diff options
Diffstat (limited to 'agent/divert-scd.c')
| -rw-r--r-- | agent/divert-scd.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/agent/divert-scd.c b/agent/divert-scd.c new file mode 100644 index 000000000..69f184474 --- /dev/null +++ b/agent/divert-scd.c @@ -0,0 +1,319 @@ +/* divert-scd.c - divert operations to the scdaemon + * Copyright (C) 2002, 2003 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include <config.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <assert.h> +#include <unistd.h> +#include <sys/stat.h> + +#include "agent.h" +#include "sexp-parse.h" +#include "i18n.h" + + +static int +ask_for_card (CTRL ctrl, const unsigned char *shadow_info, char **r_kid) +{ + int rc, i; + const unsigned char *s; + size_t n; + char *serialno; + int no_card = 0; + char *desc; + char *want_sn, *want_kid; + int want_sn_displen; + + *r_kid = NULL; + s = shadow_info; + if (*s != '(') + return gpg_error (GPG_ERR_INV_SEXP); + s++; + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + want_sn = xtrymalloc (n*2+1); + if (!want_sn) + return out_of_core (); + for (i=0; i < n; i++) + sprintf (want_sn+2*i, "%02X", s[i]); + s += n; + /* We assume that a 20 byte serial number is a standard one which + seems to have the property to have a zero in the last nibble. We + don't display this '0' because it may confuse the user */ + want_sn_displen = strlen (want_sn); + if (want_sn_displen == 20 && want_sn[19] == '0') + want_sn_displen--; + + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + want_kid = xtrymalloc (n+1); + if (!want_kid) + { + gpg_error_t tmperr = out_of_core (); + xfree (want_sn); + return tmperr; + } + memcpy (want_kid, s, n); + want_kid[n] = 0; + + for (;;) + { + rc = agent_card_serialno (&serialno); + if (!rc) + { + log_debug ("detected card with S/N %s\n", serialno); + i = strcmp (serialno, want_sn); + xfree (serialno); + serialno = NULL; + if (!i) + { + xfree (want_sn); + *r_kid = want_kid; + return 0; /* yes, we have the correct card */ + } + } + else if (gpg_err_code (rc) == GPG_ERR_CARD_NOT_PRESENT) + { + log_debug ("no card present\n"); + rc = 0; + no_card = 1; + } + else + { + log_error ("error accesing card: %s\n", gpg_strerror (rc)); + } + + if (!rc) + { + if (asprintf (&desc, + "%s:%%0A%%0A" + " \"%.*s\"", + no_card? "Please insert the card with serial number" + : "Please remove the current card and " + "insert the one with serial number", + want_sn_displen, want_sn) < 0) + { + rc = out_of_core (); + } + else + { + rc = agent_get_confirmation (ctrl, desc, NULL, NULL); + free (desc); + } + } + if (rc) + { + xfree (want_sn); + xfree (want_kid); + return rc; + } + } +} + + +/* Put the DIGEST into an DER encoded comtainer and return it in R_VAL. */ +static int +encode_md_for_card (const unsigned char *digest, size_t digestlen, int algo, + unsigned char **r_val, size_t *r_len) +{ + byte *frame; + byte asn[100]; + size_t asnlen; + + asnlen = DIM(asn); + if (gcry_md_algo_info (algo, GCRYCTL_GET_ASNOID, asn, &asnlen)) + { + log_error ("no object identifier for algo %d\n", algo); + return gpg_error (GPG_ERR_INTERNAL); + } + + frame = xtrymalloc (asnlen + digestlen); + if (!frame) + return out_of_core (); + memcpy (frame, asn, asnlen); + memcpy (frame+asnlen, digest, digestlen); + if (DBG_CRYPTO) + log_printhex ("encoded hash:", frame, asnlen+digestlen); + + *r_val = frame; + *r_len = asnlen+digestlen; + return 0; +} + + +/* Callback used to ask for the PIN which should be set into BUF. The + buf has been allocated by the caller and is of size MAXBUF which + includes the terminating null. The function should return an UTF-8 + string with the passphrase, the buffer may optionally be padded + with arbitrary characters */ +static int +getpin_cb (void *opaque, const char *info, char *buf, size_t maxbuf) +{ + struct pin_entry_info_s *pi; + int rc; + char *desc; + CTRL ctrl = opaque; + + if (maxbuf < 2) + return gpg_error (GPG_ERR_INV_VALUE); + + + /* FIXME: keep PI and TRIES in OPAQUE. Frankly this is a whole + mess because we should call the card's verify function from the + pinentry check pin CB. */ + pi = gcry_calloc_secure (1, sizeof (*pi) + 100); + pi->max_length = maxbuf-1; + pi->min_digits = 0; /* we want a real passphrase */ + pi->max_digits = 8; + pi->max_tries = 3; + + if ( asprintf (&desc, _("Please enter the PIN%s%s%s to unlock the card"), + info? " (`":"", + info? info:"", + info? "')":"") < 0) + desc = NULL; + rc = agent_askpin (ctrl, desc?desc:info, pi); + free (desc); + if (!rc) + { + strncpy (buf, pi->pin, maxbuf-1); + buf[maxbuf-1] = 0; + } + xfree (pi); + return rc; +} + + + + +int +divert_pksign (CTRL ctrl, + const unsigned char *digest, size_t digestlen, int algo, + const unsigned char *shadow_info, unsigned char **r_sig) +{ + int rc; + char *kid; + size_t siglen; + char *sigval; + unsigned char *data; + size_t ndata; + + rc = ask_for_card (ctrl, shadow_info, &kid); + if (rc) + return rc; + + rc = encode_md_for_card (digest, digestlen, algo, + &data, &ndata); + if (rc) + return rc; + + rc = agent_card_pksign (kid, getpin_cb, ctrl, + data, ndata, &sigval, &siglen); + if (!rc) + *r_sig = sigval; + xfree (data); + xfree (kid); + + return rc; +} + + +/* Decrypt the the value given asn an S-expression in CIPHER using the + key identified by SHADOW_INFO and return the plaintext in an + allocated buffer in R_BUF. */ +int +divert_pkdecrypt (CTRL ctrl, + const unsigned char *cipher, + const unsigned char *shadow_info, + char **r_buf, size_t *r_len) +{ + int rc; + char *kid; + const unsigned char *s; + size_t n; + const unsigned char *ciphertext; + size_t ciphertextlen; + char *plaintext; + size_t plaintextlen; + + s = cipher; + if (*s != '(') + return gpg_error (GPG_ERR_INV_SEXP); + s++; + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + if (!smatch (&s, n, "enc-val")) + return gpg_error (GPG_ERR_UNKNOWN_SEXP); + if (*s != '(') + return gpg_error (GPG_ERR_UNKNOWN_SEXP); + s++; + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + if (!smatch (&s, n, "rsa")) + return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM); + if (*s != '(') + return gpg_error (GPG_ERR_UNKNOWN_SEXP); + s++; + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_INV_SEXP); + if (!smatch (&s, n, "a")) + return gpg_error (GPG_ERR_UNKNOWN_SEXP); + n = snext (&s); + if (!n) + return gpg_error (GPG_ERR_UNKNOWN_SEXP); + ciphertext = s; + ciphertextlen = n; + + rc = ask_for_card (ctrl, shadow_info, &kid); + if (rc) + return rc; + + rc = agent_card_pkdecrypt (kid, getpin_cb, ctrl, + ciphertext, ciphertextlen, + &plaintext, &plaintextlen); + if (!rc) + { + *r_buf = plaintext; + *r_len = plaintextlen; + } + xfree (kid); + return rc; +} + + +int +divert_generic_cmd (CTRL ctrl, const char *cmdline, void *assuan_context) +{ + return agent_card_scd (cmdline, getpin_cb, ctrl, assuan_context); +} + + + + + |