RSA_padding_add_PKCS1_type_1, RSA_padding_check_PKCS1_type_1,
RSA_padding_add_PKCS1_type_2, RSA_padding_check_PKCS1_type_2,
RSA_padding_add_PKCS1_OAEP, RSA_padding_check_PKCS1_OAEP,
+RSA_padding_add_PKCS1_OAEP_mgf1, RSA_padding_check_PKCS1_OAEP_mgf1,
RSA_padding_add_SSLv23, RSA_padding_check_SSLv23,
RSA_padding_add_none, RSA_padding_check_none - asymmetric encryption
padding
#include <openssl/rsa.h>
+Deprecated since OpenSSL 3.0, can be hidden entirely by defining
+B<OPENSSL_API_COMPAT> with a suitable version value, see
+L<openssl_user_macros(7)>:
+
int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen,
- unsigned char *f, int fl);
+ const unsigned char *f, int fl);
int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen,
- unsigned char *f, int fl, int rsa_len);
+ const unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen,
- unsigned char *f, int fl);
+ const unsigned char *f, int fl);
int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
- unsigned char *f, int fl, int rsa_len);
+ const unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
- unsigned char *f, int fl, unsigned char *p, int pl);
+ const unsigned char *f, int fl,
+ const unsigned char *p, int pl);
int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
- unsigned char *f, int fl, int rsa_len,
- unsigned char *p, int pl);
+ const unsigned char *f, int fl, int rsa_len,
+ const unsigned char *p, int pl);
+
+ int RSA_padding_add_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
+ const unsigned char *f, int fl,
+ const unsigned char *p, int pl,
+ const EVP_MD *md, const EVP_MD *mgf1md);
+
+ int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
+ const unsigned char *f, int fl, int rsa_len,
+ const unsigned char *p, int pl,
+ const EVP_MD *md, const EVP_MD *mgf1md);
int RSA_padding_add_SSLv23(unsigned char *to, int tlen,
- unsigned char *f, int fl);
+ const unsigned char *f, int fl);
int RSA_padding_check_SSLv23(unsigned char *to, int tlen,
- unsigned char *f, int fl, int rsa_len);
+ const unsigned char *f, int fl, int rsa_len);
int RSA_padding_add_none(unsigned char *to, int tlen,
- unsigned char *f, int fl);
+ const unsigned char *f, int fl);
int RSA_padding_check_none(unsigned char *to, int tlen,
- unsigned char *f, int fl, int rsa_len);
+ const unsigned char *f, int fl, int rsa_len);
=head1 DESCRIPTION
+All of the functions described on this page are deprecated.
+Applications should instead use the EVP PKEY APIs.
+
The RSA_padding_xxx_xxx() functions are called from the RSA encrypt,
decrypt, sign and verify functions. Normally they should not be called
from application programs.
The random number generator must be seeded prior to calling
RSA_padding_add_xxx().
+If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to
+external circumstances (see L<RAND(7)>), the operation will fail.
RSA_padding_check_xxx() verifies that the B<fl> bytes at B<f> contain
a valid encoding for a B<rsa_len> byte RSA key in the respective
For RSA_padding_xxx_OAEP(), B<p> points to the encoding parameter
of length B<pl>. B<p> may be B<NULL> if B<pl> is 0.
+For RSA_padding_xxx_OAEP_mgf1(), B<md> points to the md hash,
+if B<md> is B<NULL> that means md=sha1, and B<mgf1md> points to
+the mgf1 hash, if B<mgf1md> is B<NULL> that means mgf1md=md.
+
=head1 RETURN VALUES
The RSA_padding_add_xxx() functions return 1 on success, 0 on error.
recovered data, -1 on error. Error codes can be obtained by calling
L<ERR_get_error(3)>.
-=head1 WARNING
+=head1 WARNINGS
-The RSA_padding_check_PKCS1_type_2() padding check leaks timing
+The result of RSA_padding_check_PKCS1_type_2() is a very sensitive
information which can potentially be used to mount a Bleichenbacher
padding oracle attack. This is an inherent weakness in the PKCS #1
-v1.5 padding design. Prefer PKCS1_OAEP padding. Otherwise it can
-be recommended to pass zero-padded B<f>, so that B<fl> equals to
-B<rsa_len>, and if fixed by protocol, B<tlen> being set to the
-expected length. In such case leakage would be minimal, it would
-take attacker's ability to observe memory access pattern with byte
-granilarity as it occurs, post-factum timing analysis won't do.
+v1.5 padding design. Prefer PKCS1_OAEP padding. If that is not
+possible, the result of RSA_padding_check_PKCS1_type_2() should be
+checked in constant time if it matches the expected length of the
+plaintext and additionally some application specific consistency
+checks on the plaintext need to be performed in constant time.
+If the plaintext is rejected it must be kept secret which of the
+checks caused the application to reject the message.
+Do not remove the zero-padding from the decrypted raw RSA data
+which was computed by RSA_private_decrypt() with B<RSA_NO_PADDING>,
+as this would create a small timing side channel which could be
+used to mount a Bleichenbacher attack against any padding mode
+including PKCS1_OAEP.
=head1 SEE ALSO
L<RSA_public_encrypt(3)>,
L<RSA_private_decrypt(3)>,
-L<RSA_sign(3)>, L<RSA_verify(3)>
+L<RSA_sign(3)>, L<RSA_verify(3)>,
+L<RAND(7)>
+
+=head1 HISTORY
+
+All of these functions were deprecated in OpenSSL 3.0.
=head1 COPYRIGHT
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 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
projects / openssl.git / blobdiff