1=pod 2 3=head1 NAME 4 5pem_password_cb, 6PEM_read_bio_PrivateKey_ex, PEM_read_bio_PrivateKey, 7PEM_read_PrivateKey_ex, PEM_read_PrivateKey, 8PEM_write_bio_PrivateKey_ex, PEM_write_bio_PrivateKey, 9PEM_write_bio_PrivateKey_traditional, 10PEM_write_PrivateKey_ex, PEM_write_PrivateKey, 11PEM_write_bio_PKCS8PrivateKey, PEM_write_PKCS8PrivateKey, 12PEM_write_bio_PKCS8PrivateKey_nid, PEM_write_PKCS8PrivateKey_nid, 13PEM_read_bio_PUBKEY_ex, PEM_read_bio_PUBKEY, 14PEM_read_PUBKEY_ex, PEM_read_PUBKEY, 15PEM_write_bio_PUBKEY_ex, PEM_write_bio_PUBKEY, 16PEM_write_PUBKEY_ex, PEM_write_PUBKEY, 17PEM_read_bio_RSAPrivateKey, PEM_read_RSAPrivateKey, 18PEM_write_bio_RSAPrivateKey, PEM_write_RSAPrivateKey, 19PEM_read_bio_RSAPublicKey, PEM_read_RSAPublicKey, PEM_write_bio_RSAPublicKey, 20PEM_write_RSAPublicKey, PEM_read_bio_RSA_PUBKEY, PEM_read_RSA_PUBKEY, 21PEM_write_bio_RSA_PUBKEY, PEM_write_RSA_PUBKEY, PEM_read_bio_DSAPrivateKey, 22PEM_read_DSAPrivateKey, PEM_write_bio_DSAPrivateKey, PEM_write_DSAPrivateKey, 23PEM_read_bio_DSA_PUBKEY, PEM_read_DSA_PUBKEY, PEM_write_bio_DSA_PUBKEY, 24PEM_write_DSA_PUBKEY, PEM_read_bio_Parameters_ex, PEM_read_bio_Parameters, 25PEM_write_bio_Parameters, PEM_read_bio_DSAparams, PEM_read_DSAparams, 26PEM_write_bio_DSAparams, PEM_write_DSAparams, PEM_read_bio_DHparams, 27PEM_read_DHparams, PEM_write_bio_DHparams, PEM_write_DHparams, 28PEM_read_bio_X509, PEM_read_X509, PEM_write_bio_X509, PEM_write_X509, 29PEM_read_bio_X509_AUX, PEM_read_X509_AUX, PEM_write_bio_X509_AUX, 30PEM_write_X509_AUX, PEM_read_bio_X509_REQ, PEM_read_X509_REQ, 31PEM_write_bio_X509_REQ, PEM_write_X509_REQ, PEM_write_bio_X509_REQ_NEW, 32PEM_write_X509_REQ_NEW, PEM_read_bio_X509_CRL, PEM_read_X509_CRL, 33PEM_write_bio_X509_CRL, PEM_write_X509_CRL, PEM_read_bio_PKCS7, PEM_read_PKCS7, 34PEM_write_bio_PKCS7, PEM_write_PKCS7 - PEM routines 35 36=head1 SYNOPSIS 37 38 #include <openssl/pem.h> 39 40 typedef int pem_password_cb(char *buf, int size, int rwflag, void *u); 41 42 EVP_PKEY *PEM_read_bio_PrivateKey_ex(BIO *bp, EVP_PKEY **x, 43 pem_password_cb *cb, void *u, 44 OSSL_LIB_CTX *libctx, const char *propq); 45 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, 46 pem_password_cb *cb, void *u); 47 EVP_PKEY *PEM_read_PrivateKey_ex(FILE *fp, EVP_PKEY **x, pem_password_cb *cb, 48 void *u, OSSL_LIB_CTX *libctx, 49 const char *propq); 50 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, 51 pem_password_cb *cb, void *u); 52 int PEM_write_bio_PrivateKey_ex(BIO *bp, const EVP_PKEY *x, 53 const EVP_CIPHER *enc, 54 unsigned char *kstr, int klen, 55 pem_password_cb *cb, void *u, 56 OSSL_LIB_CTX *libctx, const char *propq); 57 int PEM_write_bio_PrivateKey(BIO *bp, const EVP_PKEY *x, const EVP_CIPHER *enc, 58 unsigned char *kstr, int klen, 59 pem_password_cb *cb, void *u); 60 int PEM_write_bio_PrivateKey_traditional(BIO *bp, EVP_PKEY *x, 61 const EVP_CIPHER *enc, 62 unsigned char *kstr, int klen, 63 pem_password_cb *cb, void *u); 64 int PEM_write_PrivateKey_ex(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 65 unsigned char *kstr, int klen, 66 pem_password_cb *cb, void *u, 67 OSSL_LIB_CTX *libctx, const char *propq); 68 int PEM_write_PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 69 unsigned char *kstr, int klen, 70 pem_password_cb *cb, void *u); 71 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc, 72 char *kstr, int klen, 73 pem_password_cb *cb, void *u); 74 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc, 75 char *kstr, int klen, 76 pem_password_cb *cb, void *u); 77 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, const EVP_PKEY *x, int nid, 78 char *kstr, int klen, 79 pem_password_cb *cb, void *u); 80 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, const EVP_PKEY *x, int nid, 81 char *kstr, int klen, 82 pem_password_cb *cb, void *u); 83 84 EVP_PKEY *PEM_read_bio_PUBKEY_ex(BIO *bp, EVP_PKEY **x, 85 pem_password_cb *cb, void *u, 86 OSSL_LIB_CTX *libctx, const char *propq); 87 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, 88 pem_password_cb *cb, void *u); 89 EVP_PKEY *PEM_read_PUBKEY_ex(FILE *fp, EVP_PKEY **x, 90 pem_password_cb *cb, void *u, 91 OSSL_LIB_CTX *libctx, const char *propq); 92 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, 93 pem_password_cb *cb, void *u); 94 int PEM_write_bio_PUBKEY_ex(BIO *bp, EVP_PKEY *x, 95 OSSL_LIB_CTX *libctx, const char *propq); 96 int PEM_write_bio_PUBKEY(BIO *bp, EVP_PKEY *x); 97 int PEM_write_PUBKEY_ex(FILE *fp, EVP_PKEY *x, 98 OSSL_LIB_CTX *libctx, const char *propq); 99 int PEM_write_PUBKEY(FILE *fp, EVP_PKEY *x); 100 101 EVP_PKEY *PEM_read_bio_Parameters_ex(BIO *bp, EVP_PKEY **x, 102 OSSL_LIB_CTX *libctx, const char *propq); 103 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x); 104 int PEM_write_bio_Parameters(BIO *bp, const EVP_PKEY *x); 105 106 X509 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 107 X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 108 int PEM_write_bio_X509(BIO *bp, X509 *x); 109 int PEM_write_X509(FILE *fp, X509 *x); 110 111 X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u); 112 X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u); 113 int PEM_write_bio_X509_AUX(BIO *bp, X509 *x); 114 int PEM_write_X509_AUX(FILE *fp, X509 *x); 115 116 X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x, 117 pem_password_cb *cb, void *u); 118 X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x, 119 pem_password_cb *cb, void *u); 120 int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x); 121 int PEM_write_X509_REQ(FILE *fp, X509_REQ *x); 122 int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x); 123 int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *x); 124 125 X509_CRL *PEM_read_bio_X509_CRL(BIO *bp, X509_CRL **x, 126 pem_password_cb *cb, void *u); 127 X509_CRL *PEM_read_X509_CRL(FILE *fp, X509_CRL **x, 128 pem_password_cb *cb, void *u); 129 int PEM_write_bio_X509_CRL(BIO *bp, X509_CRL *x); 130 int PEM_write_X509_CRL(FILE *fp, X509_CRL *x); 131 132 PKCS7 *PEM_read_bio_PKCS7(BIO *bp, PKCS7 **x, pem_password_cb *cb, void *u); 133 PKCS7 *PEM_read_PKCS7(FILE *fp, PKCS7 **x, pem_password_cb *cb, void *u); 134 int PEM_write_bio_PKCS7(BIO *bp, PKCS7 *x); 135 int PEM_write_PKCS7(FILE *fp, PKCS7 *x); 136 137Deprecated since OpenSSL 3.0, can be hidden entirely by defining 138B<OPENSSL_API_COMPAT> with a suitable version value, see 139L<openssl_user_macros(7)>: 140 141 RSA *PEM_read_bio_RSAPrivateKey(BIO *bp, RSA **x, 142 pem_password_cb *cb, void *u); 143 RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **x, 144 pem_password_cb *cb, void *u); 145 int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER *enc, 146 unsigned char *kstr, int klen, 147 pem_password_cb *cb, void *u); 148 int PEM_write_RSAPrivateKey(FILE *fp, RSA *x, const EVP_CIPHER *enc, 149 unsigned char *kstr, int klen, 150 pem_password_cb *cb, void *u); 151 152 RSA *PEM_read_bio_RSAPublicKey(BIO *bp, RSA **x, 153 pem_password_cb *cb, void *u); 154 RSA *PEM_read_RSAPublicKey(FILE *fp, RSA **x, 155 pem_password_cb *cb, void *u); 156 int PEM_write_bio_RSAPublicKey(BIO *bp, RSA *x); 157 int PEM_write_RSAPublicKey(FILE *fp, RSA *x); 158 159 RSA *PEM_read_bio_RSA_PUBKEY(BIO *bp, RSA **x, 160 pem_password_cb *cb, void *u); 161 RSA *PEM_read_RSA_PUBKEY(FILE *fp, RSA **x, 162 pem_password_cb *cb, void *u); 163 int PEM_write_bio_RSA_PUBKEY(BIO *bp, RSA *x); 164 int PEM_write_RSA_PUBKEY(FILE *fp, RSA *x); 165 166 DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **x, 167 pem_password_cb *cb, void *u); 168 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **x, 169 pem_password_cb *cb, void *u); 170 int PEM_write_bio_DSAPrivateKey(BIO *bp, DSA *x, const EVP_CIPHER *enc, 171 unsigned char *kstr, int klen, 172 pem_password_cb *cb, void *u); 173 int PEM_write_DSAPrivateKey(FILE *fp, DSA *x, const EVP_CIPHER *enc, 174 unsigned char *kstr, int klen, 175 pem_password_cb *cb, void *u); 176 177 DSA *PEM_read_bio_DSA_PUBKEY(BIO *bp, DSA **x, 178 pem_password_cb *cb, void *u); 179 DSA *PEM_read_DSA_PUBKEY(FILE *fp, DSA **x, 180 pem_password_cb *cb, void *u); 181 int PEM_write_bio_DSA_PUBKEY(BIO *bp, DSA *x); 182 int PEM_write_DSA_PUBKEY(FILE *fp, DSA *x); 183 DSA *PEM_read_bio_DSAparams(BIO *bp, DSA **x, pem_password_cb *cb, void *u); 184 DSA *PEM_read_DSAparams(FILE *fp, DSA **x, pem_password_cb *cb, void *u); 185 int PEM_write_bio_DSAparams(BIO *bp, DSA *x); 186 int PEM_write_DSAparams(FILE *fp, DSA *x); 187 188 DH *PEM_read_bio_DHparams(BIO *bp, DH **x, pem_password_cb *cb, void *u); 189 DH *PEM_read_DHparams(FILE *fp, DH **x, pem_password_cb *cb, void *u); 190 int PEM_write_bio_DHparams(BIO *bp, DH *x); 191 int PEM_write_DHparams(FILE *fp, DH *x); 192 193=head1 DESCRIPTION 194 195All of the functions described on this page that have a I<TYPE> of B<DH>, B<DSA> 196and B<RSA> are deprecated. Applications should use OSSL_ENCODER_to_bio() and 197OSSL_DECODER_from_bio() instead. 198 199The PEM functions read or write structures in PEM format. In 200this sense PEM format is simply base64 encoded data surrounded 201by header lines. 202 203For more details about the meaning of arguments see the 204B<PEM FUNCTION ARGUMENTS> section. 205 206Each operation has four functions associated with it. For 207brevity the term "B<I<TYPE>> functions" will be used below to collectively 208refer to the B<PEM_read_bio_I<TYPE>>(), B<PEM_read_I<TYPE>>(), 209B<PEM_write_bio_I<TYPE>>(), and B<PEM_write_I<TYPE>>() functions. 210 211Some operations have additional variants that take a library context I<libctx> 212and a property query string I<propq>. 213 214The B<PrivateKey> functions read or write a private key in PEM format using 215an EVP_PKEY structure. The write routines use PKCS#8 private key format and are 216equivalent to PEM_write_bio_PKCS8PrivateKey(). The read functions transparently 217handle traditional and PKCS#8 format encrypted and unencrypted keys. 218 219PEM_write_bio_PrivateKey_traditional() writes out a private key in the 220"traditional" format with a simple private key marker and should only 221be used for compatibility with legacy programs. 222 223PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a private 224key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo format using 225PKCS#5 v2.0 password based encryption algorithms. The I<cipher> argument 226specifies the encryption algorithm to use: unlike some other PEM routines the 227encryption is applied at the PKCS#8 level and not in the PEM headers. If 228I<cipher> is NULL then no encryption is used and a PKCS#8 PrivateKeyInfo 229structure is used instead. 230 231PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid() 232also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo however 233it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead. The algorithm 234to use is specified in the I<nid> parameter and should be the NID of the 235corresponding OBJECT IDENTIFIER (see NOTES section). 236 237The B<PUBKEY> functions process a public key using an EVP_PKEY 238structure. The public key is encoded as a SubjectPublicKeyInfo 239structure. 240 241The B<RSAPrivateKey> functions process an RSA private key using an 242RSA structure. The write routines uses traditional format. The read 243routines handles the same formats as the B<PrivateKey> 244functions but an error occurs if the private key is not RSA. 245 246The B<RSAPublicKey> functions process an RSA public key using an 247RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey 248structure. 249 250The B<RSA_PUBKEY> functions also process an RSA public key using 251an RSA structure. However, the public key is encoded using a 252SubjectPublicKeyInfo structure and an error occurs if the public 253key is not RSA. 254 255The B<DSAPrivateKey> functions process a DSA private key using a 256DSA structure. The write routines uses traditional format. The read 257routines handles the same formats as the B<PrivateKey> 258functions but an error occurs if the private key is not DSA. 259 260The B<DSA_PUBKEY> functions process a DSA public key using 261a DSA structure. The public key is encoded using a 262SubjectPublicKeyInfo structure and an error occurs if the public 263key is not DSA. 264 265The B<Parameters> functions read or write key parameters in PEM format using 266an EVP_PKEY structure. The encoding depends on the type of key; for DSA key 267parameters, it will be a Dss-Parms structure as defined in RFC2459, and for DH 268key parameters, it will be a PKCS#3 DHparameter structure. I<These functions 269only exist for the B<BIO> type>. 270 271The B<DSAparams> functions process DSA parameters using a DSA 272structure. The parameters are encoded using a Dss-Parms structure 273as defined in RFC2459. 274 275The B<DHparams> functions process DH parameters using a DH 276structure. The parameters are encoded using a PKCS#3 DHparameter 277structure. 278 279The B<X509> functions process an X509 certificate using an X509 280structure. They will also process a trusted X509 certificate but 281any trust settings are discarded. 282 283The B<X509_AUX> functions process a trusted X509 certificate using 284an X509 structure. 285 286The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10 287certificate request using an X509_REQ structure. The B<X509_REQ> 288write functions use B<CERTIFICATE REQUEST> in the header whereas 289the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST> 290(as required by some CAs). The B<X509_REQ> read functions will 291handle either form so there are no B<X509_REQ_NEW> read functions. 292 293The B<X509_CRL> functions process an X509 CRL using an X509_CRL 294structure. 295 296The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7 297structure. 298 299=head1 PEM FUNCTION ARGUMENTS 300 301The PEM functions have many common arguments. 302 303The I<bp> BIO parameter (if present) specifies the BIO to read from 304or write to. 305 306The I<fp> FILE parameter (if present) specifies the FILE pointer to 307read from or write to. 308 309The PEM read functions all take an argument I<B<TYPE> **x> and return 310a I<B<TYPE> *> pointer. Where I<B<TYPE>> is whatever structure the function 311uses. If I<x> is NULL then the parameter is ignored. If I<x> is not 312NULL but I<*x> is NULL then the structure returned will be written 313to I<*x>. If neither I<x> nor I<*x> is NULL then an attempt is made 314to reuse the structure at I<*x> (but see BUGS and EXAMPLES sections). 315Irrespective of the value of I<x> a pointer to the structure is always 316returned (or NULL if an error occurred). 317 318The PEM functions which write private keys take an I<enc> parameter 319which specifies the encryption algorithm to use, encryption is done 320at the PEM level. If this parameter is set to NULL then the private 321key is written in unencrypted form. 322 323The I<cb> argument is the callback to use when querying for the pass 324phrase used for encrypted PEM structures (normally only private keys). 325 326For the PEM write routines if the I<kstr> parameter is not NULL then 327I<klen> bytes at I<kstr> are used as the passphrase and I<cb> is 328ignored. 329 330If the I<cb> parameters is set to NULL and the I<u> parameter is not 331NULL then the I<u> parameter is interpreted as a null terminated string 332to use as the passphrase. If both I<cb> and I<u> are NULL then the 333default callback routine is used which will typically prompt for the 334passphrase on the current terminal with echoing turned off. 335 336The default passphrase callback is sometimes inappropriate (for example 337in a GUI application) so an alternative can be supplied. The callback 338routine has the following form: 339 340 int cb(char *buf, int size, int rwflag, void *u); 341 342I<buf> is the buffer to write the passphrase to. I<size> is the maximum 343length of the passphrase (i.e. the size of buf). I<rwflag> is a flag 344which is set to 0 when reading and 1 when writing. A typical routine 345will ask the user to verify the passphrase (for example by prompting 346for it twice) if I<rwflag> is 1. The I<u> parameter has the same 347value as the I<u> parameter passed to the PEM routine. It allows 348arbitrary data to be passed to the callback by the application 349(for example a window handle in a GUI application). The callback 350I<must> return the number of characters in the passphrase or -1 if 351an error occurred. 352 353Some implementations may need to use cryptographic algorithms during their 354operation. If this is the case and I<libctx> and I<propq> parameters have been 355passed then any algorithm fetches will use that library context and property 356query string. Otherwise the default library context and property query string 357will be used. 358 359=head1 NOTES 360 361The PEM reading functions will skip any extraneous content or PEM data of 362a different type than they expect. This allows for example having a certificate 363(or multiple certificates) and a key in the PEM format in a single file. 364 365The old B<PrivateKey> write routines are retained for compatibility. 366New applications should write private keys using the 367PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines 368because they are more secure (they use an iteration count of 2048 whereas 369the traditional routines use a count of 1) unless compatibility with older 370versions of OpenSSL is important. 371 372The B<PrivateKey> read routines can be used in all applications because 373they handle all formats transparently. 374 375A frequent cause of problems is attempting to use the PEM routines like 376this: 377 378 X509 *x; 379 380 PEM_read_bio_X509(bp, &x, 0, NULL); 381 382this is a bug because an attempt will be made to reuse the data at I<x> 383which is an uninitialised pointer. 384 385These functions make no assumption regarding the pass phrase received from the 386password callback. 387It will simply be treated as a byte sequence. 388 389=head1 PEM ENCRYPTION FORMAT 390 391These old B<PrivateKey> routines use a non standard technique for encryption. 392 393The private key (or other data) takes the following form: 394 395 -----BEGIN RSA PRIVATE KEY----- 396 Proc-Type: 4,ENCRYPTED 397 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89 398 399 ...base64 encoded data... 400 -----END RSA PRIVATE KEY----- 401 402The line beginning with I<Proc-Type> contains the version and the 403protection on the encapsulated data. The line beginning I<DEK-Info> 404contains two comma separated values: the encryption algorithm name as 405used by EVP_get_cipherbyname() and an initialization vector used by the 406cipher encoded as a set of hexadecimal digits. After those two lines is 407the base64-encoded encrypted data. 408 409The encryption key is derived using EVP_BytesToKey(). The cipher's 410initialization vector is passed to EVP_BytesToKey() as the I<salt> 411parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used 412(regardless of the size of the initialization vector). The user's 413password is passed to EVP_BytesToKey() using the I<data> and I<datal> 414parameters. Finally, the library uses an iteration count of 1 for 415EVP_BytesToKey(). 416 417The I<key> derived by EVP_BytesToKey() along with the original initialization 418vector is then used to decrypt the encrypted data. The I<iv> produced by 419EVP_BytesToKey() is not utilized or needed, and NULL should be passed to 420the function. 421 422The pseudo code to derive the key would look similar to: 423 424 EVP_CIPHER* cipher = EVP_des_ede3_cbc(); 425 EVP_MD* md = EVP_md5(); 426 427 unsigned int nkey = EVP_CIPHER_get_key_length(cipher); 428 unsigned int niv = EVP_CIPHER_get_iv_length(cipher); 429 unsigned char key[nkey]; 430 unsigned char iv[niv]; 431 432 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv); 433 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/); 434 if (rc != nkey) 435 /* Error */ 436 437 /* On success, use key and iv to initialize the cipher */ 438 439=head1 BUGS 440 441The PEM read routines in some versions of OpenSSL will not correctly reuse 442an existing structure. Therefore, the following: 443 444 PEM_read_bio_X509(bp, &x, 0, NULL); 445 446where I<x> already contains a valid certificate, may not work, whereas: 447 448 X509_free(x); 449 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 450 451is guaranteed to work. 452 453=head1 RETURN VALUES 454 455The read routines return either a pointer to the structure read or NULL 456if an error occurred. 457 458The write routines return 1 for success or 0 for failure. 459 460=head1 EXAMPLES 461 462Although the PEM routines take several arguments in almost all applications 463most of them are set to 0 or NULL. 464 465To read a certificate with a library context in PEM format from a BIO: 466 467 X509 *x = X509_new_ex(libctx, NULL); 468 469 if (x == NULL) 470 /* Error */ 471 472 if (PEM_read_bio_X509(bp, &x, 0, NULL) == NULL) 473 /* Error */ 474 475Read a certificate in PEM format from a BIO: 476 477 X509 *x; 478 479 x = PEM_read_bio_X509(bp, NULL, 0, NULL); 480 if (x == NULL) 481 /* Error */ 482 483Alternative method: 484 485 X509 *x = NULL; 486 487 if (!PEM_read_bio_X509(bp, &x, 0, NULL)) 488 /* Error */ 489 490Write a certificate to a BIO: 491 492 if (!PEM_write_bio_X509(bp, x)) 493 /* Error */ 494 495Write a private key (using traditional format) to a BIO using 496triple DES encryption, the pass phrase is prompted for: 497 498 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL)) 499 /* Error */ 500 501Write a private key (using PKCS#8 format) to a BIO using triple 502DES encryption, using the pass phrase "hello": 503 504 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(), 505 NULL, 0, 0, "hello")) 506 /* Error */ 507 508Read a private key from a BIO using a pass phrase callback: 509 510 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key"); 511 if (key == NULL) 512 /* Error */ 513 514Skeleton pass phrase callback: 515 516 int pass_cb(char *buf, int size, int rwflag, void *u) 517 { 518 519 /* We'd probably do something else if 'rwflag' is 1 */ 520 printf("Enter pass phrase for \"%s\"\n", (char *)u); 521 522 /* get pass phrase, length 'len' into 'tmp' */ 523 char *tmp = "hello"; 524 if (tmp == NULL) /* An error occurred */ 525 return -1; 526 527 size_t len = strlen(tmp); 528 529 if (len > size) 530 len = size; 531 memcpy(buf, tmp, len); 532 return len; 533 } 534 535=head1 SEE ALSO 536 537L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>, 538L<passphrase-encoding(7)> 539 540=head1 HISTORY 541 542The old Netscape certificate sequences were no longer documented 543in OpenSSL 1.1.0; applications should use the PKCS7 standard instead 544as they will be formally deprecated in a future releases. 545 546PEM_read_bio_PrivateKey_ex(), PEM_read_PrivateKey_ex(), 547PEM_read_bio_PUBKEY_ex(), PEM_read_PUBKEY_ex() and 548PEM_read_bio_Parameters_ex() were introduced in OpenSSL 3.0. 549 550The functions PEM_read_bio_RSAPrivateKey(), PEM_read_RSAPrivateKey(), 551PEM_write_bio_RSAPrivateKey(), PEM_write_RSAPrivateKey(), 552PEM_read_bio_RSAPublicKey(), PEM_read_RSAPublicKey(), 553PEM_write_bio_RSAPublicKey(), PEM_write_RSAPublicKey(), 554PEM_read_bio_RSA_PUBKEY(), PEM_read_RSA_PUBKEY(), 555PEM_write_bio_RSA_PUBKEY(), PEM_write_RSA_PUBKEY(), 556PEM_read_bio_DSAPrivateKey(), PEM_read_DSAPrivateKey(), 557PEM_write_bio_DSAPrivateKey(), PEM_write_DSAPrivateKey(), 558PEM_read_bio_DSA_PUBKEY(), PEM_read_DSA_PUBKEY(), 559PEM_write_bio_DSA_PUBKEY(), PEM_write_DSA_PUBKEY(); 560PEM_read_bio_DSAparams(), PEM_read_DSAparams(), 561PEM_write_bio_DSAparams(), PEM_write_DSAparams(), 562PEM_read_bio_DHparams(), PEM_read_DHparams(), 563PEM_write_bio_DHparams() and PEM_write_DHparams() were deprecated in 3.0. 564 565 566=head1 COPYRIGHT 567 568Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved. 569 570Licensed under the Apache License 2.0 (the "License"). You may not use 571this file except in compliance with the License. You can obtain a copy 572in the file LICENSE in the source distribution or at 573L<https://www.openssl.org/source/license.html>. 574 575=cut 576