| Index: openssl/doc/crypto/EVP_PKEY_decrypt.pod
|
| ===================================================================
|
| --- openssl/doc/crypto/EVP_PKEY_decrypt.pod (revision 0)
|
| +++ openssl/doc/crypto/EVP_PKEY_decrypt.pod (revision 0)
|
| @@ -0,0 +1,93 @@
|
| +=pod
|
| +
|
| +=head1 NAME
|
| +
|
| +EVP_PKEY_decrypt_init, EVP_PKEY_decrypt - decrypt using a public key algorithm
|
| +
|
| +=head1 SYNOPSIS
|
| +
|
| + #include <openssl/evp.h>
|
| +
|
| + int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
|
| + int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx,
|
| + unsigned char *out, size_t *outlen,
|
| + const unsigned char *in, size_t inlen);
|
| +
|
| +=head1 DESCRIPTION
|
| +
|
| +The EVP_PKEY_decrypt_init() function initializes a public key algorithm
|
| +context using key B<pkey> for a decryption operation.
|
| +
|
| +The EVP_PKEY_decrypt() function performs a public key decryption operation
|
| +using B<ctx>. The data to be decrypted 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 decrypted data is written to
|
| +B<out> and the amount of data written to B<outlen>.
|
| +
|
| +=head1 NOTES
|
| +
|
| +After the call to EVP_PKEY_decrypt_init() algorithm specific control
|
| +operations can be performed to set any appropriate parameters for the
|
| +operation.
|
| +
|
| +The function EVP_PKEY_decrypt() can be called more than once on the same
|
| +context if several operations are performed using the same parameters.
|
| +
|
| +=head1 RETURN VALUES
|
| +
|
| +EVP_PKEY_decrypt_init() and EVP_PKEY_decrypt() 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
|
| +
|
| +Decrypt data using OAEP (for RSA keys):
|
| +
|
| + #include <openssl/evp.h>
|
| + #include <openssl/rsa.h>
|
| +
|
| + EVP_PKEY_CTX *ctx;
|
| + unsigned char *out, *in;
|
| + size_t outlen, inlen;
|
| + EVP_PKEY *key;
|
| + /* NB: assumes key in, inlen are already set up
|
| + * and that key is an RSA private key
|
| + */
|
| + ctx = EVP_PKEY_CTX_new(key);
|
| + if (!ctx)
|
| + /* Error occurred */
|
| + if (EVP_PKEY_decrypt_init(ctx) <= 0)
|
| + /* Error */
|
| + if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
|
| + /* Error */
|
| +
|
| + /* Determine buffer length */
|
| + if (EVP_PKEY_decrypt(ctx, NULL, &outlen, in, inlen) <= 0)
|
| + /* Error */
|
| +
|
| + out = OPENSSL_malloc(outlen);
|
| +
|
| + if (!out)
|
| + /* malloc failure */
|
| +
|
| + if (EVP_PKEY_decrypt(ctx, out, &outlen, in, inlen) <= 0)
|
| + /* Error */
|
| +
|
| + /* Decrypted data is outlen bytes written to buffer out */
|
| +
|
| +=head1 SEE ALSO
|
| +
|
| +L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>,
|
| +L<EVP_PKEY_encrypt(3)|EVP_PKEY_encrypt(3)>,
|
| +L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>,
|
| +L<EVP_PKEY_verify(3)|EVP_PKEY_verify(3)>,
|
| +L<EVP_PKEY_verifyrecover(3)|EVP_PKEY_verifyrecover(3)>,
|
| +L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)>
|
| +
|
| +=head1 HISTORY
|
| +
|
| +These functions were first added to OpenSSL 1.0.0.
|
| +
|
| +=cut
|
|
|