.\" $OpenBSD: evp.3,v 1.26 2023/12/01 10:40:21 schwarze Exp $ .\" full merge up to: OpenSSL man7/evp 24a535ea Sep 22 13:14:20 2020 +0100 .\" .\" This file was written by Ulf Moeller , .\" Matt Caswell , Geoff Thorpe , .\" and Dr. Stephen Henson . .\" Copyright (c) 2000, 2002, 2006, 2013, 2016 The OpenSSL Project. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in .\" the documentation and/or other materials provided with the .\" distribution. .\" .\" 3. 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IN NO EVENT SHALL THE OpenSSL PROJECT OR .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED .\" OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: December 1 2023 $ .Dt EVP 3 .Os .Sh NAME .Nm evp .Nd high-level cryptographic functions .Sh SYNOPSIS .In openssl/evp.h .Sh DESCRIPTION The EVP library provides a high-level interface to cryptographic functions. .Pp .Xr EVP_SealInit 3 and .Xr EVP_OpenInit 3 provide public key encryption and decryption to implement digital "envelopes". .Pp The .Xr EVP_DigestSignInit 3 and .Xr EVP_DigestVerifyInit 3 functions implement digital signatures and Message Authentication Codes (MACs). Also see the older .Xr EVP_SignInit 3 and .Xr EVP_VerifyInit 3 functions. .Pp Symmetric encryption is available with the .Xr EVP_EncryptInit 3 functions. The .Xr EVP_DigestInit 3 functions provide message digests. .Pp Authenticated encryption with additional data (AEAD) is available with the .Xr EVP_AEAD_CTX_init 3 functions. .Pp The .Fn EVP_PKEY_* functions provide a high-level interface to asymmetric algorithms. To create a new .Vt EVP_PKEY , see .Xr EVP_PKEY_new 3 . .Vt EVP_PKEY Ns s can be associated with a private key of a particular algorithm by using the functions described in the .Xr EVP_PKEY_set1_RSA 3 page, or new keys can be generated using .Xr EVP_PKEY_keygen 3 . .Vt EVP_PKEY Ns s can be compared using .Xr EVP_PKEY_cmp 3 or printed using .Xr EVP_PKEY_print_private 3 . .Pp The .Fn EVP_PKEY_* functions support the full range of asymmetric algorithm operations: .Bl -bullet .It For key agreement, see .Xr EVP_PKEY_derive 3 . .It For signing and verifying, see .Xr EVP_PKEY_sign 3 , .Xr EVP_PKEY_verify 3 , and .Xr EVP_PKEY_verify_recover 3 . However, note that these functions do not perform a digest of the data to be signed. Therefore, normally you would use the .Xr EVP_DigestSignInit 3 functions for this purpose. .It For encryption and decryption see .Xr EVP_PKEY_encrypt 3 and .Xr EVP_PKEY_decrypt 3 , respectively. However, note that these functions perform encryption and decryption only. As public key encryption is an expensive operation, normally you would wrap an encrypted message in a digital envelope using the .Xr EVP_SealInit 3 and .Xr EVP_OpenInit 3 functions. .El .Pp The .Xr EVP_BytesToKey 3 function provides some limited support for password based encryption. Careful selection of the parameters will provide a PKCS#5 PBKDF1 compatible implementation. However, new applications should typically not use this (preferring, for example, PBKDF2 from PCKS#5). .Pp The .Xr EVP_EncodeInit 3 family of functions provides base64 encoding and decoding. .Sh SEE ALSO .Xr ASN1_item_digest 3 , .Xr ASN1_item_sign 3 , .Xr BIO_f_cipher 3 , .Xr BIO_f_md 3 , .Xr CMAC_Init 3 , .Xr CMS_encrypt 3 , .Xr CMS_sign 3 , .Xr crypto 3 , .Xr d2i_PKCS8PrivateKey_bio 3 , .Xr d2i_PrivateKey 3 , .Xr EVP_add_cipher 3 , .Xr EVP_AEAD_CTX_init 3 , .Xr EVP_aes_128_cbc 3 , .Xr EVP_BytesToKey 3 , .Xr EVP_camellia_128_cbc 3 , .Xr EVP_chacha20 3 , .Xr EVP_CIPHER_CTX_ctrl 3 , .Xr EVP_CIPHER_CTX_get_cipher_data 3 , .Xr EVP_CIPHER_CTX_init 3 , .Xr EVP_CIPHER_CTX_set_flags 3 , .Xr EVP_CIPHER_do_all 3 , .Xr EVP_CIPHER_meth_new 3 , .Xr EVP_CIPHER_nid 3 , .Xr EVP_des_cbc 3 , .Xr EVP_DigestInit 3 , .Xr EVP_DigestSignInit 3 , .Xr EVP_DigestVerifyInit 3 , .Xr EVP_EncodeInit 3 , .Xr EVP_EncryptInit 3 , .Xr EVP_MD_CTX_ctrl 3 , .Xr EVP_MD_meth_new 3 , .Xr EVP_MD_nid 3 , .Xr EVP_OpenInit 3 , .Xr EVP_PKCS82PKEY 3 , .Xr EVP_PKEY_add1_attr 3 , .Xr EVP_PKEY_asn1_get_count 3 , .Xr EVP_PKEY_asn1_new 3 , .Xr EVP_PKEY_check 3 , .Xr EVP_PKEY_cmp 3 , .Xr EVP_PKEY_CTX_ctrl 3 , .Xr EVP_PKEY_CTX_get_operation 3 , .Xr EVP_PKEY_CTX_new 3 , .Xr EVP_PKEY_CTX_set_hkdf_md 3 , .Xr EVP_PKEY_decrypt 3 , .Xr EVP_PKEY_derive 3 , .Xr EVP_PKEY_encrypt 3 , .Xr EVP_PKEY_get_default_digest_nid 3 , .Xr EVP_PKEY_keygen 3 , .Xr EVP_PKEY_meth_get0_info 3 , .Xr EVP_PKEY_meth_new 3 , .Xr EVP_PKEY_new 3 , .Xr EVP_PKEY_print_private 3 , .Xr EVP_PKEY_set1_RSA 3 , .Xr EVP_PKEY_sign 3 , .Xr EVP_PKEY_size 3 , .Xr EVP_PKEY_verify 3 , .Xr EVP_PKEY_verify_recover 3 , .Xr EVP_rc4 3 , .Xr EVP_SealInit 3 , .Xr EVP_sha1 3 , .Xr EVP_sha3_224 3 , .Xr EVP_SignInit 3 , .Xr EVP_sm3 3 , .Xr EVP_sm4_cbc 3 , .Xr EVP_VerifyInit 3 , .Xr EVP_whirlpool 3 , .Xr HMAC 3 , .Xr OCSP_basic_sign 3 , .Xr OCSP_request_sign 3 , .Xr PEM_get_EVP_CIPHER_INFO 3 , .Xr PEM_read_bio_PrivateKey 3 , .Xr PKCS12_create 3 , .Xr PKCS5_PBKDF2_HMAC 3 , .Xr PKCS7_encrypt 3 , .Xr PKCS7_sign 3 , .Xr RSA_pkey_ctx_ctrl 3 , .Xr SSL_CTX_set_tlsext_ticket_key_cb 3 , .Xr X509_ALGOR_set_md 3 , .Xr X509_check_private_key 3 , .Xr X509_CRL_METHOD_new 3 , .Xr X509_digest 3 , .Xr X509_get_pubkey 3 , .Xr X509_PUBKEY_set 3 , .Xr X509_sign 3 , .Xr X509_to_X509_REQ 3