ASN1_ITEM_DIGEST(3)        Library Functions Manual        ASN1_ITEM_DIGEST(3)

NAME
     ASN1_item_digest - DER-encode and hash an ASN.1 value

SYNOPSIS
     #include <openssl/x509.h>

     int
     ASN1_item_digest(const ASN1_ITEM *it, const EVP_MD *type, void *val_in,
         unsigned char *md, unsigned int *s);

DESCRIPTION
     ASN1_item_digest() assumes that val_in is an ASN1_VALUE of the type
     specified by it, encodes it into DER format by calling ASN1_item_i2d(3),
     hashes the resulting byte array using the digest type by calling
     EVP_Digest(3), places the digest value into *md, and, unless s is NULL,
     places the length in bytes of the digest into *s.  Providing a buffer *md
     large enough to contain the digest is the responsibility of the caller;
     providing a buffer of EVP_MAX_MD_SIZE bytes is recommended.

RETURN VALUES
     ASN1_item_digest() returns 1 for success or 0 if encoding or hashing
     fails.

SEE ALSO
     ASN1_item_i2d(3), ASN1_item_sign(3), EVP_Digest(3)

HISTORY
     ASN1_item_digest() first appeared in OpenSSL 0.9.7 and has been available
     since OpenBSD 3.1.

Linux 6.8.7-arch1-1           September 11, 2022           Linux 6.8.7-arch1-1