2 ''' $RCSfile$$Revision$$Date$
20 .ie \\n(.$>=3 .ne \\$3
36 ''' Set up \*(-- to give an unbreakable dash;
37 ''' string Tr holds user defined translation string.
38 ''' Bell System Logo is used as a dummy character.
44 .if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
45 .if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
48 ''' \*(M", \*(S", \*(N" and \*(T" are the equivalent of
49 ''' \*(L" and \*(R", except that they are used on ".xx" lines,
50 ''' such as .IP and .SH, which do another additional levels of
51 ''' double-quote interpretation
80 .\" If the F register is turned on, we'll generate
81 .\" index entries out stderr for the following things:
86 .\" X<> Xref (embedded
87 .\" Of course, you have to process the output yourself
88 .\" in some meaninful fashion.
91 .tm Index:\\$1\t\\n%\t"\\$2"
96 .TH BIO_f_cipher 3 "0.9.7d" "2/Sep/2004" "OpenSSL"
100 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
101 .de CQ \" put $1 in typewriter font
107 \\&\\$2 \\$3 \\$4 \\$5 \\$6 \\$7
110 .\" @(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2
111 . \" AM - accent mark definitions
113 . \" fudge factors for nroff and troff
122 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
128 . \" simple accents for nroff and troff
141 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
142 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
143 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
144 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
145 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
146 . ds ? \s-2c\h'-\w'c'u*7/10'\u\h'\*(#H'\zi\d\s+2\h'\w'c'u*8/10'
147 . ds ! \s-2\(or\s+2\h'-\w'\(or'u'\v'-.8m'.\v'.8m'
148 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
149 . ds q o\h'-\w'o'u*8/10'\s-4\v'.4m'\z\(*i\v'-.4m'\s+4\h'\w'o'u*8/10'
151 . \" troff and (daisy-wheel) nroff accents
152 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
153 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
154 .ds v \\k:\h'-(\\n(.wu*9/10-\*(#H)'\v'-\*(#V'\*(#[\s-4v\s0\v'\*(#V'\h'|\\n:u'\*(#]
155 .ds _ \\k:\h'-(\\n(.wu*9/10-\*(#H+(\*(#F*2/3))'\v'-.4m'\z\(hy\v'.4m'\h'|\\n:u'
156 .ds . \\k:\h'-(\\n(.wu*8/10)'\v'\*(#V*4/10'\z.\v'-\*(#V*4/10'\h'|\\n:u'
157 .ds 3 \*(#[\v'.2m'\s-2\&3\s0\v'-.2m'\*(#]
158 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
159 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
160 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
161 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
162 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
163 .ds ae a\h'-(\w'a'u*4/10)'e
164 .ds Ae A\h'-(\w'A'u*4/10)'E
165 .ds oe o\h'-(\w'o'u*4/10)'e
166 .ds Oe O\h'-(\w'O'u*4/10)'E
167 . \" corrections for vroff
168 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
169 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
170 . \" for low resolution devices (crt and lpr)
171 .if \n(.H>23 .if \n(.V>19 \
175 . ds v \h'-1'\o'\(aa\(ga'
191 BIO_f_cipher, BIO_set_cipher, BIO_get_cipher_status, BIO_get_cipher_ctx \- cipher BIO filter
195 \& #include <openssl/bio.h>
196 \& #include <openssl/evp.h>
199 \& BIO_METHOD * BIO_f_cipher(void);
200 \& void BIO_set_cipher(BIO *b,const EVP_CIPHER *cipher,
201 \& unsigned char *key, unsigned char *iv, int enc);
202 \& int BIO_get_cipher_status(BIO *b)
203 \& int BIO_get_cipher_ctx(BIO *b, EVP_CIPHER_CTX **pctx)
206 \fIBIO_f_cipher()\fR returns the cipher BIO method. This is a filter
207 BIO that encrypts any data written through it, and decrypts any data
208 read from it. It is a BIO wrapper for the cipher routines
209 \fIEVP_CipherInit()\fR, \fIEVP_CipherUpdate()\fR and \fIEVP_CipherFinal()\fR.
211 Cipher BIOs do not support \fIBIO_gets()\fR or \fIBIO_puts()\fR.
213 \fIBIO_flush()\fR on an encryption BIO that is being written through is
214 used to signal that no more data is to be encrypted: this is used
215 to flush and possibly pad the final block through the BIO.
217 \fIBIO_set_cipher()\fR sets the cipher of BIO \fBb\fR to \fBcipher\fR using key \fBkey\fR
218 and IV \fBiv\fR. \fBenc\fR should be set to 1 for encryption and zero for
221 When reading from an encryption BIO the final block is automatically
222 decrypted and checked when EOF is detected. \fIBIO_get_cipher_status()\fR
223 is a \fIBIO_ctrl()\fR macro which can be called to determine whether the
224 decryption operation was successful.
226 \fIBIO_get_cipher_ctx()\fR is a \fIBIO_ctrl()\fR macro which retrieves the internal
227 BIO cipher context. The retrieved context can be used in conjunction
228 with the standard cipher routines to set it up. This is useful when
229 \fIBIO_set_cipher()\fR is not flexible enough for the applications needs.
231 When encrypting \fIBIO_flush()\fR \fBmust\fR be called to flush the final block
232 through the BIO. If it is not then the final block will fail a subsequent
235 When decrypting an error on the final block is signalled by a zero
236 return value from the read operation. A successful decrypt followed
237 by EOF will also return zero for the final read. \fIBIO_get_cipher_status()\fR
238 should be called to determine if the decrypt was successful.
240 As always, if \fIBIO_gets()\fR or \fIBIO_puts()\fR support is needed then it can
241 be achieved by preceding the cipher BIO with a buffering BIO.
243 \fIBIO_f_cipher()\fR returns the cipher BIO method.
245 \fIBIO_set_cipher()\fR does not return a value.
247 \fIBIO_get_cipher_status()\fR returns 1 for a successful decrypt and 0
250 \fIBIO_get_cipher_ctx()\fR currently always returns 1.
257 .IX Title "BIO_f_cipher 3"
258 .IX Name "BIO_f_cipher, BIO_set_cipher, BIO_get_cipher_status, BIO_get_cipher_ctx - cipher BIO filter"
262 .IX Header "SYNOPSIS"
264 .IX Header "DESCRIPTION"
268 .IX Header "RETURN VALUES"
270 .IX Header "EXAMPLES"
272 .IX Header "SEE ALSO"