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scd:p15: Show a pretty PIN prompt.

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* scd/app-p15.c (struct prkdf_object_s): New fields common_name and
serial_number.
(release_prkdflist): Free them.
(keygrip_from_prkdf): Parse cert and set them.
(any_control_or_space): New.
(make_pin_prompt): New.
(verify_pin): Construct a pretty PIN prompt.
(do_sign): Remove debug output.
--

The D-Trust card has the SerialNumber part of the Subject printed on
the front matter, we assume this is also possible with other cards and
thus we show this as serial number.

The holder of the card is also extracted from the card's subject.

Signed-off-by: Werner Koch <wk@gnupg.org>
This commit is contained in:
Werner Koch 2020-04-07 20:38:15 +02:00
parent f28795b615
commit 9ec8d984be
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 197 additions and 13 deletions
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210
scd/app-p15.c
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@ -40,6 +40,7 @@
#include "scdaemon.h"
#include "iso7816.h"
#include "../common/i18n.h"
#include "../common/tlv.h"
#include "apdu.h" /* fixme: we should move the card detection to a
separate file */
@ -209,6 +210,14 @@ struct prkdf_object_s
* modulus). It is valid if the keygrip is also valid. */
unsigned int keynbits;
/* Malloced CN from the Subject-DN of the corresponding certificate
* or NULL if not known. */
char *common_name;
/* Malloced SerialNumber from the Subject-DN of the corresponding
* certificate or NULL if not known. */
char *serial_number;
/* Length and allocated buffer with the Id of this object. */
size_t objidlen;
unsigned char *objid;
@ -392,6 +401,8 @@ release_prkdflist (prkdf_object_t a)
while (a)
{
prkdf_object_t tmp = a->next;
xfree (a->common_name);
xfree (a->serial_number);
xfree (a->objid);
xfree (a->authid);
xfree (a);
@ -2625,7 +2636,7 @@ send_certinfo (app_t app, ctrl_t ctrl, const char *certtype,
/* Get the keygrip of the private key object PRKDF. On success the
* keygrip, the algo and the length are stored in the KEYGRIP,
* KEYALFO, and KEYNBITS fields of the PRKDF object. */
* KEYALGO, and KEYNBITS fields of the PRKDF object. */
static gpg_error_t
keygrip_from_prkdf (app_t app, prkdf_object_t prkdf)
{
@ -2640,6 +2651,11 @@ keygrip_from_prkdf (app_t app, prkdf_object_t prkdf)
if (prkdf->keygrip_valid)
return 0;
xfree (prkdf->common_name);
prkdf->common_name = NULL;
xfree (prkdf->serial_number);
prkdf->serial_number = NULL;
/* FIXME: We should check whether a public key directory file and a
matching public key for PRKDF is available. This should make
extraction of the key much easier. My current test card doesn't
@ -2678,6 +2694,59 @@ keygrip_from_prkdf (app_t app, prkdf_object_t prkdf)
xfree (der);
if (!err)
err = app_help_get_keygrip_string (cert, prkdf->keygrip, &s_pkey);
if (!err)
{
/* Try to get the CN and the SerialNumber from the certificate;
* we use a very simple approach here which should work in many
* cases. Eventually we should add a rfc-2253 parser into
* libksba to make it easier to parse such a string.
*
* First example string:
* "CN=Otto Schily,O=Miniluv,C=DE"
* Second example string:
* "2.5.4.5=#445452323030303236333531,2.5.4.4=#4B6F6368,"
* "2.5.4.42=#5765726E6572,CN=Werner Koch,OU=For testing"
* " purposes only!,O=Testorganisation,C=DE"
*/
char *dn = ksba_cert_get_subject (cert, 0);
if (dn)
{
char *p, *pend, *buf;
p = strstr (dn, "CN=");
if (p && (p==dn || p[-1] == ','))
{
p += 3;
if (!(pend = strchr (p, ',')))
pend = p + strlen (p);
if (pend && pend > p
&& (prkdf->common_name = xtrymalloc ((pend - p) + 1)))
{
memcpy (prkdf->common_name, p, pend-p);
prkdf->common_name[pend-p] = 0;
}
}
p = strstr (dn, "2.5.4.5=#"); /* OID of the SerialNumber */
if (p && (p==dn || p[-1] == ','))
{
p += 9;
if (!(pend = strchr (p, ',')))
pend = p + strlen (p);
if (pend && pend > p
&& (buf = xtrymalloc ((pend - p) + 1)))
{
memcpy (buf, p, pend-p);
buf[pend-p] = 0;
if (!hex2str (buf, buf, strlen (buf)+1, NULL))
xfree (buf); /* Invalid hex encoding. */
else
prkdf->serial_number = buf;
}
}
ksba_free (dn);
}
}
ksba_cert_release (cert);
if (err)
goto leave;
@ -3231,6 +3300,90 @@ prepare_verify_pin (app_t app, const char *keyref,
}
static int
any_control_or_space (const char *string)
{
const unsigned char *s;
for (s = string; *string; string++)
if (*s <= 0x20 || *s >= 0x7f)
return 1;
return 0;
}
/* Return an allocated string to be used as prompt. Returns NULL on
* malloc error. */
static char *
make_pin_prompt (app_t app, int remaining, const char *firstline,
const char *common_name, const char *serial_number)
{
char *serial, *tmpbuf, *result;
const char *dispsn;
/* We prefer the SerialNumber RDN from the Subject-DN but we don't
* use it if it features a percent sign (special character in pin
* prompts) or has any control character. */
if (serial_number && *serial_number
&& !strchr (serial_number, '%')
&& !any_control_or_space (serial_number))
{
serial = NULL;
dispsn = serial_number;
}
else
{
serial = app_get_serialno (app);
if (!serial)
return NULL; /* Ooops. */
dispsn = serial;
}
/* TRANSLATORS: Put a \x1f right before a colon. This can be
* used by pinentry to nicely align the names and values. Keep
* the %s at the start and end of the string. */
result = xtryasprintf (_("%s"
"Number\x1f: %s%%0A"
"Holder\x1f: %s"
"%s"),
"\x1e",
dispsn,
common_name? common_name: "",
"");
if (!result)
return NULL; /* Out of core. */
xfree (serial);
/* Append a "remaining attempts" info if needed. */
if (remaining != -1 && remaining < 3)
{
char *rembuf;
/* TRANSLATORS: This is the number of remaining attempts to
* enter a PIN. Use %%0A (double-percent,0A) for a linefeed. */
rembuf = xtryasprintf (_("Remaining attempts: %d"), remaining);
if (rembuf)
{
tmpbuf = strconcat (firstline, "%0A%0A", result,
"%0A%0A", rembuf, NULL);
xfree (rembuf);
}
else
tmpbuf = NULL;
xfree (result);
result = tmpbuf;
}
else
{
tmpbuf = strconcat (firstline, "%0A%0A", result, NULL);
xfree (result);
result = tmpbuf;
}
return result;
}
/* Given the private key object PRKDF and its authentication object
* AODF ask for the PIN and verify that PIN. IF AODF is NULL, no
* authentication is done. */
@ -3242,25 +3395,61 @@ verify_pin (app_t app,
gpg_error_t err;
char *pinvalue;
size_t pinvaluelen;
const char *label;
const char *errstr;
const char *s;
int remaining;
int pin_reference;
int i;
if (!aodf)
return 0;
pin_reference = aodf->pin_reference_valid? aodf->pin_reference : 0;
if (app->app_local->card_type == CARD_TYPE_CARDOS_50)
{
/* We know that this card supports a verify status check. Note
* that in contrast to PIV cards ISO7816_VERIFY_NOT_NEEDED is
* not supported. */
remaining = iso7816_verify_status (app_get_slot (app), pin_reference);
if (remaining < 0)
remaining = -1; /* We don't care about the concrete error. */
if (remaining < 3)
{
if (remaining >= 0)
log_info ("p15: PIN has %d attempts left\n", remaining);
/* On error or if less than 3 better ask. */
prkdf->pin_verified = 0;
}
}
else
remaining = -1; /* Unknown. */
/* Check whether we already verified it. */
if (prkdf->pin_verified)
return 0; /* Already done. */
if (prkdf->usageflags.non_repudiation
&& app->app_local->card_type == CARD_TYPE_BELPIC)
err = pincb (pincb_arg, "PIN (qualified signature!)", &pinvalue);
&& (app->app_local->card_type == CARD_TYPE_BELPIC
|| app->app_local->card_product == CARD_PRODUCT_DTRUST))
label = _("||Please enter the PIN for the key to create "
"qualified signatures.");
else
err = pincb (pincb_arg, "PIN", &pinvalue);
label = _("||Please enter the PIN for the standard keys.");
{
char *prompt = make_pin_prompt (app, remaining, label,
prkdf->common_name, prkdf->serial_number);
if (!prompt)
err = gpg_error_from_syserror ();
else
err = pincb (pincb_arg, prompt, &pinvalue);
xfree (prompt);
}
if (err)
{
log_info ("p15: PIN callback returned error: %s\n",
gpg_strerror (err));
log_info ("p15: PIN callback returned error: %s\n", gpg_strerror (err));
return err;
}
@ -3386,10 +3575,8 @@ verify_pin (app_t app,
pinvaluelen = strlen (pinvalue);
/* log_printhex (pinvalue, pinvaluelen, */
/* "about to verify with ref %lu pin:", */
/* aodf->pin_reference_valid? aodf->pin_reference : 0); */
err = iso7816_verify (app_get_slot (app),
aodf->pin_reference_valid? aodf->pin_reference : 0,
/* "about to verify with ref %lu pin:", pin_reference); */
err = iso7816_verify (app_get_slot (app), pin_reference,
pinvalue, pinvaluelen);
xfree (pinvalue);
if (err)
@ -3652,9 +3839,6 @@ do_sign (app_t app, ctrl_t ctrl, const char *keyidstr, int hashalgo,
exmode, dataptr, datalen,
le_value, outdata, outdatalen);
if (!err)
log_printhex (*outdata, *outdatalen, "sign output:");
return err;
}