RSA_sign.3ossl - Man Page

RSA signatures

Synopsis

 #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);

Description

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.

Return Values

RSA_sign() returns 1 on success. RSA_verify() returns 1 on successful verification.

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

Conforming to

SSL, PKCS #1 v2.0

See Also

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

History

All of these functions were deprecated in OpenSSL 3.0.

Referenced By

RSA_meth_new.3ossl(3), RSA_padding_add_PKCS1_type_1.3ossl(3), RSA_private_encrypt.3ossl(3), RSA_sign_ASN1_OCTET_STRING.3ossl(3).

The man page RSA_verify.3ossl(3) is an alias of RSA_sign.3ossl(3).

2022-09-12 3.0.5 OpenSSL