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Diffstat (limited to 'doc/man3/EVP_PKEY_encrypt.pod')
-rw-r--r-- | doc/man3/EVP_PKEY_encrypt.pod | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/doc/man3/EVP_PKEY_encrypt.pod b/doc/man3/EVP_PKEY_encrypt.pod new file mode 100644 index 000000000000..4e9a34e740f3 --- /dev/null +++ b/doc/man3/EVP_PKEY_encrypt.pod @@ -0,0 +1,110 @@ +=pod + +=head1 NAME + +EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx); + int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, + unsigned char *out, size_t *outlen, + const unsigned char *in, size_t inlen); + +=head1 DESCRIPTION + +The EVP_PKEY_encrypt_init() function initializes a public key algorithm +context using key B<pkey> for an encryption operation. + +The EVP_PKEY_encrypt() function performs a public key encryption operation +using B<ctx>. The data to be encrypted is specified using the B<in> and +B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output +buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then +before the call the B<outlen> parameter should contain the length of the +B<out> buffer, if the call is successful the encrypted data is written to +B<out> and the amount of data written to B<outlen>. + +=head1 NOTES + +After the call to EVP_PKEY_encrypt_init() algorithm specific control +operations can be performed to set any appropriate parameters for the +operation. + +The function EVP_PKEY_encrypt() can be called more than once on the same +context if several operations are performed using the same parameters. + +=head1 RETURN VALUES + +EVP_PKEY_encrypt_init() and EVP_PKEY_encrypt() return 1 for success and 0 +or a negative value for failure. In particular a return value of -2 +indicates the operation is not supported by the public key algorithm. + +=head1 EXAMPLE + +Encrypt data using OAEP (for RSA keys). See also L<PEM_read_PUBKEY(3)> or +L<d2i_X509(3)> for means to load a public key. You may also simply +set 'eng = NULL;' to start with the default OpenSSL RSA implementation: + + #include <openssl/evp.h> + #include <openssl/rsa.h> + #include <openssl/engine.h> + + EVP_PKEY_CTX *ctx; + ENGINE *eng; + unsigned char *out, *in; + size_t outlen, inlen; + EVP_PKEY *key; + + /* + * NB: assumes eng, key, in, inlen are already set up, + * and that key is an RSA public key + */ + ctx = EVP_PKEY_CTX_new(key, eng); + if (!ctx) + /* Error occurred */ + if (EVP_PKEY_encrypt_init(ctx) <= 0) + /* Error */ + if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0) + /* Error */ + + /* Determine buffer length */ + if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0) + /* Error */ + + out = OPENSSL_malloc(outlen); + + if (!out) + /* malloc failure */ + + if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0) + /* Error */ + + /* Encrypted data is outlen bytes written to buffer out */ + +=head1 SEE ALSO + +L<d2i_X509(3)>, +L<ENGINE_by_id(3)>, +L<EVP_PKEY_CTX_new(3)>, +L<EVP_PKEY_decrypt(3)>, +L<EVP_PKEY_sign(3)>, +L<EVP_PKEY_verify(3)>, +L<EVP_PKEY_verify_recover(3)>, +L<EVP_PKEY_derive(3)> + +=head1 HISTORY + +These functions were first added to OpenSSL 1.0.0. + +=head1 COPYRIGHT + +Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L<https://www.openssl.org/source/license.html>. + +=cut |