6 PEM_read_bio_PrivateKey, PEM_read_PrivateKey, PEM_write_bio_PrivateKey,
7 PEM_write_bio_PrivateKey_traditional, PEM_write_PrivateKey,
8 PEM_write_bio_PKCS8PrivateKey, PEM_write_PKCS8PrivateKey,
9 PEM_write_bio_PKCS8PrivateKey_nid, PEM_write_PKCS8PrivateKey_nid,
10 PEM_read_bio_PUBKEY, PEM_read_PUBKEY, PEM_write_bio_PUBKEY, PEM_write_PUBKEY,
11 PEM_read_bio_RSAPrivateKey, PEM_read_RSAPrivateKey,
12 PEM_write_bio_RSAPrivateKey, PEM_write_RSAPrivateKey,
13 PEM_read_bio_RSAPublicKey, PEM_read_RSAPublicKey, PEM_write_bio_RSAPublicKey,
14 PEM_write_RSAPublicKey, PEM_read_bio_RSA_PUBKEY, PEM_read_RSA_PUBKEY,
15 PEM_write_bio_RSA_PUBKEY, PEM_write_RSA_PUBKEY, PEM_read_bio_DSAPrivateKey,
16 PEM_read_DSAPrivateKey, PEM_write_bio_DSAPrivateKey, PEM_write_DSAPrivateKey,
17 PEM_read_bio_DSA_PUBKEY, PEM_read_DSA_PUBKEY, PEM_write_bio_DSA_PUBKEY,
18 PEM_write_DSA_PUBKEY, PEM_read_bio_DSAparams, PEM_read_DSAparams,
19 PEM_write_bio_DSAparams, PEM_write_DSAparams, PEM_read_bio_DHparams,
20 PEM_read_DHparams, PEM_write_bio_DHparams, PEM_write_DHparams,
21 PEM_read_bio_X509, PEM_read_X509, PEM_write_bio_X509, PEM_write_X509,
22 PEM_read_bio_X509_AUX, PEM_read_X509_AUX, PEM_write_bio_X509_AUX,
23 PEM_write_X509_AUX, PEM_read_bio_X509_REQ, PEM_read_X509_REQ,
24 PEM_write_bio_X509_REQ, PEM_write_X509_REQ, PEM_write_bio_X509_REQ_NEW,
25 PEM_write_X509_REQ_NEW, PEM_read_bio_X509_CRL, PEM_read_X509_CRL,
26 PEM_write_bio_X509_CRL, PEM_write_X509_CRL, PEM_read_bio_PKCS7, PEM_read_PKCS7,
27 PEM_write_bio_PKCS7, PEM_write_PKCS7 - PEM routines
31 #include <openssl/pem.h>
33 typedef int pem_password_cb(char *buf, int size, int rwflag, void *u);
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, const 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 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc,
51 pem_password_cb *cb, void *u);
52 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc,
54 pem_password_cb *cb, void *u);
55 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, const EVP_PKEY *x, int nid,
57 pem_password_cb *cb, void *u);
58 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, const EVP_PKEY *x, int nid,
60 pem_password_cb *cb, void *u);
62 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x,
63 pem_password_cb *cb, void *u);
64 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x,
65 pem_password_cb *cb, void *u);
66 int PEM_write_bio_PUBKEY(BIO *bp, EVP_PKEY *x);
67 int PEM_write_PUBKEY(FILE *fp, EVP_PKEY *x);
69 RSA *PEM_read_bio_RSAPrivateKey(BIO *bp, RSA **x,
70 pem_password_cb *cb, void *u);
71 RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **x,
72 pem_password_cb *cb, void *u);
73 int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER *enc,
74 unsigned char *kstr, int klen,
75 pem_password_cb *cb, void *u);
76 int PEM_write_RSAPrivateKey(FILE *fp, RSA *x, const EVP_CIPHER *enc,
77 unsigned char *kstr, int klen,
78 pem_password_cb *cb, void *u);
80 RSA *PEM_read_bio_RSAPublicKey(BIO *bp, RSA **x,
81 pem_password_cb *cb, void *u);
82 RSA *PEM_read_RSAPublicKey(FILE *fp, RSA **x,
83 pem_password_cb *cb, void *u);
84 int PEM_write_bio_RSAPublicKey(BIO *bp, RSA *x);
85 int PEM_write_RSAPublicKey(FILE *fp, RSA *x);
87 RSA *PEM_read_bio_RSA_PUBKEY(BIO *bp, RSA **x,
88 pem_password_cb *cb, void *u);
89 RSA *PEM_read_RSA_PUBKEY(FILE *fp, RSA **x,
90 pem_password_cb *cb, void *u);
91 int PEM_write_bio_RSA_PUBKEY(BIO *bp, RSA *x);
92 int PEM_write_RSA_PUBKEY(FILE *fp, RSA *x);
94 DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **x,
95 pem_password_cb *cb, void *u);
96 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **x,
97 pem_password_cb *cb, void *u);
98 int PEM_write_bio_DSAPrivateKey(BIO *bp, DSA *x, const EVP_CIPHER *enc,
99 unsigned char *kstr, int klen,
100 pem_password_cb *cb, void *u);
101 int PEM_write_DSAPrivateKey(FILE *fp, DSA *x, const EVP_CIPHER *enc,
102 unsigned char *kstr, int klen,
103 pem_password_cb *cb, void *u);
105 DSA *PEM_read_bio_DSA_PUBKEY(BIO *bp, DSA **x,
106 pem_password_cb *cb, void *u);
107 DSA *PEM_read_DSA_PUBKEY(FILE *fp, DSA **x,
108 pem_password_cb *cb, void *u);
109 int PEM_write_bio_DSA_PUBKEY(BIO *bp, DSA *x);
110 int PEM_write_DSA_PUBKEY(FILE *fp, DSA *x);
112 DSA *PEM_read_bio_DSAparams(BIO *bp, DSA **x, pem_password_cb *cb, void *u);
113 DSA *PEM_read_DSAparams(FILE *fp, DSA **x, pem_password_cb *cb, void *u);
114 int PEM_write_bio_DSAparams(BIO *bp, DSA *x);
115 int PEM_write_DSAparams(FILE *fp, DSA *x);
117 DH *PEM_read_bio_DHparams(BIO *bp, DH **x, pem_password_cb *cb, void *u);
118 DH *PEM_read_DHparams(FILE *fp, DH **x, pem_password_cb *cb, void *u);
119 int PEM_write_bio_DHparams(BIO *bp, DH *x);
120 int PEM_write_DHparams(FILE *fp, DH *x);
122 X509 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
123 X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
124 int PEM_write_bio_X509(BIO *bp, X509 *x);
125 int PEM_write_X509(FILE *fp, X509 *x);
127 X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
128 X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
129 int PEM_write_bio_X509_AUX(BIO *bp, X509 *x);
130 int PEM_write_X509_AUX(FILE *fp, X509 *x);
132 X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x,
133 pem_password_cb *cb, void *u);
134 X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x,
135 pem_password_cb *cb, void *u);
136 int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x);
137 int PEM_write_X509_REQ(FILE *fp, X509_REQ *x);
138 int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x);
139 int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *x);
141 X509_CRL *PEM_read_bio_X509_CRL(BIO *bp, X509_CRL **x,
142 pem_password_cb *cb, void *u);
143 X509_CRL *PEM_read_X509_CRL(FILE *fp, X509_CRL **x,
144 pem_password_cb *cb, void *u);
145 int PEM_write_bio_X509_CRL(BIO *bp, X509_CRL *x);
146 int PEM_write_X509_CRL(FILE *fp, X509_CRL *x);
148 PKCS7 *PEM_read_bio_PKCS7(BIO *bp, PKCS7 **x, pem_password_cb *cb, void *u);
149 PKCS7 *PEM_read_PKCS7(FILE *fp, PKCS7 **x, pem_password_cb *cb, void *u);
150 int PEM_write_bio_PKCS7(BIO *bp, PKCS7 *x);
151 int PEM_write_PKCS7(FILE *fp, PKCS7 *x);
155 The PEM functions read or write structures in PEM format. In
156 this sense PEM format is simply base64 encoded data surrounded
159 For more details about the meaning of arguments see the
160 B<PEM FUNCTION ARGUMENTS> section.
162 Each operation has four functions associated with it. For
163 brevity the term "B<TYPE> functions" will be used below to collectively
164 refer to the PEM_read_bio_TYPE(), PEM_read_TYPE(),
165 PEM_write_bio_TYPE(), and PEM_write_TYPE() functions.
167 The B<PrivateKey> functions read or write a private key in PEM format using an
168 EVP_PKEY structure. The write routines use PKCS#8 private key format and are
169 equivalent to PEM_write_bio_PKCS8PrivateKey().The read functions transparently
170 handle traditional and PKCS#8 format encrypted and unencrypted keys.
172 PEM_write_bio_PrivateKey_traditional() writes out a private key in the
173 "traditional" format with a simple private key marker and should only
174 be used for compatibility with legacy programs.
176 PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a private
177 key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo format using
178 PKCS#5 v2.0 password based encryption algorithms. The B<cipher> argument
179 specifies the encryption algorithm to use: unlike some other PEM routines the
180 encryption is applied at the PKCS#8 level and not in the PEM headers. If
181 B<cipher> is NULL then no encryption is used and a PKCS#8 PrivateKeyInfo
182 structure is used instead.
184 PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid()
185 also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo however
186 it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead. The algorithm
187 to use is specified in the B<nid> parameter and should be the NID of the
188 corresponding OBJECT IDENTIFIER (see NOTES section).
190 The B<PUBKEY> functions process a public key using an EVP_PKEY
191 structure. The public key is encoded as a SubjectPublicKeyInfo
194 The B<RSAPrivateKey> functions process an RSA private key using an
195 RSA structure. The write routines uses traditional format. The read
196 routines handles the same formats as the B<PrivateKey>
197 functions but an error occurs if the private key is not RSA.
199 The B<RSAPublicKey> functions process an RSA public key using an
200 RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey
203 The B<RSA_PUBKEY> functions also process an RSA public key using
204 an RSA structure. However the public key is encoded using a
205 SubjectPublicKeyInfo structure and an error occurs if the public
208 The B<DSAPrivateKey> functions process a DSA private key using a
209 DSA structure. The write routines uses traditional format. The read
210 routines handles the same formats as the B<PrivateKey>
211 functions but an error occurs if the private key is not DSA.
213 The B<DSA_PUBKEY> functions process a DSA public key using
214 a DSA structure. The public key is encoded using a
215 SubjectPublicKeyInfo structure and an error occurs if the public
218 The B<DSAparams> functions process DSA parameters using a DSA
219 structure. The parameters are encoded using a Dss-Parms structure
220 as defined in RFC2459.
222 The B<DHparams> functions process DH parameters using a DH
223 structure. The parameters are encoded using a PKCS#3 DHparameter
226 The B<X509> functions process an X509 certificate using an X509
227 structure. They will also process a trusted X509 certificate but
228 any trust settings are discarded.
230 The B<X509_AUX> functions process a trusted X509 certificate using
233 The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10
234 certificate request using an X509_REQ structure. The B<X509_REQ>
235 write functions use B<CERTIFICATE REQUEST> in the header whereas
236 the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST>
237 (as required by some CAs). The B<X509_REQ> read functions will
238 handle either form so there are no B<X509_REQ_NEW> read functions.
240 The B<X509_CRL> functions process an X509 CRL using an X509_CRL
243 The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7
246 =head1 PEM FUNCTION ARGUMENTS
248 The PEM functions have many common arguments.
250 The B<bp> BIO parameter (if present) specifies the BIO to read from
253 The B<fp> FILE parameter (if present) specifies the FILE pointer to
254 read from or write to.
256 The PEM read functions all take an argument B<TYPE **x> and return
257 a B<TYPE *> pointer. Where B<TYPE> is whatever structure the function
258 uses. If B<x> is NULL then the parameter is ignored. If B<x> is not
259 NULL but B<*x> is NULL then the structure returned will be written
260 to B<*x>. If neither B<x> nor B<*x> is NULL then an attempt is made
261 to reuse the structure at B<*x> (but see BUGS and EXAMPLES sections).
262 Irrespective of the value of B<x> a pointer to the structure is always
263 returned (or NULL if an error occurred).
265 The PEM functions which write private keys take an B<enc> parameter
266 which specifies the encryption algorithm to use, encryption is done
267 at the PEM level. If this parameter is set to NULL then the private
268 key is written in unencrypted form.
270 The B<cb> argument is the callback to use when querying for the pass
271 phrase used for encrypted PEM structures (normally only private keys).
273 For the PEM write routines if the B<kstr> parameter is not NULL then
274 B<klen> bytes at B<kstr> are used as the passphrase and B<cb> is
277 If the B<cb> parameters is set to NULL and the B<u> parameter is not
278 NULL then the B<u> parameter is interpreted as a null terminated string
279 to use as the passphrase. If both B<cb> and B<u> are NULL then the
280 default callback routine is used which will typically prompt for the
281 passphrase on the current terminal with echoing turned off.
283 The default passphrase callback is sometimes inappropriate (for example
284 in a GUI application) so an alternative can be supplied. The callback
285 routine has the following form:
287 int cb(char *buf, int size, int rwflag, void *u);
289 B<buf> is the buffer to write the passphrase to. B<size> is the maximum
290 length of the passphrase (i.e. the size of buf). B<rwflag> is a flag
291 which is set to 0 when reading and 1 when writing. A typical routine
292 will ask the user to verify the passphrase (for example by prompting
293 for it twice) if B<rwflag> is 1. The B<u> parameter has the same
294 value as the B<u> parameter passed to the PEM routine. It allows
295 arbitrary data to be passed to the callback by the application
296 (for example a window handle in a GUI application). The callback
297 B<must> return the number of characters in the passphrase or -1 if
302 The old B<PrivateKey> write routines are retained for compatibility.
303 New applications should write private keys using the
304 PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines
305 because they are more secure (they use an iteration count of 2048 whereas
306 the traditional routines use a count of 1) unless compatibility with older
307 versions of OpenSSL is important.
309 The B<PrivateKey> read routines can be used in all applications because
310 they handle all formats transparently.
312 A frequent cause of problems is attempting to use the PEM routines like
317 PEM_read_bio_X509(bp, &x, 0, NULL);
319 this is a bug because an attempt will be made to reuse the data at B<x>
320 which is an uninitialised pointer.
322 These functions make no assumption regarding the pass phrase received from the
324 It will simply be treated as a byte sequence.
326 =head1 PEM ENCRYPTION FORMAT
328 These old B<PrivateKey> routines use a non standard technique for encryption.
330 The private key (or other data) takes the following form:
332 -----BEGIN RSA PRIVATE KEY-----
333 Proc-Type: 4,ENCRYPTED
334 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89
336 ...base64 encoded data...
337 -----END RSA PRIVATE KEY-----
339 The line beginning with I<Proc-Type> contains the version and the
340 protection on the encapsulated data. The line beginning I<DEK-Info>
341 contains two comma separated values: the encryption algorithm name as
342 used by EVP_get_cipherbyname() and an initialization vector used by the
343 cipher encoded as a set of hexadecimal digits. After those two lines is
344 the base64-encoded encrypted data.
346 The encryption key is derived using EVP_BytesToKey(). The cipher's
347 initialization vector is passed to EVP_BytesToKey() as the B<salt>
348 parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used
349 (regardless of the size of the initialization vector). The user's
350 password is passed to EVP_BytesToKey() using the B<data> and B<datal>
351 parameters. Finally, the library uses an iteration count of 1 for
354 The B<key> derived by EVP_BytesToKey() along with the original initialization
355 vector is then used to decrypt the encrypted data. The B<iv> produced by
356 EVP_BytesToKey() is not utilized or needed, and NULL should be passed to
359 The pseudo code to derive the key would look similar to:
361 EVP_CIPHER* cipher = EVP_des_ede3_cbc();
362 EVP_MD* md = EVP_md5();
364 unsigned int nkey = EVP_CIPHER_key_length(cipher);
365 unsigned int niv = EVP_CIPHER_iv_length(cipher);
366 unsigned char key[nkey];
367 unsigned char iv[niv];
369 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv);
370 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/);
374 /* On success, use key and iv to initialize the cipher */
378 The PEM read routines in some versions of OpenSSL will not correctly reuse
379 an existing structure. Therefore the following:
381 PEM_read_bio_X509(bp, &x, 0, NULL);
383 where B<x> already contains a valid certificate, may not work, whereas:
386 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
388 is guaranteed to work.
392 The read routines return either a pointer to the structure read or NULL
393 if an error occurred.
395 The write routines return 1 for success or 0 for failure.
399 Although the PEM routines take several arguments in almost all applications
400 most of them are set to 0 or NULL.
402 Read a certificate in PEM format from a BIO:
406 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
414 if (!PEM_read_bio_X509(bp, &x, 0, NULL))
417 Write a certificate to a BIO:
419 if (!PEM_write_bio_X509(bp, x))
422 Write a private key (using traditional format) to a BIO using
423 triple DES encryption, the pass phrase is prompted for:
425 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL))
428 Write a private key (using PKCS#8 format) to a BIO using triple
429 DES encryption, using the pass phrase "hello":
431 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(),
432 NULL, 0, 0, "hello"))
435 Read a private key from a BIO using a pass phrase callback:
437 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key");
441 Skeleton pass phrase callback:
443 int pass_cb(char *buf, int size, int rwflag, void *u)
446 /* We'd probably do something else if 'rwflag' is 1 */
447 printf("Enter pass phrase for \"%s\"\n", (char *)u);
449 /* get pass phrase, length 'len' into 'tmp' */
451 if (tmp == NULL) /* An error occurred */
454 size_t len = strlen(tmp);
458 memcpy(buf, tmp, len);
464 L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>,
465 L<passphrase-encoding(7)>
469 The old Netscape certificate sequences were no longer documented
470 in OpenSSL 1.1.0; applications should use the PKCS7 standard instead
471 as they will be formally deprecated in a future releases.
475 Copyright 2001-2019 The OpenSSL Project Authors. All Rights Reserved.
477 Licensed under the Apache License 2.0 (the "License"). You may not use
478 this file except in compliance with the License. You can obtain a copy
479 in the file LICENSE in the source distribution or at
480 L<https://www.openssl.org/source/license.html>.