1=pod 2 3=head1 NAME 4 5EVP_CIPHER_meth_new, EVP_CIPHER_meth_dup, EVP_CIPHER_meth_free, 6EVP_CIPHER_meth_set_iv_length, EVP_CIPHER_meth_set_flags, 7EVP_CIPHER_meth_set_impl_ctx_size, EVP_CIPHER_meth_set_init, 8EVP_CIPHER_meth_set_do_cipher, EVP_CIPHER_meth_set_cleanup, 9EVP_CIPHER_meth_set_set_asn1_params, EVP_CIPHER_meth_set_get_asn1_params, 10EVP_CIPHER_meth_set_ctrl, EVP_CIPHER_meth_get_init, 11EVP_CIPHER_meth_get_do_cipher, EVP_CIPHER_meth_get_cleanup, 12EVP_CIPHER_meth_get_set_asn1_params, EVP_CIPHER_meth_get_get_asn1_params, 13EVP_CIPHER_meth_get_ctrl - Routines to build up EVP_CIPHER methods 14 15=head1 SYNOPSIS 16 17 #include <openssl/evp.h> 18 19 EVP_CIPHER *EVP_CIPHER_meth_new(int cipher_type, int block_size, int key_len); 20 EVP_CIPHER *EVP_CIPHER_meth_dup(const EVP_CIPHER *cipher); 21 void EVP_CIPHER_meth_free(EVP_CIPHER *cipher); 22 23 int EVP_CIPHER_meth_set_iv_length(EVP_CIPHER *cipher, int iv_len); 24 int EVP_CIPHER_meth_set_flags(EVP_CIPHER *cipher, unsigned long flags); 25 int EVP_CIPHER_meth_set_impl_ctx_size(EVP_CIPHER *cipher, int ctx_size); 26 int EVP_CIPHER_meth_set_init(EVP_CIPHER *cipher, 27 int (*init)(EVP_CIPHER_CTX *ctx, 28 const unsigned char *key, 29 const unsigned char *iv, 30 int enc)); 31 int EVP_CIPHER_meth_set_do_cipher(EVP_CIPHER *cipher, 32 int (*do_cipher)(EVP_CIPHER_CTX *ctx, 33 unsigned char *out, 34 const unsigned char *in, 35 size_t inl)); 36 int EVP_CIPHER_meth_set_cleanup(EVP_CIPHER *cipher, 37 int (*cleanup)(EVP_CIPHER_CTX *)); 38 int EVP_CIPHER_meth_set_set_asn1_params(EVP_CIPHER *cipher, 39 int (*set_asn1_parameters)(EVP_CIPHER_CTX *, 40 ASN1_TYPE *)); 41 int EVP_CIPHER_meth_set_get_asn1_params(EVP_CIPHER *cipher, 42 int (*get_asn1_parameters)(EVP_CIPHER_CTX *, 43 ASN1_TYPE *)); 44 int EVP_CIPHER_meth_set_ctrl(EVP_CIPHER *cipher, 45 int (*ctrl)(EVP_CIPHER_CTX *, int type, 46 int arg, void *ptr)); 47 48 int (*EVP_CIPHER_meth_get_init(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx, 49 const unsigned char *key, 50 const unsigned char *iv, 51 int enc); 52 int (*EVP_CIPHER_meth_get_do_cipher(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *ctx, 53 unsigned char *out, 54 const unsigned char *in, 55 size_t inl); 56 int (*EVP_CIPHER_meth_get_cleanup(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *); 57 int (*EVP_CIPHER_meth_get_set_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *, 58 ASN1_TYPE *); 59 int (*EVP_CIPHER_meth_get_get_asn1_params(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *, 60 ASN1_TYPE *); 61 int (*EVP_CIPHER_meth_get_ctrl(const EVP_CIPHER *cipher))(EVP_CIPHER_CTX *, 62 int type, int arg, 63 void *ptr); 64 65=head1 DESCRIPTION 66 67The B<EVP_CIPHER> type is a structure for symmetric cipher method 68implementation. 69 70EVP_CIPHER_meth_new() creates a new B<EVP_CIPHER> structure. 71 72EVP_CIPHER_meth_dup() creates a copy of B<cipher>. 73 74EVP_CIPHER_meth_free() destroys a B<EVP_CIPHER> structure. 75 76EVP_CIPHER_meth_set_iv_length() sets the length of the IV. 77This is only needed when the implemented cipher mode requires it. 78 79EVP_CIPHER_meth_set_flags() sets the flags to describe optional 80behaviours in the particular B<cipher>. 81With the exception of cipher modes, of which only one may be present, 82several flags can be or'd together. 83The available flags are: 84 85=over 4 86 87=item EVP_CIPH_STREAM_CIPHER, EVP_CIPH_ECB_MODE EVP_CIPH_CBC_MODE, 88EVP_CIPH_CFB_MODE, EVP_CIPH_OFB_MODE, EVP_CIPH_CTR_MODE, EVP_CIPH_GCM_MODE, 89EVP_CIPH_CCM_MODE, EVP_CIPH_XTS_MODE, EVP_CIPH_WRAP_MODE, 90EVP_CIPH_OCB_MODE 91 92The cipher mode. 93 94=item EVP_CIPH_VARIABLE_LENGTH 95 96This cipher is of variable length. 97 98=item EVP_CIPH_CUSTOM_IV 99 100Storing and initialising the IV is left entirely to the 101implementation. 102 103=item EVP_CIPH_ALWAYS_CALL_INIT 104 105Set this if the implementation's init() function should be called even 106if B<key> is B<NULL>. 107 108=item EVP_CIPH_CTRL_INIT 109 110Set this to have the implementation's ctrl() function called with 111command code B<EVP_CTRL_INIT> early in its setup. 112 113=item EVP_CIPH_CUSTOM_KEY_LENGTH 114 115Checking and setting the key length after creating the B<EVP_CIPHER> 116is left to the implementation. 117Whenever someone uses EVP_CIPHER_CTX_set_key_length() on a 118B<EVP_CIPHER> with this flag set, the implementation's ctrl() function 119will be called with the control code B<EVP_CTRL_SET_KEY_LENGTH> and 120the key length in B<arg>. 121 122=item EVP_CIPH_NO_PADDING 123 124Don't use standard block padding. 125 126=item EVP_CIPH_RAND_KEY 127 128Making a key with random content is left to the implementation. 129This is done by calling the implementation's ctrl() function with the 130control code B<EVP_CTRL_RAND_KEY> and the pointer to the key memory 131storage in B<ptr>. 132 133=item EVP_CIPH_CUSTOM_COPY 134 135Set this to have the implementation's ctrl() function called with 136command code B<EVP_CTRL_COPY> at the end of EVP_CIPHER_CTX_copy(). 137The intended use is for further things to deal with after the 138implementation specific data block has been copied. 139The destination B<EVP_CIPHER_CTX> is passed to the control with the 140B<ptr> parameter. 141The implementation specific data block is reached with 142EVP_CIPHER_CTX_get_cipher_data(). 143 144=item EVP_CIPH_FLAG_DEFAULT_ASN1 145 146Use the default EVP routines to pass IV to and from ASN.1. 147 148=item EVP_CIPH_FLAG_LENGTH_BITS 149 150Signals that the length of the input buffer for encryption / 151decryption is to be understood as the number of bits instead of 152bytes for this implementation. 153This is only useful for CFB1 ciphers. 154 155=begin comment 156The FIPS flags seem to be unused, so I'm hiding them until I get an 157explanation or they get removed. /RL 158 159=item EVP_CIPH_FLAG_FIPS 160 161=item EVP_CIPH_FLAG_NON_FIPS_ALLOW 162 163=end comment 164 165=item EVP_CIPH_FLAG_CUSTOM_CIPHER 166 167This indicates that the implementation takes care of everything, 168including padding, buffering and finalization. 169The EVP routines will simply give them control and do nothing more. 170 171=item EVP_CIPH_FLAG_AEAD_CIPHER 172 173This indicates that this is an AEAD cipher implementation. 174 175=item EVP_CIPH_FLAG_TLS1_1_MULTIBLOCK 176 177Allow interleaving of crypto blocks, a particular optimization only applicable 178to certain TLS ciphers. 179 180=back 181 182EVP_CIPHER_meth_set_impl_ctx_size() sets the size of the EVP_CIPHER's 183implementation context so that it can be automatically allocated. 184 185EVP_CIPHER_meth_set_init() sets the cipher init function for 186B<cipher>. 187The cipher init function is called by EVP_CipherInit(), 188EVP_CipherInit_ex(), EVP_EncryptInit(), EVP_EncryptInit_ex(), 189EVP_DecryptInit(), EVP_DecryptInit_ex(). 190 191EVP_CIPHER_meth_set_do_cipher() sets the cipher function for 192B<cipher>. 193The cipher function is called by EVP_CipherUpdate(), 194EVP_EncryptUpdate(), EVP_DecryptUpdate(), EVP_CipherFinal(), 195EVP_EncryptFinal(), EVP_EncryptFinal_ex(), EVP_DecryptFinal() and 196EVP_DecryptFinal_ex(). 197 198EVP_CIPHER_meth_set_cleanup() sets the function for B<cipher> to do 199extra cleanup before the method's private data structure is cleaned 200out and freed. 201Note that the cleanup function is passed a B<EVP_CIPHER_CTX *>, the 202private data structure is then available with 203EVP_CIPHER_CTX_get_cipher_data(). 204This cleanup function is called by EVP_CIPHER_CTX_reset() and 205EVP_CIPHER_CTX_free(). 206 207EVP_CIPHER_meth_set_set_asn1_params() sets the function for B<cipher> 208to set the AlgorithmIdentifier "parameter" based on the passed cipher. 209This function is called by EVP_CIPHER_param_to_asn1(). 210EVP_CIPHER_meth_set_get_asn1_params() sets the function for B<cipher> 211that sets the cipher parameters based on an ASN.1 AlgorithmIdentifier 212"parameter". 213Both these functions are needed when there is a need for custom data 214(more or other than the cipher IV). 215They are called by EVP_CIPHER_param_to_asn1() and 216EVP_CIPHER_asn1_to_param() respectively if defined. 217 218EVP_CIPHER_meth_set_ctrl() sets the control function for B<cipher>. 219 220EVP_CIPHER_meth_get_init(), EVP_CIPHER_meth_get_do_cipher(), 221EVP_CIPHER_meth_get_cleanup(), EVP_CIPHER_meth_get_set_asn1_params(), 222EVP_CIPHER_meth_get_get_asn1_params() and EVP_CIPHER_meth_get_ctrl() 223are all used to retrieve the method data given with the 224EVP_CIPHER_meth_set_*() functions above. 225 226=head1 RETURN VALUES 227 228EVP_CIPHER_meth_new() and EVP_CIPHER_meth_dup() return a pointer to a 229newly created B<EVP_CIPHER>, or NULL on failure. 230All EVP_CIPHER_meth_set_*() functions return 1. 231All EVP_CIPHER_meth_get_*() functions return pointers to their 232respective B<cipher> function. 233 234=head1 SEE ALSO 235 236L<EVP_EncryptInit> 237 238=head1 HISTORY 239 240The functions described here were added in OpenSSL 1.1.0. 241 242=head1 COPYRIGHT 243 244Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved. 245 246Licensed under the OpenSSL license (the "License"). You may not use 247this file except in compliance with the License. You can obtain a copy 248in the file LICENSE in the source distribution or at 249L<https://www.openssl.org/source/license.html>. 250 251=cut 252