diff options
author | markm <markm@FreeBSD.org> | 2002-05-14 16:06:50 +0000 |
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committer | markm <markm@FreeBSD.org> | 2002-05-14 16:06:50 +0000 |
commit | aeefd5b3e2766cf2adf46ab0d391c6290c566150 (patch) | |
tree | 1b2346a595f785988975c71a5f29de7e01b24cc4 /secure/lib/libcrypto/man/des.3 | |
parent | fa71779225949e4336753dba62bf930087152e61 (diff) | |
download | FreeBSD-src-aeefd5b3e2766cf2adf46ab0d391c6290c566150.zip FreeBSD-src-aeefd5b3e2766cf2adf46ab0d391c6290c566150.tar.gz |
As the perl-generated assembler files have been committed, add the
perl-generated (.pod) manual pages too. This is another nail in the
perl5 coffin (for base perl, not the port or the language in general).
Diffstat (limited to 'secure/lib/libcrypto/man/des.3')
-rw-r--r-- | secure/lib/libcrypto/man/des.3 | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/des.3 b/secure/lib/libcrypto/man/des.3 new file mode 100644 index 0000000..20d9843 --- /dev/null +++ b/secure/lib/libcrypto/man/des.3 @@ -0,0 +1,519 @@ +.\" Automatically generated by Pod::Man version 1.15 +.\" Thu May 9 13:19:08 2002 +.\" +.\" Standard preamble: +.\" ====================================================================== +.de Sh \" Subsection heading +.br +.if t .Sp +.ne 5 +.PP +\fB\\$1\fR +.PP +.. +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Ip \" List item +.br +.ie \\n(.$>=3 .ne \\$3 +.el .ne 3 +.IP "\\$1" \\$2 +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R + +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. | will give a +.\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used +.\" to do unbreakable dashes and therefore won't be available. \*(C` and +.\" \*(C' expand to `' in nroff, nothing in troff, for use with C<> +.tr \(*W-|\(bv\*(Tr +.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' +.ie n \{\ +. ds -- \(*W- +. ds PI pi +. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch +. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch +. ds L" "" +. ds R" "" +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds -- \|\(em\| +. ds PI \(*p +. ds L" `` +. ds R" '' +'br\} +.\" +.\" If the F register is turned on, we'll generate index entries on stderr +.\" for titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and +.\" index entries marked with X<> in POD. Of course, you'll have to process +.\" the output yourself in some meaningful fashion. +.if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. nr % 0 +. rr F +.\} +.\" +.\" For nroff, turn off justification. Always turn off hyphenation; it +.\" makes way too many mistakes in technical documents. +.hy 0 +.if n .na +.\" +.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). +.\" Fear. Run. Save yourself. No user-serviceable parts. +.bd B 3 +. \" fudge factors for nroff and troff +.if n \{\ +. ds #H 0 +. ds #V .8m +. ds #F .3m +. ds #[ \f1 +. ds #] \fP +.\} +.if t \{\ +. ds #H ((1u-(\\\\n(.fu%2u))*.13m) +. ds #V .6m +. ds #F 0 +. ds #[ \& +. ds #] \& +.\} +. \" simple accents for nroff and troff +.if n \{\ +. ds ' \& +. ds ` \& +. ds ^ \& +. ds , \& +. ds ~ ~ +. ds / +.\} +.if t \{\ +. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" +. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' +. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' +. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' +. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' +. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' +.\} +. \" troff and (daisy-wheel) nroff accents +.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' +.ds 8 \h'\*(#H'\(*b\h'-\*(#H' +.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] +.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' +.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' +.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] +.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] +.ds ae a\h'-(\w'a'u*4/10)'e +.ds Ae A\h'-(\w'A'u*4/10)'E +. \" corrections for vroff +.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' +.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' +. \" for low resolution devices (crt and lpr) +.if \n(.H>23 .if \n(.V>19 \ +\{\ +. ds : e +. ds 8 ss +. ds o a +. ds d- d\h'-1'\(ga +. ds D- D\h'-1'\(hy +. ds th \o'bp' +. ds Th \o'LP' +. ds ae ae +. ds Ae AE +.\} +.rm #[ #] #H #V #F C +.\" ====================================================================== +.\" +.IX Title "DES 1" +.TH DES 1 "perl v5.6.1" "2001-02-18" "User Contributed Perl Documentation" +.UC +.SH "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_read_password, des_read_2passwords, des_read_pw_string, +des_cbc_cksum, des_quad_cksum, des_string_to_key, des_string_to_2keys, +des_fcrypt, des_crypt, des_enc_read, des_enc_write \- \s-1DES\s0 encryption +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/des.h> +.Ve +.Vb 1 +\& void des_random_key(des_cblock *ret); +.Ve +.Vb 6 +\& 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); +.Ve +.Vb 2 +\& void des_set_odd_parity(des_cblock *key); +\& int des_is_weak_key(const_des_cblock *key); +.Ve +.Vb 7 +\& 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); +.Ve +.Vb 18 +\& 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); +.Ve +.Vb 3 +\& 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); +.Ve +.Vb 9 +\& 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); +.Ve +.Vb 15 +\& 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); +.Ve +.Vb 5 +\& int des_read_password(des_cblock *key, const char *prompt, int verify); +\& int des_read_2passwords(des_cblock *key1, des_cblock *key2, +\& const char *prompt, int verify); +\& int des_read_pw_string(char *buf, int length, const char *prompt, +\& int verify); +.Ve +.Vb 8 +\& 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); +.Ve +.Vb 3 +\& char *des_fcrypt(const char *buf, const char *salt, char *ret); +\& char *des_crypt(const char *buf, const char *salt); +\& char *crypt(const char *buf, const char *salt); +.Ve +.Vb 4 +\& 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); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +This library contains a fast implementation of the \s-1DES\s0 encryption +algorithm. +.PP +There are two phases to the use of \s-1DES\s0 encryption. The first is the +generation of a \fIdes_key_schedule\fR from a key, the second is the +actual encryption. A \s-1DES\s0 key is of type \fIdes_cblock\fR. 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. +.PP +\&\fIdes_random_key()\fR generates a random key. The \s-1PRNG\s0 must be seeded +prior to using this function (see rand(3); for backward +compatibility the function \fIdes_random_seed()\fR is available as well). +If the \s-1PRNG\s0 could not generate a secure key, 0 is returned. In +earlier versions of the library, \fIdes_random_key()\fR did not generate +secure keys. +.PP +Before a \s-1DES\s0 key can be used, it must be converted into the +architecture dependent \fIdes_key_schedule\fR via the +\&\fIdes_set_key_checked()\fR or \fIdes_set_key_unchecked()\fR function. +.PP +\&\fIdes_set_key_checked()\fR 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. +.PP +\&\fIdes_set_key()\fR (called \fIdes_key_sched()\fR in the \s-1MIT\s0 library) works like +\&\fIdes_set_key_checked()\fR if the \fIdes_check_key\fR flag is non-zero, +otherwise like \fIdes_set_key_unchecked()\fR. These functions are available +for compatibility; it is recommended to use a function that does not +depend on a global variable. +.PP +\&\fIdes_set_odd_parity()\fR (called \fIdes_fixup_key_parity()\fR in the \s-1MIT\s0 +library) sets the parity of the passed \fIkey\fR to odd. +.PP +\&\fIdes_is_weak_key()\fR returns 1 is the passed key is a weak key, 0 if it +is ok. The probability that a randomly generated key is weak is +1/2^52, so it is not really worth checking for them. +.PP +The following routines mostly operate on an input and output stream of +\&\fIdes_cblock\fRs. +.PP +\&\fIdes_ecb_encrypt()\fR is the basic \s-1DES\s0 encryption routine that encrypts or +decrypts a single 8\-byte \fIdes_cblock\fR in \fIelectronic code book\fR +(\s-1ECB\s0) mode. It always transforms the input data, pointed to by +\&\fIinput\fR, into the output data, pointed to by the \fIoutput\fR argument. +If the \fIencrypt\fR argument is non-zero (\s-1DES_ENCRYPT\s0), the \fIinput\fR +(cleartext) is encrypted in to the \fIoutput\fR (ciphertext) using the +key_schedule specified by the \fIschedule\fR argument, previously set via +\&\fIdes_set_key\fR. If \fIencrypt\fR is zero (\s-1DES_DECRYPT\s0), the \fIinput\fR (now +ciphertext) is decrypted into the \fIoutput\fR (now cleartext). Input +and output may overlap. \fIdes_ecb_encrypt()\fR does not return a value. +.PP +\&\fIdes_ecb3_encrypt()\fR encrypts/decrypts the \fIinput\fR block by using +three-key Triple-DES encryption in \s-1ECB\s0 mode. This involves encrypting +the input with \fIks1\fR, decrypting with the key schedule \fIks2\fR, and +then encrypting with \fIks3\fR. This routine greatly reduces the chances +of brute force breaking of \s-1DES\s0 and has the advantage of if \fIks1\fR, +\&\fIks2\fR and \fIks3\fR are the same, it is equivalent to just encryption +using \s-1ECB\s0 mode and \fIks1\fR as the key. +.PP +The macro \fIdes_ecb2_encrypt()\fR is provided to perform two-key Triple-DES +encryption by using \fIks1\fR for the final encryption. +.PP +\&\fIdes_ncbc_encrypt()\fR encrypts/decrypts using the \fIcipher-block-chaining\fR +(\s-1CBC\s0) mode of \s-1DES\s0. If the \fIencrypt\fR argument is non-zero, the +routine cipher-block-chain encrypts the cleartext data pointed to by +the \fIinput\fR argument into the ciphertext pointed to by the \fIoutput\fR +argument, using the key schedule provided by the \fIschedule\fR argument, +and initialization vector provided by the \fIivec\fR argument. If the +\&\fIlength\fR 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. +.PP +\&\fIdes_xcbc_encrypt()\fR is \s-1RSA\s0's \s-1DESX\s0 mode of \s-1DES\s0. It uses \fIinw\fR and +\&\fIoutw\fR to 'whiten' the encryption. \fIinw\fR and \fIoutw\fR 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 \s-1CBC\s0 \s-1DES\s0. +.PP +\&\fIdes_ede3_cbc_encrypt()\fR implements outer triple \s-1CBC\s0 \s-1DES\s0 encryption with +three keys. This means that each \s-1DES\s0 operation inside the \s-1CBC\s0 mode is +really an \f(CW\*(C`C=E(ks3,D(ks2,E(ks1,M)))\*(C'\fR. This mode is used by \s-1SSL\s0. +.PP +The \fIdes_ede2_cbc_encrypt()\fR macro implements two-key Triple-DES by +reusing \fIks1\fR for the final encryption. \f(CW\*(C`C=E(ks1,D(ks2,E(ks1,M)))\*(C'\fR. +This form of Triple-DES is used by the \s-1RSAREF\s0 library. +.PP +\&\fIdes_pcbc_encrypt()\fR encrypt/decrypts using the propagating cipher block +chaining mode used by Kerberos v4. Its parameters are the same as +\&\fIdes_ncbc_encrypt()\fR. +.PP +\&\fIdes_cfb_encrypt()\fR 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 \fIivec\fR 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 \s-1DES\s0 \s-1ECB\s0 encryption per \fInumbits\fR, this function is only +suggested for use when sending small numbers of characters. +.PP +\&\fIdes_cfb64_encrypt()\fR +implements \s-1CFB\s0 mode of \s-1DES\s0 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 \s-1DES\s0 :\-). +.PP +\&\fIdes_ede3_cfb64_encrypt()\fR and \fIdes_ede2_cfb64_encrypt()\fR is the same as +\&\fIdes_cfb64_encrypt()\fR except that Triple-DES is used. +.PP +\&\fIdes_ofb_encrypt()\fR 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 \fIivec\fR 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 \s-1DES\s0 \s-1ECB\s0 encryption per numbits, this function is only +suggested for use when sending small numbers of characters. +.PP +\&\fIdes_ofb64_encrypt()\fR is the same as \fIdes_cfb64_encrypt()\fR using Output +Feed Back mode. +.PP +\&\fIdes_ede3_ofb64_encrypt()\fR and \fIdes_ede2_ofb64_encrypt()\fR is the same as +\&\fIdes_ofb64_encrypt()\fR, using Triple-DES. +.PP +The following functions are included in the \s-1DES\s0 library for +compatibility with the \s-1MIT\s0 Kerberos library. \fIdes_read_pw_string()\fR +is also available under the name \fIEVP_read_pw_string()\fR. +.PP +\&\fIdes_read_pw_string()\fR writes the string specified by \fIprompt\fR to +standard output, turns echo off and reads in input string from the +terminal. The string is returned in \fIbuf\fR, which must have space for +at least \fIlength\fR bytes. If \fIverify\fR is set, the user is asked for +the password twice and unless the two copies match, an error is +returned. A return code of \-1 indicates a system error, 1 failure due +to use interaction, and 0 is success. +.PP +\&\fIdes_read_password()\fR does the same and converts the password to a \s-1DES\s0 +key by calling \fIdes_string_to_key()\fR; \fIdes_read_2password()\fR operates in +the same way as \fIdes_read_password()\fR except that it generates two keys +by using the \fIdes_string_to_2key()\fR function. \fIdes_string_to_key()\fR is +available for backward compatibility with the \s-1MIT\s0 library. New +applications should use a cryptographic hash function. The same +applies for \fIdes_string_to_2key()\fR. +.PP +\&\fIdes_cbc_cksum()\fR produces an 8 byte checksum based on the input stream +(via \s-1CBC\s0 encryption). The last 4 bytes of the checksum are returned +and the complete 8 bytes are placed in \fIoutput\fR. This function is +used by Kerberos v4. Other applications should use +EVP_DigestInit(3) etc. instead. +.PP +\&\fIdes_quad_cksum()\fR 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 \fIout_count\fR, 1, 2, 3 or 4 times. If \fIoutput\fR is +non-NULL, the 8 bytes generated by each pass are written into +\&\fIoutput\fR. +.PP +The following are DES-based transformations: +.PP +\&\fIdes_fcrypt()\fR is a fast version of the Unix \fIcrypt\fR\|(3) function. This +version takes only a small amount of space relative to other fast +\&\fIcrypt()\fR 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. +.PP +\&\fIdes_crypt()\fR is a faster replacement for the normal system \fIcrypt()\fR. +This function calls \fIdes_fcrypt()\fR with a static array passed as the +third parameter. This emulates the normal non-thread safe semantics +of \fIcrypt\fR\|(3). +.PP +\&\fIdes_enc_write()\fR writes \fIlen\fR bytes to file descriptor \fIfd\fR from +buffer \fIbuf\fR. The data is encrypted via \fIpcbc_encrypt\fR (default) +using \fIsched\fR for the key and \fIiv\fR as a starting vector. The actual +data send down \fIfd\fR 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. +.PP +\&\fIdes_enc_read()\fR is used to read \fIlen\fR bytes from file descriptor +\&\fIfd\fR into buffer \fIbuf\fR. The data being read from \fIfd\fR is assumed to +have come from \fIdes_enc_write()\fR and is decrypted using \fIsched\fR for +the key schedule and \fIiv\fR for the initial vector. +.PP +\&\fBWarning:\fR The data format used by \fIdes_enc_write()\fR and \fIdes_enc_read()\fR +has a cryptographic weakness: When asked to write more than \s-1MAXWRITE\s0 +bytes, \fIdes_enc_write()\fR will split the data into several chunks that +are all encrypted using the same \s-1IV\s0. 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. +\&\fIdes_enc_read()\fR uses an internal state and thus cannot be used on +multiple files. +.PP +\&\fIdes_rw_mode\fR is used to specify the encryption mode to use with +\&\fIdes_enc_read()\fR and \fIdes_end_write()\fR. If set to \fI\s-1DES_PCBC_MODE\s0\fR (the +default), des_pcbc_encrypt is used. If set to \fI\s-1DES_CBC_MODE\s0\fR +des_cbc_encrypt is used. +.SH "NOTES" +.IX Header "NOTES" +Single-key \s-1DES\s0 is insecure due to its short key size. \s-1ECB\s0 mode is +not suitable for most applications; see des_modes(7). +.PP +The evp(3) library provides higher-level encryption functions. +.SH "BUGS" +.IX Header "BUGS" +\&\fIdes_3cbc_encrypt()\fR is flawed and must not be used in applications. +.PP +\&\fIdes_cbc_encrypt()\fR does not modify \fBivec\fR; use \fIdes_ncbc_encrypt()\fR +instead. +.PP +\&\fIdes_cfb_encrypt()\fR and \fIdes_ofb_encrypt()\fR 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! +.PP +\&\fIdes_read_pw_string()\fR is the most machine/OS dependent function and +normally generates the most problems when porting this code. +.SH "CONFORMING TO" +.IX Header "CONFORMING TO" +\&\s-1ANSI\s0 X3.106 +.PP +The \fBdes\fR library was written to be source code compatible with +the \s-1MIT\s0 Kerberos library. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIcrypt\fR\|(3), des_modes(7), evp(3), rand(3) +.SH "HISTORY" +.IX Header "HISTORY" +\&\fIdes_cbc_cksum()\fR, \fIdes_cbc_encrypt()\fR, \fIdes_ecb_encrypt()\fR, +\&\fIdes_is_weak_key()\fR, \fIdes_key_sched()\fR, \fIdes_pcbc_encrypt()\fR, +\&\fIdes_quad_cksum()\fR, \fIdes_random_key()\fR, \fIdes_read_password()\fR and +\&\fIdes_string_to_key()\fR are available in the \s-1MIT\s0 Kerberos library; +\&\fIdes_check_key_parity()\fR, \fIdes_fixup_key_parity()\fR and \fIdes_is_weak_key()\fR +are available in newer versions of that library. +.PP +\&\fIdes_set_key_checked()\fR and \fIdes_set_key_unchecked()\fR were added in +OpenSSL 0.9.5. +.PP +\&\fIdes_generate_random_block()\fR, \fIdes_init_random_number_generator()\fR, +\&\fIdes_new_random_key()\fR, \fIdes_set_random_generator_seed()\fR and +\&\fIdes_set_sequence_number()\fR and \fIdes_rand_data()\fR are used in newer +versions of Kerberos but are not implemented here. +.PP +\&\fIdes_random_key()\fR generated cryptographically weak random data in +SSLeay and in OpenSSL prior version 0.9.5, as well as in the original +\&\s-1MIT\s0 library. +.SH "AUTHOR" +.IX Header "AUTHOR" +Eric Young (eay@cryptsoft.com). Modified for the OpenSSL project +(http://www.openssl.org). |