flutter / third_party / openssl / 4b1b629725970384d6cf4dafe9e83e54859574cd / . / doc / man3 / RSA_private_encrypt.pod

=pod | |

=head1 NAME | |

RSA_private_encrypt, RSA_public_decrypt - low-level signature operations | |

=head1 SYNOPSIS | |

#include <openssl/rsa.h> | |

The following functions have been deprecated since OpenSSL 3.0, and can be | |

hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value, | |

see L<openssl_user_macros(7)>: | |

int RSA_private_encrypt(int flen, unsigned char *from, | |

unsigned char *to, RSA *rsa, int padding); | |

int RSA_public_decrypt(int flen, unsigned char *from, | |

unsigned char *to, RSA *rsa, int padding); | |

=head1 DESCRIPTION | |

Both of the functions described on this page are deprecated. | |

Applications should instead use L<EVP_PKEY_sign_init_ex(3)>, | |

L<EVP_PKEY_sign(3)>, L<EVP_PKEY_verify_recover_init(3)>, and | |

L<EVP_PKEY_verify_recover(3)>. | |

These functions handle RSA signatures at a low-level. | |

RSA_private_encrypt() signs the B<flen> bytes at B<from> (usually a | |

message digest with an algorithm identifier) using the private key | |

B<rsa> and stores the signature in B<to>. B<to> must point to | |

B<RSA_size(rsa)> bytes of memory. | |

B<padding> denotes one of the following modes: | |

=over 4 | |

=item RSA_PKCS1_PADDING | |

PKCS #1 v1.5 padding. This function does not handle the | |

B<algorithmIdentifier> specified in PKCS #1. When generating or | |

verifying PKCS #1 signatures, L<RSA_sign(3)> and L<RSA_verify(3)> should be | |

used. | |

=item RSA_NO_PADDING | |

Raw RSA signature. This mode should I<only> be used to implement | |

cryptographically sound padding modes in the application code. | |

Signing user data directly with RSA is insecure. | |

=back | |

RSA_public_decrypt() recovers the message digest from the B<flen> | |

bytes long signature at B<from> using the signer's public key | |

B<rsa>. B<to> must point to a memory section large enough to hold the | |

message digest (which is smaller than B<RSA_size(rsa) - | |

11>). B<padding> is the padding mode that was used to sign the data. | |

=head1 RETURN VALUES | |

RSA_private_encrypt() returns the size of the signature (i.e., | |

RSA_size(rsa)). RSA_public_decrypt() returns the size of the | |

recovered message digest. | |

On error, -1 is returned; the error codes can be | |

obtained by L<ERR_get_error(3)>. | |

=head1 SEE ALSO | |

L<ERR_get_error(3)>, | |

L<RSA_sign(3)>, L<RSA_verify(3)>, | |

L<EVP_PKEY_sign(3)>, L<EVP_PKEY_verify_recover(3)> | |

=head1 HISTORY | |

Both of these functions were deprecated in OpenSSL 3.0. | |

=head1 COPYRIGHT | |

Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. | |

Licensed under the Apache License 2.0 (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 |