pkcs12.c

00001 /*
00002  *  PKCS#12 Personal Information Exchange Syntax
00003  *
00004  *  Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
00005  *
00006  *  This file is part of mbed TLS (https://tls.mbed.org)
00007  *
00008  *  This program is free software; you can redistribute it and/or modify
00009  *  it under the terms of the GNU General Public License as published by
00010  *  the Free Software Foundation; either version 2 of the License, or
00011  *  (at your option) any later version.
00012  *
00013  *  This program is distributed in the hope that it will be useful,
00014  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  *  GNU General Public License for more details.
00017  *
00018  *  You should have received a copy of the GNU General Public License along
00019  *  with this program; if not, write to the Free Software Foundation, Inc.,
00020  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
00021  */
00022 /*
00023  *  The PKCS #12 Personal Information Exchange Syntax Standard v1.1
00024  *
00025  *  http://www.rsa.com/rsalabs/pkcs/files/h11301-wp-pkcs-12v1-1-personal-information-exchange-syntax.pdf
00026  *  ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-12/pkcs-12v1-1.asn
00027  */
00028 
00029 #if !defined(POLARSSL_CONFIG_FILE)
00030 #include "polarssl/config.h"
00031 #else
00032 #include POLARSSL_CONFIG_FILE
00033 #endif
00034 
00035 #if defined(POLARSSL_PKCS12_C)
00036 
00037 #include "polarssl/pkcs12.h"
00038 #include "polarssl/asn1.h"
00039 #include "polarssl/cipher.h"
00040 
00041 #include <string.h>
00042 
00043 #if defined(POLARSSL_ARC4_C)
00044 #include "polarssl/arc4.h"
00045 #endif
00046 
00047 #if defined(POLARSSL_DES_C)
00048 #include "polarssl/des.h"
00049 #endif
00050 
00051 /* Implementation that should never be optimized out by the compiler */
00052 static void polarssl_zeroize( void *v, size_t n ) {
00053     volatile unsigned char *p = v; while( n-- ) *p++ = 0;
00054 }
00055 
00056 static int pkcs12_parse_pbe_params( asn1_buf *params,
00057                                     asn1_buf *salt, int *iterations )
00058 {
00059     int ret;
00060     unsigned char **p = &params->p;
00061     const unsigned char *end = params->p + params->len;
00062 
00063     /*
00064      *  pkcs-12PbeParams ::= SEQUENCE {
00065      *    salt          OCTET STRING,
00066      *    iterations    INTEGER
00067      *  }
00068      *
00069      */
00070     if( params->tag != ( ASN1_CONSTRUCTED | ASN1_SEQUENCE ) )
00071         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT +
00072                 POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
00073 
00074     if( ( ret = asn1_get_tag( p, end, &salt->len, ASN1_OCTET_STRING ) ) != 0 )
00075         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT + ret );
00076 
00077     salt->p = *p;
00078     *p += salt->len;
00079 
00080     if( ( ret = asn1_get_int( p, end, iterations ) ) != 0 )
00081         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT + ret );
00082 
00083     if( *p != end )
00084         return( POLARSSL_ERR_PKCS12_PBE_INVALID_FORMAT +
00085                 POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
00086 
00087     return( 0 );
00088 }
00089 
00090 static int pkcs12_pbe_derive_key_iv( asn1_buf *pbe_params, md_type_t md_type,
00091                                      const unsigned char *pwd,  size_t pwdlen,
00092                                      unsigned char *key, size_t keylen,
00093                                      unsigned char *iv,  size_t ivlen )
00094 {
00095     int ret, iterations;
00096     asn1_buf salt;
00097     size_t i;
00098     unsigned char unipwd[258];
00099 
00100     memset( &salt, 0, sizeof(asn1_buf) );
00101     memset( &unipwd, 0, sizeof(unipwd) );
00102 
00103     if( ( ret = pkcs12_parse_pbe_params( pbe_params, &salt,
00104                                          &iterations ) ) != 0 )
00105         return( ret );
00106 
00107     for( i = 0; i < pwdlen; i++ )
00108         unipwd[i * 2 + 1] = pwd[i];
00109 
00110     if( ( ret = pkcs12_derivation( key, keylen, unipwd, pwdlen * 2 + 2,
00111                                    salt.p, salt.len, md_type,
00112                                    PKCS12_DERIVE_KEY, iterations ) ) != 0 )
00113     {
00114         return( ret );
00115     }
00116 
00117     if( iv == NULL || ivlen == 0 )
00118         return( 0 );
00119 
00120     if( ( ret = pkcs12_derivation( iv, ivlen, unipwd, pwdlen * 2 + 2,
00121                                    salt.p, salt.len, md_type,
00122                                    PKCS12_DERIVE_IV, iterations ) ) != 0 )
00123     {
00124         return( ret );
00125     }
00126     return( 0 );
00127 }
00128 
00129 int pkcs12_pbe_sha1_rc4_128( asn1_buf *pbe_params, int mode,
00130                              const unsigned char *pwd,  size_t pwdlen,
00131                              const unsigned char *data, size_t len,
00132                              unsigned char *output )
00133 {
00134 #if !defined(POLARSSL_ARC4_C)
00135     ((void) pbe_params);
00136     ((void) mode);
00137     ((void) pwd);
00138     ((void) pwdlen);
00139     ((void) data);
00140     ((void) len);
00141     ((void) output);
00142     return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00143 #else
00144     int ret;
00145     unsigned char key[16];
00146     arc4_context ctx;
00147     ((void) mode);
00148 
00149     arc4_init( &ctx );
00150 
00151     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, POLARSSL_MD_SHA1,
00152                                           pwd, pwdlen,
00153                                           key, 16, NULL, 0 ) ) != 0 )
00154     {
00155         return( ret );
00156     }
00157 
00158     arc4_setup( &ctx, key, 16 );
00159     if( ( ret = arc4_crypt( &ctx, len, data, output ) ) != 0 )
00160         goto exit;
00161 
00162 exit:
00163     polarssl_zeroize( key, sizeof( key ) );
00164     arc4_free( &ctx );
00165 
00166     return( ret );
00167 #endif /* POLARSSL_ARC4_C */
00168 }
00169 
00170 int pkcs12_pbe( asn1_buf *pbe_params, int mode,
00171                 cipher_type_t cipher_type, md_type_t md_type,
00172                 const unsigned char *pwd,  size_t pwdlen,
00173                 const unsigned char *data, size_t len,
00174                 unsigned char *output )
00175 {
00176     int ret, keylen = 0;
00177     unsigned char key[32];
00178     unsigned char iv[16];
00179     const cipher_info_t *cipher_info;
00180     cipher_context_t cipher_ctx;
00181     size_t olen = 0;
00182 
00183     cipher_info = cipher_info_from_type( cipher_type );
00184     if( cipher_info == NULL )
00185         return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00186 
00187     keylen = cipher_info->key_length / 8;
00188 
00189     if( ( ret = pkcs12_pbe_derive_key_iv( pbe_params, md_type, pwd, pwdlen,
00190                                           key, keylen,
00191                                           iv, cipher_info->iv_size ) ) != 0 )
00192     {
00193         return( ret );
00194     }
00195 
00196     cipher_init( &cipher_ctx );
00197 
00198     if( ( ret = cipher_init_ctx( &cipher_ctx, cipher_info ) ) != 0 )
00199         goto exit;
00200 
00201     if( ( ret = cipher_setkey( &cipher_ctx, key, 8 * keylen, (operation_t) mode ) ) != 0 )
00202         goto exit;
00203 
00204     if( ( ret = cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
00205         goto exit;
00206 
00207     if( ( ret = cipher_reset( &cipher_ctx ) ) != 0 )
00208         goto exit;
00209 
00210     if( ( ret = cipher_update( &cipher_ctx, data, len,
00211                                 output, &olen ) ) != 0 )
00212     {
00213         goto exit;
00214     }
00215 
00216     if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
00217         ret = POLARSSL_ERR_PKCS12_PASSWORD_MISMATCH;
00218 
00219 exit:
00220     polarssl_zeroize( key, sizeof( key ) );
00221     polarssl_zeroize( iv,  sizeof( iv  ) );
00222     cipher_free( &cipher_ctx );
00223 
00224     return( ret );
00225 }
00226 
00227 static void pkcs12_fill_buffer( unsigned char *data, size_t data_len,
00228                                 const unsigned char *filler, size_t fill_len )
00229 {
00230     unsigned char *p = data;
00231     size_t use_len;
00232 
00233     while( data_len > 0 )
00234     {
00235         use_len = ( data_len > fill_len ) ? fill_len : data_len;
00236         memcpy( p, filler, use_len );
00237         p += use_len;
00238         data_len -= use_len;
00239     }
00240 }
00241 
00242 int pkcs12_derivation( unsigned char *data, size_t datalen,
00243                        const unsigned char *pwd, size_t pwdlen,
00244                        const unsigned char *salt, size_t saltlen,
00245                        md_type_t md_type, int id, int iterations )
00246 {
00247     int ret;
00248     unsigned int j;
00249 
00250     unsigned char diversifier[128];
00251     unsigned char salt_block[128], pwd_block[128], hash_block[128];
00252     unsigned char hash_output[POLARSSL_MD_MAX_SIZE];
00253     unsigned char *p;
00254     unsigned char c;
00255 
00256     size_t hlen, use_len, v, i;
00257 
00258     const md_info_t *md_info;
00259     md_context_t md_ctx;
00260 
00261     // This version only allows max of 64 bytes of password or salt
00262     if( datalen > 128 || pwdlen > 64 || saltlen > 64 )
00263         return( POLARSSL_ERR_PKCS12_BAD_INPUT_DATA );
00264 
00265     md_info = md_info_from_type( md_type );
00266     if( md_info == NULL )
00267         return( POLARSSL_ERR_PKCS12_FEATURE_UNAVAILABLE );
00268 
00269     md_init( &md_ctx );
00270 
00271     if( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
00272         return( ret );
00273     hlen = md_get_size( md_info );
00274 
00275     if( hlen <= 32 )
00276         v = 64;
00277     else
00278         v = 128;
00279 
00280     memset( diversifier, (unsigned char) id, v );
00281 
00282     pkcs12_fill_buffer( salt_block, v, salt, saltlen );
00283     pkcs12_fill_buffer( pwd_block,  v, pwd,  pwdlen  );
00284 
00285     p = data;
00286     while( datalen > 0 )
00287     {
00288         // Calculate hash( diversifier || salt_block || pwd_block )
00289         if( ( ret = md_starts( &md_ctx ) ) != 0 )
00290             goto exit;
00291 
00292         if( ( ret = md_update( &md_ctx, diversifier, v ) ) != 0 )
00293             goto exit;
00294 
00295         if( ( ret = md_update( &md_ctx, salt_block, v ) ) != 0 )
00296             goto exit;
00297 
00298         if( ( ret = md_update( &md_ctx, pwd_block, v ) ) != 0 )
00299             goto exit;
00300 
00301         if( ( ret = md_finish( &md_ctx, hash_output ) ) != 0 )
00302             goto exit;
00303 
00304         // Perform remaining ( iterations - 1 ) recursive hash calculations
00305         for( i = 1; i < (size_t) iterations; i++ )
00306         {
00307             if( ( ret = md( md_info, hash_output, hlen, hash_output ) ) != 0 )
00308                 goto exit;
00309         }
00310 
00311         use_len = ( datalen > hlen ) ? hlen : datalen;
00312         memcpy( p, hash_output, use_len );
00313         datalen -= use_len;
00314         p += use_len;
00315 
00316         if( datalen == 0 )
00317             break;
00318 
00319         // Concatenating copies of hash_output into hash_block (B)
00320         pkcs12_fill_buffer( hash_block, v, hash_output, hlen );
00321 
00322         // B += 1
00323         for( i = v; i > 0; i-- )
00324             if( ++hash_block[i - 1] != 0 )
00325                 break;
00326 
00327         // salt_block += B
00328         c = 0;
00329         for( i = v; i > 0; i-- )
00330         {
00331             j = salt_block[i - 1] + hash_block[i - 1] + c;
00332             c = (unsigned char) (j >> 8);
00333             salt_block[i - 1] = j & 0xFF;
00334         }
00335 
00336         // pwd_block  += B
00337         c = 0;
00338         for( i = v; i > 0; i-- )
00339         {
00340             j = pwd_block[i - 1] + hash_block[i - 1] + c;
00341             c = (unsigned char) (j >> 8);
00342             pwd_block[i - 1] = j & 0xFF;
00343         }
00344     }
00345 
00346     ret = 0;
00347 
00348 exit:
00349     polarssl_zeroize( salt_block, sizeof( salt_block ) );
00350     polarssl_zeroize( pwd_block, sizeof( pwd_block ) );
00351     polarssl_zeroize( hash_block, sizeof( hash_block ) );
00352     polarssl_zeroize( hash_output, sizeof( hash_output ) );
00353 
00354     md_free( &md_ctx );
00355 
00356     return( ret );
00357 }
00358 
00359 #endif /* POLARSSL_PKCS12_C */
00360