--- /dev/null
+=pod
+
+=head1 NAME
+
+DES_random_key, DES_set_key, DES_key_sched, DES_set_key_checked,
+DES_set_key_unchecked, DES_set_odd_parity, DES_is_weak_key,
+DES_ecb_encrypt, DES_ecb2_encrypt, DES_ecb3_encrypt, DES_ncbc_encrypt,
+DES_cfb_encrypt, DES_ofb_encrypt, DES_pcbc_encrypt, DES_cfb64_encrypt,
+DES_ofb64_encrypt, DES_xcbc_encrypt, DES_ede2_cbc_encrypt,
+DES_ede2_cfb64_encrypt, DES_ede2_ofb64_encrypt, DES_ede3_cbc_encrypt,
+DES_ede3_cbcm_encrypt, DES_ede3_cfb64_encrypt, DES_ede3_ofb64_encrypt,
+DES_cbc_cksum, DES_quad_cksum, DES_string_to_key, DES_string_to_2keys,
+DES_fcrypt, DES_crypt, DES_enc_read, DES_enc_write - DES encryption
+
+=head1 SYNOPSIS
+
+ #include <openssl/des.h>
+
+ void DES_random_key(DES_cblock *ret);
+
+ int DES_set_key(const_DES_cblock *key, DES_key_schedule *schedule);
+ int DES_key_sched(const_DES_cblock *key, DES_key_schedule *schedule);
+ int DES_set_key_checked(const_DES_cblock *key,
+ DES_key_schedule *schedule);
+ void DES_set_key_unchecked(const_DES_cblock *key,
+ DES_key_schedule *schedule);
+
+ void DES_set_odd_parity(DES_cblock *key);
+ int DES_is_weak_key(const_DES_cblock *key);
+
+ void DES_ecb_encrypt(const_DES_cblock *input, DES_cblock *output,
+ DES_key_schedule *ks, int enc);
+ void DES_ecb2_encrypt(const_DES_cblock *input, DES_cblock *output,
+ DES_key_schedule *ks1, DES_key_schedule *ks2, int enc);
+ void DES_ecb3_encrypt(const_DES_cblock *input, DES_cblock *output,
+ DES_key_schedule *ks1, DES_key_schedule *ks2,
+ DES_key_schedule *ks3, int enc);
+
+ void DES_ncbc_encrypt(const unsigned char *input, unsigned char *output,
+ long length, DES_key_schedule *schedule, DES_cblock *ivec,
+ int enc);
+ void DES_cfb_encrypt(const unsigned char *in, unsigned char *out,
+ int numbits, long length, DES_key_schedule *schedule,
+ DES_cblock *ivec, int enc);
+ void DES_ofb_encrypt(const unsigned char *in, unsigned char *out,
+ int numbits, long length, DES_key_schedule *schedule,
+ DES_cblock *ivec);
+ void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
+ long length, DES_key_schedule *schedule, DES_cblock *ivec,
+ int enc);
+ void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
+ long length, DES_key_schedule *schedule, DES_cblock *ivec,
+ int *num, int enc);
+ void DES_ofb64_encrypt(const unsigned char *in, unsigned char *out,
+ long length, DES_key_schedule *schedule, DES_cblock *ivec,
+ int *num);
+
+ void DES_xcbc_encrypt(const unsigned char *input, unsigned char *output,
+ long length, DES_key_schedule *schedule, DES_cblock *ivec,
+ const_DES_cblock *inw, const_DES_cblock *outw, int enc);
+
+ void DES_ede2_cbc_encrypt(const unsigned char *input,
+ unsigned char *output, long length, DES_key_schedule *ks1,
+ DES_key_schedule *ks2, DES_cblock *ivec, int enc);
+ void DES_ede2_cfb64_encrypt(const unsigned char *in,
+ unsigned char *out, long length, DES_key_schedule *ks1,
+ DES_key_schedule *ks2, DES_cblock *ivec, int *num, int enc);
+ void DES_ede2_ofb64_encrypt(const unsigned char *in,
+ unsigned char *out, long length, DES_key_schedule *ks1,
+ DES_key_schedule *ks2, DES_cblock *ivec, int *num);
+
+ void DES_ede3_cbc_encrypt(const unsigned char *input,
+ unsigned char *output, long length, DES_key_schedule *ks1,
+ DES_key_schedule *ks2, DES_key_schedule *ks3, DES_cblock *ivec,
+ int enc);
+ void DES_ede3_cbcm_encrypt(const unsigned char *in, unsigned char *out,
+ long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
+ DES_key_schedule *ks3, DES_cblock *ivec1, DES_cblock *ivec2,
+ int enc);
+ void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
+ long length, DES_key_schedule *ks1, DES_key_schedule *ks2,
+ DES_key_schedule *ks3, DES_cblock *ivec, int *num, int enc);
+ void DES_ede3_ofb64_encrypt(const unsigned char *in, unsigned char *out,
+ long length, DES_key_schedule *ks1,
+ DES_key_schedule *ks2, DES_key_schedule *ks3,
+ DES_cblock *ivec, int *num);
+
+ DES_LONG DES_cbc_cksum(const unsigned char *input, DES_cblock *output,
+ long length, DES_key_schedule *schedule,
+ const_DES_cblock *ivec);
+ DES_LONG DES_quad_cksum(const unsigned char *input, DES_cblock output[],
+ long length, int out_count, DES_cblock *seed);
+ void DES_string_to_key(const char *str, DES_cblock *key);
+ void DES_string_to_2keys(const char *str, DES_cblock *key1,
+ DES_cblock *key2);
+
+ char *DES_fcrypt(const char *buf, const char *salt, char *ret);
+ char *DES_crypt(const char *buf, const char *salt);
+
+ int DES_enc_read(int fd, void *buf, int len, DES_key_schedule *sched,
+ DES_cblock *iv);
+ int DES_enc_write(int fd, const void *buf, int len,
+ DES_key_schedule *sched, DES_cblock *iv);
+
+=head1 DESCRIPTION
+
+This library contains a fast implementation of the DES encryption
+algorithm.
+
+There are two phases to the use of DES encryption. The first is the
+generation of a I<DES_key_schedule> from a key, the second is the
+actual encryption. A DES key is of type I<DES_cblock>. This type is
+consists of 8 bytes with odd parity. The least significant bit in
+each byte is the parity bit. The key schedule is an expanded form of
+the key; it is used to speed the encryption process.
+
+DES_random_key() generates a random key. The PRNG must be seeded
+prior to using this function (see L<rand(3)|rand(3)>). If the PRNG
+could not generate a secure key, 0 is returned.
+
+Before a DES key can be used, it must be converted into the
+architecture dependent I<DES_key_schedule> via the
+DES_set_key_checked() or DES_set_key_unchecked() function.
+
+DES_set_key_checked() will check that the key passed is of odd parity
+and is not a week or semi-weak key. If the parity is wrong, then -1
+is returned. If the key is a weak key, then -2 is returned. If an
+error is returned, the key schedule is not generated.
+
+DES_set_key() works like
+DES_set_key_checked() if the I<DES_check_key> flag is non-zero,
+otherwise like DES_set_key_unchecked(). These functions are available
+for compatibility; it is recommended to use a function that does not
+depend on a global variable.
+
+DES_set_odd_parity() sets the parity of the passed I<key> to odd.
+
+DES_is_weak_key() returns 1 if the passed key is a weak key, 0 if it
+is ok.
+
+The following routines mostly operate on an input and output stream of
+I<DES_cblock>s.
+
+DES_ecb_encrypt() is the basic DES encryption routine that encrypts or
+decrypts a single 8-byte I<DES_cblock> in I<electronic code book>
+(ECB) mode. It always transforms the input data, pointed to by
+I<input>, into the output data, pointed to by the I<output> argument.
+If the I<encrypt> argument is non-zero (DES_ENCRYPT), the I<input>
+(cleartext) is encrypted in to the I<output> (ciphertext) using the
+key_schedule specified by the I<schedule> argument, previously set via
+I<DES_set_key>. If I<encrypt> is zero (DES_DECRYPT), the I<input> (now
+ciphertext) is decrypted into the I<output> (now cleartext). Input
+and output may overlap. DES_ecb_encrypt() does not return a value.
+
+DES_ecb3_encrypt() encrypts/decrypts the I<input> block by using
+three-key Triple-DES encryption in ECB mode. This involves encrypting
+the input with I<ks1>, decrypting with the key schedule I<ks2>, and
+then encrypting with I<ks3>. This routine greatly reduces the chances
+of brute force breaking of DES and has the advantage of if I<ks1>,
+I<ks2> and I<ks3> are the same, it is equivalent to just encryption
+using ECB mode and I<ks1> as the key.
+
+The macro DES_ecb2_encrypt() is provided to perform two-key Triple-DES
+encryption by using I<ks1> for the final encryption.
+
+DES_ncbc_encrypt() encrypts/decrypts using the I<cipher-block-chaining>
+(CBC) mode of DES. If the I<encrypt> argument is non-zero, the
+routine cipher-block-chain encrypts the cleartext data pointed to by
+the I<input> argument into the ciphertext pointed to by the I<output>
+argument, using the key schedule provided by the I<schedule> argument,
+and initialization vector provided by the I<ivec> argument. If the
+I<length> argument is not an integral multiple of eight bytes, the
+last block is copied to a temporary area and zero filled. The output
+is always an integral multiple of eight bytes.
+
+DES_xcbc_encrypt() is RSA's DESX mode of DES. It uses I<inw> and
+I<outw> to 'whiten' the encryption. I<inw> and I<outw> are secret
+(unlike the iv) and are as such, part of the key. So the key is sort
+of 24 bytes. This is much better than CBC DES.
+
+DES_ede3_cbc_encrypt() implements outer triple CBC DES encryption with
+three keys. This means that each DES operation inside the CBC mode is
+an C<C=E(ks3,D(ks2,E(ks1,M)))>. This mode is used by SSL.
+
+The DES_ede2_cbc_encrypt() macro implements two-key Triple-DES by
+reusing I<ks1> for the final encryption. C<C=E(ks1,D(ks2,E(ks1,M)))>.
+This form of Triple-DES is used by the RSAREF library.
+
+DES_pcbc_encrypt() encrypt/decrypts using the propagating cipher block
+chaining mode used by Kerberos v4. Its parameters are the same as
+DES_ncbc_encrypt().
+
+DES_cfb_encrypt() encrypt/decrypts using cipher feedback mode. This
+method takes an array of characters as input and outputs and array of
+characters. It does not require any padding to 8 character groups.
+Note: the I<ivec> variable is changed and the new changed value needs to
+be passed to the next call to this function. Since this function runs
+a complete DES ECB encryption per I<numbits>, this function is only
+suggested for use when sending small numbers of characters.
+
+DES_cfb64_encrypt()
+implements CFB mode of DES with 64bit feedback. Why is this
+useful you ask? Because this routine will allow you to encrypt an
+arbitrary number of bytes, no 8 byte padding. Each call to this
+routine will encrypt the input bytes to output and then update ivec
+and num. num contains 'how far' we are though ivec. If this does
+not make much sense, read more about cfb mode of DES :-).
+
+DES_ede3_cfb64_encrypt() and DES_ede2_cfb64_encrypt() is the same as
+DES_cfb64_encrypt() except that Triple-DES is used.
+
+DES_ofb_encrypt() encrypts using output feedback mode. This method
+takes an array of characters as input and outputs and array of
+characters. It does not require any padding to 8 character groups.
+Note: the I<ivec> variable is changed and the new changed value needs to
+be passed to the next call to this function. Since this function runs
+a complete DES ECB encryption per numbits, this function is only
+suggested for use when sending small numbers of characters.
+
+DES_ofb64_encrypt() is the same as DES_cfb64_encrypt() using Output
+Feed Back mode.
+
+DES_ede3_ofb64_encrypt() and DES_ede2_ofb64_encrypt() is the same as
+DES_ofb64_encrypt(), using Triple-DES.
+
+The following functions are included in the DES library for
+compatibility with the MIT Kerberos library.
+
+DES_cbc_cksum() produces an 8 byte checksum based on the input stream
+(via CBC encryption). The last 4 bytes of the checksum are returned
+and the complete 8 bytes are placed in I<output>. This function is
+used by Kerberos v4. Other applications should use
+L<EVP_DigestInit(3)|EVP_DigestInit(3)> etc. instead.
+
+DES_quad_cksum() is a Kerberos v4 function. It returns a 4 byte
+checksum from the input bytes. The algorithm can be iterated over the
+input, depending on I<out_count>, 1, 2, 3 or 4 times. If I<output> is
+non-NULL, the 8 bytes generated by each pass are written into
+I<output>.
+
+The following are DES-based transformations:
+
+DES_fcrypt() is a fast version of the Unix crypt(3) function. This
+version takes only a small amount of space relative to other fast
+crypt() implementations. This is different to the normal crypt in
+that the third parameter is the buffer that the return value is
+written into. It needs to be at least 14 bytes long. This function
+is thread safe, unlike the normal crypt.
+
+DES_crypt() is a faster replacement for the normal system crypt().
+This function calls DES_fcrypt() with a static array passed as the
+third parameter. This emulates the normal non-thread safe semantics
+of crypt(3).
+
+DES_enc_write() writes I<len> bytes to file descriptor I<fd> from
+buffer I<buf>. The data is encrypted via I<pcbc_encrypt> (default)
+using I<sched> for the key and I<iv> as a starting vector. The actual
+data send down I<fd> consists of 4 bytes (in network byte order)
+containing the length of the following encrypted data. The encrypted
+data then follows, padded with random data out to a multiple of 8
+bytes.
+
+DES_enc_read() is used to read I<len> bytes from file descriptor
+I<fd> into buffer I<buf>. The data being read from I<fd> is assumed to
+have come from DES_enc_write() and is decrypted using I<sched> for
+the key schedule and I<iv> for the initial vector.
+
+B<Warning:> The data format used by DES_enc_write() and DES_enc_read()
+has a cryptographic weakness: When asked to write more than MAXWRITE
+bytes, DES_enc_write() will split the data into several chunks that
+are all encrypted using the same IV. So don't use these functions
+unless you are sure you know what you do (in which case you might not
+want to use them anyway). They cannot handle non-blocking sockets.
+DES_enc_read() uses an internal state and thus cannot be used on
+multiple files.
+
+I<DES_rw_mode> is used to specify the encryption mode to use with
+DES_enc_read() and DES_end_write(). If set to I<DES_PCBC_MODE> (the
+default), DES_pcbc_encrypt is used. If set to I<DES_CBC_MODE>
+DES_cbc_encrypt is used.
+
+=head1 NOTES
+
+Single-key DES is insecure due to its short key size. ECB mode is
+not suitable for most applications; see L<des_modes(7)|des_modes(7)>.
+
+The L<evp(3)|evp(3)> library provides higher-level encryption functions.
+
+=head1 BUGS
+
+DES_3cbc_encrypt() is flawed and must not be used in applications.
+
+DES_cbc_encrypt() does not modify B<ivec>; use DES_ncbc_encrypt()
+instead.
+
+DES_cfb_encrypt() and DES_ofb_encrypt() operates on input of 8 bits.
+What this means is that if you set numbits to 12, and length to 2, the
+first 12 bits will come from the 1st input byte and the low half of
+the second input byte. The second 12 bits will have the low 8 bits
+taken from the 3rd input byte and the top 4 bits taken from the 4th
+input byte. The same holds for output. This function has been
+implemented this way because most people will be using a multiple of 8
+and because once you get into pulling bytes input bytes apart things
+get ugly!
+
+DES_string_to_key() is available for backward compatibility with the
+MIT library. New applications should use a cryptographic hash function.
+The same applies for DES_string_to_2key().
+
+=head1 CONFORMING TO
+
+ANSI X3.106
+
+The B<des> library was written to be source code compatible with
+the MIT Kerberos library.
+
+=head1 SEE ALSO
+
+crypt(3), L<des_modes(7)|des_modes(7)>, L<evp(3)|evp(3)>, L<rand(3)|rand(3)>
+
+=head1 HISTORY
+
+In OpenSSL 0.9.7, all des_ functions were renamed to DES_ to avoid
+clashes with older versions of libdes. Compatibility des_ functions
+are provided for a short while, as well as crypt().
+Declarations for these are in <openssl/des_old.h>. There is no DES_
+variant for des_random_seed().
+This will happen to other functions
+as well if they are deemed redundant (des_random_seed() just calls
+RAND_seed() and is present for backward compatibility only), buggy or
+already scheduled for removal.
+
+des_cbc_cksum(), des_cbc_encrypt(), des_ecb_encrypt(),
+des_is_weak_key(), des_key_sched(), des_pcbc_encrypt(),
+des_quad_cksum(), des_random_key() and des_string_to_key()
+are available in the MIT Kerberos library;
+des_check_key_parity(), des_fixup_key_parity() and des_is_weak_key()
+are available in newer versions of that library.
+
+des_set_key_checked() and des_set_key_unchecked() were added in
+OpenSSL 0.9.5.
+
+des_generate_random_block(), des_init_random_number_generator(),
+des_new_random_key(), des_set_random_generator_seed() and
+des_set_sequence_number() and des_rand_data() are used in newer
+versions of Kerberos but are not implemented here.
+
+des_random_key() generated cryptographically weak random data in
+SSLeay and in OpenSSL prior version 0.9.5, as well as in the original
+MIT library.
+
+=head1 AUTHOR
+
+Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project
+(http://www.openssl.org).
+
+=cut
projects / cassiopeia.git / blobdiff