pem - PEM routines
#include <openssl/pem.h>
EVP_PKEY *PEM_read_bio_PrivateKey(
BIO *bp,
EVP_PKEY **x,
pem_password_cb *cb,
void *u ); EVP_PKEY *PEM_read_PrivateKey(
FILE *fp,
EVP_PKEY **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_PrivateKey(
BIO *bp,
EVP_PKEY *x,
const EVP_CIPHER *enc,
unsigned char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_PrivateKey(
FILE *fp,
EVP_PKEY *x,
const EVP_CIPHER *enc,
unsigned char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_bio_PKCS8PrivateKey(
BIO *bp,
EVP_PKEY *x,
const EVP_CIPHER *enc,
char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_PKCS8PrivateKey(
FILE *fp,
EVP_PKEY *x,
const EVP_CIPHER *enc,
char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_bio_PKCS8PrivateKey_nid(
BIO *bp,
EVP_PKEY *x,
int nid,
char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_PKCS8PrivateKey_nid(
FILE *fp,
EVP_PKEY *x,
int nid,
char *kstr,
int klen,
pem_password_cb *cb,
void *u ); EVP_PKEY *PEM_read_bio_PUBKEY(
BIO *bp,
EVP_PKEY **x,
pem_password_cb *cb,
void *u ); EVP_PKEY *PEM_read_PUBKEY(
FILE *fp,
EVP_PKEY **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_PUBKEY(
BIO *bp,
EVP_PKEY *x ); int PEM_write_PUBKEY(
FILE *fp,
EVP_PKEY *x ); RSA *PEM_read_bio_RSAPrivateKey(
BIO *bp,
RSA **x,
pem_password_cb *cb,
void *u ); RSA *PEM_read_RSAPrivateKey(
FILE *fp,
RSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_RSAPrivateKey(
BIO *bp,
RSA *x,
const EVP_CIPHER *enc,
int klen,
unsigned char *kstr,
pem_password_cb *cb,
void *u ); int PEM_write_RSAPrivateKey(
FILE *fp,
RSA *x,
const EVP_CIPHER *enc,
unsigned char *kstr,
int klen,
pem_password_cb *cb,
void *u ); RSA *PEM_read_bio_RSAPublicKey(
BIO *bp,
RSA **x,
pem_password_cb *cb,
void *u ); RSA *PEM_read_RSAPublicKey(
FILE *fp,
RSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_RSAPublicKey(
BIO *bp,
RSA *x ); int PEM_write_RSAPublicKey(
FILE *fp,
RSA *x ); RSA *PEM_read_bio_RSA_PUBKEY(
BIO *bp,
RSA **x,
pem_password_cb *cb,
void *u ); RSA *PEM_read_RSA_PUBKEY(
FILE *fp,
RSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_RSA_PUBKEY(
BIO *bp,
RSA *x ); int PEM_write_RSAPublicKey(
FILE *fp,
RSA *x ); RSA *PEM_read_bio_RSA_PUBKEY(
BIO *bp,
RSA **x,
pem_password_cb *cb,
void *u ); RSA *PEM_read_RSA_PUBKEY(
FILE *fp,
RSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_RSA_PUBKEY(
BIO *bp,
RSA *x ); int PEM_write_RSA_PUBKEY(
FILE *fp,
RSA *x ); DSA *PEM_read_bio_DSAPrivateKey(
BIO *bp,
DSA **x,
pem_password_cb *cb,
void *u ); DSA *PEM_read_DSAPrivateKey(
FILE *fp,
DSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_DSAPrivateKey(
BIO *bp,
DSA *x, const EVP_CIPHER *enc,
unsigned char *kstr,
int klen,
pem_password_cb *cb,
void *u ); int PEM_write_DSAPrivateKey(
FILE *fp,
DSA *x,
const EVP_CIPHER *enc,
unsigned char *kstr,
int klen,
pem_password_cb *cb,
void *u ); DSA *PEM_read_bio_DSA_PUBKEY(
BIO *bp,
DSA **x,
pem_password_cb *cb,
void *u ); DSA *PEM_read_DSA_PUBKEY(
FILE *fp,
DSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_DSA_PUBKEY(
BIO *bp,
DSA *x ); int PEM_write_DSA_PUBKEY(
FILE *fp,
DSA *x ); DSA *PEM_read_bio_DSAparams(
BIO *bp,
DSA **x,
pem_password_cb *cb,
void *u ); DSA *PEM_read_DSAparams(
FILE *fp,
DSA **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_DSAparams(
BIO *bp,
DSA *x ); int PEM_write_DSAparams(
FILE *fp,
DSA *x ); DH *PEM_read_bio_DHparams(
BIO *bp,
DH **x,
pem_password_cb *cb,
void *u ); DH *PEM_read_DHparams(
FILE *fp,
DH **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_DHparams(
BIO *bp,
DH *x ); int PEM_write_DHparams(
FILE *fp,
DH *x ); X509_CRL *PEM_read_bio_X509_CRL(
BIO *bp,
X509_CRL **x,
pem_password_cb *cb,
void *u ); X509_CRL *PEM_read_X509_CRL(
FILE *fp,
X509_CRL **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_X509_CRL(
BIO *bp,
X509_CRL *x ); int PEM_write_X509_CRL(
FILE *fp,
X509_CRL *x ); PKCS7 *PEM_read_bio_PKCS7(
BIO *bp,
PKCS7 **x,
pem_password_cb *cb,
void *u ); PKCS7 *PEM_read_PKCS7(
ILE *fp,
PKCS7 **x,
pem_password_cb *cb,
void *u ); int PEM_write_bio_PKCS7(
BIO *bp,
PKCS7 *x ); int PEM_write_PKCS7(
FILE *fp,
PKCS7 *x ); NETSCAPE_CERT_SEQUENCE
*PEM_read_bio_NETSCAPE_CERT_SEQUENCE(
BIO *bp,
NETSCAPE_CERT_SEQUENCE **x,
pem_password_cb *cb,
void *u ); NETSCAPE_CERT_SEQUENCE
*PEM_read_NETSCAPE_CERT_SEQUENCE(
FILE *fp,
NETSCAPE_CERT_SEQUENCE **x,
pem_password_cb *cb,
void *u ); int
PEM_write_bio_NETSCAPE_CERT_SEQUENCE(
BIO *bp,
NETSCAPE_CERT_SEQUENCE *x ); int
PEM_write_NETSCAPE_CERT_SEQUENCE(
FILE *fp,
NETSCAPE_CERT_SEQUENCE *x );
The pem() functions read or write structures in PEM format.
In this sense PEM format is simply base64 encoded
data surrounded by header lines.
Each operation has four functions associated with it. For
clarity the term foobar functions will be used to collectively
refer to the PEM_read_bio_foobar(), PEM_read_foobar(),
PEM_write_bio_foobar(), and PEM_write_foobar()
functions.
The PrivateKey functions read or write a private key in
PEM format using an EVP_PKEY structure. The write routines
use traditional private key format and can handle both RSA
and DSA private keys. The read functions can transparently
handle PKCS#8 format encrypted and unencrypted keys too.
The PEM_write_bio_PKCS8PrivateKey() and
PEM_write_PKCS8PrivateKey() functions write a private key
in an EVP_PKEY structure in PKCS#8 EncryptedPrivateKeyInfo
format using PKCS#5 v2.0 password based encryption algorithms.
The cipher argument specifies the encryption algoritm
to use. Unlike all other PEM routines the encryption
is applied at the PKCS#8 level and not in the PEM headers.
If cipher is NULL then no encryption is used and a PKCS#8
PrivateKeyInfo structure is used instead.
The PEM_write_bio_PKCS8PrivateKey_nid() and
PEM_write_PKCS8PrivateKey_nid() functions also write out a
private key as a PKCS#8 EncryptedPrivateKeyInfo however it
uses PKCS#5 v1.5 or PKCS#12 encryption algorithms instead.
The algorithm to use is specified in the nid parameter and
should be the NID of the corresponding OBJECT IDENTIFIER
(see Notes section).
The PUBKEY functions process a public key using an
EVP_PKEY structure. The public key is encoded as a SubjectPublicKeyInfo
structure.
The RSAPrivateKey functions process an RSA private key
using an RSA structure. It handles the same formats as the
PrivateKey functions but an error occurs if the private
key is not RSA.
The RSAPublicKey functions process an RSA public key using
an RSA structure. The public key is encoded using a
PKCS#1 RSAPublicKey structure.
The RSA_PUBKEY functions also process an RSA public key
using an RSA structure. However the public key is encoded
using a SubjectPublicKeyInfo structure and an error occurs
if the public key is not RSA.
The DSAPrivateKey functions process a DSA private key
using a DSA structure. It handles the same formats as the
PrivateKey functions but an error occurs if the private
key is not DSA.
The DSA_PUBKEY functions process a DSA public key using a
DSA structure. The public key is encoded using a SubjectPublicKeyInfo
structure and an error occurs if the public
key is not DSA.
The DSAparams functions process DSA parameters using a DSA
structure. The parameters are encoded using a foobar
structure.
The DHparams functions process DH parameters using a DH
structure. The parameters are encoded using a PKCS#3 DHparameter
structure.
The X509 functions process an X509 certificate using an
X509 structure. They will also process a trusted X509
certificate but any trust settings are discarded.
The X509_AUX functions process a trusted X509 certificate
using an X509 structure.
The X509_REQ and X509_REQ_NEW functions process a PKCS#10
certificate request using an X509_REQ structure. The
X509_REQ write functions use CERTIFICATE REQUEST in the
header whereas the X509_REQ_NEW functions use NEW CERTIFICATE
REQUEST (as required by some CAs). The X509_REQ read
functions will handle either form so there are no
X509_REQ_NEW read functions.
The X509_CRL functions process an X509 CRL using an
X509_CRL structure.
The PKCS7 functions process a PKCS#7 ContentInfo using a
PKCS7 structure.
The NETSCAPE_CERT_SEQUENCE functions process a Netscape
Certificate Sequence using a NETSCAPE_CERT_SEQUENCE structure.
PEM FUNCTION ARGUMENTS [Toc] [Back] The PEM functions have many common arguments.
The bp IO parameter (if present) specifies the BIO to read
from or write to.
The fp FILE parameter (if present) specifies the FILE
pointer to read from or write to.
The PEM read functions all take an argument TYPE **x and
return a TYPE * pointer. Where TYPE is whatever structure
the function uses. If x is NULL then the parameter is
ignored. If x is not NULL but *x is NULL then the structure
returned will be written to *x. If neither x nor *x
is NULL then an attempt is made to reuse the structure at
*x (see NOTES and EXAMPLES sections). Irrespective of the
value of x, a pointer to the structure is always returned
(or NULL if an error occurred).
The PEM functions which write private keys take an enc
parameter which specifies the encryption algorithm to use.
Encryption is done at the PEM level. If this parameter is
set to NULL then the private key is written in unencrypted
form.
The cb argument is the callback to use when querying for
the pass phrase used for encrypted PEM structures (normally
only private keys).
For the PEM write routines if the kstr parameter is not
NULL then klen bytes at kstr are used as the passphrase
and cb is ignored.
If the cb parameter is set to NULL and the u parameter is
not NULL then the u parameter is interpreted as a null
terminated string to use as the passphrase. If both cb and
u are NULL then the default callback routine is used which
will typically prompt for the passphrase on the current
terminal with echoing turned off.
The default passphrase callback is sometimes inappropriate
(for example in a GUI application) so an alternative can
be supplied. The callback routine has the following form:
int cb(char *buf, int size, int rwflag, void *u); buf is
the buffer to write the passphrase to. Size is the maximum
length of the passphrase (i.e. the size of buf). rwflag
is a flag which is set to 0 when reading and 1 when writing.
A typical routine will ask the user to verify the
passphrase (for example by prompting for it twice) if
rwflag is 1. The u parameter has the same value as the u
parameter passed to the PEM routine. It allows arbitrary
data to be passed to the callback by the application (for
example, a window handle in a GUI application). The callback
must return the number of characters in the
passphrase or 0 if an error occurred.
The PEM read routines in some versions of OpenSSL will not
correctly reuse an existing structure. Therefore the following
may not work where x already contains a valid certificate:
PEM_read_bio(bp, &x, 0, NULL);
However, the following is guaranteed to work:
X509_free(x); x =3D PEM_read_bio(bp, NULL, 0, NULL);
The old PrivateKey write routines are retained for compatibility.
New applications should write private keys using
the PEM_write_bio_PKCS8PrivateKey() or PEM_write_PKCS8PrivateKey()
routines because they are more secure, unless
compatibility with older versions of OpenSSL is important.
(They use an iteration count of 2048, whereas the traditional
routines use a count of 1.) The PrivateKey read
routines can be used in all applications because they handle
all formats transparently. A frequent cause of problems
is attempting to use the PEM routines in the following
manner:
X509 *x; PEM_read_bio_X509(bp, &x, 0, NULL);
This is a bug because an attempt will be made to reuse the
data at x which is an uninitialized pointer.
The read routines return either a pointer to the structure
read or NULL is an error occurred.
The write routines return 1 for success or 0 for failure.
Although the PEM routines take several arguments in almost
all applications most of them are set to 0 or NULL.
Read a certificate in PEM format from a BIO:
X509 *x; x = PEM_read_bio(bp, NULL, 0, NULL); if (x ==
NULL)
{
}
Alternative method:
X509 *x = NULL; if (!PEM_read_bio_X509(bp, &x, 0, NULL))
{
}
Write a certificate to a BIO:
if (!PEM_write_bio_X509(bp, x))
{
}
Write an unencrypted private key to a FILE pointer:
if (!PEM_write_PrivateKey(fp, key, NULL, NULL, 0, 0,
NULL))
{
}
Write a private key (using traditional format) to a BIO
using triple DES encryption, the pass phrase is prompted
for:
if (!PEM_write_bio_PrivateKey(bp, key, EVP_des_ede3_cbc(),
NULL, 0, 0, NULL))
{
}
Write a private key (using PKCS#8 format) to a BIO using
triple DES encryption, using the pass phrase ``hello'':
if (!PEM_write_bio_PKCS8PrivateKey(bp, key,
EVP_des_ede3_cbc(), NULL, 0, 0, "hello"))
{
}
Read a private key from a BIO using the pass phrase
``hello'':
key = PEM_read_bio_PrivateKey(bp, NULL, 0, "hello"); if
(key == NULL)
{
}
Read a private key from a BIO using a pass phrase callback:
key = PEM_read_bio_PrivateKey(bp, NULL, pass_cb, "My Private
Key"); if (key == NULL)
{
}
Skeleton pass phrase callback:
int pass_cb(char *buf, int size, int rwflag, void *u);
{
int len;
char *tmp;
printf("Enter pass phrase for \"%s\"\n", u);
tmp = "hello";
len = strlen(tmp);
if (len <= 0) return 0;
if (len > size) len = size;
memcpy(buf, tmp, len);
return len;
}
pem(3)
[ Back ] |
