diff options
Diffstat (limited to 'secure/lib/libcrypto/man/EVP_EncryptInit.3')
| -rw-r--r-- | secure/lib/libcrypto/man/EVP_EncryptInit.3 | 486 |
1 files changed, 486 insertions, 0 deletions
diff --git a/secure/lib/libcrypto/man/EVP_EncryptInit.3 b/secure/lib/libcrypto/man/EVP_EncryptInit.3 new file mode 100644 index 0000000..de5007d --- /dev/null +++ b/secure/lib/libcrypto/man/EVP_EncryptInit.3 @@ -0,0 +1,486 @@ +.\" Automatically generated by Pod::Man version 1.15 +.\" Thu May 9 13:17:49 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 "EVP_ENCRYPTINIT 1" +.TH EVP_ENCRYPTINIT 1 "perl v5.6.1" "2000-11-13" "User Contributed Perl Documentation" +.UC +.SH "NAME" +EVP_EncryptInit, EVP_EncryptUpdate, EVP_EncryptFinal, EVP_DecryptInit, +EVP_DecryptUpdate, EVP_DecryptFinal, EVP_CipherInit, EVP_CipherUpdate, +EVP_CipherFinal, EVP_CIPHER_CTX_set_key_length, EVP_CIPHER_CTX_ctrl, +EVP_CIPHER_CTX_cleanup, EVP_get_cipherbyname, EVP_get_cipherbynid, +EVP_get_cipherbyobj, EVP_CIPHER_nid, EVP_CIPHER_block_size, +EVP_CIPHER_key_length, EVP_CIPHER_iv_length, EVP_CIPHER_flags, +EVP_CIPHER_mode, EVP_CIPHER_type, EVP_CIPHER_CTX_cipher, EVP_CIPHER_CTX_nid, +EVP_CIPHER_CTX_block_size, EVP_CIPHER_CTX_key_length, EVP_CIPHER_CTX_iv_length, +EVP_CIPHER_CTX_get_app_data, EVP_CIPHER_CTX_set_app_data, EVP_CIPHER_CTX_type, +EVP_CIPHER_CTX_flags, EVP_CIPHER_CTX_mode, EVP_CIPHER_param_to_asn1, +EVP_CIPHER_asn1_to_param \- \s-1EVP\s0 cipher routines +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +.Ve +.Vb 6 +\& int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, +\& unsigned char *key, unsigned char *iv); +\& int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, +\& int *outl, unsigned char *in, int inl); +\& int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, +\& int *outl); +.Ve +.Vb 6 +\& int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, +\& unsigned char *key, unsigned char *iv); +\& int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, +\& int *outl, unsigned char *in, int inl); +\& int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, +\& int *outl); +.Ve +.Vb 6 +\& int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type, +\& unsigned char *key, unsigned char *iv, int enc); +\& int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, +\& int *outl, unsigned char *in, int inl); +\& int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *outm, +\& int *outl); +.Ve +.Vb 3 +\& int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *x, int keylen); +\& int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr); +\& int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *a); +.Ve +.Vb 3 +\& const EVP_CIPHER *EVP_get_cipherbyname(const char *name); +\& #define EVP_get_cipherbynid(a) EVP_get_cipherbyname(OBJ_nid2sn(a)) +\& #define EVP_get_cipherbyobj(a) EVP_get_cipherbynid(OBJ_obj2nid(a)) +.Ve +.Vb 7 +\& #define EVP_CIPHER_nid(e) ((e)->nid) +\& #define EVP_CIPHER_block_size(e) ((e)->block_size) +\& #define EVP_CIPHER_key_length(e) ((e)->key_len) +\& #define EVP_CIPHER_iv_length(e) ((e)->iv_len) +\& #define EVP_CIPHER_flags(e) ((e)->flags) +\& #define EVP_CIPHER_mode(e) ((e)->flags) & EVP_CIPH_MODE) +\& int EVP_CIPHER_type(const EVP_CIPHER *ctx); +.Ve +.Vb 10 +\& #define EVP_CIPHER_CTX_cipher(e) ((e)->cipher) +\& #define EVP_CIPHER_CTX_nid(e) ((e)->cipher->nid) +\& #define EVP_CIPHER_CTX_block_size(e) ((e)->cipher->block_size) +\& #define EVP_CIPHER_CTX_key_length(e) ((e)->key_len) +\& #define EVP_CIPHER_CTX_iv_length(e) ((e)->cipher->iv_len) +\& #define EVP_CIPHER_CTX_get_app_data(e) ((e)->app_data) +\& #define EVP_CIPHER_CTX_set_app_data(e,d) ((e)->app_data=(char *)(d)) +\& #define EVP_CIPHER_CTX_type(c) EVP_CIPHER_type(EVP_CIPHER_CTX_cipher(c)) +\& #define EVP_CIPHER_CTX_flags(e) ((e)->cipher->flags) +\& #define EVP_CIPHER_CTX_mode(e) ((e)->cipher->flags & EVP_CIPH_MODE) +.Ve +.Vb 2 +\& int EVP_CIPHER_param_to_asn1(EVP_CIPHER_CTX *c, ASN1_TYPE *type); +\& int EVP_CIPHER_asn1_to_param(EVP_CIPHER_CTX *c, ASN1_TYPE *type); +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +The \s-1EVP\s0 cipher routines are a high level interface to certain +symmetric ciphers. +.PP +\&\fIEVP_EncryptInit()\fR initializes a cipher context \fBctx\fR for encryption +with cipher \fBtype\fR. \fBtype\fR is normally supplied by a function such +as \fIEVP_des_cbc()\fR . \fBkey\fR is the symmetric key to use and \fBiv\fR is the +\&\s-1IV\s0 to use (if necessary), the actual number of bytes used for the +key and \s-1IV\s0 depends on the cipher. It is possible to set all parameters +to \s-1NULL\s0 except \fBtype\fR in an initial call and supply the remaining +parameters in subsequent calls, all of which have \fBtype\fR set to \s-1NULL\s0. +This is done when the default cipher parameters are not appropriate. +.PP +\&\fIEVP_EncryptUpdate()\fR encrypts \fBinl\fR bytes from the buffer \fBin\fR and +writes the encrypted version to \fBout\fR. This function can be called +multiple times to encrypt successive blocks of data. The amount +of data written depends on the block alignment of the encrypted data: +as a result the amount of data written may be anything from zero bytes +to (inl + cipher_block_size \- 1) so \fBoutl\fR should contain sufficient +room. The actual number of bytes written is placed in \fBoutl\fR. +.PP +\&\fIEVP_EncryptFinal()\fR encrypts the \*(L"final\*(R" data, that is any data that +remains in a partial block. It uses standard block padding (aka \s-1PKCS\s0 +padding). The encrypted final data is written to \fBout\fR which should +have sufficient space for one cipher block. The number of bytes written +is placed in \fBoutl\fR. After this function is called the encryption operation +is finished and no further calls to \fIEVP_EncryptUpdate()\fR should be made. +.PP +\&\fIEVP_DecryptInit()\fR, \fIEVP_DecryptUpdate()\fR and \fIEVP_DecryptFinal()\fR are the +corresponding decryption operations. \fIEVP_DecryptFinal()\fR will return an +error code if the final block is not correctly formatted. The parameters +and restrictions are identical to the encryption operations except that +the decrypted data buffer \fBout\fR passed to \fIEVP_DecryptUpdate()\fR should +have sufficient room for (\fBinl\fR + cipher_block_size) bytes unless the +cipher block size is 1 in which case \fBinl\fR bytes is sufficient. +.PP +\&\fIEVP_CipherInit()\fR, \fIEVP_CipherUpdate()\fR and \fIEVP_CipherFinal()\fR are functions +that can be used for decryption or encryption. The operation performed +depends on the value of the \fBenc\fR parameter. It should be set to 1 for +encryption, 0 for decryption and \-1 to leave the value unchanged (the +actual value of 'enc' being supplied in a previous call). +.PP +\&\fIEVP_CIPHER_CTX_cleanup()\fR clears all information from a cipher context. +It should be called after all operations using a cipher are complete +so sensitive information does not remain in memory. +.PP +\&\fIEVP_get_cipherbyname()\fR, \fIEVP_get_cipherbynid()\fR and \fIEVP_get_cipherbyobj()\fR +return an \s-1EVP_CIPHER\s0 structure when passed a cipher name, a \s-1NID\s0 or an +\&\s-1ASN1_OBJECT\s0 structure. +.PP +\&\fIEVP_CIPHER_nid()\fR and \fIEVP_CIPHER_CTX_nid()\fR return the \s-1NID\s0 of a cipher when +passed an \fB\s-1EVP_CIPHER\s0\fR or \fB\s-1EVP_CIPHER_CTX\s0\fR structure. The actual \s-1NID\s0 +value is an internal value which may not have a corresponding \s-1OBJECT\s0 +\&\s-1IDENTIFIER\s0. +.PP +\&\fIEVP_CIPHER_key_length()\fR and \fIEVP_CIPHER_CTX_key_length()\fR return the key +length of a cipher when passed an \fB\s-1EVP_CIPHER\s0\fR or \fB\s-1EVP_CIPHER_CTX\s0\fR +structure. The constant \fB\s-1EVP_MAX_KEY_LENGTH\s0\fR is the maximum key length +for all ciphers. Note: although \fIEVP_CIPHER_key_length()\fR is fixed for a +given cipher, the value of \fIEVP_CIPHER_CTX_key_length()\fR may be different +for variable key length ciphers. +.PP +\&\fIEVP_CIPHER_CTX_set_key_length()\fR sets the key length of the cipher ctx. +If the cipher is a fixed length cipher then attempting to set the key +length to any value other than the fixed value is an error. +.PP +\&\fIEVP_CIPHER_iv_length()\fR and \fIEVP_CIPHER_CTX_iv_length()\fR return the \s-1IV\s0 +length of a cipher when passed an \fB\s-1EVP_CIPHER\s0\fR or \fB\s-1EVP_CIPHER_CTX\s0\fR. +It will return zero if the cipher does not use an \s-1IV\s0. The constant +\&\fB\s-1EVP_MAX_IV_LENGTH\s0\fR is the maximum \s-1IV\s0 length for all ciphers. +.PP +\&\fIEVP_CIPHER_block_size()\fR and \fIEVP_CIPHER_CTX_block_size()\fR return the block +size of a cipher when passed an \fB\s-1EVP_CIPHER\s0\fR or \fB\s-1EVP_CIPHER_CTX\s0\fR +structure. The constant \fB\s-1EVP_MAX_IV_LENGTH\s0\fR is also the maximum block +length for all ciphers. +.PP +\&\fIEVP_CIPHER_type()\fR and \fIEVP_CIPHER_CTX_type()\fR return the type of the passed +cipher or context. This \*(L"type\*(R" is the actual \s-1NID\s0 of the cipher \s-1OBJECT\s0 +\&\s-1IDENTIFIER\s0 as such it ignores the cipher parameters and 40 bit \s-1RC2\s0 and +128 bit \s-1RC2\s0 have the same \s-1NID\s0. If the cipher does not have an object +identifier or does not have \s-1ASN1\s0 support this function will return +\&\fBNID_undef\fR. +.PP +\&\fIEVP_CIPHER_CTX_cipher()\fR returns the \fB\s-1EVP_CIPHER\s0\fR structure when passed +an \fB\s-1EVP_CIPHER_CTX\s0\fR structure. +.PP +\&\fIEVP_CIPHER_mode()\fR and \fIEVP_CIPHER_CTX_mode()\fR return the block cipher mode: +\&\s-1EVP_CIPH_ECB_MODE\s0, \s-1EVP_CIPH_CBC_MODE\s0, \s-1EVP_CIPH_CFB_MODE\s0 or +\&\s-1EVP_CIPH_OFB_MODE\s0. If the cipher is a stream cipher then +\&\s-1EVP_CIPH_STREAM_CIPHER\s0 is returned. +.PP +\&\fIEVP_CIPHER_param_to_asn1()\fR sets the AlgorithmIdentifier \*(L"parameter\*(R" based +on the passed cipher. This will typically include any parameters and an +\&\s-1IV\s0. The cipher \s-1IV\s0 (if any) must be set when this call is made. This call +should be made before the cipher is actually \*(L"used\*(R" (before any +\&\fIEVP_EncryptUpdate()\fR, \fIEVP_DecryptUpdate()\fR calls for example). This function +may fail if the cipher does not have any \s-1ASN1\s0 support. +.PP +\&\fIEVP_CIPHER_asn1_to_param()\fR sets the cipher parameters based on an \s-1ASN1\s0 +AlgorithmIdentifier \*(L"parameter\*(R". The precise effect depends on the cipher +In the case of \s-1RC2\s0, for example, it will set the \s-1IV\s0 and effective key length. +This function should be called after the base cipher type is set but before +the key is set. For example \fIEVP_CipherInit()\fR will be called with the \s-1IV\s0 and +key set to \s-1NULL\s0, \fIEVP_CIPHER_asn1_to_param()\fR will be called and finally +\&\fIEVP_CipherInit()\fR again with all parameters except the key set to \s-1NULL\s0. It is +possible for this function to fail if the cipher does not have any \s-1ASN1\s0 support +or the parameters cannot be set (for example the \s-1RC2\s0 effective key length +is not supported. +.PP +\&\fIEVP_CIPHER_CTX_ctrl()\fR allows various cipher specific parameters to be determined +and set. Currently only the \s-1RC2\s0 effective key length and the number of rounds of +\&\s-1RC5\s0 can be set. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fIEVP_EncryptInit()\fR, \fIEVP_EncryptUpdate()\fR and \fIEVP_EncryptFinal()\fR return 1 for success +and 0 for failure. +.PP +\&\fIEVP_DecryptInit()\fR and \fIEVP_DecryptUpdate()\fR return 1 for success and 0 for failure. +\&\fIEVP_DecryptFinal()\fR returns 0 if the decrypt failed or 1 for success. +.PP +\&\fIEVP_CipherInit()\fR and \fIEVP_CipherUpdate()\fR return 1 for success and 0 for failure. +\&\fIEVP_CipherFinal()\fR returns 1 for a decryption failure or 1 for success. +.PP +\&\fIEVP_CIPHER_CTX_cleanup()\fR returns 1 for success and 0 for failure. +.PP +\&\fIEVP_get_cipherbyname()\fR, \fIEVP_get_cipherbynid()\fR and \fIEVP_get_cipherbyobj()\fR +return an \fB\s-1EVP_CIPHER\s0\fR structure or \s-1NULL\s0 on error. +.PP +\&\fIEVP_CIPHER_nid()\fR and \fIEVP_CIPHER_CTX_nid()\fR return a \s-1NID\s0. +.PP +\&\fIEVP_CIPHER_block_size()\fR and \fIEVP_CIPHER_CTX_block_size()\fR return the block +size. +.PP +\&\fIEVP_CIPHER_key_length()\fR and \fIEVP_CIPHER_CTX_key_length()\fR return the key +length. +.PP +\&\fIEVP_CIPHER_iv_length()\fR and \fIEVP_CIPHER_CTX_iv_length()\fR return the \s-1IV\s0 +length or zero if the cipher does not use an \s-1IV\s0. +.PP +\&\fIEVP_CIPHER_type()\fR and \fIEVP_CIPHER_CTX_type()\fR return the \s-1NID\s0 of the cipher's +\&\s-1OBJECT\s0 \s-1IDENTIFIER\s0 or NID_undef if it has no defined \s-1OBJECT\s0 \s-1IDENTIFIER\s0. +.PP +\&\fIEVP_CIPHER_CTX_cipher()\fR returns an \fB\s-1EVP_CIPHER\s0\fR structure. +.PP +\&\fIEVP_CIPHER_param_to_asn1()\fR and \fIEVP_CIPHER_asn1_to_param()\fR return 1 for +success or zero for failure. +.SH "CIPHER LISTING" +.IX Header "CIPHER LISTING" +All algorithms have a fixed key length unless otherwise stated. +.Ip "\fIEVP_enc_null()\fR" 4 +.IX Item "EVP_enc_null()" +Null cipher: does nothing. +.Ip "EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void), EVP_des_ofb(void)" 4 +.IX Item "EVP_des_cbc(void), EVP_des_ecb(void), EVP_des_cfb(void), EVP_des_ofb(void)" +\&\s-1DES\s0 in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. +.Ip "EVP_des_ede_cbc(void), \fIEVP_des_ede()\fR, EVP_des_ede_ofb(void), EVP_des_ede_cfb(void)" 4 +.IX Item "EVP_des_ede_cbc(void), EVP_des_ede(), EVP_des_ede_ofb(void), EVP_des_ede_cfb(void)" +Two key triple \s-1DES\s0 in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. +.Ip "EVP_des_ede3_cbc(void), \fIEVP_des_ede3()\fR, EVP_des_ede3_ofb(void), EVP_des_ede3_cfb(void)" 4 +.IX Item "EVP_des_ede3_cbc(void), EVP_des_ede3(), EVP_des_ede3_ofb(void), EVP_des_ede3_cfb(void)" +Three key triple \s-1DES\s0 in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. +.Ip "EVP_desx_cbc(void)" 4 +.IX Item "EVP_desx_cbc(void)" +\&\s-1DESX\s0 algorithm in \s-1CBC\s0 mode. +.Ip "EVP_rc4(void)" 4 +.IX Item "EVP_rc4(void)" +\&\s-1RC4\s0 stream cipher. This is a variable key length cipher with default key length 128 bits. +.Ip "EVP_rc4_40(void)" 4 +.IX Item "EVP_rc4_40(void)" +\&\s-1RC4\s0 stream cipher with 40 bit key length. This is obsolete and new code should use \fIEVP_rc4()\fR +and the \fIEVP_CIPHER_CTX_set_key_length()\fR function. +.Ip "\fIEVP_idea_cbc()\fR EVP_idea_ecb(void), EVP_idea_cfb(void), EVP_idea_ofb(void), EVP_idea_cbc(void)" 4 +.IX Item "EVP_idea_cbc() EVP_idea_ecb(void), EVP_idea_cfb(void), EVP_idea_ofb(void), EVP_idea_cbc(void)" +\&\s-1IDEA\s0 encryption algorithm in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. +.Ip "EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(void), EVP_rc2_ofb(void)" 4 +.IX Item "EVP_rc2_cbc(void), EVP_rc2_ecb(void), EVP_rc2_cfb(void), EVP_rc2_ofb(void)" +\&\s-1RC2\s0 encryption algorithm in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. This is a variable key +length cipher with an additional parameter called \*(L"effective key bits\*(R" or \*(L"effective key length\*(R". +By default both are set to 128 bits. +.Ip "EVP_rc2_40_cbc(void), EVP_rc2_64_cbc(void)" 4 +.IX Item "EVP_rc2_40_cbc(void), EVP_rc2_64_cbc(void)" +\&\s-1RC2\s0 algorithm in \s-1CBC\s0 mode with a default key length and effective key length of 40 and 64 bits. +These are obsolete and new code should use \fIEVP_rc2_cbc()\fR, \fIEVP_CIPHER_CTX_set_key_length()\fR and +\&\fIEVP_CIPHER_CTX_ctrl()\fR to set the key length and effective key length. +.Ip "EVP_bf_cbc(void), EVP_bf_ecb(void), EVP_bf_cfb(void), EVP_bf_ofb(void);" 4 +.IX Item "EVP_bf_cbc(void), EVP_bf_ecb(void), EVP_bf_cfb(void), EVP_bf_ofb(void);" +Blowfish encryption algorithm in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. This is a variable key +length cipher. +.Ip "EVP_cast5_cbc(void), EVP_cast5_ecb(void), EVP_cast5_cfb(void), EVP_cast5_ofb(void)" 4 +.IX Item "EVP_cast5_cbc(void), EVP_cast5_ecb(void), EVP_cast5_cfb(void), EVP_cast5_ofb(void)" +\&\s-1CAST\s0 encryption algorithm in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. This is a variable key +length cipher. +.Ip "EVP_rc5_32_12_16_cbc(void), EVP_rc5_32_12_16_ecb(void), EVP_rc5_32_12_16_cfb(void), EVP_rc5_32_12_16_ofb(void)" 4 +.IX Item "EVP_rc5_32_12_16_cbc(void), EVP_rc5_32_12_16_ecb(void), EVP_rc5_32_12_16_cfb(void), EVP_rc5_32_12_16_ofb(void)" +\&\s-1RC5\s0 encryption algorithm in \s-1CBC\s0, \s-1ECB\s0, \s-1CFB\s0 and \s-1OFB\s0 modes respectively. This is a variable key length +cipher with an additional \*(L"number of rounds\*(R" parameter. By default the key length is set to 128 +bits and 12 rounds. +.SH "NOTES" +.IX Header "NOTES" +Where possible the \fB\s-1EVP\s0\fR interface to symmetric ciphers should be used in +preference to the low level interfaces. This is because the code then becomes +transparent to the cipher used and much more flexible. +.PP +\&\s-1PKCS\s0 padding works by adding \fBn\fR padding bytes of value \fBn\fR to make the total +length of the encrypted data a multiple of the block size. Padding is always +added so if the data is already a multiple of the block size \fBn\fR will equal +the block size. For example if the block size is 8 and 11 bytes are to be +encrypted then 5 padding bytes of value 5 will be added. +.PP +When decrypting the final block is checked to see if it has the correct form. +.PP +Although the decryption operation can produce an error, it is not a strong +test that the input data or key is correct. A random block has better than +1 in 256 chance of being of the correct format and problems with the +input data earlier on will not produce a final decrypt error. +.PP +The functions \fIEVP_EncryptInit()\fR, \fIEVP_EncryptUpdate()\fR, \fIEVP_EncryptFinal()\fR, +\&\fIEVP_DecryptInit()\fR, \fIEVP_DecryptUpdate()\fR, \fIEVP_CipherInit()\fR and \fIEVP_CipherUpdate()\fR +and \fIEVP_CIPHER_CTX_cleanup()\fR did not return errors in OpenSSL version 0.9.5a or +earlier. Software only versions of encryption algorithms will never return +error codes for these functions, unless there is a programming error (for example +and attempt to set the key before the cipher is set in \fIEVP_EncryptInit()\fR ). +.SH "BUGS" +.IX Header "BUGS" +For \s-1RC5\s0 the number of rounds can currently only be set to 8, 12 or 16. This is +a limitation of the current \s-1RC5\s0 code rather than the \s-1EVP\s0 interface. +.PP +It should be possible to disable \s-1PKCS\s0 padding: currently it isn't. +.PP +\&\s-1EVP_MAX_KEY_LENGTH\s0 and \s-1EVP_MAX_IV_LENGTH\s0 only refer to the internal ciphers with +default key lengths. If custom ciphers exceed these values the results are +unpredictable. This is because it has become standard practice to define a +generic key as a fixed unsigned char array containing \s-1EVP_MAX_KEY_LENGTH\s0 bytes. +.PP +The \s-1ASN1\s0 code is incomplete (and sometimes inaccurate) it has only been tested +for certain common S/MIME ciphers (\s-1RC2\s0, \s-1DES\s0, triple \s-1DES\s0) in \s-1CBC\s0 mode. +.SH "EXAMPLES" +.IX Header "EXAMPLES" +Get the number of rounds used in \s-1RC5:\s0 +.PP +.Vb 2 +\& int nrounds; +\& EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC5_ROUNDS, 0, &i); +.Ve +Get the \s-1RC2\s0 effective key length: +.PP +.Vb 2 +\& int key_bits; +\& EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GET_RC2_KEY_BITS, 0, &i); +.Ve +Set the number of rounds used in \s-1RC5:\s0 +.PP +.Vb 2 +\& int nrounds; +\& EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC5_ROUNDS, i, NULL); +.Ve +Set the number of rounds used in \s-1RC2:\s0 +.PP +.Vb 2 +\& int nrounds; +\& EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_SET_RC2_KEY_BITS, i, NULL); +.Ve +.SH "SEE ALSO" +.IX Header "SEE ALSO" +evp(3) +.SH "HISTORY" +.IX Header "HISTORY" |
