pkcs12.c

00001 /*
00002  *  PKCS#12 Personal Information Exchange Syntax
00003  *
00004  *  Copyright (C) 2006-2014, Brainspark B.V.
00005  *
00006  *  This file is part of PolarSSL (http://www.polarssl.org)
00007  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
00008  *
00009  *  All rights reserved.
00010  *
00011  *  This program is free software; you can redistribute it and/or modify
00012  *  it under the terms of the GNU General Public License as published by
00013  *  the Free Software Foundation; either version 2 of the License, or
00014  *  (at your option) any later version.
00015  *
00016  *  This program is distributed in the hope that it will be useful,
00017  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  *  GNU General Public License for more details.
00020  *
00021  *  You should have received a copy of the GNU General Public License along
00022  *  with this program; if not, write to the Free Software Foundation, Inc.,
00023  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00024  */
00025 /*
00026  *  The PKCS #12 Personal Information Exchange Syntax Standard v1.1
00027  *
00028  *  http://www.rsa.com/rsalabs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf
00029  *  ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1-1.asn
00030  */
00031 
00032 #if !defined(POLARSSL_CONFIG_FILE)
00033 #include "polarssl/config.h"
00034 #else
00035 #include POLARSSL_CONFIG_FILE
00036 #endif
00037 
00038 #if defined(POLARSSL_PKCS12_C)
00039 
00040 #include "polarssl/pkcs12.h"
00041 #include "polarssl/asn1.h"
00042 #include "polarssl/cipher.h"
00043 
00044 #if defined(POLARSSL_ARC4_C)
00045 #include "polarssl/arc4.h"
00046 #endif
00047 
00048 #if defined(POLARSSL_DES_C)
00049 #include "polarssl/des.h"
00050 #endif
00051 
00052 static int pkcs12_parse_pbe_params( asn1_buf *params,
00053                                     asn1_buf *salt, int *iterations )
00054 {
00055     int ret;
00056     unsigned char **p = &params->p;
00057     const unsigned char *end = params->p + params->len;
00058 
00059     /*
00060      *  pkcs-12PbeParams ::= SEQUENCE {
00061      *    salt          OCTET STRING,
00062      *    iterations    INTEGER
00063      *  }
00064      *
00065      */
00066     if( params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
00067         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT +
00068                 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
00069 
00070     if( ( ret = asn1_get_tag( p, end, &salt->len, ASN1_OCTET_STRING ) ) != 0 )
00071         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT + ret );
00072 
00073     salt->p = *p;
00074     *p += salt->len;
00075 
00076     if( ( ret = asn1_get_int( p, end, iterations ) ) != 0 )
00077         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT + ret );
00078 
00079     if( *p != end )
00080         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT +
00081                 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
00082 
00083     return( 0 );
00084 }
00085 
00086 static int pkcs12_pbe_derive_key_iv( asn1_buf *pbe_params, md_type_t md_type,
00087                                      const unsigned char *pwd,  size_t pwdlen,
00088                                      unsigned char *key, size_t keylen,
00089                                      unsigned char *iv,  size_t ivlen )
00090 {
00091     int ret, iterations;
00092     asn1_buf salt;
00093     size_t i;
00094     unsigned char unipwd[258];
00095 
00096     memset(&salt, 0, sizeof(asn1_buf));
00097     memset(&unipwd, 0, sizeof(unipwd));
00098 
00099     if( ( ret = pkcs12_parse_pbe_params( pbe_params, &salt,
00100                                          &iterations ) ) != 0 )
00101         return( ret );
00102 
00103     for(i = 0; i < pwdlen; i++)
00104         unipwd[i * 2 + 1] = pwd[i];
00105 
00106     if( ( ret = pkcs12_derivation( key, keylen, unipwd, pwdlen * 2 + 2,
00107                                    salt.p, salt.len, md_type,
00108                                    PKCS12_DERIVE_KEY, iterations ) ) != 0 )
00109     {
00110         return( ret );
00111     }
00112 
00113     if( iv == NULL || ivlen == 0 )
00114         return( 0 );
00115 
00116     if( ( ret = pkcs12_derivation( iv, ivlen, unipwd, pwdlen * 2 + 2,
00117                                    salt.p, salt.len, md_type,
00118                                    PKCS12_DERIVE_IV, iterations ) ) != 0 )
00119     {
00120         return( ret );
00121     }
00122     return( 0 );
00123 }
00124 
00125 int pkcs12_pbe_sha1_rc4_128( asn1_buf *pbe_params, int mode,
00126                              const unsigned char *pwd,  size_t pwdlen,
00127                              const unsigned char *data, size_t len,
00128                              unsigned char *output )
00129 {
00130 #if !defined(POLARSSL_ARC4_C)
00131     ((void) pbe_params);
00132     ((void) mode);
00133     ((void) pwd);
00134     ((void) pwdlen);
00135     ((void) data);
00136     ((void) len);
00137     ((void) output);
00138     return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00139 #else
00140     int ret;
00141     unsigned char key[16];
00142     arc4_context ctx;
00143     ((void) mode);
00144 
00145     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, POLARSSL_MD_SHA1,
00146                                           pwd, pwdlen,
00147                                           key, 16, NULL, 0 ) ) != 0 )
00148     {
00149         return( ret );
00150     }
00151 
00152     arc4_setup( &ctx, key, 16 );
00153     if( ( ret = arc4_crypt( &ctx, len, data, output ) ) != 0 )
00154         return( ret );
00155 
00156     return( 0 );
00157 #endif /* POLARSSL_ARC4_C */
00158 }
00159 
00160 int pkcs12_pbe( asn1_buf *pbe_params, int mode,
00161                 cipher_type_t cipher_type, md_type_t md_type,
00162                 const unsigned char *pwd,  size_t pwdlen,
00163                 const unsigned char *data, size_t len,
00164                 unsigned char *output )
00165 {
00166     int ret, keylen = 0;
00167     unsigned char key[32];
00168     unsigned char iv[16];
00169     const cipher_info_t *cipher_info;
00170     cipher_context_t cipher_ctx;
00171     size_t olen = 0;
00172 
00173     cipher_info = cipher_info_from_type( cipher_type );
00174     if( cipher_info == NULL )
00175         return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00176 
00177     keylen = cipher_info->key_length / 8;
00178 
00179     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, md_type, pwd, pwdlen,
00180                                           key, keylen,
00181                                           iv, cipher_info->iv_size ) ) != 0 )
00182     {
00183         return( ret );
00184     }
00185 
00186     if( ( ret = cipher_init_ctx( &cipher_ctx, cipher_info ) ) != 0 )
00187         goto exit;
00188 
00189     if( ( ret = cipher_setkey( &cipher_ctx, key, 8 * keylen, mode ) ) != 0 )
00190         goto exit;
00191 
00192     if( ( ret = cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
00193         goto exit;
00194 
00195     if( ( ret = cipher_reset( &cipher_ctx ) ) != 0 )
00196         goto exit;
00197 
00198     if( ( ret = cipher_update( &cipher_ctx, data, len,
00199                                 output, &olen ) ) != 0 )
00200     {
00201         goto exit;
00202     }
00203 
00204     if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
00205         ret = POLARSSL_ERR_PKCS12_PASSWORD_MISMATCH;
00206 
00207 exit:
00208     cipher_free_ctx( &cipher_ctx );
00209 
00210     return( ret );
00211 }
00212 
00213 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
00214                                 const unsigned char *filler, size_t fill_len )
00215 {
00216     unsigned char *p = data;
00217     size_t use_len;
00218 
00219     while( data_len > 0 )
00220     {
00221         use_len = ( data_len > fill_len ) ? fill_len : data_len;
00222         memcpy( p, filler, use_len );
00223         p += use_len;
00224         data_len -= use_len;
00225     }
00226 }
00227 
00228 int pkcs12_derivation( unsigned char *data, size_t datalen,
00229                        const unsigned char *pwd, size_t pwdlen,
00230                        const unsigned char *salt, size_t saltlen,
00231                        md_type_t md_type, int id, int iterations )
00232 {
00233     int ret;
00234     unsigned int j;
00235 
00236     unsigned char diversifier[128];
00237     unsigned char salt_block[128], pwd_block[128], hash_block[128];
00238     unsigned char hash_output[POLARSSL_MD_MAX_SIZE];
00239     unsigned char *p;
00240     unsigned char c;
00241 
00242     size_t hlen, use_len, v, i;
00243 
00244     const md_info_t *md_info;
00245     md_context_t md_ctx;
00246 
00247     // This version only allows max of 64 bytes of password or salt
00248     if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
00249         return( POLARSSL_ERR_PKCS12_BAD_INPUT_DATA );
00250 
00251     md_info = md_info_from_type( md_type );
00252     if( md_info == NULL )
00253         return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00254 
00255     if ( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
00256         return( ret );
00257     hlen = md_get_size( md_info );
00258 
00259     if( hlen <= 32 )
00260         v = 64;
00261     else
00262         v = 128;
00263 
00264     memset( diversifier, (unsigned char) id, v );
00265 
00266     pkcs12_fill_buffer( salt_block, v, salt, saltlen );
00267     pkcs12_fill_buffer( pwd_block,  v, pwd,  pwdlen  );
00268 
00269     p = data;
00270     while( datalen > 0 )
00271     {
00272         // Calculate hash( diversifier || salt_block || pwd_block )
00273         if( ( ret = md_starts( &md_ctx ) ) != 0 )
00274             goto exit;
00275 
00276         if( ( ret = md_update( &md_ctx, diversifier, v ) ) != 0 )
00277             goto exit;
00278 
00279         if( ( ret = md_update( &md_ctx, salt_block, v ) ) != 0 )
00280             goto exit;
00281 
00282         if( ( ret = md_update( &md_ctx, pwd_block, v ) ) != 0 )
00283             goto exit;
00284 
00285         if( ( ret = md_finish( &md_ctx, hash_output ) ) != 0 )
00286             goto exit;
00287 
00288         // Perform remaining ( iterations - 1 ) recursive hash calculations
00289         for( i = 1; i < (size_t) iterations; i++ )
00290         {
00291             if( ( ret = md( md_info, hash_output, hlen, hash_output ) ) != 0 )
00292                 goto exit;
00293         }
00294 
00295         use_len = ( datalen > hlen ) ? hlen : datalen;
00296         memcpy( p, hash_output, use_len );
00297         datalen -= use_len;
00298         p += use_len;
00299 
00300         if( datalen == 0 )
00301             break;
00302 
00303         // Concatenating copies of hash_output into hash_block (B)
00304         pkcs12_fill_buffer( hash_block, v, hash_output, hlen );
00305 
00306         // B += 1
00307         for( i = v; i > 0; i-- )
00308             if( ++hash_block[i - 1] != 0 )
00309                 break;
00310 
00311         // salt_block += B
00312         c = 0;
00313         for( i = v; i > 0; i-- )
00314         {
00315             j = salt_block[i - 1] + hash_block[i - 1] + c;
00316             c = (unsigned char) (j >> 8);
00317             salt_block[i - 1] = j & 0xFF;
00318         }
00319 
00320         // pwd_block  += B
00321         c = 0;
00322         for( i = v; i > 0; i-- )
00323         {
00324             j = pwd_block[i - 1] + hash_block[i - 1] + c;
00325             c = (unsigned char) (j >> 8);
00326             pwd_block[i - 1] = j & 0xFF;
00327         }
00328     }
00329 
00330     ret = 0;
00331 
00332 exit:
00333     md_free_ctx( &md_ctx );
00334 
00335     return( ret );
00336 }
00337 
00338 #endif /* POLARSSL_PKCS12_C */
00339 
00340