aboutsummaryrefslogtreecommitdiff
path: root/openssl/doc/crypto/pem.pod
diff options
context:
space:
mode:
Diffstat (limited to 'openssl/doc/crypto/pem.pod')
-rw-r--r--openssl/doc/crypto/pem.pod476
1 files changed, 476 insertions, 0 deletions
diff --git a/openssl/doc/crypto/pem.pod b/openssl/doc/crypto/pem.pod
new file mode 100644
index 000000000..4f9a27df0
--- /dev/null
+++ b/openssl/doc/crypto/pem.pod
@@ -0,0 +1,476 @@
+=pod
+
+=head1 NAME
+
+PEM - PEM routines
+
+=head1 SYNOPSIS
+
+ #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,
+ unsigned char *kstr, int klen,
+ 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_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 *PEM_read_bio_X509(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
+
+ X509 *PEM_read_X509(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
+
+ int PEM_write_bio_X509(BIO *bp, X509 *x);
+
+ int PEM_write_X509(FILE *fp, X509 *x);
+
+ X509 *PEM_read_bio_X509_AUX(BIO *bp, X509 **x, pem_password_cb *cb, void *u);
+
+ X509 *PEM_read_X509_AUX(FILE *fp, X509 **x, pem_password_cb *cb, void *u);
+
+ int PEM_write_bio_X509_AUX(BIO *bp, X509 *x);
+
+ int PEM_write_X509_AUX(FILE *fp, X509 *x);
+
+ X509_REQ *PEM_read_bio_X509_REQ(BIO *bp, X509_REQ **x,
+ pem_password_cb *cb, void *u);
+
+ X509_REQ *PEM_read_X509_REQ(FILE *fp, X509_REQ **x,
+ pem_password_cb *cb, void *u);
+
+ int PEM_write_bio_X509_REQ(BIO *bp, X509_REQ *x);
+
+ int PEM_write_X509_REQ(FILE *fp, X509_REQ *x);
+
+ int PEM_write_bio_X509_REQ_NEW(BIO *bp, X509_REQ *x);
+
+ int PEM_write_X509_REQ_NEW(FILE *fp, X509_REQ *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(FILE *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);
+
+=head1 DESCRIPTION
+
+The PEM functions read or write structures in PEM format. In
+this sense PEM format is simply base64 encoded data surrounded
+by header lines.
+
+For more details about the meaning of arguments see the
+B<PEM FUNCTION ARGUMENTS> section.
+
+Each operation has four functions associated with it. For
+clarity the term "B<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 B<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 additionally transparently
+handle PKCS#8 format encrypted and unencrypted keys too.
+
+PEM_write_bio_PKCS8PrivateKey() and PEM_write_PKCS8PrivateKey()
+write a private key in an EVP_PKEY structure in PKCS#8
+EncryptedPrivateKeyInfo format using PKCS#5 v2.0 password based encryption
+algorithms. The B<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 B<cipher> is NULL then no
+encryption is used and a PKCS#8 PrivateKeyInfo structure is used instead.
+
+PEM_write_bio_PKCS8PrivateKey_nid() and PEM_write_PKCS8PrivateKey_nid()
+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 B<nid> parameter and should be the NID of the
+corresponding OBJECT IDENTIFIER (see NOTES section).
+
+The B<PUBKEY> functions process a public key using an EVP_PKEY
+structure. The public key is encoded as a SubjectPublicKeyInfo
+structure.
+
+The B<RSAPrivateKey> functions process an RSA private key using an
+RSA structure. It handles the same formats as the B<PrivateKey>
+functions but an error occurs if the private key is not RSA.
+
+The B<RSAPublicKey> functions process an RSA public key using an
+RSA structure. The public key is encoded using a PKCS#1 RSAPublicKey
+structure.
+
+The B<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 B<DSAPrivateKey> functions process a DSA private key using a
+DSA structure. It handles the same formats as the B<PrivateKey>
+functions but an error occurs if the private key is not DSA.
+
+The B<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 B<DSAparams> functions process DSA parameters using a DSA
+structure. The parameters are encoded using a foobar structure.
+
+The B<DHparams> functions process DH parameters using a DH
+structure. The parameters are encoded using a PKCS#3 DHparameter
+structure.
+
+The B<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 B<X509_AUX> functions process a trusted X509 certificate using
+an X509 structure.
+
+The B<X509_REQ> and B<X509_REQ_NEW> functions process a PKCS#10
+certificate request using an X509_REQ structure. The B<X509_REQ>
+write functions use B<CERTIFICATE REQUEST> in the header whereas
+the B<X509_REQ_NEW> functions use B<NEW CERTIFICATE REQUEST>
+(as required by some CAs). The B<X509_REQ> read functions will
+handle either form so there are no B<X509_REQ_NEW> read functions.
+
+The B<X509_CRL> functions process an X509 CRL using an X509_CRL
+structure.
+
+The B<PKCS7> functions process a PKCS#7 ContentInfo using a PKCS7
+structure.
+
+The B<NETSCAPE_CERT_SEQUENCE> functions process a Netscape Certificate
+Sequence using a NETSCAPE_CERT_SEQUENCE structure.
+
+=head1 PEM FUNCTION ARGUMENTS
+
+The PEM functions have many common arguments.
+
+The B<bp> BIO parameter (if present) specifies the BIO to read from
+or write to.
+
+The B<fp> FILE parameter (if present) specifies the FILE pointer to
+read from or write to.
+
+The PEM read functions all take an argument B<TYPE **x> and return
+a B<TYPE *> pointer. Where B<TYPE> is whatever structure the function
+uses. If B<x> is NULL then the parameter is ignored. If B<x> is not
+NULL but B<*x> is NULL then the structure returned will be written
+to B<*x>. If neither B<x> nor B<*x> is NULL then an attempt is made
+to reuse the structure at B<*x> (but see BUGS and EXAMPLES sections).
+Irrespective of the value of B<x> a pointer to the structure is always
+returned (or NULL if an error occurred).
+
+The PEM functions which write private keys take an B<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 B<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 B<kstr> parameter is not NULL then
+B<klen> bytes at B<kstr> are used as the passphrase and B<cb> is
+ignored.
+
+If the B<cb> parameters is set to NULL and the B<u> parameter is not
+NULL then the B<u> parameter is interpreted as a null terminated string
+to use as the passphrase. If both B<cb> and B<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);
+
+B<buf> is the buffer to write the passphrase to. B<size> is the maximum
+length of the passphrase (i.e. the size of buf). B<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 B<rwflag> is 1. The B<u> parameter has the same
+value as the B<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
+B<must> return the number of characters in the passphrase or 0 if
+an error occurred.
+
+=head1 EXAMPLES
+
+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_X509(bp, NULL, 0, NULL);
+ if (x == NULL)
+ {
+ /* Error */
+ }
+
+Alternative method:
+
+ X509 *x = NULL;
+ if (!PEM_read_bio_X509(bp, &x, 0, NULL))
+ {
+ /* Error */
+ }
+
+Write a certificate to a BIO:
+
+ if (!PEM_write_bio_X509(bp, x))
+ {
+ /* Error */
+ }
+
+Write an unencrypted private key to a FILE pointer:
+
+ if (!PEM_write_PrivateKey(fp, key, NULL, NULL, 0, 0, NULL))
+ {
+ /* Error */
+ }
+
+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))
+ {
+ /* Error */
+ }
+
+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"))
+ {
+ /* Error */
+ }
+
+Read a private key from a BIO using the pass phrase "hello":
+
+ key = PEM_read_bio_PrivateKey(bp, NULL, 0, "hello");
+ if (key == NULL)
+ {
+ /* Error */
+ }
+
+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)
+ {
+ /* Error */
+ }
+
+Skeleton pass phrase callback:
+
+ int pass_cb(char *buf, int size, int rwflag, void *u);
+ {
+ int len;
+ char *tmp;
+ /* We'd probably do something else if 'rwflag' is 1 */
+ printf("Enter pass phrase for \"%s\"\n", u);
+
+ /* get pass phrase, length 'len' into 'tmp' */
+ tmp = "hello";
+ len = strlen(tmp);
+
+ if (len <= 0) return 0;
+ /* if too long, truncate */
+ if (len > size) len = size;
+ memcpy(buf, tmp, len);
+ return len;
+ }
+
+=head1 NOTES
+
+The old B<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 (they use an iteration count of 2048 whereas
+the traditional routines use a count of 1) unless compatibility with older
+versions of OpenSSL is important.
+
+The B<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 like
+this:
+
+ 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 B<x>
+which is an uninitialised pointer.
+
+=head1 PEM ENCRYPTION FORMAT
+
+This old B<PrivateKey> routines use a non standard technique for encryption.
+
+The private key (or other data) takes the following form:
+
+ -----BEGIN RSA PRIVATE KEY-----
+ Proc-Type: 4,ENCRYPTED
+ DEK-Info: DES-EDE3-CBC,3F17F5316E2BAC89
+
+ ...base64 encoded data...
+ -----END RSA PRIVATE KEY-----
+
+The line beginning DEK-Info contains two comma separated pieces of information:
+the encryption algorithm name as used by EVP_get_cipherbyname() and an 8
+byte B<salt> encoded as a set of hexadecimal digits.
+
+After this is the base64 encoded encrypted data.
+
+The encryption key is determined using EVP_bytestokey(), using B<salt> and an
+iteration count of 1. The IV used is the value of B<salt> and *not* the IV
+returned by EVP_bytestokey().
+
+=head1 BUGS
+
+The PEM read routines in some versions of OpenSSL will not correctly reuse
+an existing structure. Therefore the following:
+
+ PEM_read_bio_X509(bp, &x, 0, NULL);
+
+where B<x> already contains a valid certificate, may not work, whereas:
+
+ X509_free(x);
+ x = PEM_read_bio_X509(bp, NULL, 0, NULL);
+
+is guaranteed to work.
+
+=head1 RETURN CODES
+
+The read routines return either a pointer to the structure read or NULL
+if an error occurred.
+
+The write routines return 1 for success or 0 for failure.