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author | marha <marha@users.sourceforge.net> | 2010-03-30 12:36:28 +0000 |
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committer | marha <marha@users.sourceforge.net> | 2010-03-30 12:36:28 +0000 |
commit | ff48c0d9098080b51ea12710029135916d117806 (patch) | |
tree | 96e6af9caf170ba21a1027b24e306a07e27d7b75 /openssl/doc/crypto/EVP_PKEY_decrypt.pod | |
parent | bb731f5ac92655c4860a41fa818a7a63005f8369 (diff) | |
download | vcxsrv-ff48c0d9098080b51ea12710029135916d117806.tar.gz vcxsrv-ff48c0d9098080b51ea12710029135916d117806.tar.bz2 vcxsrv-ff48c0d9098080b51ea12710029135916d117806.zip |
svn merge -r514:HEAD ^/branches/released .
Diffstat (limited to 'openssl/doc/crypto/EVP_PKEY_decrypt.pod')
-rw-r--r-- | openssl/doc/crypto/EVP_PKEY_decrypt.pod | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/openssl/doc/crypto/EVP_PKEY_decrypt.pod b/openssl/doc/crypto/EVP_PKEY_decrypt.pod new file mode 100644 index 000000000..42b2a8c44 --- /dev/null +++ b/openssl/doc/crypto/EVP_PKEY_decrypt.pod @@ -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 |