diff options
Diffstat (limited to 'roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/PEM_read.pod')
-rw-r--r-- | roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/PEM_read.pod | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/PEM_read.pod b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/PEM_read.pod new file mode 100644 index 000000000..3c777b547 --- /dev/null +++ b/roms/edk2/CryptoPkg/Library/OpensslLib/openssl/doc/man3/PEM_read.pod @@ -0,0 +1,132 @@ +=pod + +=head1 NAME + +PEM_write, PEM_write_bio, +PEM_read, PEM_read_bio, PEM_do_header, PEM_get_EVP_CIPHER_INFO +- PEM encoding routines + +=head1 SYNOPSIS + + #include <openssl/pem.h> + + int PEM_write(FILE *fp, const char *name, const char *header, + const unsigned char *data, long len) + int PEM_write_bio(BIO *bp, const char *name, const char *header, + const unsigned char *data, long len) + + int PEM_read(FILE *fp, char **name, char **header, + unsigned char **data, long *len); + int PEM_read_bio(BIO *bp, char **name, char **header, + unsigned char **data, long *len); + + int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cinfo); + int PEM_do_header(EVP_CIPHER_INFO *cinfo, unsigned char *data, long *len, + pem_password_cb *cb, void *u); + +=head1 DESCRIPTION + +These functions read and write PEM-encoded objects, using the PEM +type B<name>, any additional B<header> information, and the raw +B<data> of length B<len>. + +PEM is the term used for binary content encoding first defined in IETF +RFC 1421. The content is a series of base64-encoded lines, surrounded +by begin/end markers each on their own line. For example: + + -----BEGIN PRIVATE KEY----- + MIICdg.... + ... bhTQ== + -----END PRIVATE KEY----- + +Optional header line(s) may appear after the begin line, and their +existence depends on the type of object being written or read. + +PEM_write() writes to the file B<fp>, while PEM_write_bio() writes to +the BIO B<bp>. The B<name> is the name to use in the marker, the +B<header> is the header value or NULL, and B<data> and B<len> specify +the data and its length. + +The final B<data> buffer is typically an ASN.1 object which can be decoded with +the B<d2i> function appropriate to the type B<name>; see L<d2i_X509(3)> +for examples. + +PEM_read() reads from the file B<fp>, while PEM_read_bio() reads +from the BIO B<bp>. +Both skip any non-PEM data that precedes the start of the next PEM object. +When an object is successfully retrieved, the type name from the "----BEGIN +<type>-----" is returned via the B<name> argument, any encapsulation headers +are returned in B<header> and the base64-decoded content and its length are +returned via B<data> and B<len> respectively. +The B<name>, B<header> and B<data> pointers are allocated via OPENSSL_malloc() +and should be freed by the caller via OPENSSL_free() when no longer needed. + +PEM_get_EVP_CIPHER_INFO() can be used to determine the B<data> returned by +PEM_read() or PEM_read_bio() is encrypted and to retrieve the associated cipher +and IV. +The caller passes a pointer to structure of type B<EVP_CIPHER_INFO> via the +B<cinfo> argument and the B<header> returned via PEM_read() or PEM_read_bio(). +If the call is successful 1 is returned and the cipher and IV are stored at the +address pointed to by B<cinfo>. +When the header is malformed, or not supported or when the cipher is unknown +or some internal error happens 0 is returned. +This function is deprecated, see B<NOTES> below. + +PEM_do_header() can then be used to decrypt the data if the header +indicates encryption. +The B<cinfo> argument is a pointer to the structure initialized by the previous +call to PEM_get_EVP_CIPHER_INFO(). +The B<data> and B<len> arguments are those returned by the previous call to +PEM_read() or PEM_read_bio(). +The B<cb> and B<u> arguments make it possible to override the default password +prompt function as described in L<PEM_read_PrivateKey(3)>. +On successful completion the B<data> is decrypted in place, and B<len> is +updated to indicate the plaintext length. +This function is deprecated, see B<NOTES> below. + +If the data is a priori known to not be encrypted, then neither PEM_do_header() +nor PEM_get_EVP_CIPHER_INFO() need be called. + +=head1 RETURN VALUES + +PEM_read() and PEM_read_bio() return 1 on success and 0 on failure, the latter +includes the case when no more PEM objects remain in the input file. +To distinguish end of file from more serious errors the caller must peek at the +error stack and check for B<PEM_R_NO_START_LINE>, which indicates that no more +PEM objects were found. See L<ERR_peek_last_error(3)>, L<ERR_GET_REASON(3)>. + +PEM_get_EVP_CIPHER_INFO() and PEM_do_header() return 1 on success, and 0 on +failure. +The B<data> is likely meaningless if these functions fail. + +=head1 NOTES + +The PEM_get_EVP_CIPHER_INFO() and PEM_do_header() functions are deprecated. +This is because the underlying PEM encryption format is obsolete, and should +be avoided. +It uses an encryption format with an OpenSSL-specific key-derivation function, +which employs MD5 with an iteration count of 1! +Instead, private keys should be stored in PKCS#8 form, with a strong PKCS#5 +v2.0 PBE. +See L<PEM_write_PrivateKey(3)> and L<d2i_PKCS8PrivateKey_bio(3)>. + +PEM_do_header() makes no assumption regarding the pass phrase received from the +password callback. +It will simply be treated as a byte sequence. + +=head1 SEE ALSO + +L<ERR_peek_last_error(3)>, L<ERR_GET_LIB(3)>, +L<d2i_PKCS8PrivateKey_bio(3)>, +L<passphrase-encoding(7)> + +=head1 COPYRIGHT + +Copyright 1998-2018 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L<https://www.openssl.org/source/license.html>. + +=cut |