scd: Minor and editorial changes to app-sc-hsm.c

* scd/app-sc-hsm.c (select_and_read_binary): Use SW_ macro.
(parse_certid): Remove useless test.
(send_certinfo, send_keypairinfo): Shrink malloc to the needed size.
(do_getattr): Ditto.
(verify_pin): Use SW_ macro.
(do_decipher): Replace OFS variable and extend comment.
--

Code parts which have not been audited are marked with a warning
pragma.
This commit is contained in:
Werner Koch 2014-07-24 16:16:53 +02:00
parent e49c851ff5
commit 2e936915cf
1 changed files with 172 additions and 149 deletions

View File

@ -2,8 +2,6 @@
* Copyright (C) 2005 Free Software Foundation, Inc.
* Copyright (C) 2014 Andreas Schwier <andreas.schwier@cardcontact.de>
*
* Code in this driver is based on app-p15.c with modifications
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
@ -20,6 +18,10 @@
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
/*
Code in this driver is based on app-p15.c with modifications.
*/
#include <config.h>
#include <errno.h>
#include <stdio.h>
@ -217,7 +219,7 @@ list_ef (int slot, unsigned char **result, size_t *resultlen)
*resultlen = 0;
sw = apdu_send_le (slot, 1, 0x80, 0x58, 0x00, 0x00, -1, NULL, 65536,
result, resultlen);
result, resultlen);
if (sw != SW_SUCCESS)
{
/* Make sure that pending buffers are released. */
@ -225,7 +227,7 @@ list_ef (int slot, unsigned char **result, size_t *resultlen)
*result = NULL;
*resultlen = 0;
}
return iso7816_map_sw(sw);
return iso7816_map_sw (sw);
}
@ -250,10 +252,10 @@ select_and_read_binary (int slot, unsigned short efid, const char *efid_desc,
sw = apdu_send_le(slot, 1, 0x00, 0xB1, efid >> 8, efid & 0xFF,
4, cdata, maxread, buffer, buflen);
if (sw == 0x6282)
sw = 0x9000;
if (sw == SW_EOF_REACHED)
sw = SW_SUCCESS;
err = iso7816_map_sw(sw);
err = iso7816_map_sw (sw);
if (err)
{
log_error ("error reading %s (0x%04X): %s\n",
@ -272,7 +274,6 @@ select_and_read_binary (int slot, unsigned short efid, const char *efid_desc,
static gpg_error_t
parse_certid (const char *certid, unsigned char **r_objid, size_t *r_objidlen)
{
char tmpbuf[10];
const char *s;
size_t objidlen;
unsigned char *objid;
@ -281,14 +282,9 @@ parse_certid (const char *certid, unsigned char **r_objid, size_t *r_objidlen)
*r_objid = NULL;
*r_objidlen = 0;
strcpy (tmpbuf, "HSM.");
if (strncmp (certid, tmpbuf, strlen (tmpbuf)) )
{
if (!strncmp (certid, "HSM.", 4))
return gpg_error (GPG_ERR_NOT_FOUND);
return gpg_error (GPG_ERR_INV_ID);
}
certid += strlen (tmpbuf);
if (strncmp (certid, "HSM.", 4))
return gpg_error (GPG_ERR_INV_ID);
certid += 4;
for (s=certid, objidlen=0; hexdigitp (s); s++, objidlen++)
;
@ -431,14 +427,19 @@ parse_keyusage_flags (const unsigned char *der, size_t derlen,
/* Read and parse a Private Key Directory File containing a single
* key description in PKCS#15 format
* For each private key a matching certificate description is created,
* if the certificate EF exists and contains a X.509 certificate*/
/*
/* Read and parse a Private Key Directory File containing a single key
description in PKCS#15 format. For each private key a matching
certificate description is created, if the certificate EF exists
and contains a X.509 certificate.
Example data:
0000 30 2A 30 13 0C 11 4A 6F 65 20 44 6F 65 20 28 52 0*0...Joe Doe (R
0010 53 41 32 30 34 38 29 30 07 04 01 01 03 02 02 74 SA2048)0.......t
0020 A1 0A 30 08 30 02 04 00 02 02 08 00 ..0.0.......
Decoded example:
SEQUENCE SIZE( 42 )
SEQUENCE SIZE( 19 )
UTF8-STRING SIZE( 17 ) -- label
@ -446,20 +447,21 @@ SEQUENCE SIZE( 42 )
0010 29 )
SEQUENCE SIZE( 7 )
OCTET-STRING SIZE( 1 ) -- id
0000 01 .
0000 01
BIT-STRING SIZE( 2 ) -- key usage
0000 02 74 .t
0000 02 74
A1 [ CONTEXT 1 ] IMPLICIT SEQUENCE SIZE( 10 )
SEQUENCE SIZE( 8 )
SEQUENCE SIZE( 2 )
OCTET-STRING SIZE( 0 ) -- empty path, req object in PKCS#15
INTEGER SIZE( 2 ) -- modulus size in bits
0000 08 00 ..
0000 08 00
*/
static gpg_error_t
read_ef_prkd (app_t app, unsigned short fid, prkdf_object_t *prkdresult,
cdf_object_t *cdresult)
{
#warning function not yet audited
gpg_error_t err;
unsigned char *buffer = NULL;
size_t buflen;
@ -854,24 +856,28 @@ read_ef_prkd (app_t app, unsigned short fid, prkdf_object_t *prkdresult,
/* Read and parse the Certificate Description File identified by FID.
On success a the CDF list gets stored at RESULT and the
caller is then responsible of releasing the object.*/
/*
On success a the CDF list gets stored at RESULT and the caller is
then responsible of releasing the object.
Example data:
0000 30 35 30 11 0C 0B 43 65 72 74 69 66 69 63 61 74 050...Certificat
0010 65 03 02 06 40 30 16 04 14 C2 01 7C 2F BA A4 4A e...@0.....|/..J
0020 4A BB B8 49 11 DB 4A CA AA 7E 6A 2D 1B A1 08 30 J..I..J..~j-...0
0030 06 30 04 04 02 CA 00 .0.....
Decoded example:
SEQUENCE SIZE( 53 )
SEQUENCE SIZE( 17 )
UTF8-STRING SIZE( 11 ) -- label
0000 43 65 72 74 69 66 69 63 61 74 65 Certificate
BIT-STRING SIZE( 2 ) -- common object attributes
0000 06 40 .@
0000 06 40
SEQUENCE SIZE( 22 )
OCTET-STRING SIZE( 20 ) -- id
0000 C2 01 7C 2F BA A4 4A 4A BB B8 49 11 DB 4A CA AA ..|/..JJ..I..J..
0010 7E 6A 2D 1B ~j-.
0000 C2 01 7C 2F BA A4 4A 4A BB B8 49 11 DB 4A CA AA
0010 7E 6A 2D 1B
A1 [ CONTEXT 1 ] IMPLICIT SEQUENCE SIZE( 8 )
SEQUENCE SIZE( 6 )
SEQUENCE SIZE( 4 )
@ -881,6 +887,7 @@ SEQUENCE SIZE( 53 )
static gpg_error_t
read_ef_cd (app_t app, unsigned short fid, cdf_object_t *result)
{
#warning needs an audit
gpg_error_t err;
unsigned char *buffer = NULL;
size_t buflen;
@ -1062,10 +1069,13 @@ read_ef_cd (app_t app, unsigned short fid, cdf_object_t *result)
/* Read the device certificate and extract the serial number
/* Read the device certificate and extract the serial number.
EF.C_DevAut (2F02) contains two CVCs, the first is the device
certificate, the second is the issuer certificate.
Example data:
EF.C_DevAut (2F02) contains two CVCs, the first is the device certificate, the
second is the issuer certificate
0000 7F 21 81 E2 7F 4E 81 9B 5F 29 01 00 42 0B 55 54 .!...N.._)..B.UT
0010 43 43 30 32 30 30 30 30 32 7F 49 4F 06 0A 04 00 CC0200002.IO....
0020 7F 00 07 02 02 02 02 03 86 41 04 6D FF D6 85 57 .........A.m...W
@ -1096,44 +1106,45 @@ second is the issuer certificate
01B0 76 E6 2B A0 4C 01 CA C1 26 0C 45 6D C6 CB EC 92 v.+.L...&.Em....
01C0 BF 38 18 AD 8F B2 29 40 A9 51 .8....)@.Q
The certificate format is defined in BSI TR-03110
The certificate format is defined in BSI TR-03110:
7F21 [ APPLICATION 33 ] IMPLICIT SEQUENCE SIZE( 226 )
7F4E [ APPLICATION 78 ] IMPLICIT SEQUENCE SIZE( 155 )
5F29 [ APPLICATION 41 ] SIZE( 1 ) -- profile id
0000 00 .
0000 00
42 [ APPLICATION 2 ] SIZE( 11 ) -- CAR
0000 55 54 43 43 30 32 30 30 30 30 32 UTCC0200002
7F49 [ APPLICATION 73 ] IMPLICIT SEQUENCE SIZE( 79 ) -- public key
OBJECT IDENTIFIER = { id-TA-ECDSA-SHA-256 }
86 [ CONTEXT 6 ] SIZE( 65 )
0000 04 6D FF D6 85 57 40 FB 10 5D 94 71 8A 94 D2 5E .m...W@..].q...^
0010 50 33 E7 1E C0 6C 63 D5 C8 FC BA F3 02 1D 70 23 P3...lc.......p#
0020 F6 47 E8 35 48 EF B5 94 72 3C 6F BE C0 EB 9A C7 .G.5H...r<o.....
0030 FB 06 59 26 CF 65 EF A1 72 E0 98 F3 F0 44 1B B7 ..Y&.e..r....D..
0040 71 q
0000 04 6D FF D6 85 57 40 FB 10 5D 94 71 8A 94 D2 5E
0010 50 33 E7 1E C0 6C 63 D5 C8 FC BA F3 02 1D 70 23
0020 F6 47 E8 35 48 EF B5 94 72 3C 6F BE C0 EB 9A C7
0030 FB 06 59 26 CF 65 EF A1 72 E0 98 F3 F0 44 1B B7
0040 71
5F20 [ APPLICATION 32 ] SIZE( 16 ) -- CHR
0000 55 54 43 43 30 32 30 30 30 31 33 30 30 30 30 30 UTCC020001300000
7F4C [ APPLICATION 76 ] IMPLICIT SEQUENCE SIZE( 16 ) -- CHAT
OBJECT IDENTIFIER = { 1 3 6 1 4 1 24991 3 1 1 }
53 [ APPLICATION 19 ] SIZE( 1 )
0000 00 .
0000 00
5F25 [ APPLICATION 37 ] SIZE( 6 ) -- Valid from
0000 01 04 00 07 01 01 ......
0000 01 04 00 07 01 01
5F24 [ APPLICATION 36 ] SIZE( 6 ) -- Valid to
0000 02 01 00 03 02 07 ......
0000 02 01 00 03 02 07
5F37 [ APPLICATION 55 ] SIZE( 64 ) -- Signature
0000 7F 73 04 3B 06 63 79 41 BE 1A 9F FC F6 77 67 2B .s.;.cyA.....wg+
0010 8A 41 D1 11 F6 9B 54 44 AD 19 FB B8 0C C6 2F 34 .A....TD....../4
0020 71 8E 4F F6 92 59 34 61 D9 4F 4A 86 36 A8 D8 9A q.O..Y4a.OJ.6...
0030 C6 3C 17 7E 71 CE A8 26 D0 C5 25 61 78 9D 01 F8 .<.~q..&..%ax...
0000 7F 73 04 3B 06 63 79 41 BE 1A 9F FC F6 77 67 2B
0010 8A 41 D1 11 F6 9B 54 44 AD 19 FB B8 0C C6 2F 34
0020 71 8E 4F F6 92 59 34 61 D9 4F 4A 86 36 A8 D8 9A
0030 C6 3C 17 7E 71 CE A8 26 D0 C5 25 61 78 9D 01 F8
the serial number is contained in tag 5F20, while the last 5 digits are
truncated
The serial number is contained in tag 5F20, while the last 5 digits
are truncated.
*/
static gpg_error_t
read_serialno(app_t app)
{
#warning audit!
gpg_error_t err;
unsigned char *buffer = NULL;
size_t buflen;
@ -1188,10 +1199,11 @@ read_serialno(app_t app)
/* Get all the basic information from the SmartCard-HSM, check the
structure and initialize our local context. This is used once at
application initialization. */
application initialization. */
static gpg_error_t
read_meta (app_t app)
{
#warning audit!
gpg_error_t err;
unsigned char *eflist = NULL;
size_t eflistlen = 0;
@ -1205,29 +1217,31 @@ read_meta (app_t app)
if (err)
return err;
for (i = 0; i < eflistlen; i += 2) {
switch(eflist[i]) {
case SC_HSM_KEY_PREFIX:
if (eflist[i + 1] == 0) /* No key with ID=0 */
for (i = 0; i < eflistlen; i += 2)
{
switch(eflist[i])
{
case SC_HSM_KEY_PREFIX:
if (eflist[i + 1] == 0) /* No key with ID=0 */
break;
err = read_ef_prkd (app, ((SC_HSM_PRKD_PREFIX << 8) | eflist[i + 1]),
&app->app_local->private_key_info,
&app->app_local->certificate_info);
if (gpg_err_code (err) == GPG_ERR_NO_DATA)
err = 0;
if (err)
return err;
break;
err = read_ef_prkd (app, (SC_HSM_PRKD_PREFIX << 8) | eflist[i + 1],
&app->app_local->private_key_info,
&app->app_local->certificate_info);
if (gpg_err_code (err) == GPG_ERR_NO_DATA)
err = 0;
if (err)
return err;
break;
case SC_HSM_CD_PREFIX:
err = read_ef_cd (app, (eflist[i] << 8) | eflist[i + 1],
&app->app_local->trusted_certificate_info);
if (gpg_err_code (err) == GPG_ERR_NO_DATA)
err = 0;
if (err)
return err;
break;
case SC_HSM_CD_PREFIX:
err = read_ef_cd (app, ((eflist[i] << 8) | eflist[i + 1]),
&app->app_local->trusted_certificate_info);
if (gpg_err_code (err) == GPG_ERR_NO_DATA)
err = 0;
if (err)
return err;
break;
}
}
}
xfree (eflist);
@ -1246,7 +1260,7 @@ send_certinfo (ctrl_t ctrl, const char *certtype, cdf_object_t certinfo)
{
char *buf, *p;
buf = xtrymalloc (9 + certinfo->objidlen*2 + 1);
buf = xtrymalloc (4 + certinfo->objidlen*2 + 1);
if (!buf)
return gpg_error_from_syserror ();
p = stpcpy (buf, "HSM.");
@ -1313,7 +1327,7 @@ send_keypairinfo (app_t app, ctrl_t ctrl, prkdf_object_t keyinfo)
char gripstr[40+1];
char *buf, *p;
buf = xtrymalloc (9 + keyinfo->objidlen*2 + 1);
buf = xtrymalloc (4 + keyinfo->objidlen*2 + 1);
if (!buf)
return gpg_error_from_syserror ();
p = stpcpy (buf, "HSM.");
@ -1393,7 +1407,8 @@ readcert_by_cdf (app_t app, cdf_object_t cdf,
return 0;
}
err = select_and_read_binary (app->slot, cdf->fid, "CD", &buffer, &buflen, 4096);
err = select_and_read_binary (app->slot, cdf->fid, "CD",
&buffer, &buflen, 4096);
if (err)
{
log_error ("error reading certificate with Id ");
@ -1481,7 +1496,7 @@ readcert_by_cdf (app_t app, cdf_object_t cdf,
the CERTINFO status lines) and return it in the freshly allocated
buffer to be stored at R_CERT and its length at R_CERTLEN. A error
code will be returned on failure and R_CERT and R_CERTLEN will be
set to NULL/0. */
set to (NULL,0). */
static gpg_error_t
do_readcert (app_t app, const char *certid,
unsigned char **r_cert, size_t *r_certlen)
@ -1493,7 +1508,7 @@ do_readcert (app_t app, const char *certid,
*r_certlen = 0;
err = cdf_object_from_certid (app, certid, &cdf);
if (!err)
err =readcert_by_cdf (app, cdf, r_cert, r_certlen);
err = readcert_by_cdf (app, cdf, r_cert, r_certlen);
return err;
}
@ -1517,7 +1532,7 @@ do_getattr (app_t app, ctrl_t ctrl, const char *name)
break;
if (prkdf)
{
buf = xtrymalloc (9 + prkdf->objidlen*2 + 1);
buf = xtrymalloc (4 + prkdf->objidlen*2 + 1);
if (!buf)
return gpg_error_from_syserror ();
p = stpcpy (buf, "HSM.");
@ -1539,18 +1554,18 @@ do_getattr (app_t app, ctrl_t ctrl, const char *name)
/* Apply PKCS#1 V1.5 padding for signature operation
* The function combines padding, digest info and the hash value. The buffer
* must be allocated by the caller matching the key size
*/
static
void apply_PKCS_padding(const unsigned char *dig, int diglen,
const unsigned char *prefix, int prefixlen,
unsigned char *buff, int bufflen)
/* Apply PKCS#1 V1.5 padding for signature operation. The function
* combines padding, digest info and the hash value. The buffer must
* be allocated by the caller matching the key size. */
static void
apply_PKCS_padding(const unsigned char *dig, int diglen,
const unsigned char *prefix, int prefixlen,
unsigned char *buff, int bufflen)
{
#warning Seems okay but needs a seconds opinion
int i;
// Caller must ensure sufficient buffer
/* Caller must ensure a sufficient buffer. */
if (diglen + prefixlen + 4 > bufflen)
return;
@ -1561,23 +1576,22 @@ void apply_PKCS_padding(const unsigned char *dig, int diglen,
*buff++ = 0x00;
if (prefix)
memcpy(buff, prefix, prefixlen);
buff+= prefixlen;
memcpy(buff, dig, diglen);
memcpy (buff, prefix, prefixlen);
buff += prefixlen;
memcpy (buff, dig, diglen);
}
/*
* Decode a digest info structure to extract the hash value. The
* buffer to receive the hash must be provided by the caller with
* hashlen pointing to the inbound length. hashlen is updated to the
* outbound length
*/
static
int hash_from_digestinfo(const unsigned char *di, size_t dilen,
unsigned char *hash, size_t *hashlen)
/* Decode a digest info structure (DI,DILEN) to extract the hash
* value. The buffer HASH to receive the digest must be provided by
* the caller with HASHLEN pointing to the inbound length. HASHLEN is
* updated to the outbound length. */
static int
hash_from_digestinfo (const unsigned char *di, size_t dilen,
unsigned char *hash, size_t *hashlen)
{
#warning audit!
const unsigned char *p,*pp;
size_t n, nn, objlen, hdrlen;
int class, tag, constructed, ndef;
@ -1630,8 +1644,8 @@ int hash_from_digestinfo(const unsigned char *di, size_t dilen,
/* Perform PIN verification
*/
static gpg_error_t
verify_pin(app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
verify_pin (app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
void *pincb_arg)
{
gpg_error_t err;
pininfo_t pininfo;
@ -1645,15 +1659,17 @@ verify_pin(app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
if (sw == SW_SUCCESS)
return 0; /* PIN already verified */
if (sw == 0x6984) {
if (sw == SW_REF_DATA_INV)
{
log_error ("SmartCard-HSM not initialized. Run sc-hsm-tool first\n");
return gpg_error (GPG_ERR_NO_PIN);
}
}
if (sw == SW_CHV_BLOCKED) {
if (sw == SW_CHV_BLOCKED)
{
log_error ("PIN Blocked\n");
return gpg_error (GPG_ERR_PIN_BLOCKED);
}
}
memset (&pininfo, 0, sizeof pininfo);
pininfo.fixedlen = 0;
@ -1668,8 +1684,7 @@ verify_pin(app_t app, gpg_error_t (*pincb)(void*, const char *, char **),
err = pincb (pincb_arg, prompt, NULL);
if (err)
{
log_info ("PIN callback returned error: %s\n",
gpg_strerror (err));
log_info ("PIN callback returned error: %s\n", gpg_strerror (err));
return err;
}
@ -1745,8 +1760,9 @@ do_sign (app_t app, const char *keyidstr, int hashalgo,
0x00, 0x04, 0x40 };
gpg_error_t err;
unsigned char cdsblk[256]; /* Raw PKCS#1 V1.5 block with padding (RSA) or hash */
prkdf_object_t prkdf; /* The private key object. */
unsigned char cdsblk[256]; /* Raw PKCS#1 V1.5 block with padding
(RSA) or hash. */
prkdf_object_t prkdf; /* The private key object. */
size_t cdsblklen;
unsigned char algoid;
int sw;
@ -1776,55 +1792,60 @@ do_sign (app_t app, const char *keyidstr, int hashalgo,
cdsblklen = 256;
if (hashalgo == GCRY_MD_SHA1 && indatalen == 20)
apply_PKCS_padding(indata, indatalen, sha1_prefix, sizeof(sha1_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
sha1_prefix, sizeof(sha1_prefix),
cdsblk, cdsblklen);
else if (hashalgo == GCRY_MD_MD5 && indatalen == 20)
apply_PKCS_padding(indata, indatalen, rmd160_prefix, sizeof(rmd160_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
rmd160_prefix, sizeof(rmd160_prefix),
cdsblk, cdsblklen);
else if (hashalgo == GCRY_MD_SHA224 && indatalen == 28)
apply_PKCS_padding(indata, indatalen, sha224_prefix, sizeof(sha224_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
sha224_prefix, sizeof(sha224_prefix),
cdsblk, cdsblklen);
else if (hashalgo == GCRY_MD_SHA256 && indatalen == 32)
apply_PKCS_padding(indata, indatalen, sha256_prefix, sizeof(sha256_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
sha256_prefix, sizeof(sha256_prefix),
cdsblk, cdsblklen);
else if (hashalgo == GCRY_MD_SHA384 && indatalen == 48)
apply_PKCS_padding(indata, indatalen, sha384_prefix, sizeof(sha384_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
sha384_prefix, sizeof(sha384_prefix),
cdsblk, cdsblklen);
else if (hashalgo == GCRY_MD_SHA512 && indatalen == 64)
apply_PKCS_padding(indata, indatalen, sha512_prefix, sizeof(sha512_prefix),
cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen,
sha512_prefix, sizeof(sha512_prefix),
cdsblk, cdsblklen);
else /* Assume it's already a digest info or TLS_MD5SHA1 */
apply_PKCS_padding(indata, indatalen, NULL, 0, cdsblk, cdsblklen);
apply_PKCS_padding (indata, indatalen, NULL, 0, cdsblk, cdsblklen);
}
else
{
algoid = 0x70;
if (indatalen != 20 && indatalen != 28 && indatalen != 32 &&
indatalen != 48 && indatalen != 64)
if (indatalen != 20 && indatalen != 28 && indatalen != 32
&& indatalen != 48 && indatalen != 64)
{
cdsblklen = sizeof(cdsblk);
err = hash_from_digestinfo(indata, indatalen, cdsblk, &cdsblklen);
err = hash_from_digestinfo (indata, indatalen, cdsblk, &cdsblklen);
if (err)
{
log_error ("DigestInfo invalid : %s\n", gpg_strerror (err));
log_error ("DigestInfo invalid: %s\n", gpg_strerror (err));
return err;
}
}
else
{
memcpy(cdsblk, indata, indatalen);
memcpy (cdsblk, indata, indatalen);
cdsblklen = indatalen;
}
}
err = verify_pin(app, pincb, pincb_arg);
err = verify_pin (app, pincb, pincb_arg);
if (err)
return err;
sw = apdu_send_le (app->slot, 1, 0x80, 0x68, prkdf->key_reference, algoid,
cdsblklen, cdsblk, 0, outdata, outdatalen);
return iso7816_map_sw(sw);
return iso7816_map_sw (sw);
}
@ -1865,14 +1886,14 @@ do_auth (app_t app, const char *keyidstr,
/* Check PKCS#1 V1.5 padding and extract plain text.
* The function allocates a buffer for the plain text. The caller must release
* the buffer
*/
/* Check PKCS#1 V1.5 padding and extract plain text. The function
* allocates a buffer for the plain text. The caller must release the
* buffer. */
static gpg_error_t
strip_PKCS15_padding(unsigned char *src, int srclen, unsigned char **dst,
size_t *dstlen)
{
#warning audit!
int c1,c2,c3;
unsigned char *p;
@ -1884,7 +1905,7 @@ strip_PKCS15_padding(unsigned char *src, int srclen, unsigned char **dst,
src++;
srclen--;
}
c3 = srclen > 0;
c3 = (srclen > 0);
if (!(c1 && c2 && c3))
return gpg_error (GPG_ERR_DECRYPT_FAILED);
@ -1896,7 +1917,7 @@ strip_PKCS15_padding(unsigned char *src, int srclen, unsigned char **dst,
if (!p)
return gpg_error_from_syserror ();
memcpy(p, src, srclen);
memcpy (p, src, srclen);
*dst = p;
*dstlen = srclen;
@ -1904,9 +1925,8 @@ strip_PKCS15_padding(unsigned char *src, int srclen, unsigned char **dst,
}
/* Decrypt a PKCS#1 V1.5 formatted cryptogram using the referenced key
*/
/* Decrypt a PKCS#1 V1.5 formatted cryptogram using the referenced
key. */
static gpg_error_t
do_decipher (app_t app, const char *keyidstr,
gpg_error_t (*pincb)(void*, const char *, char **),
@ -1917,11 +1937,11 @@ do_decipher (app_t app, const char *keyidstr,
{
gpg_error_t err;
unsigned char p1blk[256]; /* Enciphered P1 block */
prkdf_object_t prkdf; /* The private key object. */
prkdf_object_t prkdf; /* The private key object. */
unsigned char *rspdata;
size_t rspdatalen;
size_t p1blklen;
int ofs, sw;
int sw;
if (!keyidstr || !*keyidstr || !indatalen)
return gpg_error (GPG_ERR_INV_VALUE);
@ -1942,13 +1962,16 @@ do_decipher (app_t app, const char *keyidstr,
if (!p1blklen)
p1blklen = 256;
/* Due to MPI the input may be shorter or longer than the block size */
memset(p1blk, 0, sizeof(p1blk));
ofs = p1blklen - indatalen;
if (ofs < 0)
memcpy(p1blk, (unsigned char *)indata - ofs, p1blklen);
/* The input may be shorter (due to MPIs not storing leading zeroes)
or longer than the block size. We put INDATA right aligned into
the buffer. If INDATA is longer than the block size we truncate
it on the left. */
memset (p1blk, 0, sizeof(p1blk));
if (indatalen > p1blklen)
memcpy (p1blk, (unsigned char *)indata + (indatalen - p1blklen), p1blklen);
else
memcpy(p1blk + ofs, indata, indatalen);
memcpy (p1blk + (p1blklen - indatalen), indata, indatalen);
err = verify_pin(app, pincb, pincb_arg);
if (err)
@ -1956,15 +1979,15 @@ do_decipher (app_t app, const char *keyidstr,
sw = apdu_send_le (app->slot, 1, 0x80, 0x62, prkdf->key_reference, 0x21,
p1blklen, p1blk, 0, &rspdata, &rspdatalen);
err = iso7816_map_sw(sw);
err = iso7816_map_sw (sw);
if (err)
{
log_error ("Decrypt failed: %s\n", gpg_strerror (err));
return err;
}
err = strip_PKCS15_padding(rspdata, rspdatalen, outdata, outdatalen);
xfree(rspdata);
err = strip_PKCS15_padding (rspdata, rspdatalen, outdata, outdatalen);
xfree (rspdata);
if (!err)
*r_info |= APP_DECIPHER_INFO_NOPAD;