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Diffstat (limited to 'scd/app-nks.c')
| -rw-r--r-- | scd/app-nks.c | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/scd/app-nks.c b/scd/app-nks.c new file mode 100644 index 000000000..1ca8d4187 --- /dev/null +++ b/scd/app-nks.c @@ -0,0 +1,519 @@ +/* app-nks.c - The Telesec NKS 2.0 card application. + * Copyright (C) 2004 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, + * USA. + */ + +#include <config.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <time.h> + +#include "scdaemon.h" +#include "i18n.h" +#include "iso7816.h" +#include "app-common.h" +#include "tlv.h" + +static struct { + int fid; /* File ID. */ + int certtype; /* Type of certificate or 0 if it is not a certificate. */ + int iskeypair; /* If true has the FID of the correspoding certificate. */ + int issignkey; /* True if file is a key usable for signing. */ + int isenckey; /* True if file is a key usable for decryption. */ +} filelist[] = { + { 0x4531, 0, 0xC000, 1, 0 }, + { 0xC000, 101 }, + { 0x4331, 100 }, + { 0x4332, 100 }, + { 0xB000, 110 }, + { 0x45B1, 0, 0xC200, 0, 1 }, + { 0xC200, 101 }, + { 0x43B1, 100 }, + { 0x43B2, 100 }, + { 0, 0 } +}; + + + +/* Read the file with FID, assume it contains a public key and return + its keygrip in the caller provided 41 byte buffer R_GRIPSTR. */ +static gpg_error_t +keygripstr_from_pk_file (int slot, int fid, char *r_gripstr) +{ + gpg_error_t err; + unsigned char grip[20]; + unsigned char *buffer[2]; + size_t buflen[2]; + gcry_sexp_t sexp; + int i; + + err = iso7816_select_file (slot, fid, 0, NULL, NULL); + if (err) + return err; + err = iso7816_read_record (slot, 1, 1, 0, &buffer[0], &buflen[0]); + if (err) + return err; + err = iso7816_read_record (slot, 2, 1, 0, &buffer[1], &buflen[1]); + if (err) + { + xfree (buffer[0]); + return err; + } + + for (i=0; i < 2; i++) + { + /* Check that the value appears like an integer encoded as + Simple-TLV. We don't check the tag because the tests cards I + have use 1 for both, the modulus and the exponent - the + example in the documentation gives 2 for the exponent. */ + if (buflen[i] < 3) + err = gpg_error (GPG_ERR_TOO_SHORT); + else if (buffer[i][1] != buflen[i]-2 ) + err = gpg_error (GPG_ERR_INV_OBJ); + } + + if (!err) + err = gcry_sexp_build (&sexp, NULL, + "(public-key (rsa (n %b) (e %b)))", + (int)buflen[0]-2, buffer[0]+2, + (int)buflen[1]-2, buffer[1]+2); + + xfree (buffer[0]); + xfree (buffer[1]); + if (err) + return err; + + if (!gcry_pk_get_keygrip (sexp, grip)) + { + err = gpg_error (GPG_ERR_INTERNAL); /* i.e. RSA not supported by + libgcrypt. */ + } + else + { + for (i=0; i < 20; i++) + sprintf (r_gripstr+i*2, "%02X", grip[i]); + } + gcry_sexp_release (sexp); + return err; +} + + + +static gpg_error_t +do_learn_status (APP app, CTRL ctrl) +{ + gpg_error_t err; + char ct_buf[100], id_buf[100]; + int i; + + /* Output information about all useful objects. */ + for (i=0; filelist[i].fid; i++) + { + if (filelist[i].certtype) + { + size_t len; + + len = app_help_read_length_of_cert (app->slot, + filelist[i].fid, NULL); + if (len) + { + /* FIXME: We should store the length in the application's + context so that a following readcert does only need to + read that many bytes. */ + sprintf (ct_buf, "%d", filelist[i].certtype); + sprintf (id_buf, "NKS-DF01.%04X", filelist[i].fid); + send_status_info (ctrl, "CERTINFO", + ct_buf, strlen (ct_buf), + id_buf, strlen (id_buf), + NULL, (size_t)0); + } + } + else if (filelist[i].iskeypair) + { + char gripstr[40+1]; + + err = keygripstr_from_pk_file (app->slot, filelist[i].fid, gripstr); + if (err) + log_error ("can't get keygrip from FID 0x%04X: %s\n", + filelist[i].fid, gpg_strerror (err)); + else + { + sprintf (id_buf, "NKS-DF01.%04X", filelist[i].fid); + send_status_info (ctrl, "KEYPAIRINFO", + gripstr, 40, + id_buf, strlen (id_buf), + NULL, (size_t)0); + } + } + } + + return 0; +} + + + + +/* Read the certificate with id CERTID (as returned by learn_status in + the CERTINFO status lines) and return it in the freshly allocated + buffer put into CERT and the length of the certificate put into + CERTLEN. */ +static gpg_error_t +do_readcert (app_t app, const char *certid, + unsigned char **cert, size_t *certlen) +{ + int i, fid; + gpg_error_t err; + unsigned char *buffer; + const unsigned char *p; + size_t buflen, n; + int class, tag, constructed, ndef; + size_t totobjlen, objlen, hdrlen; + int rootca = 0; + + *cert = NULL; + *certlen = 0; + if (strncmp (certid, "NKS-DF01.", 9) ) + return gpg_error (GPG_ERR_INV_ID); + certid += 9; + if (!hexdigitp (certid) || !hexdigitp (certid+1) + || !hexdigitp (certid+2) || !hexdigitp (certid+3) + || certid[4]) + return gpg_error (GPG_ERR_INV_ID); + fid = xtoi_4 (certid); + for (i=0; filelist[i].fid; i++) + if ((filelist[i].certtype || filelist[i].iskeypair) + && filelist[i].fid == fid) + break; + if (!filelist[i].fid) + return gpg_error (GPG_ERR_NOT_FOUND); + + /* If the requested objects is a plain public key, redirect it to + the corresponding certificate. The whole system is a bit messy + becuase we sometime use the key directly or let the caller + retrieve the key from the certificate. The valid point behind + that is to support not-yet stored certificates. */ + if (filelist[i].iskeypair) + fid = filelist[i].iskeypair; + + + /* Read the entire file. fixme: This could be optimized by first + reading the header to figure out how long the certificate + actually is. */ + err = iso7816_select_file (app->slot, fid, 0, NULL, NULL); + if (err) + { + log_error ("error selecting FID 0x%04X: %s\n", fid, gpg_strerror (err)); + return err; + } + + err = iso7816_read_binary (app->slot, 0, 0, &buffer, &buflen); + if (err) + { + log_error ("error reading certificate from FID 0x%04X: %s\n", + fid, gpg_strerror (err)); + return err; + } + + if (!buflen || *buffer == 0xff) + { + log_info ("no certificate contained in FID 0x%04X\n", fid); + err = gpg_error (GPG_ERR_NOT_FOUND); + goto leave; + } + + /* Now figure something out about the object. */ + p = buffer; + n = buflen; + err = parse_ber_header (&p, &n, &class, &tag, &constructed, + &ndef, &objlen, &hdrlen); + if (err) + goto leave; + if ( class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && constructed ) + ; + else if ( class == CLASS_UNIVERSAL && tag == TAG_SET && constructed ) + rootca = 1; + else + return gpg_error (GPG_ERR_INV_OBJ); + totobjlen = objlen + hdrlen; + assert (totobjlen <= buflen); + + err = parse_ber_header (&p, &n, &class, &tag, &constructed, + &ndef, &objlen, &hdrlen); + if (err) + goto leave; + + if (rootca) + ; + else if (class == CLASS_UNIVERSAL && tag == TAG_OBJECT_ID && !constructed) + { + const unsigned char *save_p; + + /* The certificate seems to be contained in a userCertificate + container. Skip this and assume the following sequence is + the certificate. */ + if (n < objlen) + { + err = gpg_error (GPG_ERR_INV_OBJ); + goto leave; + } + p += objlen; + n -= objlen; + save_p = p; + err = parse_ber_header (&p, &n, &class, &tag, &constructed, + &ndef, &objlen, &hdrlen); + if (err) + goto leave; + if ( !(class == CLASS_UNIVERSAL && tag == TAG_SEQUENCE && constructed) ) + return gpg_error (GPG_ERR_INV_OBJ); + totobjlen = objlen + hdrlen; + assert (save_p + totobjlen <= buffer + buflen); + memmove (buffer, save_p, totobjlen); + } + + *cert = buffer; + buffer = NULL; + *certlen = totobjlen; + + leave: + xfree (buffer); + return err; +} + + +/* Verify the PIN if required. */ +static gpg_error_t +verify_pin (app_t app, + gpg_error_t (*pincb)(void*, const char *, char **), + void *pincb_arg) +{ + /* Note that force_chv1 is never set but we do it here anyway so + that other applications may reuse this function. For example it + makes sense to set force_chv1 for German signature law cards. + NKS is very similar to the DINSIG draft standard. */ + if (!app->did_chv1 || app->force_chv1 ) + { + char *pinvalue; + int rc; + + rc = pincb (pincb_arg, "PIN", &pinvalue); + if (rc) + { + log_info ("PIN callback returned error: %s\n", gpg_strerror (rc)); + return rc; + } + + /* The following limits are due to TCOS but also defined in the + NKS specs. */ + if (strlen (pinvalue) < 6) + { + log_error ("PIN is too short; minimum length is 6\n"); + xfree (pinvalue); + return gpg_error (GPG_ERR_BAD_PIN); + } + else if (strlen (pinvalue) > 16) + { + log_error ("PIN is too large; maximum length is 16\n"); + xfree (pinvalue); + return gpg_error (GPG_ERR_BAD_PIN); + } + + /* Also it is possible to use a local PIN, we use the gloabl + PIN for this application. */ + rc = iso7816_verify (app->slot, 0, pinvalue, strlen (pinvalue)); + if (rc) + { + if ( gpg_error (rc) == GPG_ERR_USE_CONDITIONS ) + log_error (_("the NullPIN has not yet been changed\n")); + else + log_error ("verify PIN failed\n"); + xfree (pinvalue); + return rc; + } + app->did_chv1 = 1; + xfree (pinvalue); + } + + return 0; +} + + + +/* Create the signature and return the allocated result in OUTDATA. + If a PIN is required the PINCB will be used to ask for the PIN; + that callback should return the PIN in an allocated buffer and + store that in the 3rd argument. */ +static gpg_error_t +do_sign (app_t app, const char *keyidstr, int hashalgo, + gpg_error_t (*pincb)(void*, const char *, char **), + void *pincb_arg, + const void *indata, size_t indatalen, + unsigned char **outdata, size_t *outdatalen ) +{ + static unsigned char sha1_prefix[15] = /* Object ID is 1.3.14.3.2.26 */ + { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, + 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14 }; + static unsigned char rmd160_prefix[15] = /* Object ID is 1.3.36.3.2.1 */ + { 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x24, 0x03, + 0x02, 0x01, 0x05, 0x00, 0x04, 0x14 }; + int rc, i; + int fid; + unsigned char data[35]; /* Must be large enough for a SHA-1 digest + + the largest OID _prefix above. */ + + if (!keyidstr || !*keyidstr) + return gpg_error (GPG_ERR_INV_VALUE); + if (indatalen != 20 && indatalen != 16 && indatalen != 35) + return gpg_error (GPG_ERR_INV_VALUE); + + /* Check that the provided ID is vaid. This is not really needed + but we do it to to enforce correct usage by the caller. */ + if (strncmp (keyidstr, "NKS-DF01.", 9) ) + return gpg_error (GPG_ERR_INV_ID); + keyidstr += 9; + if (!hexdigitp (keyidstr) || !hexdigitp (keyidstr+1) + || !hexdigitp (keyidstr+2) || !hexdigitp (keyidstr+3) + || keyidstr[4]) + return gpg_error (GPG_ERR_INV_ID); + fid = xtoi_4 (keyidstr); + for (i=0; filelist[i].fid; i++) + if (filelist[i].iskeypair && filelist[i].fid == fid) + break; + if (!filelist[i].fid) + return gpg_error (GPG_ERR_NOT_FOUND); + if (!filelist[i].issignkey) + return gpg_error (GPG_ERR_INV_ID); + + /* Prepare the DER object from INDATA. */ + if (indatalen == 35) + { + /* Alright, the caller was so kind to send us an already + prepared DER object. Check that it is waht we want and that + it matches the hash algorithm. */ + if (hashalgo == GCRY_MD_SHA1 && !memcmp (indata, sha1_prefix, 15)) + ; + else if (hashalgo == GCRY_MD_RMD160 && !memcmp (indata, rmd160_prefix,15)) + ; + else + return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM); + memcpy (data, indata, indatalen); + } + else + { + if (hashalgo == GCRY_MD_SHA1) + memcpy (data, sha1_prefix, 15); + else if (hashalgo == GCRY_MD_RMD160) + memcpy (data, rmd160_prefix, 15); + else + return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM); + memcpy (data+15, indata, indatalen); + } + + rc = verify_pin (app, pincb, pincb_arg); + if (!rc) + rc = iso7816_compute_ds (app->slot, data, 35, outdata, outdatalen); + return rc; +} + + + + +/* Decrypt the data in INDATA and return the allocated result in OUTDATA. + If a PIN is required the PINCB will be used to ask for the PIN; it + should return the PIN in an allocated buffer and put it into PIN. */ +static gpg_error_t +do_decipher (app_t app, const char *keyidstr, + gpg_error_t (*pincb)(void*, const char *, char **), + void *pincb_arg, + const void *indata, size_t indatalen, + unsigned char **outdata, size_t *outdatalen ) +{ + static const unsigned char mse_parm[] = { + 0x80, 1, 0x10, /* Select algorithm RSA. */ + 0x84, 1, 0x81 /* Select local secret key 1 for decryption. */ + }; + int rc, i; + int fid; + + if (!keyidstr || !*keyidstr || !indatalen) + return gpg_error (GPG_ERR_INV_VALUE); + + /* Check that the provided ID is vaid. This is not really needed + but we do it to to enforce correct usage by the caller. */ + if (strncmp (keyidstr, "NKS-DF01.", 9) ) + return gpg_error (GPG_ERR_INV_ID); + keyidstr += 9; + if (!hexdigitp (keyidstr) || !hexdigitp (keyidstr+1) + || !hexdigitp (keyidstr+2) || !hexdigitp (keyidstr+3) + || keyidstr[4]) + return gpg_error (GPG_ERR_INV_ID); + fid = xtoi_4 (keyidstr); + for (i=0; filelist[i].fid; i++) + if (filelist[i].iskeypair && filelist[i].fid == fid) + break; + if (!filelist[i].fid) + return gpg_error (GPG_ERR_NOT_FOUND); + if (!filelist[i].isenckey) + return gpg_error (GPG_ERR_INV_ID); + + /* Do the TCOS specific MSE. */ + rc = iso7816_manage_security_env (app->slot, + 0xC1, 0xB8, + mse_parm, sizeof mse_parm); + if (!rc) + rc = verify_pin (app, pincb, pincb_arg); + if (!rc) + rc = iso7816_decipher (app->slot, indata, indatalen, 0x81, + outdata, outdatalen); + return rc; +} + + + +/* Select the NKS 2.0 application on the card in SLOT. */ +gpg_error_t +app_select_nks (APP app) +{ + static char const aid[] = { 0xD2, 0x76, 0x00, 0x00, 0x03, 0x01, 0x02 }; + int slot = app->slot; + int rc; + + rc = iso7816_select_application (slot, aid, sizeof aid, 0); + if (!rc) + { + app->apptype = "NKS"; + + app->fnc.learn_status = do_learn_status; + app->fnc.readcert = do_readcert; + app->fnc.getattr = NULL; + app->fnc.setattr = NULL; + app->fnc.genkey = NULL; + app->fnc.sign = do_sign; + app->fnc.auth = NULL; + app->fnc.decipher = do_decipher; + app->fnc.change_pin = NULL; + app->fnc.check_pin = NULL; + } + + return rc; +} + + |