diff options
Diffstat (limited to 'agent/protect.c')
| -rw-r--r-- | agent/protect.c | 967 |
1 files changed, 0 insertions, 967 deletions
diff --git a/agent/protect.c b/agent/protect.c deleted file mode 100644 index 08f322bac..000000000 --- a/agent/protect.c +++ /dev/null @@ -1,967 +0,0 @@ -/* protect.c - Un/Protect a secret key - * Copyright (C) 1998, 1999, 2000, 2001, 2002 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" - -#define PROT_CIPHER GCRY_CIPHER_AES -#define PROT_CIPHER_STRING "aes" -#define PROT_CIPHER_KEYLEN (128/8) - - -/* A table containing the information needed to create a protected - private key */ -static struct { - const char *algo; - const char *parmlist; - int prot_from, prot_to; -} protect_info[] = { - { "rsa", "nedpqu", 2, 5 }, - { NULL } -}; - - -static int -hash_passphrase (const char *passphrase, int hashalgo, - int s2kmode, - const unsigned char *s2ksalt, unsigned long s2kcount, - unsigned char *key, size_t keylen); - - - -/* Calculate the MIC for a private key S-Exp. SHA1HASH should pint to - a 20 byte buffer. This function is suitable for any algorithms. */ -static int -calculate_mic (const unsigned char *plainkey, unsigned char *sha1hash) -{ - const unsigned char *hash_begin, *hash_end; - const unsigned char *s; - size_t n; - - s = plainkey; - if (*s != '(') - return GNUPG_Invalid_Sexp; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "private-key")) - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Unknown_Sexp; - hash_begin = s; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; /* skip over the algorithm name */ - - while (*s == '(') - { - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; - if ( *s != ')' ) - return GNUPG_Invalid_Sexp; - s++; - } - if (*s != ')') - return GNUPG_Invalid_Sexp; - s++; - hash_end = s; - - gcry_md_hash_buffer (GCRY_MD_SHA1, sha1hash, - hash_begin, hash_end - hash_begin); - - return 0; -} - - - -/* Encrypt the parameter block starting at PROTBEGIN with length - PROTLEN using the utf8 encoded key PASSPHRASE and return the entire - encrypted block in RESULT or ereturn with an error code. SHA1HASH - is the 20 byte SHA-1 hash required for the integrity code. - - The parameter block is expected to be an incomplete S-Expression of - the form (example in advanced format): - - (d #046129F..[some bytes not shown]..81#) - (p #00e861b..[some bytes not shown]..f1#) - (q #00f7a7c..[some bytes not shown]..61#) - (u #304559a..[some bytes not shown]..9b#) - - the returned block is the S-Expression: - - (protected mode (parms) encrypted_octet_string) - -*/ -static int -do_encryption (const char *protbegin, size_t protlen, - const char *passphrase, const unsigned char *sha1hash, - unsigned char **result, size_t *resultlen) -{ - GCRY_CIPHER_HD hd; - const char *modestr = "openpgp-s2k3-sha1-" PROT_CIPHER_STRING "-cbc"; - int blklen, enclen, outlen; - char *iv = NULL; - int rc = 0; - char *outbuf = NULL; - char *p; - int saltpos, ivpos, encpos; - - hd = gcry_cipher_open (PROT_CIPHER, GCRY_CIPHER_MODE_CBC, - GCRY_CIPHER_SECURE); - if (!hd) - return map_gcry_err (gcry_errno()); - - - /* We need to work on a copy of the data because this makes it - easier to add the trailer and the padding and more important we - have to prefix the text with 2 parenthesis, so we have to - allocate enough space for: - - ((<parameter_list>)(4:hash4:sha120:<hashvalue>)) + padding - - We always append a full block of random bytes as padding but - encrypt only what is needed for a full blocksize */ - blklen = gcry_cipher_get_algo_blklen (PROT_CIPHER); - outlen = 2 + protlen + 2 + 6 + 6 + 23 + 2 + blklen; - enclen = outlen/blklen * blklen; - outbuf = gcry_malloc_secure (outlen); - if (!outbuf) - rc = GNUPG_Out_Of_Core; - if (!rc) - { - /* allocate random bytes to be used as IV, padding and s2k salt*/ - iv = gcry_random_bytes (blklen*2+8, GCRY_WEAK_RANDOM); - if (!iv) - rc = GNUPG_Out_Of_Core; - else - rc = gcry_cipher_setiv (hd, iv, blklen); - } - if (!rc) - { - unsigned char *key; - size_t keylen = PROT_CIPHER_KEYLEN; - - key = gcry_malloc_secure (keylen); - if (!key) - rc = GNUPG_Out_Of_Core; - else - { - rc = hash_passphrase (passphrase, GCRY_MD_SHA1, - 3, iv+2*blklen, 96, key, keylen); - if (!rc) - rc = gcry_cipher_setkey (hd, key, keylen); - xfree (key); - } - } - if (!rc) - { - p = outbuf; - *p++ = '('; - *p++ = '('; - memcpy (p, protbegin, protlen); - p += protlen; - memcpy (p, ")(4:hash4:sha120:", 17); - p += 17; - memcpy (p, sha1hash, 20); - p += 20; - *p++ = ')'; - *p++ = ')'; - memcpy (p, iv+blklen, blklen); - p += blklen; - assert ( p - outbuf == outlen); - rc = gcry_cipher_encrypt (hd, outbuf, enclen, NULL, 0); - } - gcry_cipher_close (hd); - if (rc) - { - xfree (iv); - xfree (outbuf); - return rc; - } - - /* Now allocate the buffer we want to return. This is - - (protected openpgp-s2k3-sha1-aes-cbc - ((sha1 salt no_of_iterations) 16byte_iv) - encrypted_octet_string) - - in canoncical format of course. We use asprintf and %n modifier - and spaces as palceholders. */ - asprintf (&p, - "(9:protected%d:%s((4:sha18:%n_8bytes_2:96)%d:%n%*s)%d:%n%*s)", - (int)strlen (modestr), modestr, - &saltpos, - blklen, &ivpos, blklen, "", - enclen, &encpos, enclen, ""); - if (p) - { /* asprintf does not use out malloc system */ - char *psave = p; - p = xtrymalloc (strlen (psave)+1); - if (p) - strcpy (p, psave); - free (psave); - } - if (!p) - { - xfree (iv); - xfree (outbuf); - return GNUPG_Out_Of_Core; - } - *resultlen = strlen (p); - *result = p; - memcpy (p+saltpos, iv+2*blklen, 8); - memcpy (p+ivpos, iv, blklen); - memcpy (p+encpos, outbuf, enclen); - xfree (iv); - xfree (outbuf); - return 0; -} - - - -/* Protect the key encoded in canonical format in plainkey. We assume - a valid S-Exp here. */ -int -agent_protect (const unsigned char *plainkey, const char *passphrase, - unsigned char **result, size_t *resultlen) -{ - int rc; - const unsigned char *s; - const unsigned char *hash_begin, *hash_end; - const unsigned char *prot_begin, *prot_end, *real_end; - size_t n; - int c, infidx, i; - unsigned char hashvalue[20]; - unsigned char *protected; - size_t protectedlen; - int depth = 0; - unsigned char *p; - - s = plainkey; - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "private-key")) - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Unknown_Sexp; - depth++; - hash_begin = s; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - - for (infidx=0; protect_info[infidx].algo - && !smatch (&s, n, protect_info[infidx].algo); infidx++) - ; - if (!protect_info[infidx].algo) - return GNUPG_Unsupported_Algorithm; - - prot_begin = prot_end = NULL; - for (i=0; (c=protect_info[infidx].parmlist[i]); i++) - { - if (i == protect_info[infidx].prot_from) - prot_begin = s; - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (n != 1 || c != *s) - return GNUPG_Invalid_Sexp; - s += n; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s +=n; /* skip value */ - if (*s != ')') - return GNUPG_Invalid_Sexp; - depth--; - if (i == protect_info[infidx].prot_to) - prot_end = s; - s++; - } - if (*s != ')' || !prot_begin || !prot_end ) - return GNUPG_Invalid_Sexp; - depth--; - hash_end = s; - s++; - /* skip to the end of the S-exp */ - assert (depth == 1); - rc = sskip (&s, &depth); - if (rc) - return rc; - assert (!depth); - real_end = s-1; - - gcry_md_hash_buffer (GCRY_MD_SHA1, hashvalue, - hash_begin, hash_end - hash_begin + 1); - - rc = do_encryption (prot_begin, prot_end - prot_begin + 1, - passphrase, hashvalue, - &protected, &protectedlen); - if (rc) - return rc; - - /* Now create the protected version of the key. Note that the 10 - extra bytes are for for the inserted "protected-" string (the - beginning of the plaintext reads: "((11:private-key(" ). */ - *resultlen = (10 - + (prot_begin-plainkey) - + protectedlen - + (real_end-prot_end)); - *result = p = xtrymalloc (*resultlen); - if (!p) - { - xfree (protected); - return GNUPG_Out_Of_Core; - } - memcpy (p, "(21:protected-", 14); - p += 14; - memcpy (p, plainkey+4, prot_begin - plainkey - 4); - p += prot_begin - plainkey - 4; - memcpy (p, protected, protectedlen); - p += protectedlen; - memcpy (p, prot_end+1, real_end - prot_end); - p += real_end - prot_end; - assert ( p - *result == *resultlen); - xfree (protected); - return 0; -} - - -/* Do the actual decryption and check the return list for consistency. */ -static int -do_decryption (const unsigned char *protected, size_t protectedlen, - const char *passphrase, - const unsigned char *s2ksalt, unsigned long s2kcount, - const unsigned char *iv, size_t ivlen, - unsigned char **result) -{ - int rc = 0; - int blklen; - GCRY_CIPHER_HD hd; - unsigned char *outbuf; - size_t reallen; - - blklen = gcry_cipher_get_algo_blklen (PROT_CIPHER); - if (protectedlen < 4 || (protectedlen%blklen)) - return GNUPG_Corrupted_Protection; - - hd = gcry_cipher_open (PROT_CIPHER, GCRY_CIPHER_MODE_CBC, - GCRY_CIPHER_SECURE); - if (!hd) - return map_gcry_err (gcry_errno()); - - outbuf = gcry_malloc_secure (protectedlen); - if (!outbuf) - rc = GNUPG_Out_Of_Core; - if (!rc) - rc = gcry_cipher_setiv (hd, iv, ivlen); - if (!rc) - { - unsigned char *key; - size_t keylen = PROT_CIPHER_KEYLEN; - - key = gcry_malloc_secure (keylen); - if (!key) - rc = GNUPG_Out_Of_Core; - else - { - rc = hash_passphrase (passphrase, GCRY_MD_SHA1, - 3, s2ksalt, s2kcount, key, keylen); - if (!rc) - rc = gcry_cipher_setkey (hd, key, keylen); - xfree (key); - } - } - if (!rc) - rc = gcry_cipher_decrypt (hd, outbuf, protectedlen, - protected, protectedlen); - gcry_cipher_close (hd); - if (rc) - { - xfree (outbuf); - return rc; - } - /* do a quick check first */ - if (*outbuf != '(' && outbuf[1] != '(') - { - xfree (outbuf); - return GNUPG_Bad_Passphrase; - } - /* check that we have a consistent S-Exp */ - reallen = gcry_sexp_canon_len (outbuf, protectedlen, NULL, NULL); - if (!reallen || (reallen + blklen < protectedlen) ) - { - xfree (outbuf); - return GNUPG_Bad_Passphrase; - } - *result = outbuf; - return 0; -} - - -/* Merge the parameter list contained in CLEARTEXT with the original - protect lists PROTECTEDKEY by replacing the list at REPLACEPOS. - Return the new list in RESULT and the MIC value in the 20 byte - buffer SHA1HASH. */ -static int -merge_lists (const unsigned char *protectedkey, - size_t replacepos, - const unsigned char *cleartext, - unsigned char *sha1hash, unsigned char **result) -{ - size_t n, newlistlen; - unsigned char *newlist, *p; - const unsigned char *s; - const unsigned char *startpos, *endpos; - int i, rc; - - if (replacepos < 26) - return GNUPG_Bug; - - /* Estimate the required size of the resulting list. We have a large - safety margin of >20 bytes (MIC hash from CLEARTEXT and the - removed "protected-" */ - newlistlen = gcry_sexp_canon_len (protectedkey, 0, NULL, NULL); - if (!newlistlen) - return GNUPG_Bug; - n = gcry_sexp_canon_len (cleartext, 0, NULL, NULL); - if (!n) - return GNUPG_Bug; - newlistlen += n; - newlist = gcry_malloc_secure (newlistlen); - if (!newlist) - return GNUPG_Out_Of_Core; - - /* Copy the initial segment */ - strcpy (newlist, "(11:private-key"); - p = newlist + 15; - memcpy (p, protectedkey+15+10, replacepos-15-10); - p += replacepos-15-10; - - /* copy the cleartext */ - s = cleartext; - if (*s != '(' && s[1] != '(') - return GNUPG_Bug; /*we already checked this */ - s += 2; - startpos = s; - while ( *s == '(' ) - { - s++; - n = snext (&s); - if (!n) - goto invalid_sexp; - s += n; - n = snext (&s); - if (!n) - goto invalid_sexp; - s += n; - if ( *s != ')' ) - goto invalid_sexp; - s++; - } - if ( *s != ')' ) - goto invalid_sexp; - endpos = s; - s++; - /* short intermezzo: Get the MIC */ - if (*s != '(') - goto invalid_sexp; - s++; - n = snext (&s); - if (!smatch (&s, n, "hash")) - goto invalid_sexp; - n = snext (&s); - if (!smatch (&s, n, "sha1")) - goto invalid_sexp; - n = snext (&s); - if (n != 20) - goto invalid_sexp; - memcpy (sha1hash, s, 20); - s += n; - if (*s != ')') - goto invalid_sexp; - /* end intermezzo */ - - /* append the parameter list */ - memcpy (p, startpos, endpos - startpos); - p += endpos - startpos; - - /* skip overt the protected list element in the original list */ - s = protectedkey + replacepos; - assert (*s == '('); - s++; - i = 1; - rc = sskip (&s, &i); - if (rc) - goto failure; - startpos = s; - i = 2; /* we are inside this level */ - rc = sskip (&s, &i); - if (rc) - goto failure; - assert (s[-1] == ')'); - endpos = s; /* one behind the end of the list */ - - /* append the rest */ - memcpy (p, startpos, endpos - startpos); - p += endpos - startpos; - - /* ready */ - *result = newlist; - return 0; - - failure: - xfree (newlist); - return rc; - - invalid_sexp: - xfree (newlist); - return GNUPG_Invalid_Sexp; -} - - - -/* Unprotect the key encoded in canonical format. We assume a valid - S-Exp here. */ -int -agent_unprotect (const unsigned char *protectedkey, const char *passphrase, - unsigned char **result, size_t *resultlen) -{ - int rc; - const unsigned char *s; - size_t n; - int infidx, i; - unsigned char sha1hash[20], sha1hash2[20]; - const unsigned char *s2ksalt; - unsigned long s2kcount; - const unsigned char *iv; - const unsigned char *prot_begin; - unsigned char *cleartext; - unsigned char *final; - - s = protectedkey; - if (*s != '(') - return GNUPG_Invalid_Sexp; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "protected-private-key")) - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Unknown_Sexp; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - - for (infidx=0; protect_info[infidx].algo - && !smatch (&s, n, protect_info[infidx].algo); infidx++) - ; - if (!protect_info[infidx].algo) - return GNUPG_Unsupported_Algorithm; - - /* now find the list with the protected information. Here is an - example for such a list: - (protected openpgp-s2k3-sha1-aes-cbc - ((sha1 <salt> <count>) <Initialization_Vector>) - <encrypted_data>) - */ - for (;;) - { - if (*s != '(') - return GNUPG_Invalid_Sexp; - prot_begin = s; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (smatch (&s, n, "protected")) - break; - s += n; - i = 1; - rc = sskip (&s, &i); - if (rc) - return rc; - } - /* found */ - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "openpgp-s2k3-sha1-" PROT_CIPHER_STRING "-cbc")) - return GNUPG_Unsupported_Protection; - if (*s != '(' || s[1] != '(') - return GNUPG_Invalid_Sexp; - s += 2; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "sha1")) - return GNUPG_Unsupported_Protection; - n = snext (&s); - if (n != 8) - return GNUPG_Corrupted_Protection; - s2ksalt = s; - s += n; - n = snext (&s); - if (!n) - return GNUPG_Corrupted_Protection; - /* We expect a list close as next, so we can simply use strtoul() - here. We might want to check that we only have digits - but this - is nothing we should worry about */ - if (s[n] != ')' ) - return GNUPG_Invalid_Sexp; - s2kcount = strtoul (s, NULL, 10); - if (!s2kcount) - return GNUPG_Corrupted_Protection; - s += n; - s++; /* skip list end */ - - n = snext (&s); - if (n != 16) /* Wrong blocksize for IV (we support ony aes-128) */ - return GNUPG_Corrupted_Protection; - iv = s; - s += n; - if (*s != ')' ) - return GNUPG_Invalid_Sexp; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - - rc = do_decryption (s, n, - passphrase, s2ksalt, s2kcount, - iv, 16, - &cleartext); - if (rc) - return rc; - - rc = merge_lists (protectedkey, prot_begin-protectedkey, cleartext, - sha1hash, &final); - xfree (cleartext); - if (rc) - return rc; - - rc = calculate_mic (final, sha1hash2); - if (!rc && memcmp (sha1hash, sha1hash2, 20)) - rc = GNUPG_Corrupted_Protection; - if (rc) - { - xfree (final); - return rc; - } - - *result = final; - *resultlen = gcry_sexp_canon_len (final, 0, NULL, NULL); - return 0; -} - -/* Check the type of the private key, this is one of the constants: - PRIVATE_KEY_UNKNOWN if we can't figure out the type (this is the - value 0), PRIVATE_KEY_CLEAR for an unprotected private key. - PRIVATE_KEY_PROTECTED for an protected private key or - PRIVATE_KEY_SHADOWED for a sub key where the secret parts are stored - elsewhere. */ -int -agent_private_key_type (const unsigned char *privatekey) -{ - const unsigned char *s; - size_t n; - - s = privatekey; - if (*s != '(') - return PRIVATE_KEY_UNKNOWN; - s++; - n = snext (&s); - if (!n) - return PRIVATE_KEY_UNKNOWN; - if (smatch (&s, n, "protected-private-key")) - return PRIVATE_KEY_PROTECTED; - if (smatch (&s, n, "shadowed-private-key")) - return PRIVATE_KEY_SHADOWED; - if (smatch (&s, n, "private-key")) - return PRIVATE_KEY_CLEAR; - return PRIVATE_KEY_UNKNOWN; -} - - - -/* Transform a passphrase into a suitable key of length KEYLEN and - store this key in the caller provided buffer KEY. The caller must - provide an HASHALGO, a valid S2KMODE (see rfc-2440) and depending on - that mode an S2KSALT of 8 random bytes and an S2KCOUNT (a suitable - value is 96). - - Returns an error code on failure. */ -static int -hash_passphrase (const char *passphrase, int hashalgo, - int s2kmode, - const unsigned char *s2ksalt, - unsigned long s2kcount, - unsigned char *key, size_t keylen) -{ - GCRY_MD_HD md; - int pass, i; - int used = 0; - int pwlen = strlen (passphrase); - - if ( (s2kmode != 0 && s2kmode != 1 && s2kmode != 3) - || !hashalgo || !keylen || !key || !passphrase) - return GNUPG_Invalid_Value; - if ((s2kmode == 1 ||s2kmode == 3) && !s2ksalt) - return GNUPG_Invalid_Value; - - md = gcry_md_open (hashalgo, GCRY_MD_FLAG_SECURE); - if (!md) - return map_gcry_err (gcry_errno()); - - for (pass=0; used < keylen; pass++) - { - if (pass) - { - gcry_md_reset (md); - for (i=0; i < pass; i++) /* preset the hash context */ - gcry_md_putc (md, 0); - } - - if (s2kmode == 1 || s2kmode == 3) - { - int len2 = pwlen + 8; - unsigned long count = len2; - - if (s2kmode == 3) - { - count = (16ul + (s2kcount & 15)) << ((s2kcount >> 4) + 6); - if (count < len2) - count = len2; - } - - while (count > len2) - { - gcry_md_write (md, s2ksalt, 8); - gcry_md_write (md, passphrase, pwlen); - count -= len2; - } - if (count < 8) - gcry_md_write (md, s2ksalt, count); - else - { - gcry_md_write (md, s2ksalt, 8); - count -= 8; - gcry_md_write (md, passphrase, count); - } - } - else - gcry_md_write (md, passphrase, pwlen); - - gcry_md_final (md); - i = gcry_md_get_algo_dlen (hashalgo); - if (i > keylen - used) - i = keylen - used; - memcpy (key+used, gcry_md_read (md, hashalgo), i); - used += i; - } - gcry_md_close(md); - return 0; -} - - - -/* Create a shadow key from a public key. We use the shadow protocol - "ti-v1" and insert the S-expressionn SHADOW_INFO. The resulting - S-expression is returned in an allocated buffer RESULT will point - to. The input parameters are expected to be valid canonilized - S-expressions */ -int -agent_shadow_key (const unsigned char *pubkey, - const unsigned char *shadow_info, - unsigned char **result) -{ - const unsigned char *s; - const unsigned char *point; - size_t n; - int depth = 0; - unsigned char *p; - size_t pubkey_len = gcry_sexp_canon_len (pubkey, 0, NULL,NULL); - size_t shadow_info_len = gcry_sexp_canon_len (shadow_info, 0, NULL,NULL); - - if (!pubkey_len || !shadow_info_len) - return GNUPG_Invalid_Value; - s = pubkey; - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "public-key")) - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Unknown_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; /* skip over the algorithm name */ - - while (*s != ')') - { - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s +=n; /* skip value */ - if (*s != ')') - return GNUPG_Invalid_Sexp; - depth--; - s++; - } - point = s; /* insert right before the point */ - depth--; - s++; - assert (depth == 1); - - /* calculate required length by taking in account: the "shadowed-" - prefix, the "shadowed", "t1-v1" as well as some parenthesis */ - n = 12 + pubkey_len + 1 + 3+8 + 2+5 + shadow_info_len + 1; - *result = p = xtrymalloc (n); - if (!p) - return GNUPG_Out_Of_Core; - p = stpcpy (p, "(20:shadowed-private-key"); - /* (10:public-key ...)*/ - memcpy (p, pubkey+14, point - (pubkey+14)); - p += point - (pubkey+14); - p = stpcpy (p, "(8:shadowed5:t1-v1"); - memcpy (p, shadow_info, shadow_info_len); - p += shadow_info_len; - *p++ = ')'; - memcpy (p, point, pubkey_len - (point - pubkey)); - p += pubkey_len - (point - pubkey); - - return 0; -} - -/* Parse a canonical encoded shadowed key and return a pointer to the - inner list with the shadow_info */ -int -agent_get_shadow_info (const unsigned char *shadowkey, - unsigned char const **shadow_info) -{ - const unsigned char *s; - size_t n; - int depth = 0; - - s = shadowkey; - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (!smatch (&s, n, "shadowed-private-key")) - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Unknown_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s += n; /* skip over the algorithm name */ - - for (;;) - { - if (*s == ')') - return GNUPG_Unknown_Sexp; - if (*s != '(') - return GNUPG_Invalid_Sexp; - depth++; - s++; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (smatch (&s, n, "shadowed")) - break; - s += n; - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - s +=n; /* skip value */ - if (*s != ')') - return GNUPG_Invalid_Sexp; - depth--; - s++; - } - /* found the shadowed list, s points to the protocol */ - n = snext (&s); - if (!n) - return GNUPG_Invalid_Sexp; - if (smatch (&s, n, "t1-v1")) - { - if (*s != '(') - return GNUPG_Invalid_Sexp; - *shadow_info = s; - } - else - return GNUPG_Unsupported_Protocol; - return 0; -} - |