *data = NULL;
 108     long len;
 109     int slen;
 110     EVP_PKEY *ret = NULL;
 111
 112     ERR_set_mark();  /* not interested in PEM read errors */
 113     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {
 114         if (!PEM_bytes_read_bio_secmem(&data, &len, &nm,
 115                                        PEM_STRING_EVP_PKEY,
 116                                        bp, cb, u)) {
 117             ERR_pop_to_mark();
 118             return NULL;
 119          }
 120     } else {
 121         const char *pem_string = PEM_STRING_PARAMETERS;
 122
 123         if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
 124             pem_string = PEM_STRING_PUBLIC;
 125         if (!PEM_bytes_read_bio(&data, &len, &nm,
 126                                 pem_string,
 127                                 bp, cb, u)) {
 128             ERR_pop_to_mark();
 129             return NULL;
 130         }
 131     }
 132     ERR_clear_last_mark();
 133     p = data;
 134
 135     if (strcmp(nm, PEM_STRING_PKCS8INF) == 0) {
 136         PKCS8_PRIV_KEY_INFO *p8inf;
 137
 138         if ((p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len)) == NULL)
 139             goto p8err;
 140         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
 141         if (x != NULL) {
 142             EVP_PKEY_free(*x);
 143             *x = ret;
 144         }
 145         PKCS8_PRIV_KEY_INFO_free(p8inf);
 146     } else if (strcmp(nm, PEM_STRING_PKCS8) == 0) {
 147         PKCS8_PRIV_KEY_INFO *p8inf;
 148         X509_SIG *p8;
 149         int klen;
 150         char psbuf[PEM_BUFSIZE];
 151
 152         if ((p8 = d2i_X509_SIG(NULL, &p, len)) == NULL)
 153             goto p8err;
 154         if (cb != NULL)
 155             klen = cb(psbuf, PEM_BUFSIZE, 0, u);
 156         else
 157             klen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
 158         if (klen < 0) {
 159             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);
 160             X509_SIG_free(p8);
 161             goto err;
 162         }
 163         p8inf = PKCS8_decrypt(p8, psbuf, klen);
 164         X509_SIG_free(p8);
 165         OPENSSL_cleanse(psbuf, klen);
 166         if (p8inf == NULL)
 167             goto p8err;
 168         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
 169         if (x != NULL) {
 170             EVP_PKEY_free(*x);
 171             *x = ret;
 172         }
 173         PKCS8_PRIV_KEY_INFO_free(p8inf);
 174     } else if ((slen = ossl_pem_check_suffix(nm, "PRIVATE KEY")) > 0) {
 175         const EVP_PKEY_ASN1_METHOD *ameth;
 176         ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
 177         if (ameth == NULL || ameth->old_priv_decode == NULL)
 178             goto p8err;
 179         ret = ossl_d2i_PrivateKey_legacy(ameth->pkey_id, x, &p, len, libctx,
 180                                          propq);
 181     } else if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) == 0
 182                && (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0) {
 183         /* Trying legacy PUBKEY decoding only if we do not want private key. */
 184         ret = ossl_d2i_PUBKEY_legacy(x, &p, len);
 185     } else if ((selection & EVP_PKEY_KEYPAIR) == 0
 186                && (slen = ossl_pem_check_suffix(nm, "PARAMETERS")) > 0) {
 187         /* Trying legacy params decoding only if we do not want a key. */
 188         ret = EVP_PKEY_new();
 189         if (ret == NULL)
 190             goto err;
 191         if (!EVP_PKEY_set_type_str(ret, nm, slen)
 192             || !ret->ameth->param_decode
 193             || !ret->ameth->param_decode(ret, &p, len)) {
 194             EVP_PKEY_free(ret);
 195             ret = NULL;
 196             goto err;
 197         }
 198         if (x) {
 199             EVP_PKEY_free(*x);
 200             *x = ret;
 201         }
 202     }
 203
 204  p8err:
 205     if (ret == NULL && ERR_peek_last_error() == 0)
 206         /* ensure some error is reported but do not hide the real one */
 207         ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);
 208  err:
 209     OPENSSL_secure_free(nm);
 210     OPENSSL_secure_clear_free(data, len);
 211     return ret;
 212 }
 213
 214 static EVP_PKEY *pem_read_bio_key(BIO *bp, EVP_PKEY **x,
 215                                   pem_password_cb *cb, void *u,
 216                                   OSSL_LIB_CTX *libctx,
 217                                   const char *propq,
 218                                   int selection)
 219 {
 220     EVP_PKEY *ret = NULL;
 221     BIO *new_bio = NULL;
 222     int pos;
 223     struct ossl_passphrase_data_st pwdata = { 0 };
 224
 225     if ((pos = BIO_tell(bp)) < 0) {
 226         new_bio = BIO_new(BIO_f_readbuffer());
 227         if (new_bio == NULL)
 228             return NULL;
 229         bp = BIO_push(new_bio, bp);
 230         pos = BIO_tell(bp);
 231     }
 232
 233     if (cb == NULL)
 234         cb = PEM_def_callback;
 235
 236     if (!ossl_pw_set_pem_password_cb(&pwdata, cb, u)
 237         || !ossl_pw_enable_passphrase_caching(&pwdata))
 238         goto err;
 239
 240     ERR_set_mark();
 241     ret = pem_read_bio_key_decoder(bp, x, ossl_pw_pem_password, &pwdata,
 242                                    libctx, propq, selection);
 243     if (ret == NULL
 244         && (BIO_seek(bp, pos) < 0
 245             || (ret = pem_read_bio_key_legacy(bp, x,
 246                                               ossl_pw_pem_password, &pwdata,
 247                                               libctx, propq,
 248                                               selection)) == NULL))
 249         ERR_clear_last_mark();
 250     else
 251         ERR_pop_to_mark();
 252
 253  err:
 254     ossl_pw_clear_passphrase_data(&pwdata);
 255     if (new_bio != NULL) {
 256         BIO_pop(new_bio);
 257         BIO_free(new_bio);
 258     }
 259     return ret;
 260 }
 261
 262 EVP_PKEY *PEM_read_bio_PUBKEY_ex(BIO *bp, EVP_PKEY **x,
 263                                  pem_password_cb *cb, void *u,
 264                                  OSSL_LIB_CTX *libctx, const char *propq)
 265 {
 266     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
 267                             EVP_PKEY_PUBLIC_KEY);
 268 }
 269
 270 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
 271                               void *u)
 272 {
 273     return PEM_read_bio_PUBKEY_ex(bp, x, cb, u, NULL, NULL);
 274 }
 275
 276 #ifndef OPENSSL_NO_STDIO
 277 EVP_PKEY *PEM_read_PUBKEY_ex(FILE *fp, EVP_PKEY **x,
 278                              pem_password_cb *cb, void *u,
 279                              OSSL_LIB_CTX *libctx, const char *propq)
 280 {
 281     BIO *b;
 282     EVP_PKEY *ret;
 283
 284     if ((b = BIO_new(BIO_s_file())) == NULL) {
 285         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 286         return 0;
 287     }
 288     BIO_set_fp(b, fp, BIO_NOCLOSE);
 289     ret = PEM_read_bio_PUBKEY_ex(b, x, cb, u, libctx, propq);
 290     BIO_free(b);
 291     return ret;
 292 }
 293
 294 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, pem_password_cb *cb, void *u)
 295 {
 296     return PEM_read_PUBKEY_ex(fp, x, cb, u, NULL, NULL);
 297 }
 298 #endif
 299
 300 EVP_PKEY *PEM_read_bio_PrivateKey_ex(BIO *bp, EVP_PKEY **x,
 301                                      pem_password_cb *cb, void *u,
 302                                      OSSL_LIB_CTX *libctx, const char *propq)
 303 {
 304     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
 305                             /* we also want the public key, if available */
 306                             EVP_PKEY_KEYPAIR);
 307 }
 308
 309 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
 310                                   void *u)
 311 {
 312     return PEM_read_bio_PrivateKey_ex(bp, x, cb, u, NULL, NULL);
 313 }
 314
 315 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
 316 {
 317     IMPLEMENT_PEM_provided_write_body_vars(pkey, PrivateKey, propq);
 318
 319     IMPLEMENT_PEM_provided_write_body_pass();
 320     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
 321
 322  legacy:
 323     if (x != NULL && (x->ameth == NULL || x->ameth->priv_encode != NULL))
 324         return PEM_write_bio_PKCS8PrivateKey(out, x, enc,
 325                                              (const char *)kstr, klen, cb, u);
 326     return PEM_write_bio_PrivateKey_traditional(out, x, enc, kstr, klen, cb, u);
 327 }
 328
 329 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
 330 {
 331     return PEM_write_bio_PrivateKey_ex(out, x, enc, kstr, klen, cb, u,
 332                                        NULL, NULL);
 333 }
 334
 335 /*
 336  * Note: there is no way to tell a provided pkey encoder to use "traditional"
 337  * encoding.  Therefore, if the pkey is provided, we try to take a copy
 338  */
 339 int PEM_write_bio_PrivateKey_traditional(BIO *bp, const EVP_PKEY *x,
 340                                          const EVP_CIPHER *enc,
 341                                          const unsigned char *kstr, int klen,
 342                                          pem_password_cb *cb, void *u)
 343 {
 344     char pem_str[80];
 345     EVP_PKEY *copy = NULL;
 346     int ret;
 347
 348     if (x == NULL)
 349         return 0;
 350
 351     if (evp_pkey_is_assigned(x)
 352         && evp_pkey_is_provided(x)
 353         && evp_pkey_copy_downgraded(&copy, x))
 354         x = copy;
 355
 356     if (x->ameth == NULL || x->ameth->old_priv_encode == NULL) {
 357         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
 358         EVP_PKEY_free(copy);
 359         return 0;
 360     }
 361     BIO_snprintf(pem_str, 80, "%s PRIVATE KEY", x->ameth->pem_str);
 362     ret = PEM_ASN1_write_bio((i2d_of_void *)i2d_PrivateKey,
 363                              pem_str, bp, x, enc, kstr, klen, cb, u);
 364
 365     EVP_PKEY_free(copy);
 366     return ret;
 367 }
 368
 369 static int no_password_cb(char *buf, int num, int rwflag, void *userdata)
 370 {
 371     return -1;
 372 }
 373
 374 EVP_PKEY *PEM_read_bio_Parameters_ex(BIO *bp, EVP_PKEY **x,
 375                                      OSSL_LIB_CTX *libctx, const char *propq)
 376 {
 377     /*
 378      * PEM_read_bio_Parameters(_ex) should never ask for a password. Any attempt
 379      * to get a password just fails.
 380      */
 381     return pem_read_bio_key(bp, x, no_password_cb, NULL, libctx, propq,
 382                             EVP_PKEY_KEY_PARAMETERS);
 383 }
 384
 385 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x)
 386 {
 387     return PEM_read_bio_Parameters_ex(bp, x, NULL, NULL);
 388 }
 389
 390 PEM_write_fnsig(Parameters, EVP_PKEY, BIO, write_bio)
 391 {
 392     char pem_str[80];
 393     IMPLEMENT_PEM_provided_write_body_vars(pkey, Parameters, NULL);
 394
 395     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
 396
 397  legacy:
 398     if (!x->ameth || !x->ameth->param_encode)
 399         return 0;
 400
 401     BIO_snprintf(pem_str, 80, "%s PARAMETERS", x->ameth->pem_str);
 402     return PEM_ASN1_write_bio((i2d_of_void *)x->ameth->param_encode,
 403                               pem_str, out, x, NULL, NULL, 0, 0, NULL);
 404 }
 405
 406 #ifndef OPENSSL_NO_STDIO
 407 EVP_PKEY *PEM_read_PrivateKey_ex(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
 408                                  void *u, OSSL_LIB_CTX *libctx,
 409                                  const char *propq)
 410 {
 411     BIO *b;
 412     EVP_PKEY *ret;
 413
 414     if ((b = BIO_new(BIO_s_file())) == NULL) {
 415         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 416         return 0;
 417     }
 418     BIO_set_fp(b, fp, BIO_NOCLOSE);
 419     ret = PEM_read_bio_PrivateKey_ex(b, x, cb, u, libctx, propq);
 420     BIO_free(b);
 421     return ret;
 422 }
 423
 424 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
 425                               void *u)
 426 {
 427     return PEM_read_PrivateKey_ex(fp, x, cb, u, NULL, NULL);
 428 }
 429
 430 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, FILE, write)
 431 {
 432     BIO *b;
 433     int ret;
 434
 435     if ((b = BIO_new_fp(out, BIO_NOCLOSE)) == NULL) {
 436         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
 437         return 0;
 438     }
 439     ret = PEM_write_bio_PrivateKey_ex(b, x, enc, kstr, klen, cb, u,
 440                                       libctx, propq);
 441     BIO_free(b);
 442     return ret;
 443 }
 444
 445 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, FILE, write)
 446 {
 447     return PEM_write_PrivateKey_ex(out, x, enc, kstr, klen, cb, u, NULL, NULL);
 448 }
 449 #endif