D2I_X509_SIG(3)            Library Functions Manual            D2I_X509_SIG(3)

NAME
     d2i_X509_SIG, i2d_X509_SIG, d2i_PKCS8_bio, i2d_PKCS8_bio, d2i_PKCS8_fp,
     i2d_PKCS8_fp - decode and encode PKCS#7 digest information

SYNOPSIS
     #include <openssl/x509.h>

     X509_SIG *
     d2i_X509_SIG(X509_SIG **val_out, unsigned char **der_in, long length);

     int
     i2d_X509_SIG(X509_SIG *val_in, unsigned char **der_out);

     X509_SIG *
     d2i_PKCS8_bio(BIO *in_bio, X509_SIG **val_out);

     int
     i2d_PKCS8_bio(BIO *out_bio, X509_SIG *val_in);

     X509_SIG *
     d2i_PKCS8_fp(FILE *in_fp, X509_SIG **val_out);

     int
     i2d_PKCS8_fp(FILE *out_fp, X509_SIG *val_in);

DESCRIPTION
     d2i_X509_SIG() and i2d_X509_SIG() decode and encode an ASN.1 DigestInfo
     structure defined in RFC 2315 section 9.4 and equivalently in RFC 8017
     section 9.2.  For details about the semantics, examples, caveats, and
     bugs, see ASN1_item_d2i(3).

     d2i_PKCS8_bio() and d2i_PKCS8_fp() are similar to d2i_X509_SIG() except
     that they read from a BIO or FILE pointer.

     i2d_PKCS8_bio() and i2d_PKCS8_fp() are similar to i2d_X509_SIG() except
     that they write to a BIO or FILE pointer.

RETURN VALUES
     d2i_X509_SIG(), d2i_PKCS8_bio(), and d2i_PKCS8_fp() return a X509_SIG
     object or NULL if an error occurs.

     i2d_X509_SIG() returns the number of bytes successfully encoded or a
     negative value if an error occurs.

     i2d_PKCS8_bio() and i2d_PKCS8_fp() return 1 for success or 0 if an error
     occurs.

SEE ALSO
     ASN1_item_d2i(3), PKCS7_new(3), RSA_sign(3), X509_SIG_new(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
     d2i_X509_SIG() and i2d_X509_SIG() first appeared in SSLeay 0.5.1 and have
     been available since OpenBSD 2.4.

     d2i_PKCS8_bio(), i2d_PKCS8_bio(), d2i_PKCS8_fp(), and i2d_PKCS8_fp()
     first appeared in OpenSSL 0.9.4 and have been available since
     OpenBSD 2.6.

BUGS
     d2i_PKCS8_bio(), i2d_PKCS8_bio(), d2i_PKCS8_fp(), and i2d_PKCS8_fp() are
     severely misnamed and should have been called "d2i_X509_SIG_bio" and so
     on.

     Or arguably, the X509_SIG object is misnamed itself, considering that it
     represents DigestInfo from PKCS#7 and PKCS#1.  Then again, calling it
     "PKCS8" instead clearly isn't an improvement.

     Either way, these names just don't fit.

Linux 6.8.7-arch1-1             March 27, 2018             Linux 6.8.7-arch1-1