RSA_sign, RSA_verify - RSA signatures

       SSL, PKCS #1 v2.0

       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 in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

3.5.0                                              2025-06-04                                     RSA_SIGN(3SSL)

       All of the functions described on this page are deprecated.  Applications should instead use
       EVP_PKEY_sign_init(3), EVP_PKEY_sign(3), EVP_PKEY_verify_init(3) and EVP_PKEY_verify(3).

       RSA_sign() signs the message digest m of size m_len using the private key rsa using RSASSA-PKCS1-v1_5 as
       specified in RFC 3447. It stores the signature in sigret and the signature size in siglen.  sigret must
       point to RSA_size(rsa) bytes of memory.  Note that PKCS #1 adds meta-data, placing limits on the size of
       the key that can be used.  See RSA_private_encrypt(3) for lower-level operations.

       type denotes the message digest algorithm that was used to generate m.  If type is NID_md5_sha1, an SSL
       signature (MD5 and SHA1 message digests with PKCS #1 padding and no algorithm identifier) is created.

       RSA_verify() verifies that the signature sigbuf of size siglen matches a given message digest m of size
       m_len. type denotes the message digest algorithm that was used to generate the signature.  rsa is the
       signer's public key.

       All of these functions were deprecated in OpenSSL 3.0.

       RSA_sign, RSA_verify - RSA signatures

RSA_sign() returns 1 on success and 0 for failure.  RSA_verify() returns 1 on successful verification and
       0 for failure.

       The error codes can be obtained by ERR_get_error(3).

ERR_get_error(3), RSA_private_encrypt(3), RSA_public_decrypt(3)

        #include <openssl/rsa.h>

       The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining
       OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):

        int RSA_sign(int type, const unsigned char *m, unsigned int m_len,
                     unsigned char *sigret, unsigned int *siglen, RSA *rsa);

        int RSA_verify(int type, const unsigned char *m, unsigned int m_len,
                       unsigned char *sigbuf, unsigned int siglen, RSA *rsa);