X509_SIG_NEW(3) | Library Functions Manual | X509_SIG_NEW(3)

# NAME

`X509_SIG_new`, `X509_SIG_free` — PKCS#7 digest information

# SYNOPSIS

library “libcrypto”
`#include <openssl/x509.h>`

X509_SIG *
`X509_SIG_new`(void);

void
`X509_SIG_free`(X509_SIG *sig);

# DESCRIPTION

`X509_SIG_new`() allocates and initializes an empty X509_SIG object, representing an ASN.1 DigestInfo structure defined in RFC 2315 section 9.4 and equivalently in RFC 8017 section 9.2. It can hold a message digest together with information about the algorithm used.

`X509_SIG_free`() frees sig.

# RETURN VALUES

`X509_SIG_new`() returns the new X509_SIG object or `NULL` if an error occurs.

# SEE ALSO

d2i_X509_SIG(3), PEM_read_PKCS8(3), RSA_sign(3), X509_new(3), X509_SIG_get0(3)

# STANDARDS

RFC 2315: PKCS #7: Cryptographic Message Syntax, section 9: Signed-data content type

RFC 8017: PKCS #1: RSA Cryptography Specifications, section 9: Encoding Methods for Signatures

# HISTORY

`X509_SIG_new`() and `X509_SIG_free`() appeared in SSLeay 0.4 or earlier and have been available since OpenBSD 2.4.

June 8, 2025 | Debian