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_DSAparams, PEM_read_DSAparams, 19PEM_write_bio_DSAparams, PEM_write_DSAparams, PEM_read_bio_DHparams, 20PEM_read_DHparams, PEM_write_bio_DHparams, PEM_write_DHparams, 21PEM_read_bio_X509, PEM_read_X509, PEM_write_bio_X509, PEM_write_X509, 22PEM_read_bio_X509_AUX, PEM_read_X509_AUX, PEM_write_bio_X509_AUX, 23PEM_write_X509_AUX, PEM_read_bio_X509_REQ, PEM_read_X509_REQ, 24PEM_write_bio_X509_REQ, PEM_write_X509_REQ, PEM_write_bio_X509_REQ_NEW, 25PEM_write_X509_REQ_NEW, PEM_read_bio_X509_CRL, PEM_read_X509_CRL, 26PEM_write_bio_X509_CRL, PEM_write_X509_CRL, PEM_read_bio_PKCS7, PEM_read_PKCS7, 27PEM_write_bio_PKCS7, PEM_write_PKCS7 - PEM routines 28 29=head1 SYNOPSIS 30 31 #include <openssl/pem.h> 32 33 typedef int pem_password_cb(char *buf, int size, int rwflag, void *u); 34 35 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, 36 pem_password_cb *cb, void *u); 37 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, 38 pem_password_cb *cb, void *u); 39 int PEM_write_bio_PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc, 40 unsigned char *kstr, int klen, 41 pem_password_cb *cb, void *u); 42 int PEM_write_bio_PrivateKey_traditional(BIO *bp, EVP_PKEY *x, 43 const EVP_CIPHER *enc, 44 unsigned char *kstr, int klen, 45 pem_password_cb *cb, void *u); 46 int PEM_write_PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 47 unsigned char *kstr, int klen, 48 pem_password_cb *cb, void *u); 49 50 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc, 51 char *kstr, int klen, 52 pem_password_cb *cb, void *u); 53 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 54 char *kstr, int klen, 55 pem_password_cb *cb, void *u); 56 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, EVP_PKEY *x, int nid, 57 char *kstr, int klen, 58 pem_password_cb *cb, void *u); 59 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, EVP_PKEY *x, int nid, 60 char *kstr, int klen, 61 pem_password_cb *cb, void *u); 62 63 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, 64 pem_password_cb *cb, void *u); 65 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, 66 pem_password_cb *cb, void *u); 67 int PEM_write_bio_PUBKEY(BIO *bp, EVP_PKEY *x); 68 int PEM_write_PUBKEY(FILE *fp, EVP_PKEY *x); 69 70 RSA *PEM_read_bio_RSAPrivateKey(BIO *bp, RSA **x, 71 pem_password_cb *cb, void *u); 72 RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **x, 73 pem_password_cb *cb, void *u); 74 int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER *enc, 75 unsigned char *kstr, int klen, 76 pem_password_cb *cb, void *u); 77 int PEM_write_RSAPrivateKey(FILE *fp, RSA *x, const EVP_CIPHER *enc, 78 unsigned char *kstr, int klen, 79 pem_password_cb *cb, void *u); 80 81 RSA *PEM_read_bio_RSAPublicKey(BIO *bp, RSA **x, 82 pem_password_cb *cb, void *u); 83 RSA *PEM_read_RSAPublicKey(FILE *fp, RSA **x, 84 pem_password_cb *cb, void *u); 85 int PEM_write_bio_RSAPublicKey(BIO *bp, RSA *x); 86 int PEM_write_RSAPublicKey(FILE *fp, RSA *x); 87 88 RSA *PEM_read_bio_RSA_PUBKEY(BIO *bp, RSA **x, 89 pem_password_cb *cb, void *u); 90 RSA *PEM_read_RSA_PUBKEY(FILE *fp, RSA **x, 91 pem_password_cb *cb, void *u); 92 int PEM_write_bio_RSA_PUBKEY(BIO *bp, RSA *x); 93 int PEM_write_RSA_PUBKEY(FILE *fp, RSA *x); 94 95 DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **x, 96 pem_password_cb *cb, void *u); 97 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **x, 98 pem_password_cb *cb, void *u); 99 int PEM_write_bio_DSAPrivateKey(BIO *bp, DSA *x, const EVP_CIPHER *enc, 100 unsigned char *kstr, int klen, 101 pem_password_cb *cb, void *u); 102 int PEM_write_DSAPrivateKey(FILE *fp, DSA *x, const EVP_CIPHER *enc, 103 unsigned char *kstr, int klen, 104 pem_password_cb *cb, void *u); 105 106 DSA *PEM_read_bio_DSA_PUBKEY(BIO *bp, DSA **x, 107 pem_password_cb *cb, void *u); 108 DSA *PEM_read_DSA_PUBKEY(FILE *fp, DSA **x, 109 pem_password_cb *cb, void *u); 110 int PEM_write_bio_DSA_PUBKEY(BIO *bp, DSA *x); 111 int PEM_write_DSA_PUBKEY(FILE *fp, DSA *x); 112 113 DSA *PEM_read_bio_DSAparams(BIO *bp, DSA **x, pem_password_cb *cb, void *u); 114 DSA *PEM_read_DSAparams(FILE *fp, DSA **x, pem_password_cb *cb, void *u); 115 int PEM_write_bio_DSAparams(BIO *bp, DSA *x); 116 int PEM_write_DSAparams(FILE *fp, DSA *x); 117 118 DH *PEM_read_bio_DHparams(BIO *bp, DH **x, pem_password_cb *cb, void *u); 119 DH *PEM_read_DHparams(FILE *fp, DH **x, pem_password_cb *cb, void *u); 120 int PEM_write_bio_DHparams(BIO *bp, DH *x); 121 int PEM_write_DHparams(FILE *fp, DH *x); 122 123 X509 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 124 X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 125 int PEM_write_bio_X509(BIO *bp, X509 *x); 126 int PEM_write_X509(FILE *fp, X509 *x); 127 128 X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 129 X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 130 int PEM_write_bio_X509_AUX(BIO *bp, X509 *x); 131 int PEM_write_X509_AUX(FILE *fp, X509 *x); 132 133 X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x, 134 pem_password_cb *cb, void *u); 135 X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x, 136 pem_password_cb *cb, void *u); 137 int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x); 138 int PEM_write_X509_REQ(FILE *fp, X509_REQ *x); 139 int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x); 140 int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *x); 141 142 X509_CRL *PEM_read_bio_X509_CRL(BIO *bp, X509_CRL **x, 143 pem_password_cb *cb, void *u); 144 X509_CRL *PEM_read_X509_CRL(FILE *fp, X509_CRL **x, 145 pem_password_cb *cb, void *u); 146 int PEM_write_bio_X509_CRL(BIO *bp, X509_CRL *x); 147 int PEM_write_X509_CRL(FILE *fp, X509_CRL *x); 148 149 PKCS7 *PEM_read_bio_PKCS7(BIO *bp, PKCS7 **x, pem_password_cb *cb, void *u); 150 PKCS7 *PEM_read_PKCS7(FILE *fp, PKCS7 **x, pem_password_cb *cb, void *u); 151 int PEM_write_bio_PKCS7(BIO *bp, PKCS7 *x); 152 int PEM_write_PKCS7(FILE *fp, PKCS7 *x); 153 154=head1 DESCRIPTION 155 156The PEM functions read or write structures in PEM format. In 157this sense PEM format is simply base64 encoded data surrounded 158by header lines. 159 160For more details about the meaning of arguments see the 161B<PEM FUNCTION ARGUMENTS> section. 162 163Each operation has four functions associated with it. For 164brevity the term "B<TYPE> functions" will be used below to collectively 165refer to the PEM_read_bio_TYPE(), PEM_read_TYPE(), 166PEM_write_bio_TYPE(), and PEM_write_TYPE() functions. 167 168The B<PrivateKey> functions read or write a private key in PEM format using an 169EVP_PKEY structure. The write routines use PKCS#8 private key format and are 170equivalent to PEM_write_bio_PKCS8PrivateKey().The read functions transparently 171handle traditional and PKCS#8 format encrypted and unencrypted keys. 172 173PEM_write_bio_PrivateKey_traditional() writes out a private key in the 174"traditional" format with a simple private key marker and should only 175be used for compatibility with legacy programs. 176 177PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a private 178key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo format using 179PKCS#5 v2.0 password based encryption algorithms. The B<cipher> argument 180specifies the encryption algorithm to use: unlike some other PEM routines the 181encryption is applied at the PKCS#8 level and not in the PEM headers. If 182B<cipher> is NULL then no encryption is used and a PKCS#8 PrivateKeyInfo 183structure is used instead. 184 185PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid() 186also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo however 187it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead. The algorithm 188to use is specified in the B<nid> parameter and should be the NID of the 189corresponding OBJECT IDENTIFIER (see NOTES section). 190 191The B<PUBKEY> functions process a public key using an EVP_PKEY 192structure. The public key is encoded as a SubjectPublicKeyInfo 193structure. 194 195The B<RSAPrivateKey> functions process an RSA private key using an 196RSA structure. The write routines uses traditional format. The read 197routines handles the same formats as the B<PrivateKey> 198functions but an error occurs if the private key is not RSA. 199 200The B<RSAPublicKey> functions process an RSA public key using an 201RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey 202structure. 203 204The B<RSA_PUBKEY> functions also process an RSA public key using 205an RSA structure. However the public key is encoded using a 206SubjectPublicKeyInfo structure and an error occurs if the public 207key is not RSA. 208 209The B<DSAPrivateKey> functions process a DSA private key using a 210DSA structure. The write routines uses traditional format. The read 211routines handles the same formats as the B<PrivateKey> 212functions but an error occurs if the private key is not DSA. 213 214The B<DSA_PUBKEY> functions process a DSA public key using 215a DSA structure. The public key is encoded using a 216SubjectPublicKeyInfo structure and an error occurs if the public 217key is not DSA. 218 219The B<DSAparams> functions process DSA parameters using a DSA 220structure. The parameters are encoded using a Dss-Parms structure 221as defined in RFC2459. 222 223The B<DHparams> functions process DH parameters using a DH 224structure. The parameters are encoded using a PKCS#3 DHparameter 225structure. 226 227The B<X509> functions process an X509 certificate using an X509 228structure. They will also process a trusted X509 certificate but 229any trust settings are discarded. 230 231The B<X509_AUX> functions process a trusted X509 certificate using 232an X509 structure. 233 234The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10 235certificate request using an X509_REQ structure. The B<X509_REQ> 236write functions use B<CERTIFICATE REQUEST> in the header whereas 237the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST> 238(as required by some CAs). The B<X509_REQ> read functions will 239handle either form so there are no B<X509_REQ_NEW> read functions. 240 241The B<X509_CRL> functions process an X509 CRL using an X509_CRL 242structure. 243 244The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7 245structure. 246 247=head1 PEM FUNCTION ARGUMENTS 248 249The PEM functions have many common arguments. 250 251The B<bp> BIO parameter (if present) specifies the BIO to read from 252or write to. 253 254The B<fp> FILE parameter (if present) specifies the FILE pointer to 255read from or write to. 256 257The PEM read functions all take an argument B<TYPE **x> and return 258a B<TYPE *> pointer. Where B<TYPE> is whatever structure the function 259uses. If B<x> is NULL then the parameter is ignored. If B<x> is not 260NULL but B<*x> is NULL then the structure returned will be written 261to B<*x>. If neither B<x> nor B<*x> is NULL then an attempt is made 262to reuse the structure at B<*x> (but see BUGS and EXAMPLES sections). 263Irrespective of the value of B<x> a pointer to the structure is always 264returned (or NULL if an error occurred). 265 266The PEM functions which write private keys take an B<enc> parameter 267which specifies the encryption algorithm to use, encryption is done 268at the PEM level. If this parameter is set to NULL then the private 269key is written in unencrypted form. 270 271The B<cb> argument is the callback to use when querying for the pass 272phrase used for encrypted PEM structures (normally only private keys). 273 274For the PEM write routines if the B<kstr> parameter is not NULL then 275B<klen> bytes at B<kstr> are used as the passphrase and B<cb> is 276ignored. 277 278If the B<cb> parameters is set to NULL and the B<u> parameter is not 279NULL then the B<u> parameter is interpreted as a null terminated string 280to use as the passphrase. If both B<cb> and B<u> are NULL then the 281default callback routine is used which will typically prompt for the 282passphrase on the current terminal with echoing turned off. 283 284The default passphrase callback is sometimes inappropriate (for example 285in a GUI application) so an alternative can be supplied. The callback 286routine has the following form: 287 288 int cb(char *buf, int size, int rwflag, void *u); 289 290B<buf> is the buffer to write the passphrase to. B<size> is the maximum 291length of the passphrase (i.e. the size of buf). B<rwflag> is a flag 292which is set to 0 when reading and 1 when writing. A typical routine 293will ask the user to verify the passphrase (for example by prompting 294for it twice) if B<rwflag> is 1. The B<u> parameter has the same 295value as the B<u> parameter passed to the PEM routine. It allows 296arbitrary data to be passed to the callback by the application 297(for example a window handle in a GUI application). The callback 298B<must> return the number of characters in the passphrase or -1 if 299an error occurred. 300 301=head1 NOTES 302 303The old B<PrivateKey> write routines are retained for compatibility. 304New applications should write private keys using the 305PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines 306because they are more secure (they use an iteration count of 2048 whereas 307the traditional routines use a count of 1) unless compatibility with older 308versions of OpenSSL is important. 309 310The B<PrivateKey> read routines can be used in all applications because 311they handle all formats transparently. 312 313A frequent cause of problems is attempting to use the PEM routines like 314this: 315 316 X509 *x; 317 318 PEM_read_bio_X509(bp, &x, 0, NULL); 319 320this is a bug because an attempt will be made to reuse the data at B<x> 321which is an uninitialised pointer. 322 323These functions make no assumption regarding the pass phrase received from the 324password callback. 325It will simply be treated as a byte sequence. 326 327=head1 PEM ENCRYPTION FORMAT 328 329These old B<PrivateKey> routines use a non standard technique for encryption. 330 331The private key (or other data) takes the following form: 332 333 -----BEGIN RSA PRIVATE KEY----- 334 Proc-Type: 4,ENCRYPTED 335 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89 336 337 ...base64 encoded data... 338 -----END RSA PRIVATE KEY----- 339 340The line beginning with I<Proc-Type> contains the version and the 341protection on the encapsulated data. The line beginning I<DEK-Info> 342contains two comma separated values: the encryption algorithm name as 343used by EVP_get_cipherbyname() and an initialization vector used by the 344cipher encoded as a set of hexadecimal digits. After those two lines is 345the base64-encoded encrypted data. 346 347The encryption key is derived using EVP_BytesToKey(). The cipher's 348initialization vector is passed to EVP_BytesToKey() as the B<salt> 349parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used 350(regardless of the size of the initialization vector). The user's 351password is passed to EVP_BytesToKey() using the B<data> and B<datal> 352parameters. Finally, the library uses an iteration count of 1 for 353EVP_BytesToKey(). 354 355The B<key> derived by EVP_BytesToKey() along with the original initialization 356vector is then used to decrypt the encrypted data. The B<iv> produced by 357EVP_BytesToKey() is not utilized or needed, and NULL should be passed to 358the function. 359 360The pseudo code to derive the key would look similar to: 361 362 EVP_CIPHER* cipher = EVP_des_ede3_cbc(); 363 EVP_MD* md = EVP_md5(); 364 365 unsigned int nkey = EVP_CIPHER_key_length(cipher); 366 unsigned int niv = EVP_CIPHER_iv_length(cipher); 367 unsigned char key[nkey]; 368 unsigned char iv[niv]; 369 370 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv); 371 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/); 372 if (rc != nkey) 373 /* Error */ 374 375 /* On success, use key and iv to initialize the cipher */ 376 377=head1 BUGS 378 379The PEM read routines in some versions of OpenSSL will not correctly reuse 380an existing structure. Therefore the following: 381 382 PEM_read_bio_X509(bp, &x, 0, NULL); 383 384where B<x> already contains a valid certificate, may not work, whereas: 385 386 X509_free(x); 387 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 388 389is guaranteed to work. 390 391=head1 RETURN VALUES 392 393The read routines return either a pointer to the structure read or NULL 394if an error occurred. 395 396The write routines return 1 for success or 0 for failure. 397 398=head1 EXAMPLES 399 400Although the PEM routines take several arguments in almost all applications 401most of them are set to 0 or NULL. 402 403Read a certificate in PEM format from a BIO: 404 405 X509 *x; 406 407 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 408 if (x == NULL) 409 /* Error */ 410 411Alternative method: 412 413 X509 *x = NULL; 414 415 if (!PEM_read_bio_X509(bp, &x, 0, NULL)) 416 /* Error */ 417 418Write a certificate to a BIO: 419 420 if (!PEM_write_bio_X509(bp, x)) 421 /* Error */ 422 423Write a private key (using traditional format) to a BIO using 424triple DES encryption, the pass phrase is prompted for: 425 426 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL)) 427 /* Error */ 428 429Write a private key (using PKCS#8 format) to a BIO using triple 430DES encryption, using the pass phrase "hello": 431 432 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(), 433 NULL, 0, 0, "hello")) 434 /* Error */ 435 436Read a private key from a BIO using a pass phrase callback: 437 438 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key"); 439 if (key == NULL) 440 /* Error */ 441 442Skeleton pass phrase callback: 443 444 int pass_cb(char *buf, int size, int rwflag, void *u) 445 { 446 447 /* We'd probably do something else if 'rwflag' is 1 */ 448 printf("Enter pass phrase for \"%s\"\n", (char *)u); 449 450 /* get pass phrase, length 'len' into 'tmp' */ 451 char *tmp = "hello"; 452 if (tmp == NULL) /* An error occurred */ 453 return -1; 454 455 size_t len = strlen(tmp); 456 457 if (len > size) 458 len = size; 459 memcpy(buf, tmp, len); 460 return len; 461 } 462 463=head1 SEE ALSO 464 465L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>, 466L<passphrase-encoding(7)> 467 468=head1 HISTORY 469 470The old Netscape certificate sequences were no longer documented 471in OpenSSL 1.1.0; applications should use the PKCS7 standard instead 472as they will be formally deprecated in a future releases. 473 474=head1 COPYRIGHT 475 476Copyright 2001-2019 The OpenSSL Project Authors. All Rights Reserved. 477 478Licensed under the OpenSSL license (the "License"). You may not use 479this file except in compliance with the License. You can obtain a copy 480in the file LICENSE in the source distribution or at 481L<https://www.openssl.org/source/license.html>. 482 483=cut 484