gnupg/doc/DETAILS

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# doc/DETAILS -*- org -*-
#+TITLE: GnuPG Details
# Globally disable superscripts and subscripts:
#+OPTIONS: ^:{}
#+STARTUP: showall
# Note: This file uses org-mode; it should be easy to read as plain
# text but be aware of some markup peculiarities: Verbatim code is
# enclosed in #+begin-example, #+end-example blocks or marked by a
# colon as the first non-white-space character, words bracketed with
# equal signs indicate a monospace font, and the usual /italics/,
# *bold*, and _underline_ conventions are recognized.
This is the DETAILS file for GnuPG which specifies some internals and
parts of the external API for GPG and GPGSM.
* Format of the colon listings
The format is a based on colon separated record, each recods starts
with a tag string and extends to the end of the line. Here is an
example:
#+begin_example
$ gpg --with-colons --list-keys \
--with-fingerprint --with-fingerprint wk@gnupg.org
pub:f:1024:17:6C7EE1B8621CC013:899817715:1055898235::m:::scESC:
fpr:::::::::ECAF7590EB3443B5C7CF3ACB6C7EE1B8621CC013:
uid:f::::::::Werner Koch <wk@g10code.com>:
uid:f::::::::Werner Koch <wk@gnupg.org>:
sub:f:1536:16:06AD222CADF6A6E1:919537416:1036177416:::::e:
fpr:::::::::CF8BCC4B18DE08FCD8A1615906AD222CADF6A6E1:
sub:r:1536:20:5CE086B5B5A18FF4:899817788:1025961788:::::esc:
fpr:::::::::AB059359A3B81F410FCFF97F5CE086B5B5A18FF4:
#+end_example
Note that new version of GnuPG or the use of certain options may add
new fields to the output. Parsers should not assume a limit on the
number of fields per line. Some fields are not yet used or only used
with certain record types; parsers should ignore fields they are not
aware of. New versions of GnuPG or the use of certain options may add
new types of records as well. Parsers should ignore any record whose
type they do not recognize for forward-compatibility.
The double =--with-fingerprint= prints the fingerprint for the subkeys
too. Old versions of gpg used a slightly different format and required
the use of the option =--fixed-list-mode= to conform to the format
described here.
** Description of the fields
*** Field 1 - Type of record
- pub :: Public key
- crt :: X.509 certificate
- crs :: X.509 certificate and private key available
- sub :: Subkey (secondary key)
- sec :: Secret key
- ssb :: Secret subkey (secondary key)
- uid :: User id
- uat :: User attribute (same as user id except for field 10).
- sig :: Signature
- rev :: Revocation signature
- rvs :: Revocation signature (standalone) [since 2.2.9]
- fpr :: Fingerprint (fingerprint is in field 10)
- fp2 :: SHA-256 fingerprint (fingerprint is in field 10)
- pkd :: Public key data [*]
- grp :: Keygrip
- rvk :: Revocation key
- tfs :: TOFU statistics [*]
- tru :: Trust database information [*]
- spk :: Signature subpacket [*]
- cfg :: Configuration data [*]
Records marked with an asterisk are described at [[*Special%20field%20formats][*Special fields]].
*** Field 2 - Validity
This is a letter describing the computed validity of a key.
Currently this is a single letter, but be prepared that additional
information may follow in some future versions. Note that GnuPG <
2.1 does not set this field for secret key listings.
- o :: Unknown (this key is new to the system)
- i :: The key is invalid (e.g. due to a missing self-signature)
- d :: The key has been disabled
(deprecated - use the 'D' in field 12 instead)
- r :: The key has been revoked
- e :: The key has expired
- - :: Unknown validity (i.e. no value assigned)
- q :: Undefined validity. '-' and 'q' may safely be treated as
the same value for most purposes
- n :: The key is not valid
- m :: The key is marginal valid.
- f :: The key is fully valid
- u :: The key is ultimately valid. This often means that the
secret key is available, but any key may be marked as
ultimately valid.
- w :: The key has a well known private part.
- s :: The key has special validity. This means that it might be
self-signed and expected to be used in the STEED system.
If the validity information is given for a UID or UAT record, it
describes the validity calculated based on this user ID. If given
for a key record it describes the validity taken from the best
rated user ID.
For X.509 certificates a 'u' is used for a trusted root
certificate (i.e. for the trust anchor) and an 'f' for all other
valid certificates.
In "sig" records, this field may have one of these values as first
character:
- ! :: Signature is good.
- - :: Signature is bad.
- ? :: No public key to verify signature or public key is not usable.
- % :: Other error verifying a signature
More values may be added later. The field may also be empty if
gpg has been invoked in a non-checking mode (--list-sigs) or in a
fast checking mode. Since 2.2.7 '?' will also be printed by the
command --list-sigs if the key is not in the local keyring.
*** Field 3 - Key length
The length of key in bits.
*** Field 4 - Public key algorithm
The values here are those from the OpenPGP specs or if they are
greater than 255 the algorithm ids as used by Libgcrypt.
*** Field 5 - KeyID
This is the 64 bit keyid as specified by OpenPGP and the last 64
bit of the SHA-1 fingerprint of an X.509 certifciate.
*** Field 6 - Creation date
The creation date of the key is given in UTC. For UID and UAT
records, this is used for the self-signature date. Note that the
date is usually printed in seconds since epoch, however, we are
migrating to an ISO 8601 format (e.g. "19660205T091500"). This is
currently only relevant for X.509. A simple way to detect the new
format is to scan for the 'T'. Note that old versions of gpg
without using the =--fixed-list-mode= option used a "yyyy-mm-tt"
format.
*** Field 7 - Expiration date
Key or UID/UAT expiration date or empty if it does not expire.
*** Field 8 - Certificate S/N, UID hash, trust signature info
Used for serial number in crt records. For UID and UAT records,
this is a hash of the user ID contents used to represent that
exact user ID. For trust signatures, this is the trust depth
separated by the trust value by a space.
*** Field 9 - Ownertrust
This is only used on primary keys. This is a single letter, but
be prepared that additional information may follow in future
versions. For trust signatures with a regular expression, this is
the regular expression value, quoted as in field 10.
*** Field 10 - User-ID
The value is quoted like a C string to avoid control characters
(the colon is quoted =\x3a=). For a "pub" record this field is
not used on --fixed-list-mode. A UAT record puts the attribute
subpacket count here, a space, and then the total attribute
subpacket size. In gpgsm the issuer name comes here. The FPR and FP2
records store the fingerprints here. The fingerprint of a
revocation key is stored here.
*** Field 11 - Signature class
Signature class as per RFC-4880. This is a 2 digit hexnumber
followed by either the letter 'x' for an exportable signature or
the letter 'l' for a local-only signature. The class byte of an
revocation key is also given here, by a 2 digit hexnumber and
optionally followed by the letter 's' for the "sensitive"
flag. This field is not used for X.509.
"rev" and "rvs" may be followed by a comma and a 2 digit hexnumber
with the revocation reason.
*** Field 12 - Key capabilities
The defined capabilities are:
- e :: Encrypt
- s :: Sign
- c :: Certify
- a :: Authentication
- ? :: Unknown capability
A key may have any combination of them in any order. In addition
to these letters, the primary key has uppercase versions of the
letters to denote the _usable_ capabilities of the entire key, and
a potential letter 'D' to indicate a disabled key.
*** Field 13 - Issuer certificate fingerprint or other info
Used in FPR records for S/MIME keys to store the fingerprint of
the issuer certificate. This is useful to build the certificate
path based on certificates stored in the local key database it is
only filled if the issuer certificate is available. The root has
been reached if this is the same string as the fingerprint. The
advantage of using this value is that it is guaranteed to have
been built by the same lookup algorithm as gpgsm uses.
For "uid" records this field lists the preferences in the same way
gpg's --edit-key menu does.
For "sig", "rev" and "rvs" records, this is the fingerprint of the
key that issued the signature. Note that this may only be filled
if the signature verified correctly. Note also that for various
technical reasons, this fingerprint is only available if
--no-sig-cache is used. Since 2.2.7 this field will also be set
if the key is missing but the signature carries an issuer
fingerprint as meta data.
*** Field 14 - Flag field
Flag field used in the --edit-key menu output
*** Field 15 - S/N of a token
Used in sec/ssb to print the serial number of a token (internal
protect mode 1002) or a '#' if that key is a simple stub (internal
protect mode 1001). If the option --with-secret is used and a
secret key is available for the public key, a '+' indicates this.
*** Field 16 - Hash algorithm
For sig records, this is the used hash algorithm. For example:
2 = SHA-1, 8 = SHA-256.
*** Field 17 - Curve name
For pub, sub, sec, ssb, crt, and crs records this field is used
for the ECC curve name.
*** Field 18 - Compliance flags
Space separated list of asserted compliance modes and
screening result for this key.
Valid values are:
- 8 :: The key is compliant with RFC4880bis
- 23 :: The key is compliant with compliance mode "de-vs".
- 6001 :: Screening hit on the ROCA vulnerability.
*** Field 19 - Last update
The timestamp of the last update of a key or user ID. The update
time of a key is defined a lookup of the key via its unique
identifier (fingerprint); the field is empty if not known. The
update time of a user ID is defined by a lookup of the key using a
trusted mapping from mail address to key.
*** Field 20 - Origin
The origin of the key or the user ID. This is an integer
optionally followed by a space and an URL. This goes along with
the previous field. The URL is quoted in C style.
*** Field 21 - Comment
This is currently only used in "rev" and "rvs" records to carry
the the comment field of the recocation reason. The value is
quoted in C style.
** Special fields
*** PKD - Public key data
If field 1 has the tag "pkd", a listing looks like this:
#+begin_example
pkd:0:1024:B665B1435F4C2 .... FF26ABB:
! ! !-- the value
! !------ for information number of bits in the value
!--------- index (eg. DSA goes from 0 to 3: p,q,g,y)
#+end_example
*** TFS - TOFU statistics
This field may follows a UID record to convey information about
the TOFU database. The information is similar to a TOFU_STATS
status line.
- Field 2 :: tfs record version (must be 1)
- Field 3 :: validity - A number with validity code.
- Field 4 :: signcount - The number of signatures seen.
- Field 5 :: encrcount - The number of encryptions done.
- Field 6 :: policy - A string with the policy
- Field 7 :: signture-first-seen - a timestamp or 0 if not known.
- Field 8 :: signature-most-recent-seen - a timestamp or 0 if not known.
- Field 9 :: encryption-first-done - a timestamp or 0 if not known.
- Field 10 :: encryption-most-recent-done - a timestamp or 0 if not known.
*** TRU - Trust database information
Example for a "tru" trust base record:
#+begin_example
tru:o:0:1166697654:1:3:1:5
#+end_example
- Field 2 :: Reason for staleness of trust. If this field is
empty, then the trustdb is not stale. This field may
have multiple flags in it:
- o :: Trustdb is old
- t :: Trustdb was built with a different trust model
than the one we are using now.
- Field 3 :: Trust model
- 0 :: Classic trust model, as used in PGP 2.x.
- 1 :: PGP trust model, as used in PGP 6 and later.
This is the same as the classic trust model,
except for the addition of trust signatures.
GnuPG before version 1.4 used the classic trust model
by default. GnuPG 1.4 and later uses the PGP trust
model by default.
- Field 4 :: Date trustdb was created in seconds since Epoch.
- Field 5 :: Date trustdb will expire in seconds since Epoch.
- Field 6 :: Number of marginally trusted users to introduce a new
key signer (gpg's option --marginals-needed).
- Field 7 :: Number of completely trusted users to introduce a new
key signer. (gpg's option --completes-needed)
- Field 8 :: Maximum depth of a certification chain. (gpg's option
--max-cert-depth)
*** SPK - Signature subpacket records
- Field 2 :: Subpacket number as per RFC-4880 and later.
- Field 3 :: Flags in hex. Currently the only two bits assigned
are 1, to indicate that the subpacket came from the
hashed part of the signature, and 2, to indicate the
subpacket was marked critical.
- Field 4 :: Length of the subpacket. Note that this is the
length of the subpacket, and not the length of field
5 below. Due to the need for %-encoding, the length
of field 5 may be up to 3x this value.
- Field 5 :: The subpacket data. Printable ASCII is shown as
ASCII, but other values are rendered as %XX where XX
is the hex value for the byte.
*** CFG - Configuration data
--list-config outputs information about the GnuPG configuration
for the benefit of frontends or other programs that call GnuPG.
There are several list-config items, all colon delimited like the
rest of the --with-colons output. The first field is always "cfg"
to indicate configuration information. The second field is one of
(with examples):
- version :: The third field contains the version of GnuPG.
: cfg:version:1.3.5
- pubkey :: The third field contains the public key algorithms
this version of GnuPG supports, separated by
semicolons. The algorithm numbers are as specified in
RFC-4880. Note that in contrast to the --status-fd
interface these are _not_ the Libgcrypt identifiers.
Using =pubkeyname= prints names instead of numbers.
: cfg:pubkey:1;2;3;16;17
- cipher :: The third field contains the symmetric ciphers this
version of GnuPG supports, separated by semicolons.
The cipher numbers are as specified in RFC-4880.
Using =ciphername= prints names instead of numbers.
: cfg:cipher:2;3;4;7;8;9;10
- digest :: The third field contains the digest (hash) algorithms
this version of GnuPG supports, separated by
semicolons. The digest numbers are as specified in
RFC-4880. Using =digestname= prints names instead of
numbers.
: cfg:digest:1;2;3;8;9;10
- compress :: The third field contains the compression algorithms
this version of GnuPG supports, separated by
semicolons. The algorithm numbers are as specified
in RFC-4880.
: cfg:compress:0;1;2;3
- group :: The third field contains the name of the group, and the
fourth field contains the values that the group expands
to, separated by semicolons.
For example, a group of:
: group mynames = paige 0x12345678 joe patti
would result in:
: cfg:group:mynames:patti;joe;0x12345678;paige
- curve :: The third field contains the curve names this version
of GnuPG supports, separated by semicolons. Using =curveoid= prints OIDs instead of numbers.
: cfg:curve:ed25519;nistp256;nistp384;nistp521
* Format of the --status-fd output
Every line is prefixed with "[GNUPG:] ", followed by a keyword with
the type of the status line and some arguments depending on the type
(maybe none); an application should always be willing to ignore
unknown keywords that may be emitted by future versions of GnuPG.
Also, new versions of GnuPG may add arguments to existing keywords.
Any additional arguments should be ignored for forward-compatibility.
** General status codes
*** NEWSIG [<signers_uid>]
Is issued right before a signature verification starts. This is
useful to define a context for parsing ERROR status messages.
If SIGNERS_UID is given and is not "-" this is the percent-escaped
value of the OpenPGP Signer's User ID signature sub-packet.
*** GOODSIG <long_keyid_or_fpr> <username>
The signature with the keyid is good. For each signature only one
of the codes GOODSIG, BADSIG, EXPSIG, EXPKEYSIG, REVKEYSIG or
ERRSIG will be emitted. In the past they were used as a marker
for a new signature; new code should use the NEWSIG status
instead. The username is the primary one encoded in UTF-8 and %XX
escaped. The fingerprint may be used instead of the long keyid if
it is available. This is the case with CMS and might eventually
also be available for OpenPGP.
*** EXPSIG <long_keyid_or_fpr> <username>
The signature with the keyid is good, but the signature is
expired. The username is the primary one encoded in UTF-8 and %XX
escaped. The fingerprint may be used instead of the long keyid if
it is available. This is the case with CMS and might eventually
also be available for OpenPGP.
*** EXPKEYSIG <long_keyid_or_fpr> <username>
The signature with the keyid is good, but the signature was made
by an expired key. The username is the primary one encoded in
UTF-8 and %XX escaped. The fingerprint may be used instead of the
long keyid if it is available. This is the case with CMS and
might eventually also be available for OpenPGP.
*** REVKEYSIG <long_keyid_or_fpr> <username>
The signature with the keyid is good, but the signature was made
by a revoked key. The username is the primary one encoded in UTF-8
and %XX escaped. The fingerprint may be used instead of the long
keyid if it is available. This is the case with CMS and might
eventually also beñ available for OpenPGP.
*** BADSIG <long_keyid_or_fpr> <username>
The signature with the keyid has not been verified okay. The
username is the primary one encoded in UTF-8 and %XX escaped. The
fingerprint may be used instead of the long keyid if it is
available. This is the case with CMS and might eventually also be
available for OpenPGP.
*** ERRSIG <keyid> <pkalgo> <hashalgo> <sig_class> <time> <rc> <fpr>
It was not possible to check the signature. This may be caused by
a missing public key or an unsupported algorithm. A RC of 4
indicates unknown algorithm, a 9 indicates a missing public
key. The other fields give more information about this signature.
sig_class is a 2 byte hex-value. The fingerprint may be used
instead of the long_keyid_or_fpr if it is available. This is the
case with gpgsm and might eventually also be available for
OpenPGP. The ERRSIG line has FPR filed which is only available
since 2.2.7; that FPR may either be missing or - if the signature
has no fingerprint as meta data.
Note, that TIME may either be the number of seconds since Epoch or
an ISO 8601 string. The latter can be detected by the presence of
the letter 'T'.
*** VALIDSIG <args>
The args are:
- <fingerprint_in_hex>
- <sig_creation_date>
- <sig-timestamp>
- <expire-timestamp>
- <sig-version>
- <reserved>
- <pubkey-algo>
- <hash-algo>
- <sig-class>
- [ <primary-key-fpr> ]
This status indicates that the signature is cryptographically
valid. This is similar to GOODSIG, EXPSIG, EXPKEYSIG, or REVKEYSIG
(depending on the date and the state of the signature and signing
key) but has the fingerprint as the argument. Multiple status
lines (VALIDSIG and the other appropriate *SIG status) are emitted
for a valid signature. All arguments here are on one long line.
sig-timestamp is the signature creation time in seconds after the
epoch. expire-timestamp is the signature expiration time in
seconds after the epoch (zero means "does not
expire"). sig-version, pubkey-algo, hash-algo, and sig-class (a
2-byte hex value) are all straight from the signature packet.
PRIMARY-KEY-FPR is the fingerprint of the primary key or identical
to the first argument. This is useful to get back to the primary
key without running gpg again for this purpose.
The primary-key-fpr parameter is used for OpenPGP and not
available for CMS signatures. The sig-version as well as the sig
class is not defined for CMS and currently set to 0 and 00.
Note, that *-TIMESTAMP may either be a number of seconds since
Epoch or an ISO 8601 string which can be detected by the presence
of the letter 'T'.
*** SIG_ID <radix64_string> <sig_creation_date> <sig-timestamp>
This is emitted only for signatures of class 0 or 1 which have
been verified okay. The string is a signature id and may be used
in applications to detect replay attacks of signed messages. Note
that only DLP algorithms give unique ids - others may yield
duplicated ones when they have been created in the same second.
Note, that SIG-TIMESTAMP may either be a number of seconds since
Epoch or an ISO 8601 string which can be detected by the presence
of the letter 'T'.
*** ENC_TO <long_keyid> <keytype> <keylength>
The message is encrypted to this LONG_KEYID. KEYTYPE is the
numerical value of the public key algorithm or 0 if it is not
known, KEYLENGTH is the length of the key or 0 if it is not known
(which is currently always the case). Gpg prints this line
always; Gpgsm only if it knows the certificate.
*** BEGIN_DECRYPTION
Mark the start of the actual decryption process. This is also
emitted when in --list-only mode.
*** END_DECRYPTION
Mark the end of the actual decryption process. This is also
emitted when in --list-only mode.
*** DECRYPTION_KEY <fpr> <fpr2> <otrust>
This line is emitted when a public key decryption succeeded in
providing a session key. <fpr> is the hexified fingerprint of the
actual key used for decryption. <fpr2> is the fingerprint of the
primary key. <otrust> is the letter with the ownertrust; this is
in general a 'u' which stands for ultimately trusted.
*** DECRYPTION_INFO <mdc_method> <sym_algo> [<aead_algo>]
Print information about the symmetric encryption algorithm and the
MDC method. This will be emitted even if the decryption fails.
For an AEAD algorithm AEAD_ALGO is not 0. GPGSM currently does
not print such a status.
*** DECRYPTION_FAILED
The symmetric decryption failed - one reason could be a wrong
passphrase for a symmetrical encrypted message.
*** DECRYPTION_OKAY
The decryption process succeeded. This means, that either the
correct secret key has been used or the correct passphrase for a
symmetric encrypted message was given. The program itself may
return an errorcode because it may not be possible to verify a
signature for some reasons.
*** SESSION_KEY <algo>:<hexdigits>
The session key used to decrypt the message. This message will
only be emitted if the option --show-session-key is used. The
format is suitable to be passed as value for the option
--override-session-key. It is not an indication that the
decryption will or has succeeded.
*** BEGIN_ENCRYPTION <mdc_method> <sym_algo> [<aead_algo>]
Mark the start of the actual encryption process.
MDC_METHOD shall be 0 if an AEAD_ALGO is not 0. Users should
however ignore MDC_METHOD if AEAD_ALGO is not 0.
*** END_ENCRYPTION
Mark the end of the actual encryption process.
*** FILE_START <what> <filename>
Start processing a file <filename>. <what> indicates the performed
operation:
- 1 :: verify
- 2 :: encrypt
- 3 :: decrypt
*** FILE_DONE
Marks the end of a file processing which has been started
by FILE_START.
*** BEGIN_SIGNING
Mark the start of the actual signing process. This may be used as
an indication that all requested secret keys are ready for use.
*** ALREADY_SIGNED <long-keyid>
Warning: This is experimental and might be removed at any time.
*** SIG_CREATED <type> <pk_algo> <hash_algo> <class> <timestamp> <keyfpr>
A signature has been created using these parameters.
Values for type <type> are:
- D :: detached
- C :: cleartext
- S :: standard
(only the first character should be checked)
<class> are 2 hex digits with the OpenPGP signature class.
Note, that TIMESTAMP may either be a number of seconds since Epoch
or an ISO 8601 string which can be detected by the presence of the
letter 'T'.
*** NOTATION_
There are actually three related status codes to convey notation
data:
- NOTATION_NAME <name>
- NOTATION_FLAGS <critical> <human_readable>
- NOTATION_DATA <string>
<name> and <string> are %XX escaped. The data may be split among
several NOTATION_DATA lines. NOTATION_FLAGS is emitted after
NOTATION_NAME and gives the critical and human readable flags;
the flag values are either 0 or 1.
*** POLICY_URL <string>
Note that URL in <string> is %XX escaped.
*** PLAINTEXT <format> <timestamp> <filename>
This indicates the format of the plaintext that is about to be
written. The format is a 1 byte hex code that shows the format of
the plaintext: 62 ('b') is binary data, 74 ('t') is text data with
no character set specified, and 75 ('u') is text data encoded in
the UTF-8 character set. The timestamp is in seconds since the
epoch. If a filename is available it gets printed as the third
argument, percent-escaped as usual.
*** PLAINTEXT_LENGTH <length>
This indicates the length of the plaintext that is about to be
written. Note that if the plaintext packet has partial length
encoding it is not possible to know the length ahead of time. In
that case, this status tag does not appear. The length is only
exact for binary formats; other formats ('t', 'u') may do post
processing like line ending conversion so that the actual number
of bytes written may be differ.
*** ATTRIBUTE <arguments>
The list or arguments are:
- <fpr>
- <octets>
- <type>
- <index>
- <count>
- <timestamp>
- <expiredate>
- <flags>
This is one long line issued for each attribute subpacket when an
attribute packet is seen during key listing. <fpr> is the
fingerprint of the key. <octets> is the length of the attribute
subpacket. <type> is the attribute type (e.g. 1 for an image).
<index> and <count> indicate that this is the N-th indexed
subpacket of count total subpackets in this attribute packet.
<timestamp> and <expiredate> are from the self-signature on the
attribute packet. If the attribute packet does not have a valid
self-signature, then the timestamp is 0. <flags> are a bitwise OR
of:
- 0x01 :: this attribute packet is a primary uid
- 0x02 :: this attribute packet is revoked
- 0x04 :: this attribute packet is expired
*** SIG_SUBPACKET <type> <flags> <len> <data>
This indicates that a signature subpacket was seen. The format is
the same as the "spk" record above.
*** ENCRYPTION_COMPLIANCE_MODE <flags>
Indicates that the current encryption operation was in compliance
with the given set of modes for all recipients. "flags" is a
space separated list of numerical flags, see "Field 18 -
Compliance flags" above.
*** DECRYPTION_COMPLIANCE_MODE <flags>
Indicates that the current decryption operation is in compliance
with the given set of modes. "flags" is a space separated list of
numerical flags, see "Field 18 - Compliance flags" above.
*** VERIFICATION_COMPLIANCE_MODE <flags>
Indicates that the current signature verification operation is in
compliance with the given set of modes. "flags" is a space
separated list of numerical flags, see "Field 18 - Compliance
flags" above.
** Key related
*** INV_RECP, INV_SGNR
The two similar status codes:
- INV_RECP <reason> <requested_recipient>
- INV_SGNR <reason> <requested_sender>
are issued for each unusable recipient/sender. The reasons codes
currently in use are:
- 0 :: No specific reason given
- 1 :: Not Found
- 2 :: Ambiguous specification
- 3 :: Wrong key usage
- 4 :: Key revoked
- 5 :: Key expired
- 6 :: No CRL known
- 7 :: CRL too old
- 8 :: Policy mismatch
- 9 :: Not a secret key
- 10 :: Key not trusted
- 11 :: Missing certificate
- 12 :: Missing issuer certificate
- 13 :: Key disabled
- 14 :: Syntax error in specification
If no specific reason was given a previously emitted status code
KEY_CONSIDERED may be used to analyzed the problem.
Note that for historical reasons the INV_RECP status is also used
for gpgsm's SIGNER command where it relates to signer's of course.
Newer GnuPG versions are using INV_SGNR; applications should
ignore the INV_RECP during the sender's command processing once
they have seen an INV_SGNR. Different codes are used so that they
can be distinguish while doing an encrypt+sign operation.
*** NO_RECP <reserved>
Issued if no recipients are usable.
*** NO_SGNR <reserved>
Issued if no senders are usable.
*** KEY_CONSIDERED <fpr> <flags>
Issued to explain the lookup of a key. FPR is the hexified
fingerprint of the primary key. The bit values for FLAGS are:
- 1 :: The key has not been selected.
- 2 :: All subkeys of the key are expired or have been revoked.
*** KEYEXPIRED <expire-timestamp>
The key has expired. expire-timestamp is the expiration time in
seconds since Epoch. This status line is not very useful because
it will also be emitted for expired subkeys even if this subkey is
not used. To check whether a key used to sign a message has
expired, the EXPKEYSIG status line is to be used.
Note, that the TIMESTAMP may either be a number of seconds since
Epoch or an ISO 8601 string which can be detected by the presence
of the letter 'T'.
*** KEYREVOKED
The used key has been revoked by its owner. No arguments yet.
*** NO_PUBKEY <long keyid>
The public key is not available. Note the arg should in general
not be used because it is better to take it from the ERRSIG
status line which is printed right before this one.
*** NO_SECKEY <long keyid>
The secret key is not available
*** KEY_CREATED <type> <fingerprint> [<handle>]
A key has been created. Values for <type> are:
- B :: primary and subkey
- P :: primary
- S :: subkey
The fingerprint is one of the primary key for type B and P and the
one of the subkey for S. Handle is an arbitrary non-whitespace
string used to match key parameters from batch key creation run.
*** KEY_NOT_CREATED [<handle>]
The key from batch run has not been created due to errors.
*** TRUST_
These are several similar status codes:
#+begin_src
- TRUST_UNDEFINED <error_token> [<validation_model> [<mbox>]]
- TRUST_NEVER <error_token> [<validation_model> [<mbox>]]
- TRUST_MARGINAL 0 [<validation_model> [<mbox>]]
- TRUST_FULLY 0 [<validation_model> [<mbox>]]
- TRUST_ULTIMATE 0 [<validation_model> [<mbox>]]
#+end_src
For good signatures one of these status lines are emitted to
indicate the validity of the key used to create the signature.
<error_token> values other that a literal zero are currently only
emitted by gpgsm.
VALIDATION_MODEL describes the algorithm used to check the
validity of the key. The defaults are the standard Web of Trust
model for gpg and the standard X.509 model for gpgsm. The
defined values are
- classic :: The classic PGP WoT model.
- pgp :: The standard PGP WoT.
- external :: The external PGP trust model.
- tofu :: The GPG Trust-On-First-Use model.
- tofu+pgp :: Ditto but combined with mopdel "pgp".
- always :: The Always trust model.
- direct :: The Direct Trust model.
- shell :: The Standard X.509 model.
- chain :: The Chain model.
- steed :: The STEED model.
- unknown :: An unknown trust model.
Note that the term =TRUST_= in the status names is used for
historic reasons; we now speak of validity.
MBOX is the UTF-8 encoded and percent escaped addr-spec of the
User ID used to compute the validity of a signature. If this is
not known the validity is computed on the key with no specific
User ID. Note that MBOX is always the addr-spec of the User ID;
for User IDs without a proper addr-spec a dash is used to
distinguish this from the case that no User ID at all is known.
The MBOX is either taken from the Signer's User ID signature
sub-packet or from the addr-spec passed to gpg using the --sender
option. If both are available and they don't match
TRUST_UNDEFINED along with an error code is emitted. MBOX is not
used by gpgsm.
*** TOFU_USER <fingerprint_in_hex> <mbox>
This status identifies the key and the userid for all following
Tofu information. The fingerprint is the fingerprint of the
primary key and the mbox is in general the addr-spec part of the
userid encoded in UTF-8 and percent escaped. The fingerprint is
identical for all TOFU_USER lines up to a NEWSIG line.
*** TOFU_STATS <MANY_ARGS>
Statistics for the current user id.
The <MANY_ARGS> are the usual space delimited arguments. Here we
have too many of them to fit on one printed line and thus they are
given on 3 printed lines:
: <summary> <sign-count> <encryption-count>
: [<policy> [<tm1> <tm2> <tm3> <tm4>
: [<validity> [<sign-days> <encrypt-days>]]]]
Values for SUMMARY are:
- 0 :: attention, an interaction with the user is required (conflict)
- 1 :: key with no verification/encryption history
- 2 :: key with little history
- 3 :: key with enough history for basic trust
- 4 :: key with a lot of history
Values for POLICY are:
- none :: No Policy set
- auto :: Policy is "auto"
- good :: Policy is "good"
- bad :: Policy is "bad"
- ask :: Policy is "ask"
- unknown :: Policy is "unknown" (TOFU information does not
contribute to the key's validity)
TM1 is the time the first message was verified. TM2 is the time
the most recent message was verified. TM3 is the time the first
message was encrypted. TM4 is the most recent encryption. All may
either be seconds since Epoch or an ISO time string
(yyyymmddThhmmss).
VALIDITY is the same as SUMMARY with the exception that VALIDITY
doesn't reflect whether the key needs attention. That is it never
takes on value 0. Instead, if there is a conflict, VALIDITY still
reflects the key's validity (values: 1-4).
SUMMARY values use the euclidean distance (m = sqrt(a² + b²)) rather
then the sum of the magnitudes (m = a + b) to ensure a balance between
verified signatures and encrypted messages.
Values are calculated based on the number of days where a key was used
for verifying a signature or to encrypt to it.
The ranges for the values are:
- 1 :: signature_days + encryption_days == 0
- 2 :: 1 <= sqrt(signature_days² + encryption_days²) < 8
- 3 :: 8 <= sqrt(signature_days² + encryption_days²) < 42
- 4 :: sqrt(signature_days² + encryption_days²) >= 42
SIGN-COUNT and ENCRYPTION-COUNT are the number of messages that we
have seen that have been signed by this key / encryption to this
key.
SIGN-DAYS and ENCRYPTION-DAYS are similar, but the number of days
(in UTC) on which we have seen messages signed by this key /
encrypted to this key.
*** TOFU_STATS_SHORT <long_string>
Information about the TOFU binding for the signature.
Example: "15 signatures verified. 10 messages encrypted"
*** TOFU_STATS_LONG <long_string>
Information about the TOFU binding for the signature in verbose
format. The LONG_STRING is percent escaped.
Example: 'Verified 9 messages signed by "Werner Koch
(dist sig)" in the past 3 minutes, 40 seconds. The most
recent message was verified 4 seconds ago.'
*** PKA_TRUST_
This is one of:
- PKA_TRUST_GOOD <addr-spec>
- PKA_TRUST_BAD <addr-spec>
Depending on the outcome of the PKA check one of the above status
codes is emitted in addition to a =TRUST_*= status.
** Remote control
*** GET_BOOL, GET_LINE, GET_HIDDEN, GOT_IT
These status line are used with --command-fd for interactive
control of the process.
*** USERID_HINT <long main keyid> <string>
Give a hint about the user ID for a certain keyID.
*** NEED_PASSPHRASE <long keyid> <long main keyid> <keytype> <keylength>
Issued whenever a passphrase is needed. KEYTYPE is the numerical
value of the public key algorithm or 0 if this is not applicable,
KEYLENGTH is the length of the key or 0 if it is not known (this
is currently always the case).
*** NEED_PASSPHRASE_SYM <cipher_algo> <s2k_mode> <s2k_hash>
Issued whenever a passphrase for symmetric encryption is needed.
*** NEED_PASSPHRASE_PIN <card_type> <chvno> [<serialno>]
Issued whenever a PIN is requested to unlock a card.
*** MISSING_PASSPHRASE
No passphrase was supplied. An application which encounters this
message may want to stop parsing immediately because the next
message will probably be a BAD_PASSPHRASE. However, if the
application is a wrapper around the key edit menu functionality it
might not make sense to stop parsing but simply ignoring the
following BAD_PASSPHRASE.
*** BAD_PASSPHRASE <long keyid>
The supplied passphrase was wrong or not given. In the latter
case you may have seen a MISSING_PASSPHRASE.
*** GOOD_PASSPHRASE
The supplied passphrase was good and the secret key material
is therefore usable.
** Import/Export
*** IMPORT_CHECK <long keyid> <fingerprint> <user ID>
This status is emitted in interactive mode right before
the "import.okay" prompt.
*** IMPORTED <long keyid> <username>
The keyid and name of the signature just imported
*** IMPORT_OK <reason> [<fingerprint>]
The key with the primary key's FINGERPRINT has been imported.
REASON flags are:
- 0 :: Not actually changed
- 1 :: Entirely new key.
- 2 :: New user IDs
- 4 :: New signatures
- 8 :: New subkeys
- 16 :: Contains private key.
The flags may be ORed.
*** IMPORT_PROBLEM <reason> [<fingerprint>]
Issued for each import failure. Reason codes are:
- 0 :: No specific reason given.
- 1 :: Invalid Certificate.
- 2 :: Issuer Certificate missing.
- 3 :: Certificate Chain too long.
- 4 :: Error storing certificate.
*** IMPORT_RES <args>
Final statistics on import process (this is one long line). The
args are a list of unsigned numbers separated by white space:
- <count>
- <no_user_id>
- <imported>
- always 0 (formerly used for the number of RSA keys)
- <unchanged>
- <n_uids>
- <n_subk>
- <n_sigs>
- <n_revoc>
- <sec_read>
- <sec_imported>
- <sec_dups>
- <skipped_new_keys>
- <not_imported>
- <skipped_v3_keys>
*** EXPORTED <fingerprint>
The key with <fingerprint> has been exported. The fingerprint is
the fingerprint of the primary key even if the primary key has
been replaced by a stub key during secret key export.
*** EXPORT_RES <args>
Final statistics on export process (this is one long line). The
args are a list of unsigned numbers separated by white space:
- <count>
- <secret_count>
- <exported>
** Smartcard related
*** CARDCTRL <what> [<serialno>]
This is used to control smartcard operations. Defined values for
WHAT are:
- 1 :: Request insertion of a card. Serialnumber may be given
to request a specific card. Used by gpg 1.4 w/o
scdaemon
- 2 :: Request removal of a card. Used by gpg 1.4 w/o scdaemon.
- 3 :: Card with serialnumber detected
- 4 :: No card available
- 5 :: No card reader available
- 6 :: No card support available
- 7 :: Card is in termination state
*** SC_OP_FAILURE [<code>]
An operation on a smartcard definitely failed. Currently there is
no indication of the actual error code, but application should be
prepared to later accept more arguments. Defined values for
<code> are:
- 0 :: unspecified error (identically to a missing CODE)
- 1 :: canceled
- 2 :: bad PIN
*** SC_OP_SUCCESS
A smart card operation succeeded. This status is only printed for
certain operation and is mostly useful to check whether a PIN
change really worked.
** Miscellaneous status codes
*** NODATA <what>
No data has been found. Codes for WHAT are:
- 1 :: No armored data.
- 2 :: Expected a packet but did not found one.
- 3 :: Invalid packet found, this may indicate a non OpenPGP
message.
- 4 :: Signature expected but not found
You may see more than one of these status lines.
*** UNEXPECTED <what>
Unexpected data has been encountered. Codes for WHAT are:
- 0 :: Not further specified
- 1 :: Corrupted message structure
*** TRUNCATED <maxno>
The output was truncated to MAXNO items. This status code is
issued for certain external requests.
*** ERROR <error location> <error code> [<more>]
This is a generic error status message, it might be followed by
error location specific data. <error code> and <error_location>
should not contain spaces. The error code is a either a string
commencing with a letter or such a string prefixed with a
numerical error code and an underscore; e.g.: "151011327_EOF".
Some of the error locations are:
- decryption.early_plaintext :: The OpenPGP message contains more
than one plaintext.
- genkey :: Problem generating a key. The error code further
describes the problem.
- get_passphrase :: Problem getting the passphrase from the
gpg-agent.
- keyedit.passwd :: Changing the password failed.
- nomdc_with_legacy_cipher :: The message was not MDC protected.
Use the command line to lern about a workaround.
- random-compliance :: The random number generator or the used
version of Libgcrypt do not fulfill the requirements of the
current compliance setting. The error code is often
GPG_ERR_FORBIDDEN.
- set_expire :: Changing the expiration time failed.
*** WARNING <location> <error code> [<text>]
This is a generic warning status message, it might be followed by
error location specific data. <location> and <error code> may not
contain spaces. The <location> may be used to indicate a class of
warnings. The error code is a either a string commencing with a
letter or such a string prefixed with a numerical error code and
an underscore; e.g.: "151011327_EOF".
*** NOTE <location> <error code> [<text>]
This is a generic info status message the same syntax as for
WARNING messages is used.
*** SUCCESS [<location>]
Positive confirmation that an operation succeeded. It is used
similar to ISO-C's EXIT_SUCCESS. <location> is optional but if
given should not contain spaces. Used only with a few commands.
*** FAILURE <location> <error_code>
This is the counterpart to SUCCESS and used to indicate a program
failure. It is used similar to ISO-C's EXIT_FAILURE but allows
conveying more information, in particular a gpg-error error code.
That numerical error code may optionally have a suffix made of an
underscore and a string with an error symbol like "151011327_EOF".
A dash may be used instead of <location>.
*** BADARMOR
The ASCII armor is corrupted. No arguments yet.
*** DELETE_PROBLEM <reason_code>
Deleting a key failed. Reason codes are:
- 1 :: No such key
- 2 :: Must delete secret key first
- 3 :: Ambiguous specification
- 4 :: Key is stored on a smartcard.
*** PROGRESS <what> <char> <cur> <total> [<units>]
Used by the primegen and public key functions to indicate
progress. <char> is the character displayed with no --status-fd
enabled, with the linefeed replaced by an 'X'. <cur> is the
current amount done and <total> is amount to be done; a <total> of
0 indicates that the total amount is not known. Both are
non-negative integers. The condition
: TOTAL && CUR == TOTAL
may be used to detect the end of an operation.
Well known values for <what> are:
- pk_dsa :: DSA key generation
- pk_elg :: Elgamal key generation
- primegen :: Prime generation
- need_entropy :: Waiting for new entropy in the RNG
- tick :: Generic tick without any special meaning - useful
for letting clients know that the server is still
working.
- starting_agent :: A gpg-agent was started because it is not
running as a daemon.
- learncard :: Send by the agent and gpgsm while learing
the data of a smartcard.
- card_busy :: A smartcard is still working
- scd_locked :: Waiting for other clients to unlock the scdaemon
When <what> refers to a file path, it may be truncated.
<units> is sometimes used to describe the units for <current> and
<total>. For example "B", "KiB", or "MiB".
*** BACKUP_KEY_CREATED <fingerprint> <fname>
A backup of a key identified by <fingerprint> has been writte to
the file <fname>; <fname> is percent-escaped.
*** MOUNTPOINT <name>
<name> is a percent-plus escaped filename describing the
mountpoint for the current operation (e.g. used by "g13 --mount").
This may either be the specified mountpoint or one randomly
chosen by g13.
*** PINENTRY_LAUNCHED <pid>[:<extra>]
This status line is emitted by gpg to notify a client that a
Pinentry has been launched. <pid> is the PID of the Pinentry. It
may be used to display a hint to the user but can't be used to
synchronize with Pinentry. Note that there is also an Assuan
inquiry line with the same name used internally or, if enabled,
send to the client instead of this status line. Such an inquiry
may be used to sync with Pinentry
** Obsolete status codes
*** SIGEXPIRED
Removed on 2011-02-04. This is deprecated in favor of KEYEXPIRED.
*** RSA_OR_IDEA
Obsolete. This status message used to be emitted for requests to
use the IDEA or RSA algorithms. It has been dropped from GnuPG
2.1 after the respective patents expired.
*** SHM_INFO, SHM_GET, SHM_GET_BOOL, SHM_GET_HIDDEN
These were used for the ancient shared memory based co-processing.
*** BEGIN_STREAM, END_STREAM
Used to issued by the experimental pipemode.
*** GOODMDC
This is not anymore needed. Checking the DECRYPTION_OKAY status is
sufficient.
*** BADMDC
This is not anymore needed.
** Inter-component codes
Status codes are also used between the components of the GnuPG
system via the Assuan S lines. Some of them are documented here:
*** PUBKEY_INFO <n> <ubid> <flags> <uidno> <pkno>
The type of the public key in the following D-lines or
communicated via a pipe. <n> is the value of =enum pubkey_types=
and <ubid> the Unique Blob ID (UBID) which is the fingerprint of
the primary key truncated to 20 octets and formatted in hex. Note
that the keyboxd SEARCH command can be used to lookup the public
key using the <ubid> prefixed with a caret (^).
<flags> is a string extra information about the blob. The first
byte is either '-' for standard key or 'e' for an ephemeral key.
The second byte is either '-' or 'r' for a known revoked key.
<uidno> and <pkno> are the ordinal numbers for the the user id or
public key which matches the search criteria. A value of 0 means
not known.
*** KEYPAIRINFO <grip> <keyref> [<usage>] [<keytime>] [<algostr>]
This status is emitted by scdaemon and gpg-agent to convey brief
information about keypairs stored on tokens. <grip> is the
hexified keygrip of the key or, if no key is stored, an "X".
<keyref> is the ID of a card's key; for example "OPENPGP.2" for
the second key slot of an OpenPGP card. <usage> is optional and
returns technically possible key usages, this is a string of
single letters describing the usage ('c' for certify, 'e' for
encryption, 's' for signing, 'a' for authentication). A '-' can be
used to tell that usage flags are not conveyed. <keytime> is used
by OpenPGP cards for the stored key creation time. A '-' means no
info available. The format is the usual ISO string or a number
with the seconds since Epoch. <algostr> is the algorithm or curve
this key uses (e.g. "rsa2048") or a "-" if not known.
*** CERTINFO <certtype> <certref> [<label>]
This status is emitted for X.509 certifcates.
CERTTYPE is a number indicating the type of the certificate:
0 := Unknown
100 := Regular X.509 cert
101 := Trusted X.509 cert
102 := Useful X.509 cert
110 := Root CA cert in a special format (e.g. DINSIG)
111 := Root CA cert as standard X509 cert
CERTREF identifies the certificate uniquely on the card and may be
used to match it with a key's KEYREF. LABEL is an optional human
readable decription of the certificate; it won't have any space in
it and is percent encoded.
*** MANUFACTURER <n> [<string>]
This status returns the Manufactorer ID as the unsigned number N.
For OpenPGP this is well defined; for other cards this is 0. The
name of the manufacturer is also given as <string>; spaces are not
escaped. For PKCS#15 cards <string> is TokenInfo.manufactorerID;
a string in brackets describing GnuPG's own card product name may
be appended to <string>.
*** KEY-STATUS <keyref> <status>
This is the response from scdaemon on GETATTR KEY-STATUS for
OpenPGP cards. <keyref> is the usual keyref (e.g. OPENPGP.1 or
OPENPGP.129) and <status> is an integer describing the status of
the key: 0 = key is not present, 1 = key generated on card, 2 =
key imported. See section 4.4.3.8 of the OpenPGP Smart Card
Application V3.4.
*** KEY-ATTR-INFO <keyref> <string>
This is the response from scdaemon on GETATTR KEY-ATTR-INFO for
OpenPGP cards. <keyref> is the usual keyref (e.g. OPENPGP.1 or
OPENPGP.129) and <string> is the algoritm or curve name, which
is available for the key.
*** KEY-TIME <n> <timestamp>
This is a response from scdaemon on GETATTR KEY-TIME. A keyref N
of 1 gives the timestamp for the standard OpenPGP signing key, 2
for the encryption key, and 3 for an authentication key. Note
that a KEYPAIRINFO status lines carries the same information and
should be preferred.
*** KEY-LABEL <keyref> <label>
This returns the human readbable label for the keys given by
KEYREF. LABEL won't have any space in it and is percent encoded.
This info shall only be used for dispaly purposes.
* Format of the --attribute-fd output
When --attribute-fd is set, during key listings (--list-keys,
--list-secret-keys) GnuPG dumps each attribute packet to the file
descriptor specified. --attribute-fd is intended for use with
--status-fd as part of the required information is carried on the
ATTRIBUTE status tag (see above).
The contents of the attribute data is specified by RFC 4880. For
convenience, here is the Photo ID format, as it is currently the
only attribute defined:
- Byte 0-1 :: The length of the image header. Due to a historical
accident (i.e. oops!) back in the NAI PGP days, this
is a little-endian number. Currently 16 (0x10 0x00).
- Byte 2 :: The image header version. Currently 0x01.
- Byte 3 :: Encoding format. 0x01 == JPEG.
- Byte 4-15 :: Reserved, and currently unused.
All other data after this header is raw image (JPEG) data.
* Layout of the TrustDB
The TrustDB is built from fixed length records, where the first byte
describes the record type. All numeric values are stored in network
byte order. The length of each record is 40 bytes. The first
record of the DB is always of type 1 and this is the only record of
this type.
The record types: directory(2), key(3), uid(4), pref(5), sigrec(6),
and shadow directory(8) are not anymore used by version 2 of the
TrustDB.
** Record type 0
Unused record or deleted, can be reused for any purpose. Such
records should in general not exist because deleted records are of
type 254 and kept in a linked list.
** Version info (RECTYPE_VER, 1)
Version information for this TrustDB. This is always the first
record of the DB and the only one of this type.
- 1 u8 :: Record type (value: 1).
- 3 byte :: Magic value ("gpg")
- 1 u8 :: TrustDB version (value: 2).
- 1 u8 :: =marginals=. How many marginal trusted keys are required.
- 1 u8 :: =completes=. How many completely trusted keys are
required.
- 1 u8 :: =max_cert_depth=. How deep is the WoT evaluated. Along
with =marginals= and =completes=, this value is used to
check whether the cached validity value from a [FIXME
dir] record can be used.
- 1 u8 :: =trust_model=
- 1 u8 :: =min_cert_level=
- 2 byte :: Not used
- 1 u32 :: =created=. Timestamp of trustdb creation.
- 1 u32 :: =nextcheck=. Timestamp of last modification which may
affect the validity of keys in the trustdb. This value
is checked against the validity timestamp in the dir
records.
- 1 u32 :: =reserved=. Not used.
- 1 u32 :: =reserved2=. Not used.
- 1 u32 :: =firstfree=. Number of the record with the head record
of the RECTYPE_FREE linked list.
- 1 u32 :: =reserved3=. Not used.
- 1 u32 :: =trusthashtbl=. Record number of the trusthashtable.
** Hash table (RECTYPE_HTBL, 10)
Due to the fact that we use fingerprints to lookup keys, we can
implement quick access by some simple hash methods, and avoid the
overhead of gdbm. A property of fingerprints is that they can be
used directly as hash values. What we use is a dynamic multilevel
architecture, which combines hash tables, record lists, and linked
lists.
This record is a hash table of 256 entries with the property that
all these records are stored consecutively to make one big
table. The hash value is simple the 1st, 2nd, ... byte of the
fingerprint (depending on the indirection level).
- 1 u8 :: Record type (value: 10).
- 1 u8 :: Reserved
- n u32 :: =recnum=. A table with the hash table items fitting into
this record. =n= depends on the record length:
$n=(reclen-2)/4$ which yields 9 for oure current record
length of 40 bytes.
The total number of hash table records to form the table is:
$m=(256+n-1)/n$. This is 29 for our record length of 40.
To look up a key we use the first byte of the fingerprint to get
the recnum from this hash table and then look up the addressed
record:
- If that record is another hash table, we use 2nd byte to index
that hash table and so on;
- if that record is a hash list, we walk all entries until we find
a matching one; or
- if that record is a key record, we compare the fingerprint to
decide whether it is the requested key;
** Hash list (RECTYPE_HLST, 11)
See hash table above on how it is used. It may also be used for
other purposes.
- 1 u8 :: Record type (value: 11).
- 1 u8 :: Reserved.
- 1 u32 :: =next=. Record number of the next hash list record or 0
if none.
- n u32 :: =rnum=. Array with record numbers to values. With
$n=(reclen-5)/5$ and our record length of 40, n is 7.
** Trust record (RECTYPE_TRUST, 12)
- 1 u8 :: Record type (value: 12).
- 1 u8 :: Reserved.
- 20 byte :: =fingerprint=.
- 1 u8 :: =ownertrust=.
- 1 u8 :: =depth=.
- 1 u8 :: =min_ownertrust=.
- 1 byte :: Not used.
- 1 u32 :: =validlist=.
- 10 byte :: Not used.
** Validity record (RECTYPE_VALID, 13)
- 1 u8 :: Record type (value: 13).
- 1 u8 :: Reserved.
- 20 byte :: =namehash=.
- 1 u8 :: =validity=
- 1 u32 :: =next=.
- 1 u8 :: =full_count=.
- 1 u8 :: =marginal_count=.
- 11 byte :: Not used.
** Free record (RECTYPE_FREE, 254)
All these records form a linked list of unused records in the TrustDB.
- 1 u8 :: Record type (value: 254)
- 1 u8 :: Reserved.
- 1 u32 :: =next=. Record number of the next rcord of this type.
The record number to the head of this linked list is
stored in the version info record.
* Database scheme for the TOFU info
#+begin_src sql
--
-- The VERSION table holds the version of our TOFU data structures.
--
CREATE TABLE version (
version integer -- As of now this is always 1
);
--
-- The BINDINGS table associates mail addresses with keys.
--
CREATE TABLE bindings (
oid integer primary key autoincrement,
fingerprint text, -- The key's fingerprint in hex
email text, -- The normalized mail address destilled from user_id
user_id text, -- The unmodified user id
time integer, -- The time this binding was first observed.
policy boolean check
(policy in (1, 2, 3, 4, 5)), -- The trust policy with the values:
-- 1 := Auto
-- 2 := Good
-- 3 := Unknown
-- 4 := Bad
-- 5 := Ask
conflict string, -- NULL or a hex formatted fingerprint.
unique (fingerprint, email)
);
CREATE INDEX bindings_fingerprint_email on bindings (fingerprint, email);
CREATE INDEX bindings_email on bindings (email);
--
-- The SIGNATURES table records all data signatures we verified
--
CREATE TABLE signatures (
binding integer not null, -- Link to bindings table,
-- references bindings.oid.
sig_digest text, -- The digest of the signed message.
origin text, -- String describing who initially fed
-- the signature to gpg (e.g. "email:claws").
sig_time integer, -- Timestamp from the signature.
time integer, -- Time this record was created.
primary key (binding, sig_digest, origin)
);
#+end_src
* GNU extensions to the S2K algorithm
1 octet - S2K Usage: either 254 or 255.
1 octet - S2K Cipher Algo: 0
1 octet - S2K Specifier: 101
3 octets - "GNU"
1 octet - GNU S2K Extension Number.
If such a GNU extension is used neither an IV nor any kind of
checksum is used. The defined GNU S2K Extension Numbers are:
- 1 :: Do not store the secret part at all. No specific data
follows.
- 2 :: A stub to access smartcards. This data follows:
- One octet with the length of the following serial number.
- The serial number. Regardless of what the length octet
indicates no more than 16 octets are stored.
Note that gpg stores the GNU S2K Extension Number internally as an
S2K Specifier with an offset of 1000.
* Format of the OpenPGP TRUST packet
According to RFC4880 (5.10), the trust packet (aka ring trust) is
only used within keyrings and contains data that records the user's
specifications of which key holds trusted introducers. The RFC also
states that the format of this packet is implementation defined and
SHOULD NOT be emitted to output streams or should be ignored on
import. GnuPG uses this packet in several additional ways:
- 1 octet :: Trust-Value (only used by Subtype SIG)
- 1 octet :: Signature-Cache (only used by Subtype SIG; value must
be less than 128)
- 3 octets :: Fixed value: "gpg"
- 1 octet :: Subtype
- 0 :: Signature cache (SIG)
- 1 :: Key source on the primary key (KEY)
- 2 :: Key source on a user id (UID)
- 1 octet :: Key Source; i.e. the origin of the key:
- 0 :: Unknown source.
- 1 :: Public keyserver.
- 2 :: Preferred keyserver.
- 3 :: OpenPGP DANE.
- 4 :: Web Key Directory.
- 5 :: Import from a trusted URL.
- 6 :: Import from a trusted file.
- 7 :: Self generated.
- 4 octets :: Time of last update. This is a four-octet scalar
with the seconds since Epoch.
- 1 octet :: Scalar with the length of the following field.
- N octets :: String with the URL of the source. This may be a
zero-length string.
If the packets contains only two octets a Subtype of 0 is assumed;
this is the only format recognized by GnuPG versions < 2.1.18.
Trust-Value and Signature-Cache must be zero for all subtypes other
than SIG.
* Keyserver helper message format *This information is obsolete*
(Keyserver helpers have been replaced by dirmngr)
The keyserver may be contacted by a Unix Domain socket or via TCP.
The format of a request is:
#+begin_example
command-tag
"Content-length:" digits
CRLF
#+end_example
Where command-tag is
#+begin_example
NOOP
GET <user-name>
PUT
DELETE <user-name>
#+end_example
The format of a response is:
#+begin_example
"GNUPG/1.0" status-code status-text
"Content-length:" digits
CRLF
#+end_example
followed by <digits> bytes of data
Status codes are:
- 1xx :: Informational - Request received, continuing process
- 2xx :: Success - The action was successfully received, understood,
and accepted
- 4xx :: Client Error - The request contains bad syntax or cannot be
fulfilled
- 5xx :: Server Error - The server failed to fulfill an apparently
valid request
* Object identifiers
OIDs below the GnuPG arc:
#+begin_example
1.3.6.1.4.1.11591.2 GnuPG
1.3.6.1.4.1.11591.2.1 notation
1.3.6.1.4.1.11591.2.1.1 pkaAddress
1.3.6.1.4.1.11591.2.2 X.509 extensions
1.3.6.1.4.1.11591.2.2.1 standaloneCertificate
1.3.6.1.4.1.11591.2.2.2 wellKnownPrivateKey
1.3.6.1.4.1.11591.2.2.10 OpenPGP KDF/KEK parameter
1.3.6.1.4.1.11591.2.3 CMS contentType
1.3.6.1.4.1.11591.2.3.1 OpenPGP keyblock (as octet string)
1.3.6.1.4.1.11591.2.4 LDAP stuff
1.3.6.1.4.1.11591.2.4.1 attributes
1.3.6.1.4.1.11591.2.4.1.1 gpgFingerprint attribute
1.3.6.1.4.1.11591.2.4.1.2 gpgSubFingerprint attribute
1.3.6.1.4.1.11591.2.4.1.3 gpgMailbox attribute
1.3.6.1.4.1.11591.2.4.1.4 gpgSubCertID attribute
1.3.6.1.4.1.11591.2.5 LDAP URL extensions
1.3.6.1.4.1.11591.2.5.1 gpgNtds=1 (auth. with current AD user)
1.3.6.1.4.1.11591.2.6 GnuPG extended key usage
1.3.6.1.4.1.11591.2.6.1 use for certification key
1.3.6.1.4.1.11591.2.6.2 use for signing key
1.3.6.1.4.1.11591.2.6.3 use for encryption key
1.3.6.1.4.1.11591.2.6.4 use for authentication key
1.3.6.1.4.1.11591.2.12242973 invalid encoded OID
#+end_example
The OpenPGP KDF/KEK parameter extension is used to convey additional
info for OpenPGP keys as an X.509 extensions.
* Debug flags
This tables gives the flag values for the --debug option along with
the alternative names used by the components.
| | gpg | gpgsm | agent | scd | dirmngr | g13 | wks |
|-------+---------+---------+---------+---------+---------+---------+---------|
| 1 | packet | x509 | | | x509 | mount | mime |
| 2 | mpi | mpi | mpi | mpi | | | parser |
| 4 | crypto | crypto | crypto | crypto | crypto | crypto | crypto |
| 8 | filter | | | | | | |
| 16 | iobuf | | | | dns | | |
| 32 | memory | memory | memory | memory | memory | memory | memory |
| 64 | cache | cache | cache | cache | cache | | |
| 128 | memstat | memstat | memstat | memstat | memstat | memstat | memstat |
| 256 | trust | | | | | | |
| 512 | hashing | hashing | hashing | hashing | hashing | | |
| 1024 | ipc | ipc | ipc | ipc | ipc | ipc | ipc |
| 2048 | | | | cardio | network | | |
| 4096 | clock | | | reader | | | |
| 8192 | lookup | | | | lookup | | |
| 16384 | extprog | | | | | | extprog |
Description of some debug flags:
- cardio :: Used by scdaemon to trace the APDUs exchange with the
card.
- clock :: Show execution times of certain functions.
- crypto :: Trace crypto operations.
- hashing :: Create files with the hashed data.
- ipc :: Trace the Assuan commands.
- mpi :: Show the values of the MPIs.
- reader :: Used by scdaemon to trace card reader related code. For
example: Open and close reader.
* Miscellaneous notes
** List of useful RFCs
- RFC-3447 :: PKCS #1: RSA Cryptography Specifications Version 2.1
- RFC-4880 :: OpenPGP
- RFC-5083 :: CMS - Authenticated-Enveloped-Data
- RFC-5084 :: CMS - AES-GCM
- RFC-5280 :: X.509 PKI Certificate and CRL Profile
- RFC-5652 :: CMS (STD0070)
- RFC-6818 :: Updates to the X.509 PKI Certificate and CRL Profile
- RFC-8398 :: Internationalized Email Addresses in X.509 Certificates.
- RFC-8399 :: Internationalization Updates to RFC 5280
- RFC-5480 :: ECC Subject Public Key Information
- RFC-8813 :: Clarifications for ECC Subject Public Key
- RFC-5915 :: Elliptic Curve Private Key Structure
- RFC-5958 :: Asymmetric Key Packages
- RFC-7292 :: PKCS #12: Personal Information Exchange Syntax v1.1
- RFC-8351 :: The PKCS #8 EncryptedPrivateKeyInfo Media Type
** v3 fingerprints
For packet version 3 we calculate the keyids this way:
- RSA :: Low 64 bits of n
- ELGAMAL :: Build a v3 pubkey packet (with CTB 0x99) and
calculate a RMD160 hash value from it. This is used
as the fingerprint and the low 64 bits are the keyid.
** Simplified revocation certificates
Revocation certificates consist only of the signature packet;
"--import" knows how to handle this. The rationale behind it is to
keep them small.
** Documentation on HKP (the http keyserver protocol):
A minimalistic HTTP server on port 11371 recognizes a GET for
/pks/lookup. The standard http URL encoded query parameters are
this (always key=value):
- op=index (like pgp -kv), op=vindex (like pgp -kvv) and op=get (like
pgp -kxa)
- search=<stringlist>. This is a list of words that must occur in the key.
The words are delimited with space, points, @ and so on. The delimiters
are not searched for and the order of the words doesn't matter (but see
next option).
- exact=on. This switch tells the hkp server to only report exact matching
keys back. In this case the order and the "delimiters" are important.
- fingerprint=on. Also reports the fingerprints when used with 'index' or
'vindex'
The keyserver also recognizes http-POSTs to /pks/add. Use this to upload
keys.
A better way to do this would be a request like:
/pks/lookup/<gnupg_formatierte_user_id>?op=<operation>
This can be implemented using Hurd's translator mechanism.
However, I think the whole keyserver stuff has to be re-thought;
I have some ideas and probably create a white paper.
** Algorithm names for the "keygen.algo" prompt
When using a --command-fd controlled key generation or "addkey"
there is way to know the number to enter on the "keygen.algo"
prompt. The displayed numbers are for human reception and may
change with releases. To provide a stable way to enter a desired
algorithm choice the prompt also accepts predefined names for the
algorithms, which will not change.
| Name | No | Description |
|---------+----+---------------------------------|
| rsa+rsa | 1 | RSA and RSA (default) |
| dsa+elg | 2 | DSA and Elgamal |
| dsa | 3 | DSA (sign only) |
| rsa/s | 4 | RSA (sign only) |
| elg | 5 | Elgamal (encrypt only) |
| rsa/e | 6 | RSA (encrypt only) |
| dsa/* | 7 | DSA (set your own capabilities) |
| rsa/* | 8 | RSA (set your own capabilities) |
| ecc+ecc | 9 | ECC and ECC |
| ecc/s | 10 | ECC (sign only) |
| ecc/* | 11 | ECC (set your own capabilities) |
| ecc/e | 12 | ECC (encrypt only) |
| keygrip | 13 | Existing key |
| cardkey | 14 | Existing key from card |
If one of the "foo/*" names are used a "keygen.flags" prompt needs
to be answered as well. Instead of toggling the predefined flags,
it is also possible to set them direct: Use a "=" character
directly followed by a combination of "a" (for authentication), "s"
(for signing), or "c" (for certification).