path: root/lib/libcrypto/man/X509_LOOKUP_new.3

.\" $OpenBSD: X509_LOOKUP_new.3,v 1.9 2021/11/12 14:05:28 schwarze Exp $
.\"
.\" Copyright (c) 2021 Ingo Schwarze <schwarze@openbsd.org>
.\"
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.Dd $Mdocdate: November 12 2021 $
.Dt X509_LOOKUP_NEW 3
.Os
.Sh NAME
.Nm X509_LOOKUP_new ,
.Nm X509_LOOKUP_free ,
.Nm X509_LOOKUP_ctrl ,
.Nm X509_LOOKUP_add_dir ,
.Nm X509_LOOKUP_load_file ,
.Nm X509_LOOKUP_add_mem ,
.Nm X509_LOOKUP_by_subject ,
.Nm X509_LOOKUP_init ,
.Nm X509_LOOKUP_shutdown ,
.Nm X509_LOOKUP_by_issuer_serial ,
.Nm X509_LOOKUP_by_fingerprint ,
.Nm X509_LOOKUP_by_alias ,
.Nm X509_get_default_cert_dir ,
.Nm X509_get_default_cert_file ,
.Nm X509_get_default_cert_dir_env ,
.Nm X509_get_default_cert_file_env
.\" X509_get_default_private_dir is intentionally undocumented
.\" because it appears to be unused by any real-world software
.\" and because it doesn't do much in the first place.
.Nd certificate lookup object
.Sh SYNOPSIS
.In openssl/x509_vfy.h
.Ft X509_LOOKUP *
.Fn X509_LOOKUP_new "X509_LOOKUP_METHOD *method"
.Ft void
.Fn X509_LOOKUP_free "X509_LOOKUP *lookup"
.Ft int
.Fo X509_LOOKUP_ctrl
.Fa "X509_LOOKUP *lookup"
.Fa "int command"
.Fa "const char *source"
.Fa "long type"
.Fa "char **ret"
.Fc
.Ft int
.Fo X509_LOOKUP_add_dir
.Fa "X509_LOOKUP *lookup"
.Fa "const char *source"
.Fa "long type"
.Fc
.Ft int
.Fo X509_LOOKUP_load_file
.Fa "X509_LOOKUP *lookup"
.Fa "const char *source"
.Fa "long type"
.Fc
.Ft int
.Fo X509_LOOKUP_add_mem
.Fa "X509_LOOKUP *lookup"
.Fa "const struct iovec *source"
.Fa "long type"
.Fc
.Ft int
.Fo X509_LOOKUP_by_subject
.Fa "X509_LOOKUP *lookup"
.Fa "X509_LOOKUP_TYPE type"
.Fa "X509_NAME *name"
.Fa "X509_OBJECT *object"
.Fc
.Ft int
.Fn X509_LOOKUP_init "X509_LOOKUP *lookup"
.Ft int
.Fn X509_LOOKUP_shutdown "X509_LOOKUP *lookup"
.Ft int
.Fo X509_LOOKUP_by_issuer_serial
.Fa "X509_LOOKUP *lookup"
.Fa "X509_LOOKUP_TYPE type"
.Fa "X509_NAME *name"
.Fa "ASN1_INTEGER *serial"
.Fa "X509_OBJECT *object"
.Fc
.Ft int
.Fo X509_LOOKUP_by_fingerprint
.Fa "X509_LOOKUP *lookup"
.Fa "X509_LOOKUP_TYPE type"
.Fa "const unsigned char *bytes"
.Fa "int length"
.Fa "X509_OBJECT *object"
.Fc
.Ft int
.Fo X509_LOOKUP_by_alias
.Fa "X509_LOOKUP *lookup"
.Fa "X509_LOOKUP_TYPE type"
.Fa "const char *string"
.Fa "int length"
.Fa "X509_OBJECT *object"
.Fc
.In openssl/x509.h
.Ft const char *
.Fn X509_get_default_cert_dir void
.Ft const char *
.Fn X509_get_default_cert_file void
.Ft const char *
.Fn X509_get_default_cert_dir_env void
.Ft const char *
.Fn X509_get_default_cert_file_env void
.Sh DESCRIPTION
.Fn X509_LOOKUP_new
allocates a new, empty
.Vt X509_LOOKUP
object and associates it with the
.Fa method
which is a static object returned from either
.Xr X509_LOOKUP_hash_dir 3
or
.Xr X509_LOOKUP_file 3
or
.Xr X509_LOOKUP_mem 3 .
.Pp
.Fn X509_LOOKUP_free
releases the memory used by
.Fa lookup .
If
.Fa lookup
is a
.Dv NULL
pointer, no action occurs.
.Pp
The operation of
.Fn X509_LOOKUP_ctrl
depends on the
.Vt X509_LOOKUP_METHOD
used by
.Fa lookup :
.Bl -tag -width 4n
.It Xr X509_LOOKUP_hash_dir 3
The
.Fa command
is required to be
.Dv X509_L_ADD_DIR
and the
.Fa source
argument is interpreted
as a colon-separated, NUL-terminated list of directory names.
These directories are added to an internal list of directories to search
for certificate files of the given
.Fa type .
.Pp
If
.Fa type
is
.Dv X509_FILETYPE_DEFAULT ,
the
.Fa source
argument is ignored and
.Pa /etc/ssl/certs
and a type of
.Dv X509_FILETYPE_PEM
are used instead.
.Pp
.Fn X509_LOOKUP_add_dir
is a macro that calls
.Fn X509_LOOKUP_ctrl
with a
.Fa command
of
.Dv X509_L_ADD_DIR
and
.Fa ret
set to
.Dv NULL .
.Pp
This lookup method is peculiar in so far as calling
.Fn X509_LOOKUP_ctrl
on a lookup object using it does not yet add any certificates to the associated
.Vt X509_STORE
object.
They need to be added selectively using
.Fn X509_LOOKUP_by_subject .
.It Xr X509_LOOKUP_file 3
The
.Fa command
is required to be
.Dv X509_L_FILE_LOAD
and the
.Fa source
argument is interpreted as a NUL-terminated file name.
If the
.Fa type
is
.Dv X509_FILETYPE_PEM ,
the file is read with
.Xr BIO_new_file 3
and
.Xr PEM_X509_INFO_read_bio 3
and the certificates and revocation lists found are added to the
.Vt X509_STORE
object associated with
.Fa lookup
using
.Xr X509_STORE_add_cert 3
and
.Xr X509_STORE_add_crl 3 .
If
.Fa type
is
.Dv X509_FILETYPE_DEFAULT ,
the
.Fa source
argument is ignored and
.Pa /etc/ssl/certs.pem
and a type of
.Dv X509_FILETYPE_PEM
are used instead.
If
.Fa type
is
.Dv X509_FILETYPE_ASN1 ,
the file is read with
.Xr d2i_X509_bio 3
and the single certificate is added to the
.Vt X509_STORE
object associated with
.Fa lookup
using
.Xr X509_STORE_add_cert 3 .
.Pp
.Fn X509_LOOKUP_load_file
is a macro calling
.Fn X509_LOOKUP_ctrl
with a
.Fa command
of
.Dv X509_L_FILE_LOAD
and
.Fa ret
set to
.Dv NULL .
.It Xr X509_LOOKUP_mem 3
The
.Fa command
and
.Fa type
are required to be
.Dv X509_L_MEM
and
.Dv X509_FILETYPE_PEM ,
respectively.
The
.Fa source
argument is interpreted as a pointer to an
.Vt iovec
structure defined in
.In sys/uio.h .
The memory area described by that structure is read with
.Xr BIO_new_mem_buf 3
and
.Xr PEM_X509_INFO_read_bio 3
and the certificates and revocation lists found are added to the
.Vt X509_STORE
object associated with
.Fa lookup
using
.Xr X509_STORE_add_cert 3
and
.Xr X509_STORE_add_crl 3 .
.Pp
.Fn X509_LOOKUP_add_mem
is a macro calling
.Fn X509_LOOKUP_ctrl
with a command of
.Dv X509_L_MEM
and
.Fa ret
set to
.Dv NULL .
.El
.Pp
With LibreSSL,
.Fn X509_LOOKUP_ctrl
always ignores the
.Fa ret
argument.
.Pp
With LibreSSL,
.Fn X509_LOOKUP_by_subject
is only useful if
.Fa lookup
uses
.Xr X509_LOOKUP_hash_dir 3 .
It passes the
.Fa name
to
.Xr X509_NAME_hash 3
and converts the resulting hash to an eight-digit lower-case
hexadecimal number.
.Pp
If the
.Fa type
is
.Dv X509_LU_X509 ,
it searches the configured directories for files having that name,
with a file name extension that is a small, non-negative decimal integer
starting at
.Qq ".0" .
These files are read with
.Xr X509_load_cert_file 3 .
In each directory, the search is ended once a file with the expected name
and extension does not exists.
.Pp
If the
.Fa type
is
.Dv X509_LU_CRL ,
the file name extensions are expected to have a prefix of
.Qq "r" ,
i.e. they start with
.Qq ".r0" ,
and the files are read with
.Xr X509_load_crl_file 3 .
.Pp
In case of success, the first match is returned in the
.Pf * Fa object
provided by the caller, overwriting any previous content.
.Pp
With LibreSSL,
.Fn X509_LOOKUP_init ,
.Fn X509_LOOKUP_shutdown ,
.Fn X509_LOOKUP_by_issuer_serial ,
.Fn X509_LOOKUP_by_fingerprint ,
and
.Fn X509_LOOKUP_by_alias
have no effect.
.Sh RETURN VALUES
.Fn X509_LOOKUP_new
returns the new object or
.Dv NULL
if memory allocation fails.
.Pp
.Fn X509_LOOKUP_ctrl
returns 1 for success or 0 for failure.
With library implementations other than LibreSSL,
it might also return \-1 for internal errors.
.Pp
.Fn X509_LOOKUP_by_subject
returns 1 for success or 0 for failure.
In particular, it fails if
.Fa lookup
uses
.Xr X509_LOOKUP_file 3
or
.Xr X509_LOOKUP_mem 3 ,
if
.Fa name
is
.Dv NULL ,
if
.Fa type
is neither
.Dv X509_LU_X509
nor
.Dv X509_LU_CRL ,
if no match is found, or if memory allocation fails.
With library implementations other than LibreSSL,
it might also return negative values for internal errors.
.Pp
.Fn X509_LOOKUP_init
and
.Fn X509_LOOKUP_shutdown
are supposed to return 1 for success and 0 for failure.
With LibreSSL, they always return 1.
.Pp
With LibreSSL,
.Fn X509_LOOKUP_by_issuer_serial ,
.Fn X509_LOOKUP_by_fingerprint ,
and
.Fn X509_LOOKUP_by_alias
always return 0.
.Pp
.Fn X509_get_default_cert_dir
returns a pointer to the constant string
.Qq /etc/ssl/certs ,
.Fn X509_get_default_cert_file
to
.Qq /etc/ssl/certs.pem ,
.Fn X509_get_default_cert_dir_env
to
.Qq SSL_CERT_DIR ,
and
.Fn X509_get_default_cert_file_env
to
.Qq SSL_CERT_FILE .
.Sh ENVIRONMENT
For reasons of security and simplicity,
LibreSSL ignores the environment variables
.Ev SSL_CERT_DIR
and
.Ev SSL_CERT_FILE ,
but other library implementations may use their contents instead
of the standard locations for trusted certificates, and a few
third-party application programs also inspect these variables
directly and may pass their values to
.Fn X509_LOOKUP_add_dir
and
.Fn X509_LOOKUP_load_file .
.Sh FILES
.Bl -tag -width /etc/ssl/certs.pem -compact
.It Pa /etc/ssl/certs/
default directory for storing trusted certificates
.It Pa /etc/ssl/certs.pem
default file for storing trusted certificates
.El
.Sh ERRORS
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 ERR_R_ASN1_LIB Qq "ASN1 lib"
.Xr d2i_X509_bio 3
failed in
.Fn X509_LOOKUP_ctrl .
.It Dv X509_R_BAD_X509_FILETYPE Qq "bad x509 filetype"
.Fn X509_LOOKUP_ctrl
was called with an invalid
.Fa type .
.It Dv ERR_R_BUF_LIB Qq "BUF lib"
Memory allocation failed in
.Fn X509_LOOKUP_by_subject .
.It Dv X509_R_INVALID_DIRECTORY Qq "invalid directory"
The
.Fa source
argument of
.Fn X509_LOOKUP_ctrl
with
.Dv X509_L_ADD_DIR
or
.Fn X509_LOOKUP_add_dir
was
.Dv NULL
or an empty string.
.It Dv X509_R_LOADING_CERT_DIR Qq "loading cert dir"
.Fn X509_LOOKUP_ctrl
with
.Dv X509_L_ADD_DIR
or
.Fn X509_LOOKUP_add_dir
was called with
.Dv X509_FILETYPE_DEFAULT
and adding the default directories failed.
This error is added after and in addition to a more specific diagnostic.
.It Dv X509_R_LOADING_DEFAULTS Qq "loading defaults"
.Fn X509_LOOKUP_ctrl
with
.Dv X509_L_FILE_LOAD
or
.Fn X509_LOOKUP_load_file
was called with
.Dv X509_FILETYPE_DEFAULT
and adding the certificates and revocation lists failed.
This error is added after and in addition to a more specific diagnostic.
.It Dv ERR_R_MALLOC_FAILURE Qq "malloc failure"
Memory allocation failed in
.Fn X509_LOOKUP_ctrl
or
.Fn X509_LOOKUP_by_subject .
.It Dv ERR_R_PEM_LIB Qq "PEM lib"
.Xr PEM_X509_INFO_read_bio 3 ,
.Xr PEM_read_bio_X509_AUX 3 ,
or
.Xr PEM_read_bio_X509_CRL 3
failed in
.Fn X509_LOOKUP_ctrl .
.It Dv ERR_R_SYS_LIB Qq "system lib"
.Xr BIO_new 3 ,
.Xr BIO_new_file 3 ,
or
.Xr BIO_read_filename 3
failed in
.Fn X509_LOOKUP_ctrl .
.It Dv X509_R_WRONG_LOOKUP_TYPE Qq "wrong lookup type"
.Fn X509_LOOKUP_by_subject
was called with an invalid
.Fa type .
.El
.Pp
Passing an invalid
.Fa command
to
.Fn X509_LOOKUP_ctrl
or calling
.Fn X509_LOOKUP_by_subject
with a
.Dv NULL
.Fa name
or with arguments that yield no match
causes failure but provides no diagnostics.
.Sh SEE ALSO
.Xr d2i_X509_bio 3 ,
.Xr PEM_read_bio_X509_AUX 3 ,
.Xr PEM_X509_INFO_read_bio 3 ,
.Xr X509_load_cert_file 3 ,
.Xr X509_LOOKUP_hash_dir 3 ,
.Xr X509_NAME_hash 3 ,
.Xr X509_NAME_new 3 ,
.Xr X509_new 3 ,
.Xr X509_OBJECT_get_type 3 ,
.Xr X509_STORE_add_cert 3 ,
.Xr X509_STORE_get_by_subject 3
.Sh HISTORY
.Fn X509_get_default_cert_dir ,
.Fn X509_get_default_cert_file ,
.Fn X509_get_default_cert_dir_env ,
and
.Fn X509_get_default_cert_file_env
first appeared in SSLeay 0.4.1 and have been available since
.Ox 2.4 .
.Pp
.Fn X509_LOOKUP_add_mem
first appeared in
.Ox 5.7 .
.Pp
The other functions first appeared in SSLeay 0.8.0
and have been available since
.Ox 2.4 .
.Sh BUGS
If the
.Fa type
is
.Dv X509_FILETYPE_DEFAULT
or
.Dv X509_FILETYPE_PEM ,
.Fn X509_LOOKUP_ctrl
with
.Dv X509_L_FILE_LOAD
and
.Fn X509_LOOKUP_load_file
silently ignore failure of
.Xr X509_STORE_add_cert 3
and
.Xr X509_STORE_add_crl 3
and indicate success anyway.
.Pp
Handling of a
.Dv NULL
.Fa source
is inconsistent for
.Fn X509_LOOKUP_ctrl
with
.Dv X509_L_FILE_LOAD
and for
.Fn X509_LOOKUP_load_file .
With
.Dv X509_FILETYPE_PEM ,
it causes failure, but with
.Dv X509_FILETYPE_ASN1 ,
no action occurs and success is indicated.
.Pp
When called on a
.Fa lookup
object using
.Xr X509_LOOKUP_mem 3 ,
.Fn X509_LOOKUP_ctrl
raises
.Dv ERR_R_PEM_LIB
when called with an invalid
.Fa command
or
.Fa type ,
when
.Xr BIO_new_mem_buf 3
fails, when
.Fa source
contains zero objects, or when
.Xr X509_STORE_add_cert 3
fails on the first object encountered, which is all inconsistent
with the behaviour of the other lookup methods.