1PEM_READ_BIO_PRIVATEKEY(3) OpenSSL PEM_READ_BIO_PRIVATEKEY(3)
2
6 pem_password_cb, PEM_read_bio_PrivateKey, PEM_read_PrivateKey,
7 PEM_write_bio_PrivateKey, PEM_write_bio_PrivateKey_traditional,
8 PEM_write_PrivateKey, PEM_write_bio_PKCS8PrivateKey,
9 PEM_write_PKCS8PrivateKey, PEM_write_bio_PKCS8PrivateKey_nid,
10 PEM_write_PKCS8PrivateKey_nid, PEM_read_bio_PUBKEY, PEM_read_PUBKEY,
11 PEM_write_bio_PUBKEY, PEM_write_PUBKEY, PEM_read_bio_RSAPrivateKey,
12 PEM_read_RSAPrivateKey, PEM_write_bio_RSAPrivateKey,
13 PEM_write_RSAPrivateKey, PEM_read_bio_RSAPublicKey,
14 PEM_read_RSAPublicKey, PEM_write_bio_RSAPublicKey,
15 PEM_write_RSAPublicKey, PEM_read_bio_RSA_PUBKEY, PEM_read_RSA_PUBKEY,
16 PEM_write_bio_RSA_PUBKEY, PEM_write_RSA_PUBKEY,
17 PEM_read_bio_DSAPrivateKey, PEM_read_DSAPrivateKey,
18 PEM_write_bio_DSAPrivateKey, PEM_write_DSAPrivateKey,
19 PEM_read_bio_DSA_PUBKEY, PEM_read_DSA_PUBKEY, PEM_write_bio_DSA_PUBKEY,
20 PEM_write_DSA_PUBKEY, PEM_read_bio_Parameters,
21 PEM_write_bio_Parameters, PEM_read_bio_DSAparams, PEM_read_DSAparams,
22 PEM_write_bio_DSAparams, PEM_write_DSAparams, PEM_read_bio_DHparams,
23 PEM_read_DHparams, PEM_write_bio_DHparams, PEM_write_DHparams,
24 PEM_read_bio_X509, PEM_read_X509, PEM_write_bio_X509, PEM_write_X509,
25 PEM_read_bio_X509_AUX, PEM_read_X509_AUX, PEM_write_bio_X509_AUX,
26 PEM_write_X509_AUX, PEM_read_bio_X509_REQ, PEM_read_X509_REQ,
27 PEM_write_bio_X509_REQ, PEM_write_X509_REQ, PEM_write_bio_X509_REQ_NEW,
28 PEM_write_X509_REQ_NEW, PEM_read_bio_X509_CRL, PEM_read_X509_CRL,
29 PEM_write_bio_X509_CRL, PEM_write_X509_CRL, PEM_read_bio_PKCS7,
30 PEM_read_PKCS7, PEM_write_bio_PKCS7, PEM_write_PKCS7 - PEM routines
31
33 #include <openssl/pem.h>
34 typedef int pem_password_cb(char *buf, int size, int rwflag, void *u);
36 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x,
38 pem_password_cb *cb, void *u);
39 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x,
40 pem_password_cb *cb, void *u);
41 int PEM_write_bio_PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc,
42 unsigned char *kstr, int klen,
43 pem_password_cb *cb, void *u);
44 int PEM_write_bio_PrivateKey_traditional(BIO *bp, EVP_PKEY *x,
45 const EVP_CIPHER *enc,
46 unsigned char *kstr, int klen,
47 pem_password_cb *cb, void *u);
48 int PEM_write_PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc,
49 unsigned char *kstr, int klen,
50 pem_password_cb *cb, void *u);
51 int PEM_write_bio_PKCS8PrivateKey(BIO *bp, EVP_PKEY *x, const EVP_CIPHER *enc,
53 char *kstr, int klen,
54 pem_password_cb *cb, void *u);
55 int PEM_write_PKCS8PrivateKey(FILE *fp, EVP_PKEY *x, const EVP_CIPHER *enc,
56 char *kstr, int klen,
57 pem_password_cb *cb, void *u);
58 int PEM_write_bio_PKCS8PrivateKey_nid(BIO *bp, EVP_PKEY *x, int nid,
59 char *kstr, int klen,
60 pem_password_cb *cb, void *u);
61 int PEM_write_PKCS8PrivateKey_nid(FILE *fp, EVP_PKEY *x, int nid,
62 char *kstr, int klen,
63 pem_password_cb *cb, void *u);
64 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x,
66 pem_password_cb *cb, void *u);
67 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x,
68 pem_password_cb *cb, void *u);
69 int PEM_write_bio_PUBKEY(BIO *bp, EVP_PKEY *x);
70 int PEM_write_PUBKEY(FILE *fp, EVP_PKEY *x);
71 RSA *PEM_read_bio_RSAPrivateKey(BIO *bp, RSA **x,
73 pem_password_cb *cb, void *u);
74 RSA *PEM_read_RSAPrivateKey(FILE *fp, RSA **x,
75 pem_password_cb *cb, void *u);
76 int PEM_write_bio_RSAPrivateKey(BIO *bp, RSA *x, const EVP_CIPHER *enc,
77 unsigned char *kstr, int klen,
78 pem_password_cb *cb, void *u);
79 int PEM_write_RSAPrivateKey(FILE *fp, RSA *x, const EVP_CIPHER *enc,
80 unsigned char *kstr, int klen,
81 pem_password_cb *cb, void *u);
82 RSA *PEM_read_bio_RSAPublicKey(BIO *bp, RSA **x,
84 pem_password_cb *cb, void *u);
85 RSA *PEM_read_RSAPublicKey(FILE *fp, RSA **x,
86 pem_password_cb *cb, void *u);
87 int PEM_write_bio_RSAPublicKey(BIO *bp, RSA *x);
88 int PEM_write_RSAPublicKey(FILE *fp, RSA *x);
89 RSA *PEM_read_bio_RSA_PUBKEY(BIO *bp, RSA **x,
91 pem_password_cb *cb, void *u);
92 RSA *PEM_read_RSA_PUBKEY(FILE *fp, RSA **x,
93 pem_password_cb *cb, void *u);
94 int PEM_write_bio_RSA_PUBKEY(BIO *bp, RSA *x);
95 int PEM_write_RSA_PUBKEY(FILE *fp, RSA *x);
96 DSA *PEM_read_bio_DSAPrivateKey(BIO *bp, DSA **x,
98 pem_password_cb *cb, void *u);
99 DSA *PEM_read_DSAPrivateKey(FILE *fp, DSA **x,
100 pem_password_cb *cb, void *u);
101 int PEM_write_bio_DSAPrivateKey(BIO *bp, DSA *x, const EVP_CIPHER *enc,
102 unsigned char *kstr, int klen,
103 pem_password_cb *cb, void *u);
104 int PEM_write_DSAPrivateKey(FILE *fp, DSA *x, const EVP_CIPHER *enc,
105 unsigned char *kstr, int klen,
106 pem_password_cb *cb, void *u);
107 DSA *PEM_read_bio_DSA_PUBKEY(BIO *bp, DSA **x,
109 pem_password_cb *cb, void *u);
110 DSA *PEM_read_DSA_PUBKEY(FILE *fp, DSA **x,
111 pem_password_cb *cb, void *u);
112 int PEM_write_bio_DSA_PUBKEY(BIO *bp, DSA *x);
113 int PEM_write_DSA_PUBKEY(FILE *fp, DSA *x);
114 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x);
116 int PEM_write_bio_Parameters(BIO *bp, const EVP_PKEY *x);
117 DSA *PEM_read_bio_DSAparams(BIO *bp, DSA **x, pem_password_cb *cb, void *u);
119 DSA *PEM_read_DSAparams(FILE *fp, DSA **x, pem_password_cb *cb, void *u);
120 int PEM_write_bio_DSAparams(BIO *bp, DSA *x);
121 int PEM_write_DSAparams(FILE *fp, DSA *x);
122 DH *PEM_read_bio_DHparams(BIO *bp, DH **x, pem_password_cb *cb, void *u);
124 DH *PEM_read_DHparams(FILE *fp, DH **x, pem_password_cb *cb, void *u);
125 int PEM_write_bio_DHparams(BIO *bp, DH *x);
126 int PEM_write_DHparams(FILE *fp, DH *x);
127 X509 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
129 X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
130 int PEM_write_bio_X509(BIO *bp, X509 *x);
131 int PEM_write_X509(FILE *fp, X509 *x);
132 X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
134 X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
135 int PEM_write_bio_X509_AUX(BIO *bp, X509 *x);
136 int PEM_write_X509_AUX(FILE *fp, X509 *x);
137 X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x,
139 pem_password_cb *cb, void *u);
140 X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x,
141 pem_password_cb *cb, void *u);
142 int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x);
143 int PEM_write_X509_REQ(FILE *fp, X509_REQ *x);
144 int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x);
145 int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *x);
146 X509_CRL *PEM_read_bio_X509_CRL(BIO *bp, X509_CRL **x,
148 pem_password_cb *cb, void *u);
149 X509_CRL *PEM_read_X509_CRL(FILE *fp, X509_CRL **x,
150 pem_password_cb *cb, void *u);
151 int PEM_write_bio_X509_CRL(BIO *bp, X509_CRL *x);
152 int PEM_write_X509_CRL(FILE *fp, X509_CRL *x);
153 PKCS7 *PEM_read_bio_PKCS7(BIO *bp, PKCS7 **x, pem_password_cb *cb, void *u);
155 PKCS7 *PEM_read_PKCS7(FILE *fp, PKCS7 **x, pem_password_cb *cb, void *u);
156 int PEM_write_bio_PKCS7(BIO *bp, PKCS7 *x);
157 int PEM_write_PKCS7(FILE *fp, PKCS7 *x);
158
160 The PEM functions read or write structures in PEM format. In this sense
161 PEM format is simply base64 encoded data surrounded by header lines.
162 For more details about the meaning of arguments see the PEM FUNCTION
164 ARGUMENTS section.
165 Each operation has four functions associated with it. For brevity the
167 term "TYPE functions" will be used below to collectively refer to the
168 PEM_read_bio_TYPE(), PEM_read_TYPE(), PEM_write_bio_TYPE(), and
169 PEM_write_TYPE() functions.
170 The PrivateKey functions read or write a private key in PEM format
172 using an EVP_PKEY structure. The write routines use PKCS#8 private key
173 format and are equivalent to PEM_write_bio_PKCS8PrivateKey().The read
174 functions transparently handle traditional and PKCS#8 format encrypted
175 and unencrypted keys.
176 PEM_write_bio_PrivateKey_traditional() writes out a private key in the
178 "traditional" format with a simple private key marker and should only
179 be used for compatibility with legacy programs.
180 PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey() write a
182 private key in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo
183 format using PKCS#5 v2.0 password based encryption algorithms. The
184 cipher argument specifies the encryption algorithm to use: unlike some
185 other PEM routines the encryption is applied at the PKCS#8 level and
186 not in the PEM headers. If cipher is NULL then no encryption is used
187 and a PKCS#8 PrivateKeyInfo structure is used instead.
188 PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid()
190 also write out a private key as a PKCS#8 EncryptedPrivateKeyInfo
191 however it uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead.
192 The algorithm to use is specified in the nid parameter and should be
193 the NID of the corresponding OBJECT IDENTIFIER (see NOTES section).
194 The PUBKEY functions process a public key using an EVP_PKEY structure.
196 The public key is encoded as a SubjectPublicKeyInfo structure.
197 The RSAPrivateKey functions process an RSA private key using an RSA
199 structure. The write routines uses traditional format. The read
200 routines handles the same formats as the PrivateKey functions but an
201 error occurs if the private key is not RSA.
202 The RSAPublicKey functions process an RSA public key using an RSA
204 structure. The public key is encoded using a PKCS#1 RSAPublicKey
205 structure.
206 The RSA_PUBKEY functions also process an RSA public key using an RSA
208 structure. However, the public key is encoded using a
209 SubjectPublicKeyInfo structure and an error occurs if the public key is
210 not RSA.
211 The DSAPrivateKey functions process a DSA private key using a DSA
213 structure. The write routines uses traditional format. The read
214 routines handles the same formats as the PrivateKey functions but an
215 error occurs if the private key is not DSA.
216 The DSA_PUBKEY functions process a DSA public key using a DSA
218 structure. The public key is encoded using a SubjectPublicKeyInfo
219 structure and an error occurs if the public key is not DSA.
220 The Parameters functions read or write key parameters in PEM format
222 using an EVP_PKEY structure. The encoding depends on the type of key;
223 for DSA key parameters, it will be a Dss-Parms structure as defined in
224 RFC2459, and for DH key parameters, it will be a PKCS#3 DHparameter
225 structure. These functions only exist for the BIO type.
226 The DSAparams functions process DSA parameters using a DSA structure.
228 The parameters are encoded using a Dss-Parms structure as defined in
229 RFC2459.
230 The DHparams functions process DH parameters using a DH structure. The
232 parameters are encoded using a PKCS#3 DHparameter structure.
233 The X509 functions process an X509 certificate using an X509 structure.
235 They will also process a trusted X509 certificate but any trust
236 settings are discarded.
237 The X509_AUX functions process a trusted X509 certificate using an X509
239 structure.
240 The X509_REQ and X509_REQ_NEW functions process a PKCS#10 certificate
242 request using an X509_REQ structure. The X509_REQ write functions use
243 CERTIFICATE REQUEST in the header whereas the X509_REQ_NEW functions
244 use NEW CERTIFICATE REQUEST (as required by some CAs). The X509_REQ
245 read functions will handle either form so there are no X509_REQ_NEW
246 read functions.
247 The X509_CRL functions process an X509 CRL using an X509_CRL structure.
249 The PKCS7 functions process a PKCS#7 ContentInfo using a PKCS7
251 structure.
252
254 The PEM functions have many common arguments.
255 The bp BIO parameter (if present) specifies the BIO to read from or
257 write to.
258 The fp FILE parameter (if present) specifies the FILE pointer to read
260 from or write to.
261 The PEM read functions all take an argument TYPE **x and return a TYPE
263 * pointer. Where TYPE is whatever structure the function uses. If x is
264 NULL then the parameter is ignored. If x is not NULL but *x is NULL
265 then the structure returned will be written to *x. If neither x nor *x
266 is NULL then an attempt is made to reuse the structure at *x (but see
267 BUGS and EXAMPLES sections). Irrespective of the value of x a pointer
268 to the structure is always returned (or NULL if an error occurred).
269 The PEM functions which write private keys take an enc parameter which
271 specifies the encryption algorithm to use, encryption is done at the
272 PEM level. If this parameter is set to NULL then the private key is
273 written in unencrypted form.
274 The cb argument is the callback to use when querying for the pass
276 phrase used for encrypted PEM structures (normally only private keys).
277 For the PEM write routines if the kstr parameter is not NULL then klen
279 bytes at kstr are used as the passphrase and cb is ignored.
280 If the cb parameters is set to NULL and the u parameter is not NULL
282 then the u parameter is interpreted as a null terminated string to use
283 as the passphrase. If both cb and u are NULL then the default callback
284 routine is used which will typically prompt for the passphrase on the
285 current terminal with echoing turned off.
286 The default passphrase callback is sometimes inappropriate (for example
288 in a GUI application) so an alternative can be supplied. The callback
289 routine has the following form:
290 int cb(char *buf, int size, int rwflag, void *u);
292 buf is the buffer to write the passphrase to. size is the maximum
294 length of the passphrase (i.e. the size of buf). rwflag is a flag which
295 is set to 0 when reading and 1 when writing. A typical routine will ask
296 the user to verify the passphrase (for example by prompting for it
297 twice) if rwflag is 1. The u parameter has the same value as the u
298 parameter passed to the PEM routine. It allows arbitrary data to be
299 passed to the callback by the application (for example a window handle
300 in a GUI application). The callback must return the number of
301 characters in the passphrase or -1 if an error occurred.
302
304 The old PrivateKey write routines are retained for compatibility. New
305 applications should write private keys using the
306 PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey() routines
307 because they are more secure (they use an iteration count of 2048
308 whereas the traditional routines use a count of 1) unless compatibility
309 with older versions of OpenSSL is important.
310 The PrivateKey read routines can be used in all applications because
312 they handle all formats transparently.
313 A frequent cause of problems is attempting to use the PEM routines like
315 this:
316 X509 *x;
318 PEM_read_bio_X509(bp, &x, 0, NULL);
320 this is a bug because an attempt will be made to reuse the data at x
322 which is an uninitialised pointer.
323 These functions make no assumption regarding the pass phrase received
325 from the password callback. It will simply be treated as a byte
326 sequence.
327
329 These old PrivateKey routines use a non standard technique for
330 encryption.
331 The private key (or other data) takes the following form:
333 -----BEGIN RSA PRIVATE KEY-----
335 Proc-Type: 4,ENCRYPTED
336 DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89
337 ...base64 encoded data...
339 -----END RSA PRIVATE KEY-----
340 The line beginning with Proc-Type contains the version and the
342 protection on the encapsulated data. The line beginning DEK-Info
343 contains two comma separated values: the encryption algorithm name as
344 used by EVP_get_cipherbyname() and an initialization vector used by the
345 cipher encoded as a set of hexadecimal digits. After those two lines is
346 the base64-encoded encrypted data.
347 The encryption key is derived using EVP_BytesToKey(). The cipher's
349 initialization vector is passed to EVP_BytesToKey() as the salt
350 parameter. Internally, PKCS5_SALT_LEN bytes of the salt are used
351 (regardless of the size of the initialization vector). The user's
352 password is passed to EVP_BytesToKey() using the data and datal
353 parameters. Finally, the library uses an iteration count of 1 for
354 EVP_BytesToKey().
355 The key derived by EVP_BytesToKey() along with the original
357 initialization vector is then used to decrypt the encrypted data. The
358 iv produced by EVP_BytesToKey() is not utilized or needed, and NULL
359 should be passed to the function.
360 The pseudo code to derive the key would look similar to:
362 EVP_CIPHER* cipher = EVP_des_ede3_cbc();
364 EVP_MD* md = EVP_md5();
365 unsigned int nkey = EVP_CIPHER_key_length(cipher);
367 unsigned int niv = EVP_CIPHER_iv_length(cipher);
368 unsigned char key[nkey];
369 unsigned char iv[niv];
370 memcpy(iv, HexToBin("3F17F5316E2BAC89"), niv);
372 rc = EVP_BytesToKey(cipher, md, iv /*salt*/, pword, plen, 1, key, NULL /*iv*/);
373 if (rc != nkey)
374 /* Error */
375 /* On success, use key and iv to initialize the cipher */
377
379 The PEM read routines in some versions of OpenSSL will not correctly
380 reuse an existing structure. Therefore, the following:
381 PEM_read_bio_X509(bp, &x, 0, NULL);
383 where x already contains a valid certificate, may not work, whereas:
385 X509_free(x);
387 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
388 is guaranteed to work.
390
392 The read routines return either a pointer to the structure read or NULL
393 if an error occurred.
394 The write routines return 1 for success or 0 for failure.
396
398 Although the PEM routines take several arguments in almost all
399 applications most of them are set to 0 or NULL.
400 Read a certificate in PEM format from a BIO:
402 X509 *x;
404 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
406 if (x == NULL)
407 /* Error */
408 Alternative method:
410 X509 *x = NULL;
412 if (!PEM_read_bio_X509(bp, &x, 0, NULL))
414 /* Error */
415 Write a certificate to a BIO:
417 if (!PEM_write_bio_X509(bp, x))
419 /* Error */
420 Write a private key (using traditional format) to a BIO using triple
422 DES encryption, the pass phrase is prompted for:
423 if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(), NULL, 0, 0, NULL))
425 /* Error */
426 Write a private key (using PKCS#8 format) to a BIO using triple DES
428 encryption, using the pass phrase "hello":
429 if (!PEM_write_bio_PKCS8PrivateKey(bp, key, EVP_des_ede3_cbc(),
431 NULL, 0, 0, "hello"))
432 /* Error */
433 Read a private key from a BIO using a pass phrase callback:
435 key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private Key");
437 if (key == NULL)
438 /* Error */
439 Skeleton pass phrase callback:
441 int pass_cb(char *buf, int size, int rwflag, void *u)
443 {
444 /* We'd probably do something else if 'rwflag' is 1 */
446 printf("Enter pass phrase for \"%s\"\n", (char *)u);
447 /* get pass phrase, length 'len' into 'tmp' */
449 char *tmp = "hello";
450 if (tmp == NULL) /* An error occurred */
451 return -1;
452 size_t len = strlen(tmp);
454 if (len > size)
456 len = size;
457 memcpy(buf, tmp, len);
458 return len;
459 }
460
462 EVP_EncryptInit(3), EVP_BytesToKey(3), passphrase-encoding(7)
463
465 The old Netscape certificate sequences were no longer documented in
466 OpenSSL 1.1.0; applications should use the PKCS7 standard instead as
467 they will be formally deprecated in a future releases.
468
470 Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
471 Licensed under the OpenSSL license (the "License"). You may not use
473 this file except in compliance with the License. You can obtain a copy
474 in the file LICENSE in the source distribution or at
475 <https://www.openssl.org/source/license.html>.
4761.1.1q 2022-07-07 PEM_READ_BIO_PRIVATEKEY(3)