.\" $OpenBSD: X509_PUBKEY_new.3,v 1.17 2021/10/26 10:01:23 schwarze Exp $
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.Dd $Mdocdate: October 26 2021 $
.Dt X509_PUBKEY_NEW 3
.Os
.Sh NAME
.Nm X509_PUBKEY_new ,
.Nm X509_PUBKEY_free ,
.Nm X509_PUBKEY_set ,
.Nm X509_PUBKEY_get0 ,
.Nm X509_PUBKEY_get ,
.Nm d2i_X509_PUBKEY ,
.Nm i2d_X509_PUBKEY ,
.Nm d2i_PUBKEY ,
.Nm i2d_PUBKEY ,
.Nm d2i_PUBKEY_bio ,
.Nm d2i_PUBKEY_fp ,
.Nm i2d_PUBKEY_fp ,
.Nm i2d_PUBKEY_bio ,
.Nm X509_PUBKEY_set0_param ,
.Nm X509_PUBKEY_get0_param
.Nd X.509 SubjectPublicKeyInfo structure
.Sh SYNOPSIS
.In openssl/x509.h
.Ft X509_PUBKEY *
.Fn X509_PUBKEY_new void
.Ft void
.Fo X509_PUBKEY_free
.Fa "X509_PUBKEY *a"
.Fc
.Ft int
.Fo X509_PUBKEY_set
.Fa "X509_PUBKEY **x"
.Fa "EVP_PKEY *pkey"
.Fc
.Ft EVP_PKEY *
.Fo X509_PUBKEY_get0
.Fa "X509_PUBKEY *key"
.Fc
.Ft EVP_PKEY *
.Fo X509_PUBKEY_get
.Fa "X509_PUBKEY *key"
.Fc
.Ft X509_PUBKEY *
.Fo d2i_X509_PUBKEY
.Fa "X509_PUBKEY **val_out"
.Fa "const unsigned char **der_in"
.Fa "long length"
.Fc
.Ft int
.Fo i2d_X509_PUBKEY
.Fa "X509_PUBKEY *val_in"
.Fa "unsigned char **der_out"
.Fc
.Ft EVP_PKEY *
.Fo d2i_PUBKEY
.Fa "EVP_PKEY **val_out"
.Fa "const unsigned char **der_in"
.Fa "long length"
.Fc
.Ft int
.Fo i2d_PUBKEY
.Fa "EVP_PKEY *val_in"
.Fa "unsigned char **der_out"
.Fc
.Ft EVP_PKEY *
.Fo d2i_PUBKEY_bio
.Fa "BIO *bp"
.Fa "EVP_PKEY **val_out"
.Fc
.Ft EVP_PKEY *
.Fo d2i_PUBKEY_fp
.Fa "FILE *fp"
.Fa "EVP_PKEY **val_out"
.Fc
.Ft int
.Fo i2d_PUBKEY_fp
.Fa "FILE *fp"
.Fa "EVP_PKEY *val_in"
.Fc
.Ft int
.Fo i2d_PUBKEY_bio
.Fa "BIO *bp"
.Fa "EVP_PKEY *val_in"
.Fc
.Ft int
.Fo X509_PUBKEY_set0_param
.Fa "X509_PUBKEY *pub"
.Fa "ASN1_OBJECT *aobj"
.Fa "int ptype"
.Fa "void *pval"
.Fa "unsigned char *penc"
.Fa "int penclen"
.Fc
.Ft int
.Fo X509_PUBKEY_get0_param
.Fa "ASN1_OBJECT **ppkalg"
.Fa "const unsigned char **pk"
.Fa "int *ppklen"
.Fa "X509_ALGOR **pa"
.Fa "X509_PUBKEY *pub"
.Fc
.Sh DESCRIPTION
The
.Vt X509_PUBKEY
structure represents the ASN.1
.Vt SubjectPublicKeyInfo
structure defined in RFC 5280 section 4.1 and used in certificates
and certificate requests.
.Pp
.Fn X509_PUBKEY_new
allocates and initializes an
.Vt X509_PUBKEY
structure.
.Pp
.Fn X509_PUBKEY_free
frees up the
.Vt X509_PUBKEY
structure
.Fa a .
If
.Fa a
is a
.Dv NULL
pointer, no action occurs.
.Pp
.Fn X509_PUBKEY_set
sets the public key in
.Pf * Fa x
to the public key contained in the
.Vt EVP_PKEY
structure
.Fa pkey .
If
.Pf * Fa x
is not
.Dv NULL ,
any existing public key structure will be freed.
.Pp
.Fn X509_PUBKEY_get0
returns the public key contained in
.Fa key .
The returned value is an internal pointer which must not be freed after use.
.Pp
.Fn X509_PUBKEY_get
is similar to
.Fn X509_PUBKEY_get0
except that the reference
count on the returned key is incremented so it must be freed using
.Xr EVP_PKEY_free 3
after use.
.Pp
.Fn d2i_X509_PUBKEY ,
.Fn i2d_X509_PUBKEY ,
.Fn d2i_PUBKEY ,
and
.Fn i2d_PUBKEY
decode and encode an ASN.1
.Vt SubjectPublicKeyInfo
structure using either the
.Vt X509_PUBKEY
or the
.Vt EVP_PKEY
object type, respectively.
For details about the semantics, examples, caveats, and bugs, see
.Xr ASN1_item_d2i 3 .
.Fn d2i_PUBKEY_bio ,
.Fn d2i_PUBKEY_fp ,
.Fn i2d_PUBKEY_bio
and
.Fn i2d_PUBKEY_fp
are similar to
.Fn d2i_PUBKEY
and
.Fn i2d_PUBKEY
except they decode or encode using a
.Vt BIO
or
.Vt FILE
pointer.
.Pp
.Fn X509_PUBKEY_set0_param
sets the public key parameters of
.Fa pub .
The OID associated with the algorithm is set to
.Fa aobj .
The type of the algorithm parameters is set to
.Fa ptype
using the structure
.Fa pval .
The encoding of the public key itself is set to the
.Fa penclen
bytes contained in buffer
.Fa penc .
On success ownership of all the supplied parameters is passed to
.Fa pub
so they must not be freed after the call.
.Pp
.Fn X509_PUBKEY_get0_param
retrieves the public key parameters from
.Fa pub ,
.Pf * Fa ppkalg
is set to the associated OID and the encoding consists of
.Pf * Fa ppklen
bytes at
.Pf * Fa pk ,
and
.Pf * Fa pa
is set to the associated
.Vt AlgorithmIdentifier
for the public key.
If the value of any of these parameters is not required,
it can be set to
.Dv NULL .
All of the retrieved pointers are internal and must not be freed after
the call.
.Sh RETURN VALUES
If the allocation fails,
.Fn X509_PUBKEY_new
returns
.Dv NULL
and sets an error code that can be obtained by
.Xr ERR_get_error 3 .
Otherwise it returns a pointer to the newly allocated structure.
.Pp
.Fn X509_PUBKEY_get0
returns an internal pointer or
.Dv NULL
if an error occurs.
.Pp
.Fn X509_PUBKEY_get
returns a pointer to an object that had its reference count incremented or
.Dv NULL
if an error occurs.
.Pp
.Fn d2i_X509_PUBKEY ,
.Fn d2i_PUBKEY ,
.Fn d2i_PUBKEY_bio ,
and
.Fn d2i_PUBKEY_fp
return a pointer to a valid object or
.Dv NULL
if an error occurs.
.Pp
.Fn i2d_X509_PUBKEY
and
.Fn i2d_PUBKEY
return the number of bytes successfully encoded or a negative value
if an error occurs.
.Pp
.Fn X509_PUBKEY_set ,
.Fn X509_PUBKEY_set0_param ,
.Fn X509_PUBKEY_get0_param ,
.Fn i2d_PUBKEY_fp ,
and
.Fn i2d_PUBKEY_bio
return 1 for success and 0 if an error occurred.
.Sh ERRORS
After failure of
.Fn X509_PUBKEY_get0
or
.Fn X509_PUBKEY_get ,
one of the following diagnostics can be retrieved with
.Xr ERR_get_error 3 ,
.Xr ERR_GET_REASON 3 ,
and
.Xr ERR_reason_error_string 3 :
.Bl -tag -width Ds
.It Dv X509_R_UNSUPPORTED_ALGORITHM Qq "unsupported algorithm"
The public key uses an algorithm unsupported by
.Xr EVP_PKEY_set_type 3 .
.It X509_R_METHOD_NOT_SUPPORTED Qq "method not supported"
While the algorithm is known to
.Xr EVP_PKEY_set_type 3 ,
using it for decoding is not supported.
.It X509_R_PUBLIC_KEY_DECODE_ERROR Qq "public key decode error"
Decoding the public key failed.
.It Dv ERR_R_MALLOC_FAILURE Qq "malloc failure"
Memory was exhausted when trying to allocate the new
.Vt EVP_PKEY
object.
.El
.Pp
If
.Fa key
is
.Dv NULL
or does not contain a public key,
these functions fail but no error is pushed onto the stack.
.Sh SEE ALSO
.Xr d2i_X509 3 ,
.Xr EVP_PKEY_asn1_set_public 3 ,
.Xr X509_ALGOR_new 3 ,
.Xr X509_get_pubkey 3 ,
.Xr X509_new 3
.Sh STANDARDS
RFC 5280: Internet X.509 Public Key Infrastructure Certificate and
Certificate Revocation List (CRL) Profile
.Sh HISTORY
.Fn X509_PUBKEY_new
and
.Fn X509_PUBKEY_free
appeared in SSLeay 0.4 or earlier.
.Fn d2i_X509_PUBKEY
and
.Fn i2d_X509_PUBKEY
first appeared in SSLeay 0.5.1.
.Fn X509_PUBKEY_set
and
.Fn X509_PUBKEY_get
first appeared in SSLeay 0.8.0.
These functions have been available since
.Ox 2.4 .
.Pp
.Fn d2i_PUBKEY
and
.Fn i2d_PUBKEY
first appeared in OpenSSL 0.9.5 and have been available since
.Ox 2.7 .
.Pp
.Fn d2i_PUBKEY_bio ,
.Fn d2i_PUBKEY_fp ,
.Fn i2d_PUBKEY_fp ,
and
.Fn i2d_PUBKEY_bio
first appeared in OpenSSL 0.9.6 and have been available since
.Ox 2.9 .
.Pp
.Fn X509_PUBKEY_set0_param
and
.Fn X509_PUBKEY_get0_param
first appeared in OpenSSL 1.0.0 and have been available since
.Ox 4.9 .
.Pp
.Fn X509_PUBKEY_get0
first appeared in OpenSSL 1.1.0 and has been available since
.Ox 6.3 .