CODESIGN(1) General Commands Manual CODESIGN(1)
codesign – Create and manipulate code signatures
codesign -s identity [-i identifier] [-r requirements] [-fv] [path ...]
codesign -v [-R requirement] [-v] [path|pid ...]
codesign -d [-v] [path|pid ...]
codesign -h [-v] [pid ...]
The codesign command is used to create, check, and display code signatures,
as well as inquire into the dynamic status of signed code in the system.
codesign requires exactly one operation option to determine what action is
to be performed, as well as any number of other options to modify its
behavior. It can act on any number of objects per invocation, but performs
the same operation on all of them.
codesign accepts single-character (classic) options, as well as GNU-style
long options of the form --name and --name=value. Common options have both
forms; less frequent and specialized options have only long form. Note
that the form --name value (without equal sign) will not work as expected
on options with optional values.
The options are as follows:
When verifying a code signature on code that has a universal
("fat") Mach-O binary, separately verify each architecture
contained. This is the default unless overridden with the -a
-a, --architecture architecture
When verifying or displaying signatures, explicitly select the
Mach-O architecture given. The architecture can be specified either
by name (e.g. i386) or by number; if by number, a sub-architecture
may be appended separated by a comma. This option applies only to
Mach-O binary code and is ignored for other types. If the path
uses the Mach-O format and contains no code of the given
architecture, the command will fail. The default for verification
is --all-architectures, to verify all architectures present. The
default for display is to report on the native architecture of the
host system. When signing, codesign will always sign all
architectures contained in a universal Mach-O file.
When handling versioned bundles such as frameworks, explicitly
specify the version to operate on. This must be one of the names in
the "Versions" directory of the bundle. If not specified, codesign
uses the bundle's default version. Note that most frameworks
delivered with the system have only one version, and thus this
option is irrelevant for them. There is currently no facility for
operating on all versions of a bundle at once.
When verifying the code at the path(s) given, force an online
notarization check to see if a notarization ticket is available.
Display information about the code at the path(s) given. Increasing
levels of verbosity produce more output. The format is designed to
be moderately easy to parse by simple scripts while still making
sense to human eyes. In addition, the -r, --file-list, --extract-
certificates, and --entitlements options can be used to retrieve
-D, --detached filename
When signing, designates that a detached signature should be
written to the specified file. The code being signed is not
modified and need not be writable. When verifying, designates a
file containing a detached signature to be used for verification.
Any embedded signature in the code is ignored.
--deep When signing a bundle, specifies that nested code content such as
helpers, frameworks, and plug-ins, should be recursively signed in
turn. Beware that all signing options you specify will apply, in
turn, to such nested content.
When verifying a bundle, specifies that any nested code content
will be recursively verified as to its full content. By default,
verification of nested content is limited to a shallow
investigation that may not detect changes to the nested code.
When displaying a signature, specifies that a list of directly
nested code should be written to the display output. This lists
only code directly nested within the subject; anything nested
indirectly will require recursive application of the codesign
When signing, specifies that a detached signature should be
generated as with the --detached option, but that the resulting
signature should be written into a system database, from where it
is made automatically available whenever apparently unsigned code
is validated on the system.
Writing to this system database requires elevated process
privileges that are not available to ordinary users.
When signing, causes codesign to replace any existing signature on
the path(s) given. Without this option, existing signatures will
not be replaced, and the signing operation fails.
When signing, convert the supplied entitlements XML data to DER and
embed the entitlements as both XML and DER in the signature.
Embedding DER entitlements is default behavior as of macOS 12.0
when signing for all platforms. This argument was introduced in
macOS 10.14 (Mojave).
Constructs and prints the hosting chain of a running program. The
pid arguments must denote running code (pids etc.) With verbose
options, this also displays the individual dynamic validity status
of each element of the hosting chain.
-i, --identifier identifier
During signing, explicitly specify the unique identifier string
that is embedded in code signatures. If this option is omitted, the
identifier is derived from either the Info.plist (if present), or
the filename of the executable being signed, possibly modified by
the --prefix option. It is a very bad idea to sign different
programs with the same identifier.
-o, --options flag,...
During signing, specifies a set of option flags to be embedded in
the code signature. The value takes the form of a comma-separated
list of names (with no spaces). Alternatively, a numeric value can
be used to directly specify the option mask (CodeDirectory flag
word). See OPTION FLAGS below.
-P, --pagesize pagesize
Indicates the granularity of code signing. Pagesize must be a power
of two. Chunks of pagesize bytes are separately signed and can
thus be independently verified as needed. As a special case, a
pagesize of zero indicates that the entire code should be signed
and verified as a single, possibly gigantic page. This option only
applies to the main executable and has no effect on the sealing of
associated data, including resources.
Removes the current code signature from the path(s) given.
-r, --requirements requirements
During signing, indicates that internal requirements should be
embedded in the code path(s) as specified. See "specifying
requirements" below. Defaults will be applied to requirement types
that are not explicitly specified; if you want to defeat such a
default, specify "never" for that type.
During display, indicates where to write the code's internal
requirements. Use -r- to write them to standard output.
-R, --test-requirement requirement
During verification, indicates that the path(s) given should be
verified against the code requirement specified. If this option is
omitted, the code is verified only for internal integrity and
against its own designated requirement.
-s, --sign identity
Sign the code at the path(s) given using this identity. See SIGNING
Sets (with a numeric value) or increments the verbosity level of
output. Without the verbose option, no output is produced upon
success, in the classic UNIX style. If no other options request a
different action, the first -v encountered will be interpreted as
--verify instead (and does not increase verbosity).
Requests verification of code signatures. If other actions (sign,
display, etc.) are also requested, -v is interpreted to mean
Instructs codesign to continue processing path arguments even if
processing one fails. If this option is given, exit due to
operational errors is deferred until all path arguments have been
considered. The exit code will then indicate the most severe
failure (or, with equal severity, the first such failure
During signing, performs almost all signing operations, but does
not actually write the result anywhere. Cryptographic signatures
are still generated, actually using the given signing identity and
triggering any access control checks normally, though the resulting
signature is then discarded.
When signing, take the file at the given path and embed its
contents in the signature as entitlement data. If the data at path
does not already begin with a suitable binary ("blob") header, one
is attached automatically.
When displaying a signature, extract any entitlement data from the
signature and write it to the path given in an abstract
representation. If needed --xml or --der may be passed in to output
the entitlements in a desired format, if you pass in both then DER
will be printed. Use "-" as the path to write to standard output.
If the signature has no entitlement data, nothing is written (this
is not an error).
When displaying a signature, extract the certificates in the
embedded certificate chain and write them to individual files. The
prefix argument is appended with numbers 0, 1, ... to form the
filenames, which can be relative or absolute. Certificate 0 is the
leaf (signing) certificate, and as many files are written as there
are certificates in the signature. The files are in ASN.1 (DER)
form. If prefix is omitted, the default prefix is "codesign" in
the current directory.
When signing or displaying a signature, codesign writes to the
given path a list of files that may have been modified as part of
the signing process. This is useful for installer or patcher
programs that need to know what was changed or what files are
needed to make up the "signature" of a program. The file given is
appended-to, with one line per absolute path written. An argument
of "-" (single dash) denotes standard output. Note that the list
may be somewhat pessimistic - all files not listed are guaranteed
to be unchanged by the signing process, but some of the listed
files may not actually have changed. Also note that changes may
have been made to extended attributes of these files.
During static validation, do not validate the contents of the
code's resources. In effect, this will pass validation on code
whose resources have been corrupted (or inappropriately signed). On
large programs, it will also substantially speed up static
validation, since all the resources will not be read into memory.
Obviously, the outcome of such a validation should be considered on
During signing, only search for the signing identity in the
keychain file specified. This can be used to break any matching
ties if you have multiple similarly-named identities in several
keychains on the user's search list. Note that the standard
keychain search path is still consulted while constructing the
certificate chain being embedded in the signature.
Note that filename will not be searched to resolve the signing
identity's certificate chain unless it is also on the user's
keychain search list.
If no explicit unique identifier is specified (using the -i
option), and if the implicitly generated identifier does not
contain any dot (.) characters, then the given string is prefixed
to the identifier before use. If the implicit identifier contains a
dot, it is used as-is. Typically, this is used to deal with command
tools without Info.plists, whose default identifier is simply the
command's filename; the conventional prefix used is com.domain.
(note that the final dot needs to be explicit).
When re-signing code that is already signed, reuse some information
from the old signature. If new data is specified explicitly, it is
preferred. You still need to specify the -f (--force) option to
enable overwriting signatures at all. If this option is absent,
any old signature has no effect on the signing process.
Note: if the linker-signed flag is present on the previous binary,
then this option is ignored.
This option takes a comma-separated list of names, which you may
identifier Preserve the signing identifier (--identifier)
instead of generating a default identifier.
entitlements Preserve the entitlement data (--entitlements).
requirements Preserve the internal requirements (--requirements
option), including any explicit Designated
Requirement. Note that all internal requirements are
preserved or regenerated as a whole; you cannot pick
and choose individual elements with this option.
flags Preserve the option flags (-o), see the OPTION FLAGS
runtime Preserve the hardened runtime version (-o runtime
flag, --runtime-version option) instead of overriding
or deriving the version.
For historical reasons, this option can be given without a value,
which preserves all of these values as presently known. This use is
deprecated and will eventually be removed; always specify an
explicit list of preserved items.
When validating code, apply additional restrictions beyond the
symlinks Check that symbolic links inside the code bundle point to
sealed files inside its bundle. This means that broken
symbolic links are rejected, as are links to places
outside the bundle and to places that are not, for
whatever reason, sealed by the signature.
sideband Check that no resource forks, Finder attributes, or
similar sideband data is present in the signed code.
This is now automatically enforced by signing operations.
Options can be specified as a comma-separated list. Use plain
--strict or --strict=all to be as strict as possible. Note that
--strict=all may include more checking types over time.
Not all strictness check make sense in all circumstances, which is
why these behaviors are not the defualt.
During signing, requests that a timestamp authority server be
contacted to authenticate the time of signing. The server contacted
is given by the URL value. If this option is given without a
value, a default server provided by Apple is used. Note that this
server may not support signatures made with identities not
furnished by Apple. If the timestamp authority service cannot be
contacted over the Internet, or it malfunctions or refuses service,
the signing operation will fail.
If this option is not given at all, a system-specific default
behavior is invoked. This may result in some but not all code
signatures being timestamped.
The special value none explicitly disables the use of timestamp
During signing, when the runtime OPTION FLAG is set, explicitly
specify the hardened runtime version stored in the code signature.
If this option is omitted, but the runtime OPTION FLAG is set then
the hardened runtime version is omitted for non-Mach-O files and
derived from the SDK version of Mach-O files.
In the first synopsis form, codesign attempts to sign the code objects at
the path(s) given, using the identity provided. Internal requirements and
entitlements are embedded if requested. Internal requirements not specified
may be assigned suitable default values. Defaulting applies separately to
each type of internal requirement. If an identifier is explicitly given,
it is sealed into all path(s). Otherwise, each path derives its identifier
independently from its Info.plist or pathname. Code nested within bundle
directories must already be signed or the signing operation will fail,
unless the --deep option is given, in which case any unsigned nested code
will be recursively signed before proceeding, using the same signing
options and parameters. If the --force option is given, any existing top-
level signature is replaced, subject to any --preserve-metadata options
also present. Combining the --force and --deep options results in forcible
replacement of all signatures within the target bundle.
In the second synopsis form, codesign verifies the code signatures on all
the path(s) given. The verification confirms that the code at those path(s)
is signed, that the signature is valid, and that all sealed components are
unaltered. If a requirement is given, each path is also checked against
this requirement (but see DIAGNOSTICS below). If verbose verification is
requested, the program is also checked against its own designated
requirement, which should never fail for a properly signed program.
If a path begins with a decimal digit, it is interpreted as the process id
of a running process in the system, and dynamic validation is performed on
that process instead. This checks the code's dynamic status and just
enough static data to close the nominal security envelope. Add at least one
level of verbosity to also perform a full static check.
In the third synopsis form, codesign displays the contents of the
signatures on the path(s) given. More information is displayed as the
verbosity level increases. This form may not completely verify the
signatures on the path(s); though it may perform some verification steps in
the process of obtaining information about the path(s). If the -r path
option is given, internal requirements will be extracted from the path(s)
and written to path; specify a dash "-" to write to standard output. If the
code does not contain an explicit designated requirement, the implied one
will be retrieved and written out as a source comment. If the
--entitlements path option is given, embedded entitlement data will be
extracted likewise and written to the file specified.
In the fourth synopsis form, codesign constructs the hosting path for each
pid given and writes it, one host per line, to standard output. The hosting
path is the chain of code signing hosts starting with the most specific
code known to be running, and ending with the root of trust (the kernel).
If the --verbose option is given, the dynamic validity status of each host
is also displayed, separated from the path by a tab character. Note that
hosting chains can at times be constructed for invalid or even unsigned
code, and the output of this form of the codesign command should not be
taken as a statement of formal code validity. Only codesign --verify can do
that; and in fact, formal verification constructs the hosting chain as part
of its operation (but does not display it).
To be used for code signing, a digital identity must be stored in a
keychain that is on the calling user's keychain search list. All keychain
sources are supported if properly configured. In particular, it is possible
to sign code with an identity stored on a supported smart card. If your
signing identity is stored in a different form, you need to make it
available in keychain form to sign code with it.
If the --keychain argument is used, identity is only looked-for in the
specific keychain given. This is meant to help disambiguate references to
identities. Even in that case, the full keychain search list is still
consulted for additional certificates needed to complete the signature.
The identity is first considered as the full name of a keychain identity
preference. If such a preference exists, it directly names the identity
used. Otherwise, the identity is located by searching all keychains for a
certificate whose subject common name (only) contains the identity string
given. If there are multiple matches, the operation fails and no signing is
performed; however, an exact match is preferred over a partial match.
These comparisons are case sensitive. Multiple instances of the exactly
same certificate in multiple keychains are tolerated as harmless.
If identity consists of exactly forty hexadecimal digits, it is instead
interpreted as the SHA-1 hash of the certificate part of the desired
identity. In this case, the identity's subject name is not considered.
Both identity preferences and certificate hashes can be used to identify a
particular signing identity regardless of name. Identity preferences are
global settings for each user and provide a layer of indirection.
Certificate hashes are very explicit and local. These choices, combined
with what is placed into Xcode project and target build variables and/or
script settings, allows for very flexible designation of signing
If identity is the single letter "-" (dash), ad-hoc signing is performed.
Ad-hoc signing does not use an identity at all, and identifies exactly one
instance of code. Significant restrictions apply to the use of ad-hoc
signed code; consult documentation before using this.
codesign will attempt to embed the entire certificate chain documenting the
signing identity in the code signature it generates, including any
intermediate certificates and the anchor certificate. It looks for those in
the keychain search list of the user performing the signing operation. If
it cannot generate the entire certificate chain, signing may still succeed,
but verification may fail if the verifying code does not have an
independent source for the missing certificates (from its keychains).
The requirement(s) arguments (-r and -R) can be given in various forms. A
plain text argument is taken to be a path to a file containing the
requirement(s). codesign will accept both binary files containing properly
compiled requirements code, and source files that are automatically
compiled before use. An argument of "-" requests that the requirement(s)
are read from standard input. Finally, an argument that begins with an
equal sign "=" is taken as a literal requirements source text, and is
compiled accordingly for use.
When signing, a set of option flags can be specified to change the behavior
of the system when using the signed code. The following flags are
recognized by codesign; other flags may exist at the API level. Note that
you can specify any valid flags by giving a (single) numeric value instead
of a list of option names.
kill Forces the signed code's kill flag to be set when the code begins
execution. Code with the kill flag set will die when it becomes
dynamically invalid. It is therefore safe to assume that code
marked this way, once validated, will have continue to have a
valid identity while alive.
hard Forces the signed code's hard flag to be set when the code begins
execution. The hard flag is a hint to the system that the code
prefers to be denied access to resources if gaining such access
would invalidate its identity.
host Marks the code as capable of hosting guest code. You must set this
option if you want the code to act as a code signing host,
controlling subsidiary ("guest") code. This flag is set
automatically if you specify an internal guest requirement.
expires Forces any validation of the code to consider expiration of the
certificates involved. Code signatures generated with this flag
will fail to verify once any of the certificates in the chain has
expired, regardless of the intentions of the verifier. Note that
this flag does not affect any other checks that may cause
signature validation to fail, including checks for certificate
library Forces the signed code's library validation flag to be set when
the code begins execution. The code will only be able to link
against system libraries and frameworks, or libraries, frameworks,
and plug-in bundles with the same team identifier embedded in the
code directory. Team identifiers are automatically recorded in
signatures when signing with suitable Apple-issued signing
certificates. Note that the flag is not supported for i386
binaries, and only applies to the main executable. The flag has
no effect when set on frameworks and libraries.
runtime On macOS versions >= 10.14.0, opts signed processes into a
hardened runtime environment which includes runtime code signing
enforcement, library validation, hard, kill, and debugging
restrictions. These restrictions can be selectively relaxed via
entitlements. Note: macOS versions older than 10.14.0 ignore the
presence of this flag in the code signature.
Identifies a signature as signed by the linker. Linker signatures
are very similar to adhoc signatures, except:
• linker signatures can be replaced without using the --force
• linker signatures are never preserved regardless of the use of
the --preserve-metadata option.
• linker signatures will usually not contain any embedded code
requirements including a designated requirement.
Note that code can set the hard and kill flags on itself at any time. The
signing options only affect their initial state. Once set by any means,
these flags cannot be cleared for the lifetime of the code. Therefore,
specifying such flags as signing options guarantees that they will be set
whenever the signed code runs.
If the code being signed has an Info.plist that contains a key named
CSFlags, the value of that key is taken as the default value for the
options. The value of CSFlags can be a string in the same form as the
--options option, or an integer number specifying the absolute numeric
value. Note however that while you can abbreviate flag names on the command
lines, you must spell them out in the Info.plist.
To sign application Terminal.app with a signing identity named "authority":
codesign --sign authority Terminal.app
To sign the command-line tool "helper" with the same identity, overwriting
any existing signature, using the signing identifier "com.mycorp.helper",
and embedding a custom designated requirement
codesign -f --sign authority --prefix=com.mycorp. -r="designated =>
anchor /tmp/foo" helper
To enable the hardened runtime on Terminal.app and sign with the signing
identity named "authority":
codesign --sign authority --options runtime Terminal.app
To verify the signature on Terminal.app and produce some verbose output:
codesign --verify --verbose Terminal.app
To verify the dynamic validity of process 666:
codesign --verify +666
To display all information about Terminal.app's code signature:
codesign --display --verbose=4 Terminal.app
To extract the internal requirements from Terminal.app to standard output:
codesign --display -r- Terminal.app
To display the entitlements of a binary or bundle:
codesign --display --entitlements - /sbin/launchd
codesign --display --entitlements - --der Terminal.app
To display the entitlements of process 666:
codesign --display --entitlements - +666
To display the XML entitlements of process 1337:
codesign --display --entitlements - --xml +1337
A common source of confusion when using codesign arises from the ordering
of command line options. If codesign is not behaving as expected, consult
this manual and check the ordering of your arguments. As a general rule
codesign follows a verb noun rule. For example --sign should be placed
before --options in the invocation. This is because you are performing a
"sign" action with a given set of options.
If these are inverted and --options is provided before --sign in the
invocation, the value of --options is ignored silently.
codesign exits 0 if all operations succeed. This indicates that all codes
were signed, or all codes verified properly as requested. If a signing or
verification operation fails, the exit code is 1. Exit code 2 indicates
invalid arguments or parameters. Exit code 3 indicates that during
verification, all path(s) were properly signed but at least one of them
failed to satisfy the requirement specified with the -R option.
For verification, all path arguments are always investigated before the
program exits. For all other operations, the program exits upon the first
error encountered, and any further path arguments are ignored, unless the
--continue option was specified, in which case codesign will defer the
failure exit until after it has attempted to process all path arguments in
When a signing operation fails for a particular code, the code may already
have been modified in certain ways by adding requisite signature data. Such
information will not change the operation of the code, and the code will
not be considered signed even with these pieces in place. You may repeat
the signing operation without difficulty. Note however that a previous
valid signature may have been effectively destroyed if you specified the -f
If you require atomicity of signing stricter than provided by codesign, you
need to make an explicit copy of your code and sign that.
If the CODESIGN_ALLOCATE environment variable is set, it identifies a
substitute codesign_allocate tool used to allocate space for code
signatures in Mach-O binaries. This is used by Xcode SDK distributions to
provide architectural support for non-native platforms such as iPhones.
The system will not accept such substitutes unless they are specially
signed (by Apple).
/var/db/DetachedSignatures System-wide database of detached code
signatures for unsigned code.
csreq(1), xcodebuild(1), codesign_allocate(1)
The codesign command first appeared in Mac OS 10.5.0 (Leopard).
Some options only apply to particular operations, and codesign ignores them
(without complaining) if you specify them for an operation for which they
have no meaning.
The --preserve-metadata option used to take no value, and varied across
releases in what exactly it preserved. The ensuing confusion is still with
you if you need to make backward-compatible scripts.
The dual meaning of the -v option, indicating either verbosity or
verification, confuses some people. If you find it confusing, use the
unambiguous long forms --verbose and --verify instead.
The --verify option can take either a file or a pid. If your file path
starts with a number you should prefix it with "./" to force codesign to
interpret the argument as a path. For example:
codesign --verify 666
codesign --verify ./666
The Xcode build system invokes codesign automatically if the
CODE_SIGN_IDENTITY build variable is set. You can express any combination
of codesign options with additional build variables there.
codesign is fundamentally a shell around the code signing APIs, and
performs nothing of the underlying work. Replacing it with older or newer
versions is unlikely to have a useful effect.
codesign has several operations and options that are purposely left
undocumented in this manual page because they are either experimental (and
subject to change at any time), or unadvised to the unwary. The
interminably curious are referred to the published source code.
macOS 12.1 May 7, 2011 macOS 12.1