1=pod 2 3=head1 NAME 4 5EVP_CIPHER_CTX_get_original_iv, EVP_CIPHER_CTX_get_updated_iv, 6EVP_CIPHER_CTX_iv, EVP_CIPHER_CTX_original_iv, 7EVP_CIPHER_CTX_iv_noconst - Routines to inspect EVP_CIPHER_CTX IV data 8 9=head1 SYNOPSIS 10 11 #include <openssl/evp.h> 12 13 int EVP_CIPHER_CTX_get_original_iv(EVP_CIPHER_CTX *ctx, void *buf, size_t len); 14 int EVP_CIPHER_CTX_get_updated_iv(EVP_CIPHER_CTX *ctx, void *buf, size_t len); 15 16The following functions have been deprecated since OpenSSL 3.0, and can be 17hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, 18see L<openssl_user_macros(7)>: 19 20 const unsigned char *EVP_CIPHER_CTX_iv(const EVP_CIPHER_CTX *ctx); 21 const unsigned char *EVP_CIPHER_CTX_original_iv(const EVP_CIPHER_CTX *ctx); 22 unsigned char *EVP_CIPHER_CTX_iv_noconst(EVP_CIPHER_CTX *ctx); 23 24=head1 DESCRIPTION 25 26EVP_CIPHER_CTX_get_original_iv() and EVP_CIPHER_CTX_get_updated_iv() copy 27initialization vector (IV) information from the B<EVP_CIPHER_CTX> into the 28caller-supplied buffer. L<EVP_CIPHER_CTX_get_iv_length(3)> can be used to 29determine an appropriate buffer size, and if the supplied buffer is too small, 30an error will be returned (and no data copied). 31EVP_CIPHER_CTX_get_original_iv() accesses the ("original") IV that was 32supplied when the B<EVP_CIPHER_CTX> was initialized, and 33EVP_CIPHER_CTX_get_updated_iv() accesses the current "IV state" 34of the cipher, which is updated during cipher operation for certain cipher modes 35(e.g., CBC and OFB). 36 37The functions EVP_CIPHER_CTX_iv(), EVP_CIPHER_CTX_original_iv(), and 38EVP_CIPHER_CTX_iv_noconst() are deprecated functions that provide similar (at 39a conceptual level) functionality. EVP_CIPHER_CTX_iv() returns a pointer to 40the beginning of the "IV state" as maintained internally in the 41B<EVP_CIPHER_CTX>; EVP_CIPHER_CTX_original_iv() returns a pointer to the 42beginning of the ("original") IV, as maintained by the B<EVP_CIPHER_CTX>, that 43was provided when the B<EVP_CIPHER_CTX> was initialized; and 44EVP_CIPHER_CTX_get_iv_noconst() is the same as EVP_CIPHER_CTX_iv() but has a 45different return type for the pointer. 46 47=head1 RETURN VALUES 48 49EVP_CIPHER_CTX_get_original_iv() and EVP_CIPHER_CTX_get_updated_iv() return 1 50on success and 0 on failure. 51 52The functions EVP_CIPHER_CTX_iv(), EVP_CIPHER_CTX_original_iv(), and 53EVP_CIPHER_CTX_iv_noconst() return a pointer to an IV as an array of bytes on 54success, and NULL on failure. 55 56=head1 HISTORY 57 58EVP_CIPHER_CTX_get_original_iv() and EVP_CIPHER_CTX_get_updated_iv() were added 59in OpenSSL 3.0.0. 60 61EVP_CIPHER_CTX_iv(), EVP_CIPHER_CTX_original_iv(), and 62EVP_CIPHER_CTX_iv_noconst() were added in OpenSSL 1.1.0, and were deprecated 63in OpenSSL 3.0.0. 64 65=head1 COPYRIGHT 66 67Copyright 2020-2021 The OpenSSL Project Authors. All Rights Reserved. 68 69Licensed under the Apache License 2.0 (the "License"). You may not use 70this file except in compliance with the License. You can obtain a copy 71in the file LICENSE in the source distribution or at 72L<https://www.openssl.org/source/license.html>. 73 74=cut 75