mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-11-30 00:54:24 +01:00
358 lines
10 KiB
C
358 lines
10 KiB
C
/*
|
|
* Privacy Enhanced Mail (PEM) decoding
|
|
*
|
|
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
|
|
*
|
|
* This file is part of mbed TLS (https://polarssl.org)
|
|
*
|
|
* This program 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.
|
|
*
|
|
* This program 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 "polarssl/config.h"
|
|
|
|
#if defined(POLARSSL_PEM_C)
|
|
|
|
#include "polarssl/pem.h"
|
|
#include "polarssl/base64.h"
|
|
#include "polarssl/des.h"
|
|
#include "polarssl/aes.h"
|
|
#include "polarssl/md5.h"
|
|
#include "polarssl/cipher.h"
|
|
|
|
#include <stdlib.h>
|
|
|
|
/* Implementation that should never be optimized out by the compiler */
|
|
static void polarssl_zeroize( void *v, size_t n ) {
|
|
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
|
|
}
|
|
|
|
void pem_init( pem_context *ctx )
|
|
{
|
|
memset( ctx, 0, sizeof( pem_context ) );
|
|
}
|
|
|
|
#if defined(POLARSSL_MD5_C) && (defined(POLARSSL_DES_C) || defined(POLARSSL_AES_C))
|
|
/*
|
|
* Read a 16-byte hex string and convert it to binary
|
|
*/
|
|
static int pem_get_iv( const unsigned char *s, unsigned char *iv, size_t iv_len )
|
|
{
|
|
size_t i, j, k;
|
|
|
|
memset( iv, 0, iv_len );
|
|
|
|
for( i = 0; i < iv_len * 2; i++, s++ )
|
|
{
|
|
if( *s >= '0' && *s <= '9' ) j = *s - '0'; else
|
|
if( *s >= 'A' && *s <= 'F' ) j = *s - '7'; else
|
|
if( *s >= 'a' && *s <= 'f' ) j = *s - 'W'; else
|
|
return( POLARSSL_ERR_PEM_INVALID_ENC_IV );
|
|
|
|
k = ( ( i & 1 ) != 0 ) ? j : j << 4;
|
|
|
|
iv[i >> 1] = (unsigned char)( iv[i >> 1] | k );
|
|
}
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
static void pem_pbkdf1( unsigned char *key, size_t keylen,
|
|
unsigned char *iv,
|
|
const unsigned char *pwd, size_t pwdlen )
|
|
{
|
|
md5_context md5_ctx;
|
|
unsigned char md5sum[16];
|
|
size_t use_len;
|
|
|
|
/*
|
|
* key[ 0..15] = MD5(pwd || IV)
|
|
*/
|
|
md5_starts( &md5_ctx );
|
|
md5_update( &md5_ctx, pwd, pwdlen );
|
|
md5_update( &md5_ctx, iv, 8 );
|
|
md5_finish( &md5_ctx, md5sum );
|
|
|
|
if( keylen <= 16 )
|
|
{
|
|
memcpy( key, md5sum, keylen );
|
|
|
|
polarssl_zeroize( &md5_ctx, sizeof( md5_ctx ) );
|
|
polarssl_zeroize( md5sum, 16 );
|
|
return;
|
|
}
|
|
|
|
memcpy( key, md5sum, 16 );
|
|
|
|
/*
|
|
* key[16..23] = MD5(key[ 0..15] || pwd || IV])
|
|
*/
|
|
md5_starts( &md5_ctx );
|
|
md5_update( &md5_ctx, md5sum, 16 );
|
|
md5_update( &md5_ctx, pwd, pwdlen );
|
|
md5_update( &md5_ctx, iv, 8 );
|
|
md5_finish( &md5_ctx, md5sum );
|
|
|
|
use_len = 16;
|
|
if( keylen < 32 )
|
|
use_len = keylen - 16;
|
|
|
|
memcpy( key + 16, md5sum, use_len );
|
|
|
|
polarssl_zeroize( &md5_ctx, sizeof( md5_ctx ) );
|
|
polarssl_zeroize( md5sum, 16 );
|
|
}
|
|
|
|
#if defined(POLARSSL_DES_C)
|
|
/*
|
|
* Decrypt with DES-CBC, using PBKDF1 for key derivation
|
|
*/
|
|
static void pem_des_decrypt( unsigned char des_iv[8],
|
|
unsigned char *buf, size_t buflen,
|
|
const unsigned char *pwd, size_t pwdlen )
|
|
{
|
|
des_context des_ctx;
|
|
unsigned char des_key[8];
|
|
|
|
pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen );
|
|
|
|
des_setkey_dec( &des_ctx, des_key );
|
|
des_crypt_cbc( &des_ctx, DES_DECRYPT, buflen,
|
|
des_iv, buf, buf );
|
|
|
|
polarssl_zeroize( &des_ctx, sizeof( des_ctx ) );
|
|
polarssl_zeroize( des_key, 8 );
|
|
}
|
|
|
|
/*
|
|
* Decrypt with 3DES-CBC, using PBKDF1 for key derivation
|
|
*/
|
|
static void pem_des3_decrypt( unsigned char des3_iv[8],
|
|
unsigned char *buf, size_t buflen,
|
|
const unsigned char *pwd, size_t pwdlen )
|
|
{
|
|
des3_context des3_ctx;
|
|
unsigned char des3_key[24];
|
|
|
|
pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen );
|
|
|
|
des3_set3key_dec( &des3_ctx, des3_key );
|
|
des3_crypt_cbc( &des3_ctx, DES_DECRYPT, buflen,
|
|
des3_iv, buf, buf );
|
|
|
|
polarssl_zeroize( &des3_ctx, sizeof( des3_ctx ) );
|
|
polarssl_zeroize( des3_key, 24 );
|
|
}
|
|
#endif /* POLARSSL_DES_C */
|
|
|
|
#if defined(POLARSSL_AES_C)
|
|
/*
|
|
* Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
|
|
*/
|
|
static void pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen,
|
|
unsigned char *buf, size_t buflen,
|
|
const unsigned char *pwd, size_t pwdlen )
|
|
{
|
|
aes_context aes_ctx;
|
|
unsigned char aes_key[32];
|
|
|
|
pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen );
|
|
|
|
aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 );
|
|
aes_crypt_cbc( &aes_ctx, AES_DECRYPT, buflen,
|
|
aes_iv, buf, buf );
|
|
|
|
polarssl_zeroize( &aes_ctx, sizeof( aes_ctx ) );
|
|
polarssl_zeroize( aes_key, keylen );
|
|
}
|
|
#endif /* POLARSSL_AES_C */
|
|
|
|
#endif /* POLARSSL_MD5_C && (POLARSSL_AES_C || POLARSSL_DES_C) */
|
|
|
|
int pem_read_buffer( pem_context *ctx, char *header, char *footer, const unsigned char *data, const unsigned char *pwd, size_t pwdlen, size_t *use_len )
|
|
{
|
|
int ret, enc;
|
|
size_t len;
|
|
unsigned char *buf;
|
|
const unsigned char *s1, *s2, *end;
|
|
#if defined(POLARSSL_MD5_C) && (defined(POLARSSL_DES_C) || defined(POLARSSL_AES_C))
|
|
unsigned char pem_iv[16];
|
|
cipher_type_t enc_alg = POLARSSL_CIPHER_NONE;
|
|
#else
|
|
((void) pwd);
|
|
((void) pwdlen);
|
|
#endif /* POLARSSL_MD5_C && (POLARSSL_AES_C || POLARSSL_DES_C) */
|
|
|
|
if( ctx == NULL )
|
|
return( POLARSSL_ERR_PEM_BAD_INPUT_DATA );
|
|
|
|
s1 = (unsigned char *) strstr( (const char *) data, header );
|
|
|
|
if( s1 == NULL )
|
|
return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
|
|
|
|
s2 = (unsigned char *) strstr( (const char *) data, footer );
|
|
|
|
if( s2 == NULL || s2 <= s1 )
|
|
return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
|
|
|
|
s1 += strlen( header );
|
|
if( *s1 == '\r' ) s1++;
|
|
if( *s1 == '\n' ) s1++;
|
|
else return( POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
|
|
|
|
end = s2;
|
|
end += strlen( footer );
|
|
if( *end == '\r' ) end++;
|
|
if( *end == '\n' ) end++;
|
|
*use_len = end - data;
|
|
|
|
enc = 0;
|
|
|
|
if( memcmp( s1, "Proc-Type: 4,ENCRYPTED", 22 ) == 0 )
|
|
{
|
|
#if defined(POLARSSL_MD5_C) && (defined(POLARSSL_DES_C) || defined(POLARSSL_AES_C))
|
|
enc++;
|
|
|
|
s1 += 22;
|
|
if( *s1 == '\r' ) s1++;
|
|
if( *s1 == '\n' ) s1++;
|
|
else return( POLARSSL_ERR_PEM_INVALID_DATA );
|
|
|
|
|
|
#if defined(POLARSSL_DES_C)
|
|
if( memcmp( s1, "DEK-Info: DES-EDE3-CBC,", 23 ) == 0 )
|
|
{
|
|
enc_alg = POLARSSL_CIPHER_DES_EDE3_CBC;
|
|
|
|
s1 += 23;
|
|
if( pem_get_iv( s1, pem_iv, 8 ) != 0 )
|
|
return( POLARSSL_ERR_PEM_INVALID_ENC_IV );
|
|
|
|
s1 += 16;
|
|
}
|
|
else if( memcmp( s1, "DEK-Info: DES-CBC,", 18 ) == 0 )
|
|
{
|
|
enc_alg = POLARSSL_CIPHER_DES_CBC;
|
|
|
|
s1 += 18;
|
|
if( pem_get_iv( s1, pem_iv, 8) != 0 )
|
|
return( POLARSSL_ERR_PEM_INVALID_ENC_IV );
|
|
|
|
s1 += 16;
|
|
}
|
|
#endif /* POLARSSL_DES_C */
|
|
|
|
#if defined(POLARSSL_AES_C)
|
|
if( memcmp( s1, "DEK-Info: AES-", 14 ) == 0 )
|
|
{
|
|
if( memcmp( s1, "DEK-Info: AES-128-CBC,", 22 ) == 0 )
|
|
enc_alg = POLARSSL_CIPHER_AES_128_CBC;
|
|
else if( memcmp( s1, "DEK-Info: AES-192-CBC,", 22 ) == 0 )
|
|
enc_alg = POLARSSL_CIPHER_AES_192_CBC;
|
|
else if( memcmp( s1, "DEK-Info: AES-256-CBC,", 22 ) == 0 )
|
|
enc_alg = POLARSSL_CIPHER_AES_256_CBC;
|
|
else
|
|
return( POLARSSL_ERR_PEM_UNKNOWN_ENC_ALG );
|
|
|
|
s1 += 22;
|
|
if( pem_get_iv( s1, pem_iv, 16 ) != 0 )
|
|
return( POLARSSL_ERR_PEM_INVALID_ENC_IV );
|
|
|
|
s1 += 32;
|
|
}
|
|
#endif /* POLARSSL_AES_C */
|
|
|
|
if( enc_alg == POLARSSL_CIPHER_NONE )
|
|
return( POLARSSL_ERR_PEM_UNKNOWN_ENC_ALG );
|
|
|
|
if( *s1 == '\r' ) s1++;
|
|
if( *s1 == '\n' ) s1++;
|
|
else return( POLARSSL_ERR_PEM_INVALID_DATA );
|
|
#else
|
|
return( POLARSSL_ERR_PEM_FEATURE_UNAVAILABLE );
|
|
#endif /* POLARSSL_MD5_C && (POLARSSL_AES_C || POLARSSL_DES_C) */
|
|
}
|
|
|
|
len = 0;
|
|
ret = base64_decode( NULL, &len, s1, s2 - s1 );
|
|
|
|
if( ret == POLARSSL_ERR_BASE64_INVALID_CHARACTER )
|
|
return( POLARSSL_ERR_PEM_INVALID_DATA + ret );
|
|
|
|
if( ( buf = (unsigned char *) malloc( len ) ) == NULL )
|
|
return( POLARSSL_ERR_PEM_MALLOC_FAILED );
|
|
|
|
if( ( ret = base64_decode( buf, &len, s1, s2 - s1 ) ) != 0 )
|
|
{
|
|
free( buf );
|
|
return( POLARSSL_ERR_PEM_INVALID_DATA + ret );
|
|
}
|
|
|
|
if( enc != 0 )
|
|
{
|
|
#if defined(POLARSSL_MD5_C) && (defined(POLARSSL_DES_C) || defined(POLARSSL_AES_C))
|
|
if( pwd == NULL )
|
|
{
|
|
free( buf );
|
|
return( POLARSSL_ERR_PEM_PASSWORD_REQUIRED );
|
|
}
|
|
|
|
#if defined(POLARSSL_DES_C)
|
|
if( enc_alg == POLARSSL_CIPHER_DES_EDE3_CBC )
|
|
pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen );
|
|
else if( enc_alg == POLARSSL_CIPHER_DES_CBC )
|
|
pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen );
|
|
#endif /* POLARSSL_DES_C */
|
|
|
|
#if defined(POLARSSL_AES_C)
|
|
if( enc_alg == POLARSSL_CIPHER_AES_128_CBC )
|
|
pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen );
|
|
else if( enc_alg == POLARSSL_CIPHER_AES_192_CBC )
|
|
pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen );
|
|
else if( enc_alg == POLARSSL_CIPHER_AES_256_CBC )
|
|
pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen );
|
|
#endif /* POLARSSL_AES_C */
|
|
|
|
if( buf[0] != 0x30 || buf[1] != 0x82 ||
|
|
buf[4] != 0x02 || buf[5] != 0x01 )
|
|
{
|
|
free( buf );
|
|
return( POLARSSL_ERR_PEM_PASSWORD_MISMATCH );
|
|
}
|
|
#else
|
|
free( buf );
|
|
return( POLARSSL_ERR_PEM_FEATURE_UNAVAILABLE );
|
|
#endif
|
|
}
|
|
|
|
ctx->buf = buf;
|
|
ctx->buflen = len;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
void pem_free( pem_context *ctx )
|
|
{
|
|
if( ctx->buf )
|
|
free( ctx->buf );
|
|
|
|
if( ctx->info )
|
|
free( ctx->info );
|
|
|
|
polarssl_zeroize( ctx, sizeof( pem_context ) );
|
|
}
|
|
|
|
#endif
|