path: root/lib/libcrypto/man/ASN1_INTEGER_get.3

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.Dd $Mdocdate: November 23 2021 $
.Dt ASN1_INTEGER_GET 3
.Os
.Sh NAME
.Nm ASN1_INTEGER_get ,
.Nm ASN1_INTEGER_set ,
.Nm ASN1_INTEGER_cmp ,
.Nm ASN1_INTEGER_dup ,
.Nm BN_to_ASN1_INTEGER ,
.Nm ASN1_INTEGER_to_BN ,
.Nm ASN1_ENUMERATED_get ,
.Nm ASN1_ENUMERATED_set ,
.Nm BN_to_ASN1_ENUMERATED ,
.Nm ASN1_ENUMERATED_to_BN
.Nd ASN.1 INTEGER and ENUMERATED utilities
.Sh SYNOPSIS
.In openssl/asn1.h
.Ft long
.Fo ASN1_INTEGER_get
.Fa "const ASN1_INTEGER *a"
.Fc
.Ft int
.Fo ASN1_INTEGER_set
.Fa "ASN1_INTEGER *a"
.Fa "long v"
.Fc
.Ft int
.Fo ASN1_INTEGER_cmp
.Fa "const ASN1_INTEGER *a1"
.Fa "const ASN1_INTEGER *a2"
.Fc
.Ft ASN1_INTEGER *
.Fo ASN1_INTEGER_dup
.Fa "const ASN1_INTEGER *a"
.Fc
.Ft ASN1_INTEGER *
.Fo BN_to_ASN1_INTEGER
.Fa "const BIGNUM *bn"
.Fa "ASN1_INTEGER *ai"
.Fc
.Ft BIGNUM *
.Fo ASN1_INTEGER_to_BN
.Fa "const ASN1_INTEGER *ai"
.Fa "BIGNUM *bn"
.Fc
.Ft long
.Fo ASN1_ENUMERATED_get
.Fa "const ASN1_ENUMERATED *a"
.Fc
.Ft int
.Fo ASN1_ENUMERATED_set
.Fa "ASN1_ENUMERATED *a"
.Fa "long v"
.Fc
.Ft ASN1_ENUMERATED *
.Fo BN_to_ASN1_ENUMERATED
.Fa "const BIGNUM *bn"
.Fa "ASN1_ENUMERATED *ai"
.Fc
.Ft BIGNUM *
.Fo ASN1_ENUMERATED_to_BN
.Fa "const ASN1_ENUMERATED *ai"
.Fa "BIGNUM *bn"
.Fc
.Sh DESCRIPTION
These functions convert to and from
.Vt ASN1_INTEGER
and
.Vt ASN1_ENUMERATED
objects.
.Pp
.Fn ASN1_INTEGER_get
converts
.Fa a
to the
.Vt long
type.
.Pp
.Fn ASN1_INTEGER_set
sets the type of
.Fa a
to
.Dv V_ASN1_INTEGER
or
.Dv V_ASN1_NEG_INTEGER
depending on the sign of
.Fa v
and sets the value of
.Fa a
to
.Fa v .
.Pp
.Fn ASN1_INTEGER_cmp
compares the signed integer numbers represented by
.Fa a1
and
.Fa a2 .
.Pp
.Fn ASN1_INTEGER_dup
does exactly the same as
.Xr ASN1_STRING_dup 3
without providing any type safety,
except that it fails if the
.Xr ASN1_STRING_length 3
of
.Fa a
is 0.
.Pp
.Fn BN_to_ASN1_INTEGER
converts
.Fa bn
to an
.Vt ASN1_INTEGER .
If
.Fa ai
is
.Dv NULL ,
a new
.Vt ASN1_INTEGER
object is returned.
Otherwise, the existing object
.Fa ai
is used instead.
.Pp
.Fn ASN1_INTEGER_to_BN
converts
.Fa ai
into a
.Vt BIGNUM .
If
.Fa bn
is
.Dv NULL ,
a new
.Vt BIGNUM
object is returned.
Otherwise, the existing object
.Fa bn
is used instead.
.Pp
.Fn ASN1_ENUMERATED_get ,
.Fn ASN1_ENUMERATED_set ,
.Fn BN_to_ASN1_ENUMERATED ,
and
.Fn ASN1_ENUMERATED_to_BN
behave like their
.Vt ASN1_INTEGER
counterparts except that they operate on an
.Vt ASN1_ENUMERATED
object.
.Sh RETURN VALUES
.Fn ASN1_INTEGER_get
and
.Fn ASN1_ENUMERATED_get
return the converted value, 0 if
.Fa a
is
.Dv NULL ,
or \-1 on error, which is ambiguous because \-1 is a legitimate
value for an
.Vt ASN1_INTEGER .
.Pp
.Fn ASN1_INTEGER_set
and
.Fn ASN1_ENUMERATED_set
return 1 for success or 0 for failure.
They only fail if a memory allocation error occurs.
.Pp
.Fn ASN1_INTEGER_cmp
returns a value greater than, equal to, or less than 0
if the signed integer number represented by
.Fa a1
is greater than, equal to, or less than
the signed integer number represented by
.Fa a2 ,
respectively.
.Pp
.Fn ASN1_INTEGER_dup
returns a pointer to a newly allocated
.Vt ASN1_STRING
structure or
.Dv NULL
if
.Fa a
is a
.Dv NULL
pointer, if the length of
.Fa a
is 0, or if memory allocation fails.
.Pp
.Fn BN_to_ASN1_INTEGER
and
.Fn BN_to_ASN1_ENUMERATED
return an
.Vt ASN1_INTEGER
or
.Vt ASN1_ENUMERATED
object, respectively, or
.Dv NULL
if an error occurs.
They only fail due to memory allocation errors.
.Pp
.Fn ASN1_INTEGER_to_BN
and
.Fn ASN1_ENUMERATED_to_BN
return a
.Vt BIGNUM
object of
.Dv NULL
if an error occurs.
They can fail if the passed type is incorrect (due to a programming error)
or due to memory allocation failures.
.Sh SEE ALSO
.Xr ASN1_INTEGER_new 3 ,
.Xr ASN1_STRING_length 3
.Sh HISTORY
.Fn ASN1_INTEGER_set
first appeared in SSLeay 0.5.1.
.Fn ASN1_INTEGER_get ,
.Fn BN_to_ASN1_INTEGER ,
and
.Fn ASN1_INTEGER_to_BN
first appeared in SSLeay 0.6.0.
.Fn ASN1_INTEGER_cmp
and
.Fn ASN1_INTEGER_dup
first appeared in SSLeay 0.6.5.
These functions have been available since
.Ox 2.3 .
.Pp
.Fn ASN1_ENUMERATED_get ,
.Fn ASN1_ENUMERATED_set ,
.Fn BN_to_ASN1_ENUMERATED ,
and
.Fn ASN1_ENUMERATED_to_BN
first appeared in OpenSSL 0.9.2b and have been available since
.Ox 2.6 .
.Sh CAVEATS
In general an
.Vt ASN1_INTEGER
or
.Vt ASN1_ENUMERATED
type can contain an integer of almost arbitrary size
and so cannot always be represented by a C
.Vt long
type.
The ambiguous return values of
.Fn ASN1_INTEGER_get
and
.Fn ASN1_ENUMERATED_get
imply that these functions should be avoided if possible.
.Sh BUGS
.Fn ASN1_INTEGER_cmp ,
.Fn ASN1_INTEGER_dup ,
and
.Fn ASN1_INTEGER_to_BN
do not check whether their arguments are really of the type
.Dv V_ASN1_INTEGER
or
.Dv V_ASN1_NEG_INTEGER .
They may report success even if their arguments are of a wrong type.
Consequently, even in case of success, the return value of
.Fn ASN1_INTEGER_dup
is not guaranteed to be of the type
.Dv V_ASN1_INTEGER
or
.Dv V_ASN1_NEG_INTEGER
either.
.Pp
Similarly,
.Fn ASN1_ENUMERATED_to_BN
does not check whether its argument is really of the type
.Dv V_ASN1_ENUMERATED
or
.Dv V_ASN1_NEG_ENUMERATED
and may report success even if the argument is of a wrong type.