'\"
'\" Generated from file 'pki\&.man' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 2010, 2011, 2012, 2013, 2021 - 2024 Roy Keene, Andreas Kupries, Ashok P\&. Nadkarni
'\"
.TH "pki" n 0\&.22 tcllib "public key encryption"
.\" The -*- nroff -*- definitions below are for supplemental macros used
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.BS
.SH NAME
pki \- Implementation of the public key cipher
.SH SYNOPSIS
package require \fBTcl 8\&.5 9\fR
.sp
package require \fBpki ?0\&.22?\fR
.sp
\fB::pki::encrypt\fR ?\fI-binary\fR? ?\fI-hex\fR? ?\fI-pad\fR? ?\fI-nopad\fR? ?\fI-priv\fR? ?\fI-pub\fR? ?\fI--\fR? \fIinput\fR \fIkey\fR
.sp
\fB::pki::decrypt\fR ?\fI-binary\fR? ?\fI-hex\fR? ?\fI-unpad\fR? ?\fI-nounpad\fR? ?\fI-priv\fR? ?\fI-pub\fR? ?\fI--\fR? \fIinput\fR \fIkey\fR
.sp
\fB::pki::sign\fR \fIinput\fR \fIkey\fR ?\fIalgo\fR?
.sp
\fB::pki::verify\fR \fIsignedmessage\fR \fIplaintext\fR \fIkey\fR ?\fIalgo\fR?
.sp
\fB::pki::key\fR \fIkey\fR ?\fIpassword\fR? ?\fIencodePem\fR?
.sp
\fB::pki::pkcs::parse_key\fR \fIkey\fR ?\fIpassword\fR?
.sp
\fB::pki::x509::parse_cert\fR \fIcert\fR
.sp
\fB::pki::rsa::generate\fR \fIbitlength\fR ?\fIexponent\fR?
.sp
\fB::pki::x509::verify_cert\fR \fIcert\fR \fItrustedcerts\fR ?\fIintermediatecerts\fR?
.sp
\fB::pki::x509::validate_cert\fR \fIcert\fR ?\fB-sign_message\fR \fIdn_of_signer\fR? ?\fB-encrypt_message\fR \fIdn_of_signer\fR? ?\fB-sign_cert\fR \fIdn_to_be_signed\fR \fIca_depth\fR? ?\fB-ssl\fR \fIdn\fR?
.sp
\fB::pki::pkcs::create_csr\fR \fIkeylist\fR \fInamelist\fR ?\fIencodePem\fR? ?\fIalgo\fR?
.sp
\fB::pki::pkcs::parse_csr\fR \fIcsr\fR
.sp
\fB::pki::x509::create_cert\fR \fIsignreqlist\fR \fIcakeylist\fR \fIserial_number\fR \fInotBefore\fR \fInotAfter\fR \fIisCA\fR \fIextensions\fR ?\fIencodePem\fR? ?\fIalgo\fR?
.sp
.BE
.SH DESCRIPTION
.PP
.SH COMMANDS
.TP
\fB::pki::encrypt\fR ?\fI-binary\fR? ?\fI-hex\fR? ?\fI-pad\fR? ?\fI-nopad\fR? ?\fI-priv\fR? ?\fI-pub\fR? ?\fI--\fR? \fIinput\fR \fIkey\fR
Encrypt a message using PKI (probably RSA)\&.
.sp
Requires the caller to specify either \fB-priv\fR to encrypt with
the private key or \fB-pub\fR to encrypt with the public key\&.  The
default option is to pad and return in hex\&.  One of \fB-pub\fR or
\fB-priv\fR must be specified\&.
.sp
The \fB-hex\fR option causes the data to be returned in encoded as
a hexidecimal string, while the \fB-binary\fR option causes the data
to be returned as a binary string\&.  If they are specified multiple
times, the last one specified is used\&.
.sp
The \fB-pad\fR option causes the data to be padded per PKCS#1 prior
to being encrypted\&.  The \fB-nopad\fR inhibits this behaviour\&.  If
they are specified multiple times, the last one specified is used\&.
.sp
The input to encrypt is specified as \fIinput\fR\&.
.sp
The \fIkey\fR parameter, holding the key to use, is a return value
from either
\fB::pki::pkcs::parse_key\fR,
\fB::pki::x509::parse_cert\fR, or
\fB::pki::rsa::generate\fR\&.
.sp
Mapping to OpenSSL's \fBopenssl\fR application:
.RS
.IP [1]
"openssl rsautl -encrypt" == "::pki::encrypt -binary -pub"
.IP [2]
"openssl rsautl -sign"    == "::pki::encrypt -binary -priv"
.RE
.TP
\fB::pki::decrypt\fR ?\fI-binary\fR? ?\fI-hex\fR? ?\fI-unpad\fR? ?\fI-nounpad\fR? ?\fI-priv\fR? ?\fI-pub\fR? ?\fI--\fR? \fIinput\fR \fIkey\fR
Decrypt a message using PKI (probably RSA)\&. See \fB::pki::encrypt\fR for option handling\&.
.sp
Mapping to OpenSSL's \fBopenssl\fR application:
.RS
.IP [1]
"openssl rsautl -decrypt" == "::pki::decrypt -binary -priv"
.IP [2]
"openssl rsautl -verify"  == "::pki::decrypt -binary -pub"
.RE
.TP
\fB::pki::sign\fR \fIinput\fR \fIkey\fR ?\fIalgo\fR?
Digitally sign message \fIinput\fR using the private \fIkey\fR\&.
.sp
If \fIalgo\fR is ommited "sha1" is assumed\&. Possible values for
\fIalgo\fR include "\fBmd5\fR", "\fBsha1\fR", "\fBsha256\fR",
and "\fBraw\fR"\&. Specifying "\fBraw\fR" for \fIalgo\fR will inhibit the
building of an ASN\&.1 structure to encode which hashing algorithm was
chosen\&.
\fIAttention\fR: In this case the corresponding \fBpkgi::verify\fR
must be called \fBwith\fR algorithm information\&.
Conversely, specifying a non-"\fBraw\fR" algorithm here means that
the corresponding \fBpkgi::verify\fR invokation has to be made
\fIwithout\fR algorithm information\&.
.sp
The \fIinput\fR should be the plain text, hashing will be
performed on it\&.
.sp
The \fIkey\fR should include the private key\&.
.TP
\fB::pki::verify\fR \fIsignedmessage\fR \fIplaintext\fR \fIkey\fR ?\fIalgo\fR?
Verify a digital signature using a public \fIkey\fR\&.  Returns true or false\&.
.sp
\fIAttention\fR: The algorithm information \fIalgo\fR has to
be specified if and only if the \fBpki::sign\fR which generated the
\fIsignedmessage\fR was called with algorithm "\fBraw\fR"\&. This
inhibited the building of the ASN\&.1 structure encoding the chosen
hashing algorithm\&. Conversely, if a proper algorithm was specified
during signing then you \fImust not\fR specify an algorithm here\&.
.TP
\fB::pki::key\fR \fIkey\fR ?\fIpassword\fR? ?\fIencodePem\fR?
Convert a key structure into a serialized PEM (default) or DER encoded private key suitable for other applications\&.  For RSA keys this means PKCS#1\&.
.TP
\fB::pki::pkcs::parse_key\fR \fIkey\fR ?\fIpassword\fR?
Convert a PKCS#1 private \fIkey\fR into a usable key, i\&.e\&. one which
can be used as argument for
\fB::pki::encrypt\fR,
\fB::pki::decrypt\fR,
\fB::pki::sign\fR, and
\fB::pki::verify\fR\&.
.TP
\fB::pki::x509::parse_cert\fR \fIcert\fR
Convert an X\&.509 certificate to a usable (public) key\&. The returned
dictionary can be used as argument for
\fB::pki:encrypt\fR,
\fB::pki::decrypt\fR, and
\fB::pki::verify\fR\&.
The \fIcert\fR argument can be either PEM or DER encoded\&.
In addition to the public keying information, the dictionary contains the following
keys containing certificate content as defined in
\fIRFC5280\fR [https://www\&.rfc-editor\&.org/rfc/rfc5280#section-4\&.1]:
.RS
.IP \(bu
\fBsubject\fR holds the name of the subject from the certificate\&.
.IP \(bu
\fBissuer\fR holds the name of the issuing CA\&.
.IP \(bu
\fBserial_number\fR holds the serial number of the certificate\&.
.IP \(bu
\fBnotBefore\fR holds the starting date for certificate validity\&.
.IP \(bu
\fBnotAfter\fR holds the ending date for certificate validity\&.
.IP \(bu
\fBversion\fR holds the X\&.509 version format\&.
.IP \(bu
\fBextensions\fR holds a dictionary containing the extensions included
in the certificate (see below)\&.
.RE
.IP
The dictionary holds additional entries related to keying\&. These are intended for
use of the above-mentioned commands for cryptographic operations\&.
.sp
The \fBextensions\fR key in the returned dictionary holds a nested
dictionary whose keys correspond to the names (with same exact case) in
\fICertificate Extensions\fR [https://www\&.rfc-editor\&.org/rfc/rfc5280#section-4\&.2]
in RFC5280\&. The format of each value is also based on the ASN\&.1 structures
defined there\&.
See the \fIExamples\fR [#section3] for an illustration\&.
.TP
\fB::pki::rsa::generate\fR \fIbitlength\fR ?\fIexponent\fR?
Generate a new RSA key pair, the parts of which can be used as
argument for
\fB::pki::encrypt\fR,
\fB::pki::decrypt\fR,
\fB::pki::sign\fR, and
\fB::pki::verify\fR\&.
.sp
The \fIbitlength\fR argument is the length of the public key modulus\&.
.sp
The \fIexponent\fR argument should generally not be specified unless
you really know what you are doing\&.
.TP
\fB::pki::x509::verify_cert\fR \fIcert\fR \fItrustedcerts\fR ?\fIintermediatecerts\fR?
Verify that a trust can be found between the certificate specified in the
\fIcert\fR argument and one of the certificates specified in the list
of certificates in the \fItrustedcerts\fR argument\&.  (Eventually the
chain can be through untrusted certificates listed in the \fIintermediatecerts\fR
argument, but this is currently unimplemented)\&.
The certificates specified in the \fIcert\fR and \fItrustedcerts\fR option
should be parsed (from \fB::pki::x509::parse_cert\fR)\&.
.TP
\fB::pki::x509::validate_cert\fR \fIcert\fR ?\fB-sign_message\fR \fIdn_of_signer\fR? ?\fB-encrypt_message\fR \fIdn_of_signer\fR? ?\fB-sign_cert\fR \fIdn_to_be_signed\fR \fIca_depth\fR? ?\fB-ssl\fR \fIdn\fR?
Validate that a certificate is valid to be used in some capacity\&.  If
multiple options are specified they must all be met for this procedure
to return "true"\&.
.sp
Currently, only the \fB-sign_cert\fR option is functional\&.
Its arguments are \fIdn_to_be_signed\fR
and \fIca_depth\fR\&.  The \fIdn_to_be_signed\fR is the distinguished from
the subject of a certificate to verify that the certificate specified in
the \fIcert\fR argument can sign\&.  The \fIca_depth\fR argument is used to
indicate at which depth the verification should be done at\&.  Some
certificates are limited to how far down the chain they can be used to
verify a given certificate\&.
.TP
\fB::pki::pkcs::create_csr\fR \fIkeylist\fR \fInamelist\fR ?\fIencodePem\fR? ?\fIalgo\fR?
Generate a certificate signing request from a key pair specified in
the \fIkeylist\fR argument\&.
.sp
The \fInamelist\fR argument is a list of "name" followed by "value"
pairs to encoding as the requested distinguished name in the CSR\&.
.sp
The \fIencodePem\fR option specifies whether or not the result should
be PEM encoded or DER encoded\&.  A "true" value results in the result
being PEM encoded, while any other value 9results in the the result
being DER encoded\&.  DER encoding is the default\&.
.sp
The \fIalgo\fR argument specifies the hashing algorithm we should use
to sign this certificate signing request with\&.  The default is "sha1"\&.
Other possible values include "md5" and "sha256"\&.
.TP
\fB::pki::pkcs::parse_csr\fR \fIcsr\fR
Parse a Certificate Signing Request\&. The \fIcsr\fR argument can be either PEM or
DER encoded\&. The command returns a dictionary that includes the following keys:
.RS
.IP \(bu
\fBsubject\fR - contains the subject name from the CSR\&.
.IP \(bu
\fBtype\fR - contains the public key algorithm name\&. Currently only
\fBrsa\fR is supported\&.
.IP \(bu
\fBextensionRequest\fR - contains a dictionary with the contents of
the \fI\fBextensionRequest\fR\fR [https://datatracker\&.ietf\&.org/doc/html/rfc2986#page-5] information in the CSR\&. This has the same form as described for
the \fBextensions\fR dictionary in the documentation for \fBparse_cert\fR\&.
.RE
.IP
There may be other keys in the dictionary related to the public key algorithm
in use\&.
.TP
\fB::pki::x509::create_cert\fR \fIsignreqlist\fR \fIcakeylist\fR \fIserial_number\fR \fInotBefore\fR \fInotAfter\fR \fIisCA\fR \fIextensions\fR ?\fIencodePem\fR? ?\fIalgo\fR?
Sign a signing request (usually from \fB::pki::pkcs::create_csr\fR or
\fB::pki::pkcs::parse_csr\fR) with a Certificate Authority (CA) certificate\&.
.sp
The \fIsignreqlist\fR argument should be the parsed signing request\&.
.sp
The \fIcakeylist\fR argument should be the parsed CA certificate\&.
.sp
The \fIserial_number\fR argument should be a serial number unique to
this certificate from this certificate authority\&.
.sp
The \fInotBefore\fR and \fInotAfter\fR arguments should contain the
time before and after which (respectively) the certificate should
be considered invalid\&.  The time should be encoded as something
\fBclock format\fR will accept (i\&.e\&., the results of \fBclock seconds\fR
and \fBclock add\fR)\&.
.sp
The \fIisCA\fR argument is a boolean argument describing whether or not
the signed certificate should be a a CA certificate\&.  If specified as
true the "id-ce-basicConstraints" extension is added with the arguments
of "critical" being true, "allowCA" being true, and caDepth being
-1 (infinite)\&.
.sp
The \fIextensions\fR argument is a list of extensions and their parameters
that should be encoded into the created certificate\&.   Currently only one
extension is understood ("id-ce-basicConstraints")\&.  It accepts three
arguments \fIcritical\fR \fIallowCA\fR \fIcaDepth\fR\&.  The \fIcritical\fR
argument to this extension (and any extension) whether or not the
validator should reject the certificate as invalid if it does not
understand the extension (if set to "true") or should ignore the extension
(if set to "false")\&.  The \fIallowCA\fR argument is used to specify
as a boolean value whether or not we can be used a certificate
authority (CA)\&.  The \fIcaDepth\fR argument indicates how many children
CAs can be children of this CA in a depth-wise fashion\&.  A value of "0"
for the \fIcaDepth\fR argument means that this CA cannot sign a CA
certificate and have the result be valid\&.  A value of "-1" indicates
infinite depth\&.
.PP
.SH EXAMPLES
The example below retrieves a certificate from \fIwww\&.example\&.com\fR using
the TLS extension and dumps its content\&.
.CS


    % set so [tls::socket www\&.example\&.com 443]
    sock00000229EB84E710
    % tls::handshake $so
    1
    % set status [tls::status $so]
    \&.\&.\&.output not shown\&.\&.\&.
    % set cert_pem [dict get $status certificate]
    \&.\&.\&.output not shown\&.\&.\&.
    % set cert [::pki::x509::parse_cert $cert_pem]
    \&.\&.\&.output not shown\&.\&.\&.
    % dict get $cert subject
    C=US, ST=California, L=Los Angeles, O=Internet Corporation for Assigned Names and Numbers, CN=www\&.example\&.org
    % dict get $cert issuer
    C=US, O=DigiCert Inc, CN=DigiCert TLS RSA SHA256 2020 CA1
    % clock format [dict get $cert notAfter]
    Sun Dec 26 05:29:59 +0530 2021
    % set extensions [dict get $cert extensions]
    \&.\&.\&.output not shown\&.\&.\&.
    % dict keys $extensions
    authorityKeyIdentifier subjectKeyIdentifier subjectAltName keyUsage extKeyUsage cRLDistributionPoints certificatePolicies authorityInfoAccess id-ce-basicConstraints basicConstraints 1\&.3\&.6\&.1\&.4\&.1\&.11129\&.2\&.4\&.2
    dict get $extensions basicConstraints
    1 {0 -1}
    % dict get $extensions keyUsage
    1 {5 digitalSignature keyEncipherment}
    % dict get $extensions extKeyUsage
    0 {serverAuth clientAuth}
    % dict get $extensions subjectAltName
    0 {dNSName www\&.example\&.org dNSName example\&.com dNSName example\&.edu dNSName example\&.net dNSName example\&.org dNSName www\&.example\&.com dNSName www\&.example\&.edu dNSName www\&.example\&.net}
    % dict get $extensions basicConstraints
    1 {0 -1}
    % dict get $extensions keyUsage
    1 {5 digitalSignature keyEncipherment}
    % dict get $extensions extKeyUsage
    0 {serverAuth clientAuth}

.CE
.SH REFERENCES
.IP [1]
\fIInternet X\&.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile\fR [https://www\&.rfc-editor\&.org/rfc/rfc5280]
.IP [2]
\fINew ASN\&.1 Modules for the Public Key Infrastructure Using X\&.509 (PKIX)\fR [https://www\&.rfc-editor\&.org/rfc/rfc5912]
.IP [3]
\fIPKCS #10: Certification Request Syntax Specification\fR [https://www\&.rfc-editor\&.org/rfc/rfc2986]
.PP
.SH AUTHORS
Roy Keene, Ashok P\&. Nadkarni
.SH "BUGS, IDEAS, FEEDBACK"
This document, and the package it describes, will undoubtedly contain
bugs and other problems\&.
Please report such in the category \fIrsa\fR of the
\fITcllib Trackers\fR [http://core\&.tcl\&.tk/tcllib/reportlist]\&.
Please also report any ideas for enhancements you may have for either
package and/or documentation\&.
.PP
When proposing code changes, please provide \fIunified diffs\fR,
i\&.e the output of \fBdiff -u\fR\&.
.PP
Note further that \fIattachments\fR are strongly preferred over
inlined patches\&. Attachments can be made by going to the \fBEdit\fR
form of the ticket immediately after its creation, and then using the
left-most button in the secondary navigation bar\&.
.SH "SEE ALSO"
aes(n), blowfish(n), des(n), md5(n), sha1(n)
.SH KEYWORDS
cipher, data integrity, encryption, public key cipher, rsa, security
.SH CATEGORY
Hashes, checksums, and encryption
.SH COPYRIGHT
.nf
Copyright (c) 2010, 2011, 2012, 2013, 2021 - 2024 Roy Keene, Andreas Kupries, Ashok P\&. Nadkarni

.fi