| =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)|pem(3)> or |
| L<d2i_X509(3)|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)|d2i_X509(3)>, |
| L<engine(3)|engine(3)>, |
| L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>, |
| L<EVP_PKEY_decrypt(3)|EVP_PKEY_decrypt(3)>, |
| L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>, |
| L<EVP_PKEY_verify(3)|EVP_PKEY_verify(3)>, |
| L<EVP_PKEY_verify_recover(3)|EVP_PKEY_verify_recover(3)>, |
| L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)> |
| |
| =head1 HISTORY |
| |
| These functions were first added to OpenSSL 1.0.0. |
| |
| =cut |
