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, 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);
50 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc,
52 pem_password_cb *cb, void *u);
53 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc,
55 pem_password_cb *cb, void *u);
56 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, EVP_PKEY *x, int nid,
58 pem_password_cb *cb, void *u);
59 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, EVP_PKEY *x, int nid,
61 pem_password_cb *cb, void *u);
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);
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);
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);
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);
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);
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);
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);
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);
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);
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);
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);
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);
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);
156 The PEM functions read or write structures in PEM format. In
157 this sense PEM format is simply base64 encoded data surrounded
160 For more details about the meaning of arguments see the
161 B<PEM FUNCTION ARGUMENTS> section.
163 Each operation has four functions associated with it. For
164 brevity the term "B<TYPE> functions" will be used below to collectively
165 refer to the PEM_read_bio_TYPE(), PEM_read_TYPE(),
166 PEM_write_bio_TYPE(), and PEM_write_TYPE() functions.
168 The B<PrivateKey> functions read or write a private key in PEM format using an
169 EVP_PKEY structure. The write routines use PKCS#8 private key format and are
170 equivalent to PEM_write_bio_PKCS8PrivateKey().The read functions transparently
171 handle traditional and PKCS#8 format encrypted and unencrypted keys.
173 PEM_write_bio_PrivateKey_traditional() writes out a private key in the
174 "traditional" format with a simple private key marker and should only
175 be used for compatibility with legacy programs.
177 PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a private
178 key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo format using
179 PKCS#5 v2.0 password based encryption algorithms. The B<cipher> argument
180 specifies the encryption algorithm to use: unlike some other PEM routines the
181 encryption is applied at the PKCS#8 level and not in the PEM headers. If
182 B<cipher> is NULL then no encryption is used and a PKCS#8 PrivateKeyInfo
183 structure is used instead.
185 PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid()
186 also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo however
187 it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead. The algorithm
188 to use is specified in the B<nid> parameter and should be the NID of the
189 corresponding OBJECT IDENTIFIER (see NOTES section).
191 The B<PUBKEY> functions process a public key using an EVP_PKEY
192 structure. The public key is encoded as a SubjectPublicKeyInfo
195 The B<RSAPrivateKey> functions process an RSA private key using an
196 RSA structure. The write routines uses traditional format. The read
197 routines handles the same formats as the B<PrivateKey>
198 functions but an error occurs if the private key is not RSA.
200 The B<RSAPublicKey> functions process an RSA public key using an
201 RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey
204 The B<RSA_PUBKEY> functions also process an RSA public key using
205 an RSA structure. However the public key is encoded using a
206 SubjectPublicKeyInfo structure and an error occurs if the public
209 The B<DSAPrivateKey> functions process a DSA private key using a
210 DSA structure. The write routines uses traditional format. The read
211 routines handles the same formats as the B<PrivateKey>
212 functions but an error occurs if the private key is not DSA.
214 The B<DSA_PUBKEY> functions process a DSA public key using
215 a DSA structure. The public key is encoded using a
216 SubjectPublicKeyInfo structure and an error occurs if the public
219 The B<DSAparams> functions process DSA parameters using a DSA
220 structure. The parameters are encoded using a Dss-Parms structure
221 as defined in RFC2459.
223 The B<DHparams> functions process DH parameters using a DH
224 structure. The parameters are encoded using a PKCS#3 DHparameter
227 The B<X509> functions process an X509 certificate using an X509
228 structure. They will also process a trusted X509 certificate but
229 any trust settings are discarded.
231 The B<X509_AUX> functions process a trusted X509 certificate using
234 The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10
235 certificate request using an X509_REQ structure. The B<X509_REQ>
236 write functions use B<CERTIFICATE REQUEST> in the header whereas
237 the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST>
238 (as required by some CAs). The B<X509_REQ> read functions will
239 handle either form so there are no B<X509_REQ_NEW> read functions.
241 The B<X509_CRL> functions process an X509 CRL using an X509_CRL
244 The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7
247 =head1 PEM FUNCTION ARGUMENTS
249 The PEM functions have many common arguments.
251 The B<bp> BIO parameter (if present) specifies the BIO to read from
254 The B<fp> FILE parameter (if present) specifies the FILE pointer to
255 read from or write to.
257 The PEM read functions all take an argument B<TYPE **x> and return
258 a B<TYPE *> pointer. Where B<TYPE> is whatever structure the function
259 uses. If B<x> is NULL then the parameter is ignored. If B<x> is not
260 NULL but B<*x> is NULL then the structure returned will be written
261 to B<*x>. If neither B<x> nor B<*x> is NULL then an attempt is made
262 to reuse the structure at B<*x> (but see BUGS and EXAMPLES sections).
263 Irrespective of the value of B<x> a pointer to the structure is always
264 returned (or NULL if an error occurred).
266 The PEM functions which write private keys take an B<enc> parameter
267 which specifies the encryption algorithm to use, encryption is done
268 at the PEM level. If this parameter is set to NULL then the private
269 key is written in unencrypted form.
271 The B<cb> argument is the callback to use when querying for the pass
272 phrase used for encrypted PEM structures (normally only private keys).
274 For the PEM write routines if the B<kstr> parameter is not NULL then
275 B<klen> bytes at B<kstr> are used as the passphrase and B<cb> is
278 If the B<cb> parameters is set to NULL and the B<u> parameter is not
279 NULL then the B<u> parameter is interpreted as a null terminated string
280 to use as the passphrase. If both B<cb> and B<u> are NULL then the
281 default callback routine is used which will typically prompt for the
282 passphrase on the current terminal with echoing turned off.
284 The default passphrase callback is sometimes inappropriate (for example
285 in a GUI application) so an alternative can be supplied. The callback
286 routine has the following form:
288 int cb(char *buf, int size, int rwflag, void *u);
290 B<buf> is the buffer to write the passphrase to. B<size> is the maximum
291 length of the passphrase (i.e. the size of buf). B<rwflag> is a flag
292 which is set to 0 when reading and 1 when writing. A typical routine
293 will ask the user to verify the passphrase (for example by prompting
294 for it twice) if B<rwflag> is 1. The B<u> parameter has the same
295 value as the B<u> parameter passed to the PEM routine. It allows
296 arbitrary data to be passed to the callback by the application
297 (for example a window handle in a GUI application). The callback
298 B<must> return the number of characters in the passphrase or -1 if
303 Although the PEM routines take several arguments in almost all applications
304 most of them are set to 0 or NULL.
306 Read a certificate in PEM format from a BIO:
310 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
318 if (!PEM_read_bio_X509(bp, &x, 0, NULL))
321 Write a certificate to a BIO:
323 if (!PEM_write_bio_X509(bp, x))
326 Write a private key (using traditional format) to a BIO using
327 triple DES encryption, the pass phrase is prompted for:
329 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL))
332 Write a private key (using PKCS#8 format) to a BIO using triple
333 DES encryption, using the pass phrase "hello":
335 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(),
336 NULL, 0, 0, "hello"))
339 Read a private key from a BIO using a pass phrase callback:
341 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key");
345 Skeleton pass phrase callback:
347 int pass_cb(char *buf, int size, int rwflag, void *u)
350 /* We'd probably do something else if 'rwflag' is 1 */
351 printf("Enter pass phrase for \"%s\"\n", (char *)u);
353 /* get pass phrase, length 'len' into 'tmp' */
355 if (tmp == NULL) /* An error occurred */
358 size_t len = strlen(tmp);
362 memcpy(buf, tmp, len);
368 The old B<PrivateKey> write routines are retained for compatibility.
369 New applications should write private keys using the
370 PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines
371 because they are more secure (they use an iteration count of 2048 whereas
372 the traditional routines use a count of 1) unless compatibility with older
373 versions of OpenSSL is important.
375 The B<PrivateKey> read routines can be used in all applications because
376 they handle all formats transparently.
378 A frequent cause of problems is attempting to use the PEM routines like
383 PEM_read_bio_X509(bp, &x, 0, NULL);
385 this is a bug because an attempt will be made to reuse the data at B<x>
386 which is an uninitialised pointer.
388 These functions make no assumption regarding the pass phrase received from the
390 It will simply be treated as a byte sequence.
392 =head1 PEM ENCRYPTION FORMAT
394 These old B<PrivateKey> routines use a non standard technique for encryption.
396 The private key (or other data) takes the following form:
398 -----BEGIN RSA PRIVATE KEY-----
399 Proc-Type: 4,ENCRYPTED
400 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89
402 ...base64 encoded data...
403 -----END RSA PRIVATE KEY-----
405 The line beginning with I<Proc-Type> contains the version and the
406 protection on the encapsulated data. The line beginning I<DEK-Info>
407 contains two comma separated values: the encryption algorithm name as
408 used by EVP_get_cipherbyname() and an initialization vector used by the
409 cipher encoded as a set of hexadecimal digits. After those two lines is
410 the base64-encoded encrypted data.
412 The encryption key is derived using EVP_BytesToKey(). The cipher's
413 initialization vector is passed to EVP_BytesToKey() as the B<salt>
414 parameter. Internally, B<PKCS5_SALT_LEN> bytes of the salt are used
415 (regardless of the size of the initialization vector). The user's
416 password is passed to EVP_BytesToKey() using the B<data> and B<datal>
417 parameters. Finally, the library uses an iteration count of 1 for
420 The B<key> derived by EVP_BytesToKey() along with the original initialization
421 vector is then used to decrypt the encrypted data. The B<iv> produced by
422 EVP_BytesToKey() is not utilized or needed, and NULL should be passed to
425 The pseudo code to derive the key would look similar to:
427 EVP_CIPHER* cipher = EVP_des_ede3_cbc();
428 EVP_MD* md = EVP_md5();
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];
435 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv);
436 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/);
440 /* On success, use key and iv to initialize the cipher */
444 The PEM read routines in some versions of OpenSSL will not correctly reuse
445 an existing structure. Therefore the following:
447 PEM_read_bio_X509(bp, &x, 0, NULL);
449 where B<x> already contains a valid certificate, may not work, whereas:
452 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
454 is guaranteed to work.
458 The read routines return either a pointer to the structure read or NULL
459 if an error occurred.
461 The write routines return 1 for success or 0 for failure.
465 The old Netscape certificate sequences were no longer documented
466 in OpenSSL 1.1.0; applications should use the PKCS7 standard instead
467 as they will be formally deprecated in a future releases.
471 L<EVP_EncryptInit(3)>, L<EVP_BytesToKey(3)>,
472 L<passphrase-encoding(7)>
476 Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved.
478 Licensed under the OpenSSL license (the "License"). You may not use
479 this file except in compliance with the License. You can obtain a copy
480 in the file LICENSE in the source distribution or at
481 L<https://www.openssl.org/source/license.html>.