1=pod 2 3=head1 NAME 4 5EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm 6 7=head1 SYNOPSIS 8 9 #include <openssl/evp.h> 10 11 int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx); 12 int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, 13 unsigned char *out, size_t *outlen, 14 const unsigned char *in, size_t inlen); 15 16=head1 DESCRIPTION 17 18The EVP_PKEY_encrypt_init() function initializes a public key algorithm 19context using key B<pkey> for an encryption operation. 20 21The EVP_PKEY_encrypt() function performs a public key encryption operation 22using B<ctx>. The data to be encrypted is specified using the B<in> and 23B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output 24buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then 25before the call the B<outlen> parameter should contain the length of the 26B<out> buffer, if the call is successful the encrypted data is written to 27B<out> and the amount of data written to B<outlen>. 28 29=head1 NOTES 30 31After the call to EVP_PKEY_encrypt_init() algorithm specific control 32operations can be performed to set any appropriate parameters for the 33operation. 34 35The function EVP_PKEY_encrypt() can be called more than once on the same 36context if several operations are performed using the same parameters. 37 38=head1 RETURN VALUES 39 40EVP_PKEY_encrypt_init() and EVP_PKEY_encrypt() return 1 for success and 0 41or a negative value for failure. In particular a return value of -2 42indicates the operation is not supported by the public key algorithm. 43 44=head1 EXAMPLE 45 46Encrypt data using OAEP (for RSA keys). See also L<PEM_read_PUBKEY(3)|pem(3)> or 47L<d2i_X509(3)|d2i_X509(3)> for means to load a public key. You may also simply 48set 'eng = NULL;' to start with the default OpenSSL RSA implementation: 49 50 #include <openssl/evp.h> 51 #include <openssl/rsa.h> 52 #include <openssl/engine.h> 53 54 EVP_PKEY_CTX *ctx; 55 ENGINE *eng; 56 unsigned char *out, *in; 57 size_t outlen, inlen; 58 EVP_PKEY *key; 59 /* NB: assumes eng, key, in, inlen are already set up, 60 * and that key is an RSA public key 61 */ 62 ctx = EVP_PKEY_CTX_new(key,eng); 63 if (!ctx) 64 /* Error occurred */ 65 if (EVP_PKEY_encrypt_init(ctx) <= 0) 66 /* Error */ 67 if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0) 68 /* Error */ 69 70 /* Determine buffer length */ 71 if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0) 72 /* Error */ 73 74 out = OPENSSL_malloc(outlen); 75 76 if (!out) 77 /* malloc failure */ 78 79 if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0) 80 /* Error */ 81 82 /* Encrypted data is outlen bytes written to buffer out */ 83 84=head1 SEE ALSO 85 86L<d2i_X509(3)|d2i_X509(3)>, 87L<engine(3)|engine(3)>, 88L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>, 89L<EVP_PKEY_decrypt(3)|EVP_PKEY_decrypt(3)>, 90L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>, 91L<EVP_PKEY_verify(3)|EVP_PKEY_verify(3)>, 92L<EVP_PKEY_verify_recover(3)|EVP_PKEY_verify_recover(3)>, 93L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)> 94 95=head1 HISTORY 96 97These functions were first added to OpenSSL 1.0.0. 98 99=cut 100