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 EXAMPLES 302 303Although the PEM routines take several arguments in almost all applications 304most of them are set to 0 or NULL. 305 306Read a certificate in PEM format from a BIO: 307 308 X509 *x; 309 310 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 311 if (x == NULL) 312 /* Error */ 313 314Alternative method: 315 316 X509 *x = NULL; 317 318 if (!PEM_read_bio_X509(bp, &x, 0, NULL)) 319 /* Error */ 320 321Write a certificate to a BIO: 322 323 if (!PEM_write_bio_X509(bp, x)) 324 /* Error */ 325 326Write a private key (using traditional format) to a BIO using 327triple DES encryption, the pass phrase is prompted for: 328 329 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL)) 330 /* Error */ 331 332Write a private key (using PKCS#8 format) to a BIO using triple 333DES encryption, using the pass phrase "hello": 334 335 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(), 336 NULL, 0, 0, "hello")) 337 /* Error */ 338 339Read a private key from a BIO using a pass phrase callback: 340 341 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key"); 342 if (key == NULL) 343 /* Error */ 344 345Skeleton pass phrase callback: 346 347 int pass_cb(char *buf, int size, int rwflag, void *u) 348 { 349 350 /* We'd probably do something else if 'rwflag' is 1 */ 351 printf("Enter pass phrase for \"%s\"\n", (char *)u); 352 353 /* get pass phrase, length 'len' into 'tmp' */ 354 char *tmp = "hello"; 355 if (tmp == NULL) /* An error occurred */ 356 return -1; 357 358 size_t len = strlen(tmp); 359 360 if (len > size) 361 len = size; 362 memcpy(buf, tmp, len); 363 return len; 364 } 365 366=head1 NOTES 367 368The old B<PrivateKey> write routines are retained for compatibility. 369New applications should write private keys using the 370PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines 371because they are more secure (they use an iteration count of 2048 whereas 372the traditional routines use a count of 1) unless compatibility with older 373versions of OpenSSL is important. 374 375The B<PrivateKey> read routines can be used in all applications because 376they handle all formats transparently. 377 378A frequent cause of problems is attempting to use the PEM routines like 379this: 380 381 X509 *x; 382 383 PEM_read_bio_X509(bp, &x, 0, NULL); 384 385this is a bug because an attempt will be made to reuse the data at B<x> 386which is an uninitialised pointer. 387 388These functions make no assumption regarding the pass phrase received from the 389password callback. 390It will simply be treated as a byte sequence. 391 392=head1 PEM ENCRYPTION FORMAT 393 394These old B<PrivateKey> routines use a non standard technique for encryption. 395 396The private key (or other data) takes the following form: 397 398 -----BEGIN RSA PRIVATE KEY----- 399 Proc-Type: 4,ENCRYPTED 400 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89 401 402 ...base64 encoded data... 403 -----END RSA PRIVATE KEY----- 404 405The line beginning with I<Proc-Type> contains the version and the 406protection on the encapsulated data. The line beginning I<DEK-Info> 407contains two comma separated values: the encryption algorithm name as 408used by EVP_get_cipherbyname() and an initialization vector used by the 409cipher encoded as a set of hexadecimal digits. After those two lines is 410the base64-encoded encrypted data. 411 412The encryption key is derived using EVP_BytesToKey(). The cipher's 413initialization vector is passed to EVP_BytesToKey() as the B<salt> 414parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used 415(regardless of the size of the initialization vector). The user's 416password is passed to EVP_BytesToKey() using the B<data> and B<datal> 417parameters. Finally, the library uses an iteration count of 1 for 418EVP_BytesToKey(). 419 420The B<key> derived by EVP_BytesToKey() along with the original initialization 421vector is then used to decrypt the encrypted data. The B<iv> produced by 422EVP_BytesToKey() is not utilized or needed, and NULL should be passed to 423the function. 424 425The pseudo code to derive the key would look similar to: 426 427 EVP_CIPHER* cipher = EVP_des_ede3_cbc(); 428 EVP_MD* md = EVP_md5(); 429 430 unsigned int nkey = EVP_CIPHER_key_length(cipher); 431 unsigned int niv = EVP_CIPHER_iv_length(cipher); 432 unsigned char key[nkey]; 433 unsigned char iv[niv]; 434 435 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv); 436 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/); 437 if (rc != nkey) 438 /* Error */ 439 440 /* On success, use key and iv to initialize the cipher */ 441 442=head1 BUGS 443 444The PEM read routines in some versions of OpenSSL will not correctly reuse 445an existing structure. Therefore the following: 446 447 PEM_read_bio_X509(bp, &x, 0, NULL); 448 449where B<x> already contains a valid certificate, may not work, whereas: 450 451 X509_free(x); 452 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 453 454is guaranteed to work. 455 456=head1 RETURN VALUES 457 458The read routines return either a pointer to the structure read or NULL 459if an error occurred. 460 461The write routines return 1 for success or 0 for failure. 462 463=head1 HISTORY 464 465The old Netscape certificate sequences were no longer documented 466in OpenSSL 1.1.0; applications should use the PKCS7 standard instead 467as they will be formally deprecated in a future releases. 468 469=head1 SEE ALSO 470 471L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>, 472L<passphrase-encoding(7)> 473 474=head1 COPYRIGHT 475 476Copyright 2001-2018 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