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X509_SIGN(3) Library Functions Manual X509_SIGN(3)

NAME

X509_sign, X509_sign_ctx, X509_verify, X509_REQ_sign, X509_REQ_sign_ctx, X509_REQ_verify, X509_CRL_sign, X509_CRL_sign_ctx, X509_CRL_verifysign or verify certificate, certificate request, or CRL signature

SYNOPSIS

#include <openssl/x509.h>

int
X509_sign(X509 *x, EVP_PKEY *pkey, const EVP_MD *md);

int
X509_sign_ctx(X509 *x, EVP_MD_CTX *ctx);

int
X509_verify(X509 *a, EVP_PKEY *r);

int
X509_REQ_sign(X509_REQ *x, EVP_PKEY *pkey, const EVP_MD *md);

int
X509_REQ_sign_ctx(X509_REQ *x, EVP_MD_CTX *ctx);

int
X509_REQ_verify(X509_REQ *a, EVP_PKEY *r);

int
X509_CRL_sign(X509_CRL *x, EVP_PKEY *pkey, const EVP_MD *md);

int
X509_CRL_sign_ctx(X509_CRL *x, EVP_MD_CTX *ctx);

int
X509_CRL_verify(X509_CRL *a, EVP_PKEY *r);

DESCRIPTION

() signs the certificate x using the private key pkey and the message digest md and sets the signature in x. X509_sign_ctx() also signs the certificate x but uses the parameters contained in digest context ctx.

() verifies the signature of certificate x using the public key pkey. Only the signature is checked: no other checks (such as certificate chain validity) are performed.

(), (), (), (), (), and () sign and verify certificate requests and CRLs, respectively.

() is used where the default parameters for the corresponding public key and digest are not suitable. It can be used to sign keys using RSA-PSS for example.

RETURN VALUES

X509_sign(), X509_sign_ctx(), X509_REQ_sign(), X509_REQ_sign_ctx(), X509_CRL_sign(), and X509_CRL_sign_ctx() return the size of the signature in bytes for success or 0 for failure.

X509_verify(), X509_REQ_verify(), and X509_CRL_verify() return 1 if the signature is valid or 0 if the signature check fails. If the signature could not be checked at all because it was invalid or some other error occurred, then -1 is returned.

In some cases of failure, the reason can be determined with ERR_get_error(3).

SEE ALSO

d2i_X509(3), EVP_DigestInit(3), X509_CRL_get0_by_serial(3), X509_CRL_new(3), X509_get_pubkey(3), X509_get_subject_name(3), X509_get_version(3), X509_NAME_add_entry_by_txt(3), X509_NAME_ENTRY_get_object(3), X509_NAME_get_index_by_NID(3), X509_NAME_print_ex(3), X509_new(3), X509_REQ_new(3), X509_verify_cert(3), X509V3_get_d2i(3)

HISTORY

X509_verify() appeared in SSLeay 0.4 or earlier. X509_sign() and X509_REQ_sign() first appeared in SSLeay 0.4.4. X509_REQ_verify() and X509_CRL_verify() first appeared in SSLeay 0.4.5b. X509_CRL_sign() first appeared in SSLeay 0.5.1. These functions have been available since OpenBSD 2.4.

X509_sign_ctx(), X509_REQ_sign_ctx(), and X509_CRL_sign_ctx() first appeared in OpenSSL 1.0.1 and have been available since OpenBSD 5.3.

March 6, 2024 Linux 6.4.0-150600.23.25-default