1=pod 2 3=head1 NAME 4 5pem_password_cb, 6PEM_read_bio_PrivateKey, PEM_read_PrivateKey, PEM_write_bio_PrivateKey, 7PEM_write_bio_PrivateKey_traditional, PEM_write_PrivateKey, 8PEM_write_bio_PKCS8PrivateKey, PEM_write_PKCS8PrivateKey, 9PEM_write_bio_PKCS8PrivateKey_nid, PEM_write_PKCS8PrivateKey_nid, 10PEM_read_bio_PUBKEY, PEM_read_PUBKEY, PEM_write_bio_PUBKEY, PEM_write_PUBKEY, 11PEM_read_bio_RSAPrivateKey, PEM_read_RSAPrivateKey, 12PEM_write_bio_RSAPrivateKey, PEM_write_RSAPrivateKey, 13PEM_read_bio_RSAPublicKey, PEM_read_RSAPublicKey, PEM_write_bio_RSAPublicKey, 14PEM_write_RSAPublicKey, PEM_read_bio_RSA_PUBKEY, PEM_read_RSA_PUBKEY, 15PEM_write_bio_RSA_PUBKEY, PEM_write_RSA_PUBKEY, PEM_read_bio_DSAPrivateKey, 16PEM_read_DSAPrivateKey, PEM_write_bio_DSAPrivateKey, PEM_write_DSAPrivateKey, 17PEM_read_bio_DSA_PUBKEY, PEM_read_DSA_PUBKEY, PEM_write_bio_DSA_PUBKEY, 18PEM_write_DSA_PUBKEY, PEM_read_bio_Parameters, PEM_write_bio_Parameters, 19PEM_read_bio_DSAparams, PEM_read_DSAparams, 20PEM_write_bio_DSAparams, PEM_write_DSAparams, PEM_read_bio_DHparams, 21PEM_read_DHparams, PEM_write_bio_DHparams, PEM_write_DHparams, 22PEM_read_bio_X509, PEM_read_X509, PEM_write_bio_X509, PEM_write_X509, 23PEM_read_bio_X509_AUX, PEM_read_X509_AUX, PEM_write_bio_X509_AUX, 24PEM_write_X509_AUX, PEM_read_bio_X509_REQ, PEM_read_X509_REQ, 25PEM_write_bio_X509_REQ, PEM_write_X509_REQ, PEM_write_bio_X509_REQ_NEW, 26PEM_write_X509_REQ_NEW, PEM_read_bio_X509_CRL, PEM_read_X509_CRL, 27PEM_write_bio_X509_CRL, PEM_write_X509_CRL, PEM_read_bio_PKCS7, PEM_read_PKCS7, 28PEM_write_bio_PKCS7, PEM_write_PKCS7 - PEM routines 29 30=head1 SYNOPSIS 31 32 #include <openssl/pem.h> 33 34 typedef int pem_password_cb(char *buf, int size, int rwflag, void *u); 35 36 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, 37 pem_password_cb *cb, void *u); 38 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, 39 pem_password_cb *cb, void *u); 40 int PEM_write_bio_PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc, 41 unsigned char *kstr, int klen, 42 pem_password_cb *cb, void *u); 43 int PEM_write_bio_PrivateKey_traditional(BIO *bp, EVP_PKEY *x, 44 const EVP_CIPHER *enc, 45 unsigned char *kstr, int klen, 46 pem_password_cb *cb, void *u); 47 int PEM_write_PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 48 unsigned char *kstr, int klen, 49 pem_password_cb *cb, void *u); 50 51 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc, 52 char *kstr, int klen, 53 pem_password_cb *cb, void *u); 54 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 55 char *kstr, int klen, 56 pem_password_cb *cb, void *u); 57 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, EVP_PKEY *x, int nid, 58 char *kstr, int klen, 59 pem_password_cb *cb, void *u); 60 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, EVP_PKEY *x, int nid, 61 char *kstr, int klen, 62 pem_password_cb *cb, void *u); 63 64 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, 65 pem_password_cb *cb, void *u); 66 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, 67 pem_password_cb *cb, void *u); 68 int PEM_write_bio_PUBKEY(BIO *bp, EVP_PKEY *x); 69 int PEM_write_PUBKEY(FILE *fp, EVP_PKEY *x); 70 71 RSA *PEM_read_bio_RSAPrivateKey(BIO *bp, RSA **x, 72 pem_password_cb *cb, void *u); 73 RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **x, 74 pem_password_cb *cb, void *u); 75 int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER *enc, 76 unsigned char *kstr, int klen, 77 pem_password_cb *cb, void *u); 78 int PEM_write_RSAPrivateKey(FILE *fp, RSA *x, const EVP_CIPHER *enc, 79 unsigned char *kstr, int klen, 80 pem_password_cb *cb, void *u); 81 82 RSA *PEM_read_bio_RSAPublicKey(BIO *bp, RSA **x, 83 pem_password_cb *cb, void *u); 84 RSA *PEM_read_RSAPublicKey(FILE *fp, RSA **x, 85 pem_password_cb *cb, void *u); 86 int PEM_write_bio_RSAPublicKey(BIO *bp, RSA *x); 87 int PEM_write_RSAPublicKey(FILE *fp, RSA *x); 88 89 RSA *PEM_read_bio_RSA_PUBKEY(BIO *bp, RSA **x, 90 pem_password_cb *cb, void *u); 91 RSA *PEM_read_RSA_PUBKEY(FILE *fp, RSA **x, 92 pem_password_cb *cb, void *u); 93 int PEM_write_bio_RSA_PUBKEY(BIO *bp, RSA *x); 94 int PEM_write_RSA_PUBKEY(FILE *fp, RSA *x); 95 96 DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **x, 97 pem_password_cb *cb, void *u); 98 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **x, 99 pem_password_cb *cb, void *u); 100 int PEM_write_bio_DSAPrivateKey(BIO *bp, DSA *x, const EVP_CIPHER *enc, 101 unsigned char *kstr, int klen, 102 pem_password_cb *cb, void *u); 103 int PEM_write_DSAPrivateKey(FILE *fp, DSA *x, const EVP_CIPHER *enc, 104 unsigned char *kstr, int klen, 105 pem_password_cb *cb, void *u); 106 107 DSA *PEM_read_bio_DSA_PUBKEY(BIO *bp, DSA **x, 108 pem_password_cb *cb, void *u); 109 DSA *PEM_read_DSA_PUBKEY(FILE *fp, DSA **x, 110 pem_password_cb *cb, void *u); 111 int PEM_write_bio_DSA_PUBKEY(BIO *bp, DSA *x); 112 int PEM_write_DSA_PUBKEY(FILE *fp, DSA *x); 113 114 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x); 115 int PEM_write_bio_Parameters(BIO *bp, const EVP_PKEY *x); 116 117 DSA *PEM_read_bio_DSAparams(BIO *bp, DSA **x, pem_password_cb *cb, void *u); 118 DSA *PEM_read_DSAparams(FILE *fp, DSA **x, pem_password_cb *cb, void *u); 119 int PEM_write_bio_DSAparams(BIO *bp, DSA *x); 120 int PEM_write_DSAparams(FILE *fp, DSA *x); 121 122 DH *PEM_read_bio_DHparams(BIO *bp, DH **x, pem_password_cb *cb, void *u); 123 DH *PEM_read_DHparams(FILE *fp, DH **x, pem_password_cb *cb, void *u); 124 int PEM_write_bio_DHparams(BIO *bp, DH *x); 125 int PEM_write_DHparams(FILE *fp, DH *x); 126 127 X509 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 128 X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 129 int PEM_write_bio_X509(BIO *bp, X509 *x); 130 int PEM_write_X509(FILE *fp, X509 *x); 131 132 X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 133 X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 134 int PEM_write_bio_X509_AUX(BIO *bp, X509 *x); 135 int PEM_write_X509_AUX(FILE *fp, X509 *x); 136 137 X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x, 138 pem_password_cb *cb, void *u); 139 X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x, 140 pem_password_cb *cb, void *u); 141 int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x); 142 int PEM_write_X509_REQ(FILE *fp, X509_REQ *x); 143 int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x); 144 int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *x); 145 146 X509_CRL *PEM_read_bio_X509_CRL(BIO *bp, X509_CRL **x, 147 pem_password_cb *cb, void *u); 148 X509_CRL *PEM_read_X509_CRL(FILE *fp, X509_CRL **x, 149 pem_password_cb *cb, void *u); 150 int PEM_write_bio_X509_CRL(BIO *bp, X509_CRL *x); 151 int PEM_write_X509_CRL(FILE *fp, X509_CRL *x); 152 153 PKCS7 *PEM_read_bio_PKCS7(BIO *bp, PKCS7 **x, pem_password_cb *cb, void *u); 154 PKCS7 *PEM_read_PKCS7(FILE *fp, PKCS7 **x, pem_password_cb *cb, void *u); 155 int PEM_write_bio_PKCS7(BIO *bp, PKCS7 *x); 156 int PEM_write_PKCS7(FILE *fp, PKCS7 *x); 157 158=head1 DESCRIPTION 159 160The PEM functions read or write structures in PEM format. In 161this sense PEM format is simply base64 encoded data surrounded 162by header lines. 163 164For more details about the meaning of arguments see the 165B<PEM FUNCTION ARGUMENTS> section. 166 167Each operation has four functions associated with it. For 168brevity the term "B<TYPE> functions" will be used below to collectively 169refer to the PEM_read_bio_TYPE(), PEM_read_TYPE(), 170PEM_write_bio_TYPE(), and PEM_write_TYPE() functions. 171 172The B<PrivateKey> functions read or write a private key in PEM format using an 173EVP_PKEY structure. The write routines use PKCS#8 private key format and are 174equivalent to PEM_write_bio_PKCS8PrivateKey().The read functions transparently 175handle traditional and PKCS#8 format encrypted and unencrypted keys. 176 177PEM_write_bio_PrivateKey_traditional() writes out a private key in the 178"traditional" format with a simple private key marker and should only 179be used for compatibility with legacy programs. 180 181PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a private 182key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo format using 183PKCS#5 v2.0 password based encryption algorithms. The B<cipher> argument 184specifies the encryption algorithm to use: unlike some other PEM routines the 185encryption is applied at the PKCS#8 level and not in the PEM headers. If 186B<cipher> is NULL then no encryption is used and a PKCS#8 PrivateKeyInfo 187structure is used instead. 188 189PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid() 190also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo however 191it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead. The algorithm 192to use is specified in the B<nid> parameter and should be the NID of the 193corresponding OBJECT IDENTIFIER (see NOTES section). 194 195The B<PUBKEY> functions process a public key using an EVP_PKEY 196structure. The public key is encoded as a SubjectPublicKeyInfo 197structure. 198 199The B<RSAPrivateKey> functions process an RSA private key using an 200RSA structure. The write routines uses traditional format. The read 201routines handles the same formats as the B<PrivateKey> 202functions but an error occurs if the private key is not RSA. 203 204The B<RSAPublicKey> functions process an RSA public key using an 205RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey 206structure. 207 208The B<RSA_PUBKEY> functions also process an RSA public key using 209an RSA structure. However, the public key is encoded using a 210SubjectPublicKeyInfo structure and an error occurs if the public 211key is not RSA. 212 213The B<DSAPrivateKey> functions process a DSA private key using a 214DSA structure. The write routines uses traditional format. The read 215routines handles the same formats as the B<PrivateKey> 216functions but an error occurs if the private key is not DSA. 217 218The B<DSA_PUBKEY> functions process a DSA public key using 219a DSA structure. The public key is encoded using a 220SubjectPublicKeyInfo structure and an error occurs if the public 221key is not DSA. 222 223The B<Parameters> functions read or write key parameters in PEM format using 224an EVP_PKEY structure. The encoding depends on the type of key; for DSA key 225parameters, it will be a Dss-Parms structure as defined in RFC2459, and for DH 226key parameters, it will be a PKCS#3 DHparameter structure. I<These functions 227only exist for the B<BIO> type>. 228 229The B<DSAparams> functions process DSA parameters using a DSA 230structure. The parameters are encoded using a Dss-Parms structure 231as defined in RFC2459. 232 233The B<DHparams> functions process DH parameters using a DH 234structure. The parameters are encoded using a PKCS#3 DHparameter 235structure. 236 237The B<X509> functions process an X509 certificate using an X509 238structure. They will also process a trusted X509 certificate but 239any trust settings are discarded. 240 241The B<X509_AUX> functions process a trusted X509 certificate using 242an X509 structure. 243 244The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10 245certificate request using an X509_REQ structure. The B<X509_REQ> 246write functions use B<CERTIFICATE REQUEST> in the header whereas 247the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST> 248(as required by some CAs). The B<X509_REQ> read functions will 249handle either form so there are no B<X509_REQ_NEW> read functions. 250 251The B<X509_CRL> functions process an X509 CRL using an X509_CRL 252structure. 253 254The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7 255structure. 256 257=head1 PEM FUNCTION ARGUMENTS 258 259The PEM functions have many common arguments. 260 261The B<bp> BIO parameter (if present) specifies the BIO to read from 262or write to. 263 264The B<fp> FILE parameter (if present) specifies the FILE pointer to 265read from or write to. 266 267The PEM read functions all take an argument B<TYPE **x> and return 268a B<TYPE *> pointer. Where B<TYPE> is whatever structure the function 269uses. If B<x> is NULL then the parameter is ignored. If B<x> is not 270NULL but B<*x> is NULL then the structure returned will be written 271to B<*x>. If neither B<x> nor B<*x> is NULL then an attempt is made 272to reuse the structure at B<*x> (but see BUGS and EXAMPLES sections). 273Irrespective of the value of B<x> a pointer to the structure is always 274returned (or NULL if an error occurred). 275 276The PEM functions which write private keys take an B<enc> parameter 277which specifies the encryption algorithm to use, encryption is done 278at the PEM level. If this parameter is set to NULL then the private 279key is written in unencrypted form. 280 281The B<cb> argument is the callback to use when querying for the pass 282phrase used for encrypted PEM structures (normally only private keys). 283 284For the PEM write routines if the B<kstr> parameter is not NULL then 285B<klen> bytes at B<kstr> are used as the passphrase and B<cb> is 286ignored. 287 288If the B<cb> parameters is set to NULL and the B<u> parameter is not 289NULL then the B<u> parameter is interpreted as a null terminated string 290to use as the passphrase. If both B<cb> and B<u> are NULL then the 291default callback routine is used which will typically prompt for the 292passphrase on the current terminal with echoing turned off. 293 294The default passphrase callback is sometimes inappropriate (for example 295in a GUI application) so an alternative can be supplied. The callback 296routine has the following form: 297 298 int cb(char *buf, int size, int rwflag, void *u); 299 300B<buf> is the buffer to write the passphrase to. B<size> is the maximum 301length of the passphrase (i.e. the size of buf). B<rwflag> is a flag 302which is set to 0 when reading and 1 when writing. A typical routine 303will ask the user to verify the passphrase (for example by prompting 304for it twice) if B<rwflag> is 1. The B<u> parameter has the same 305value as the B<u> parameter passed to the PEM routine. It allows 306arbitrary data to be passed to the callback by the application 307(for example a window handle in a GUI application). The callback 308B<must> return the number of characters in the passphrase or -1 if 309an error occurred. 310 311=head1 NOTES 312 313The old B<PrivateKey> write routines are retained for compatibility. 314New applications should write private keys using the 315PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines 316because they are more secure (they use an iteration count of 2048 whereas 317the traditional routines use a count of 1) unless compatibility with older 318versions of OpenSSL is important. 319 320The B<PrivateKey> read routines can be used in all applications because 321they handle all formats transparently. 322 323A frequent cause of problems is attempting to use the PEM routines like 324this: 325 326 X509 *x; 327 328 PEM_read_bio_X509(bp, &x, 0, NULL); 329 330this is a bug because an attempt will be made to reuse the data at B<x> 331which is an uninitialised pointer. 332 333These functions make no assumption regarding the pass phrase received from the 334password callback. 335It will simply be treated as a byte sequence. 336 337=head1 PEM ENCRYPTION FORMAT 338 339These old B<PrivateKey> routines use a non standard technique for encryption. 340 341The private key (or other data) takes the following form: 342 343 -----BEGIN RSA PRIVATE KEY----- 344 Proc-Type: 4,ENCRYPTED 345 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89 346 347 ...base64 encoded data... 348 -----END RSA PRIVATE KEY----- 349 350The line beginning with I<Proc-Type> contains the version and the 351protection on the encapsulated data. The line beginning I<DEK-Info> 352contains two comma separated values: the encryption algorithm name as 353used by EVP_get_cipherbyname() and an initialization vector used by the 354cipher encoded as a set of hexadecimal digits. After those two lines is 355the base64-encoded encrypted data. 356 357The encryption key is derived using EVP_BytesToKey(). The cipher's 358initialization vector is passed to EVP_BytesToKey() as the B<salt> 359parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used 360(regardless of the size of the initialization vector). The user's 361password is passed to EVP_BytesToKey() using the B<data> and B<datal> 362parameters. Finally, the library uses an iteration count of 1 for 363EVP_BytesToKey(). 364 365The B<key> derived by EVP_BytesToKey() along with the original initialization 366vector is then used to decrypt the encrypted data. The B<iv> produced by 367EVP_BytesToKey() is not utilized or needed, and NULL should be passed to 368the function. 369 370The pseudo code to derive the key would look similar to: 371 372 EVP_CIPHER* cipher = EVP_des_ede3_cbc(); 373 EVP_MD* md = EVP_md5(); 374 375 unsigned int nkey = EVP_CIPHER_key_length(cipher); 376 unsigned int niv = EVP_CIPHER_iv_length(cipher); 377 unsigned char key[nkey]; 378 unsigned char iv[niv]; 379 380 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv); 381 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/); 382 if (rc != nkey) 383 /* Error */ 384 385 /* On success, use key and iv to initialize the cipher */ 386 387=head1 BUGS 388 389The PEM read routines in some versions of OpenSSL will not correctly reuse 390an existing structure. Therefore, the following: 391 392 PEM_read_bio_X509(bp, &x, 0, NULL); 393 394where B<x> already contains a valid certificate, may not work, whereas: 395 396 X509_free(x); 397 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 398 399is guaranteed to work. 400 401=head1 RETURN VALUES 402 403The read routines return either a pointer to the structure read or NULL 404if an error occurred. 405 406The write routines return 1 for success or 0 for failure. 407 408=head1 EXAMPLES 409 410Although the PEM routines take several arguments in almost all applications 411most of them are set to 0 or NULL. 412 413Read a certificate in PEM format from a BIO: 414 415 X509 *x; 416 417 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 418 if (x == NULL) 419 /* Error */ 420 421Alternative method: 422 423 X509 *x = NULL; 424 425 if (!PEM_read_bio_X509(bp, &x, 0, NULL)) 426 /* Error */ 427 428Write a certificate to a BIO: 429 430 if (!PEM_write_bio_X509(bp, x)) 431 /* Error */ 432 433Write a private key (using traditional format) to a BIO using 434triple DES encryption, the pass phrase is prompted for: 435 436 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL)) 437 /* Error */ 438 439Write a private key (using PKCS#8 format) to a BIO using triple 440DES encryption, using the pass phrase "hello": 441 442 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(), 443 NULL, 0, 0, "hello")) 444 /* Error */ 445 446Read a private key from a BIO using a pass phrase callback: 447 448 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key"); 449 if (key == NULL) 450 /* Error */ 451 452Skeleton pass phrase callback: 453 454 int pass_cb(char *buf, int size, int rwflag, void *u) 455 { 456 457 /* We'd probably do something else if 'rwflag' is 1 */ 458 printf("Enter pass phrase for \"%s\"\n", (char *)u); 459 460 /* get pass phrase, length 'len' into 'tmp' */ 461 char *tmp = "hello"; 462 if (tmp == NULL) /* An error occurred */ 463 return -1; 464 465 size_t len = strlen(tmp); 466 467 if (len > size) 468 len = size; 469 memcpy(buf, tmp, len); 470 return len; 471 } 472 473=head1 SEE ALSO 474 475L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>, 476L<passphrase-encoding(7)> 477 478=head1 HISTORY 479 480The old Netscape certificate sequences were no longer documented 481in OpenSSL 1.1.0; applications should use the PKCS7 standard instead 482as they will be formally deprecated in a future releases. 483 484=head1 COPYRIGHT 485 486Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved. 487 488Licensed under the OpenSSL license (the "License"). You may not use 489this file except in compliance with the License. You can obtain a copy 490in the file LICENSE in the source distribution or at 491L<https://www.openssl.org/source/license.html>. 492 493=cut 494