Mark Radbourne / mbedtls

mbed TLS Build

Dependents:   Encrypt_Decrypt1 mbed_blink_tls encrypt encrypt

library/pem.c@0:cdf462088d13, 2017-01-05 (annotated)

Committer:
markrad
Date:
Thu Jan 05 00:18:44 2017 +0000
Revision:
0:cdf462088d13
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
markrad 0:cdf462088d13 1 /*
markrad 0:cdf462088d13 2 * Privacy Enhanced Mail (PEM) decoding
markrad 0:cdf462088d13 3 *
markrad 0:cdf462088d13 4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
markrad 0:cdf462088d13 5 * SPDX-License-Identifier: Apache-2.0
markrad 0:cdf462088d13 6 *
markrad 0:cdf462088d13 7 * Licensed under the Apache License, Version 2.0 (the "License"); you may
markrad 0:cdf462088d13 8 * not use this file except in compliance with the License.
markrad 0:cdf462088d13 9 * You may obtain a copy of the License at
markrad 0:cdf462088d13 10 *
markrad 0:cdf462088d13 11 * http://www.apache.org/licenses/LICENSE-2.0
markrad 0:cdf462088d13 12 *
markrad 0:cdf462088d13 13 * Unless required by applicable law or agreed to in writing, software
markrad 0:cdf462088d13 14 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
markrad 0:cdf462088d13 15 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
markrad 0:cdf462088d13 16 * See the License for the specific language governing permissions and
markrad 0:cdf462088d13 17 * limitations under the License.
markrad 0:cdf462088d13 18 *
markrad 0:cdf462088d13 19 * This file is part of mbed TLS (https://tls.mbed.org)
markrad 0:cdf462088d13 20 */
markrad 0:cdf462088d13 21
markrad 0:cdf462088d13 22 #if !defined(MBEDTLS_CONFIG_FILE)
markrad 0:cdf462088d13 23 #include "mbedtls/config.h"
markrad 0:cdf462088d13 24 #else
markrad 0:cdf462088d13 25 #include MBEDTLS_CONFIG_FILE
markrad 0:cdf462088d13 26 #endif
markrad 0:cdf462088d13 27
markrad 0:cdf462088d13 28 #if defined(MBEDTLS_PEM_PARSE_C) || defined(MBEDTLS_PEM_WRITE_C)
markrad 0:cdf462088d13 29
markrad 0:cdf462088d13 30 #include "mbedtls/pem.h"
markrad 0:cdf462088d13 31 #include "mbedtls/base64.h"
markrad 0:cdf462088d13 32 #include "mbedtls/des.h"
markrad 0:cdf462088d13 33 #include "mbedtls/aes.h"
markrad 0:cdf462088d13 34 #include "mbedtls/md5.h"
markrad 0:cdf462088d13 35 #include "mbedtls/cipher.h"
markrad 0:cdf462088d13 36
markrad 0:cdf462088d13 37 #include <string.h>
markrad 0:cdf462088d13 38
markrad 0:cdf462088d13 39 #if defined(MBEDTLS_PLATFORM_C)
markrad 0:cdf462088d13 40 #include "mbedtls/platform.h"
markrad 0:cdf462088d13 41 #else
markrad 0:cdf462088d13 42 #include <stdlib.h>
markrad 0:cdf462088d13 43 #define mbedtls_calloc calloc
markrad 0:cdf462088d13 44 #define mbedtls_free free
markrad 0:cdf462088d13 45 #endif
markrad 0:cdf462088d13 46
markrad 0:cdf462088d13 47 /* Implementation that should never be optimized out by the compiler */
markrad 0:cdf462088d13 48 static void mbedtls_zeroize( void *v, size_t n ) {
markrad 0:cdf462088d13 49 volatile unsigned char *p = v; while( n-- ) *p++ = 0;
markrad 0:cdf462088d13 50 }
markrad 0:cdf462088d13 51
markrad 0:cdf462088d13 52 #if defined(MBEDTLS_PEM_PARSE_C)
markrad 0:cdf462088d13 53 void mbedtls_pem_init( mbedtls_pem_context *ctx )
markrad 0:cdf462088d13 54 {
markrad 0:cdf462088d13 55 memset( ctx, 0, sizeof( mbedtls_pem_context ) );
markrad 0:cdf462088d13 56 }
markrad 0:cdf462088d13 57
markrad 0:cdf462088d13 58 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
markrad 0:cdf462088d13 59 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
markrad 0:cdf462088d13 60 /*
markrad 0:cdf462088d13 61 * Read a 16-byte hex string and convert it to binary
markrad 0:cdf462088d13 62 */
markrad 0:cdf462088d13 63 static int pem_get_iv( const unsigned char *s, unsigned char *iv,
markrad 0:cdf462088d13 64 size_t iv_len )
markrad 0:cdf462088d13 65 {
markrad 0:cdf462088d13 66 size_t i, j, k;
markrad 0:cdf462088d13 67
markrad 0:cdf462088d13 68 memset( iv, 0, iv_len );
markrad 0:cdf462088d13 69
markrad 0:cdf462088d13 70 for( i = 0; i < iv_len * 2; i++, s++ )
markrad 0:cdf462088d13 71 {
markrad 0:cdf462088d13 72 if( *s >= '0' && *s <= '9' ) j = *s - '0'; else
markrad 0:cdf462088d13 73 if( *s >= 'A' && *s <= 'F' ) j = *s - '7'; else
markrad 0:cdf462088d13 74 if( *s >= 'a' && *s <= 'f' ) j = *s - 'W'; else
markrad 0:cdf462088d13 75 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
markrad 0:cdf462088d13 76
markrad 0:cdf462088d13 77 k = ( ( i & 1 ) != 0 ) ? j : j << 4;
markrad 0:cdf462088d13 78
markrad 0:cdf462088d13 79 iv[i >> 1] = (unsigned char)( iv[i >> 1] | k );
markrad 0:cdf462088d13 80 }
markrad 0:cdf462088d13 81
markrad 0:cdf462088d13 82 return( 0 );
markrad 0:cdf462088d13 83 }
markrad 0:cdf462088d13 84
markrad 0:cdf462088d13 85 static void pem_pbkdf1( unsigned char *key, size_t keylen,
markrad 0:cdf462088d13 86 unsigned char *iv,
markrad 0:cdf462088d13 87 const unsigned char *pwd, size_t pwdlen )
markrad 0:cdf462088d13 88 {
markrad 0:cdf462088d13 89 mbedtls_md5_context md5_ctx;
markrad 0:cdf462088d13 90 unsigned char md5sum[16];
markrad 0:cdf462088d13 91 size_t use_len;
markrad 0:cdf462088d13 92
markrad 0:cdf462088d13 93 mbedtls_md5_init( &md5_ctx );
markrad 0:cdf462088d13 94
markrad 0:cdf462088d13 95 /*
markrad 0:cdf462088d13 96 * key[ 0..15] = MD5(pwd || IV)
markrad 0:cdf462088d13 97 */
markrad 0:cdf462088d13 98 mbedtls_md5_starts( &md5_ctx );
markrad 0:cdf462088d13 99 mbedtls_md5_update( &md5_ctx, pwd, pwdlen );
markrad 0:cdf462088d13 100 mbedtls_md5_update( &md5_ctx, iv, 8 );
markrad 0:cdf462088d13 101 mbedtls_md5_finish( &md5_ctx, md5sum );
markrad 0:cdf462088d13 102
markrad 0:cdf462088d13 103 if( keylen <= 16 )
markrad 0:cdf462088d13 104 {
markrad 0:cdf462088d13 105 memcpy( key, md5sum, keylen );
markrad 0:cdf462088d13 106
markrad 0:cdf462088d13 107 mbedtls_md5_free( &md5_ctx );
markrad 0:cdf462088d13 108 mbedtls_zeroize( md5sum, 16 );
markrad 0:cdf462088d13 109 return;
markrad 0:cdf462088d13 110 }
markrad 0:cdf462088d13 111
markrad 0:cdf462088d13 112 memcpy( key, md5sum, 16 );
markrad 0:cdf462088d13 113
markrad 0:cdf462088d13 114 /*
markrad 0:cdf462088d13 115 * key[16..23] = MD5(key[ 0..15] || pwd || IV])
markrad 0:cdf462088d13 116 */
markrad 0:cdf462088d13 117 mbedtls_md5_starts( &md5_ctx );
markrad 0:cdf462088d13 118 mbedtls_md5_update( &md5_ctx, md5sum, 16 );
markrad 0:cdf462088d13 119 mbedtls_md5_update( &md5_ctx, pwd, pwdlen );
markrad 0:cdf462088d13 120 mbedtls_md5_update( &md5_ctx, iv, 8 );
markrad 0:cdf462088d13 121 mbedtls_md5_finish( &md5_ctx, md5sum );
markrad 0:cdf462088d13 122
markrad 0:cdf462088d13 123 use_len = 16;
markrad 0:cdf462088d13 124 if( keylen < 32 )
markrad 0:cdf462088d13 125 use_len = keylen - 16;
markrad 0:cdf462088d13 126
markrad 0:cdf462088d13 127 memcpy( key + 16, md5sum, use_len );
markrad 0:cdf462088d13 128
markrad 0:cdf462088d13 129 mbedtls_md5_free( &md5_ctx );
markrad 0:cdf462088d13 130 mbedtls_zeroize( md5sum, 16 );
markrad 0:cdf462088d13 131 }
markrad 0:cdf462088d13 132
markrad 0:cdf462088d13 133 #if defined(MBEDTLS_DES_C)
markrad 0:cdf462088d13 134 /*
markrad 0:cdf462088d13 135 * Decrypt with DES-CBC, using PBKDF1 for key derivation
markrad 0:cdf462088d13 136 */
markrad 0:cdf462088d13 137 static void pem_des_decrypt( unsigned char des_iv[8],
markrad 0:cdf462088d13 138 unsigned char *buf, size_t buflen,
markrad 0:cdf462088d13 139 const unsigned char *pwd, size_t pwdlen )
markrad 0:cdf462088d13 140 {
markrad 0:cdf462088d13 141 mbedtls_des_context des_ctx;
markrad 0:cdf462088d13 142 unsigned char des_key[8];
markrad 0:cdf462088d13 143
markrad 0:cdf462088d13 144 mbedtls_des_init( &des_ctx );
markrad 0:cdf462088d13 145
markrad 0:cdf462088d13 146 pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen );
markrad 0:cdf462088d13 147
markrad 0:cdf462088d13 148 mbedtls_des_setkey_dec( &des_ctx, des_key );
markrad 0:cdf462088d13 149 mbedtls_des_crypt_cbc( &des_ctx, MBEDTLS_DES_DECRYPT, buflen,
markrad 0:cdf462088d13 150 des_iv, buf, buf );
markrad 0:cdf462088d13 151
markrad 0:cdf462088d13 152 mbedtls_des_free( &des_ctx );
markrad 0:cdf462088d13 153 mbedtls_zeroize( des_key, 8 );
markrad 0:cdf462088d13 154 }
markrad 0:cdf462088d13 155
markrad 0:cdf462088d13 156 /*
markrad 0:cdf462088d13 157 * Decrypt with 3DES-CBC, using PBKDF1 for key derivation
markrad 0:cdf462088d13 158 */
markrad 0:cdf462088d13 159 static void pem_des3_decrypt( unsigned char des3_iv[8],
markrad 0:cdf462088d13 160 unsigned char *buf, size_t buflen,
markrad 0:cdf462088d13 161 const unsigned char *pwd, size_t pwdlen )
markrad 0:cdf462088d13 162 {
markrad 0:cdf462088d13 163 mbedtls_des3_context des3_ctx;
markrad 0:cdf462088d13 164 unsigned char des3_key[24];
markrad 0:cdf462088d13 165
markrad 0:cdf462088d13 166 mbedtls_des3_init( &des3_ctx );
markrad 0:cdf462088d13 167
markrad 0:cdf462088d13 168 pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen );
markrad 0:cdf462088d13 169
markrad 0:cdf462088d13 170 mbedtls_des3_set3key_dec( &des3_ctx, des3_key );
markrad 0:cdf462088d13 171 mbedtls_des3_crypt_cbc( &des3_ctx, MBEDTLS_DES_DECRYPT, buflen,
markrad 0:cdf462088d13 172 des3_iv, buf, buf );
markrad 0:cdf462088d13 173
markrad 0:cdf462088d13 174 mbedtls_des3_free( &des3_ctx );
markrad 0:cdf462088d13 175 mbedtls_zeroize( des3_key, 24 );
markrad 0:cdf462088d13 176 }
markrad 0:cdf462088d13 177 #endif /* MBEDTLS_DES_C */
markrad 0:cdf462088d13 178
markrad 0:cdf462088d13 179 #if defined(MBEDTLS_AES_C)
markrad 0:cdf462088d13 180 /*
markrad 0:cdf462088d13 181 * Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
markrad 0:cdf462088d13 182 */
markrad 0:cdf462088d13 183 static void pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen,
markrad 0:cdf462088d13 184 unsigned char *buf, size_t buflen,
markrad 0:cdf462088d13 185 const unsigned char *pwd, size_t pwdlen )
markrad 0:cdf462088d13 186 {
markrad 0:cdf462088d13 187 mbedtls_aes_context aes_ctx;
markrad 0:cdf462088d13 188 unsigned char aes_key[32];
markrad 0:cdf462088d13 189
markrad 0:cdf462088d13 190 mbedtls_aes_init( &aes_ctx );
markrad 0:cdf462088d13 191
markrad 0:cdf462088d13 192 pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen );
markrad 0:cdf462088d13 193
markrad 0:cdf462088d13 194 mbedtls_aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 );
markrad 0:cdf462088d13 195 mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_DECRYPT, buflen,
markrad 0:cdf462088d13 196 aes_iv, buf, buf );
markrad 0:cdf462088d13 197
markrad 0:cdf462088d13 198 mbedtls_aes_free( &aes_ctx );
markrad 0:cdf462088d13 199 mbedtls_zeroize( aes_key, keylen );
markrad 0:cdf462088d13 200 }
markrad 0:cdf462088d13 201 #endif /* MBEDTLS_AES_C */
markrad 0:cdf462088d13 202
markrad 0:cdf462088d13 203 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
markrad 0:cdf462088d13 204 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
markrad 0:cdf462088d13 205
markrad 0:cdf462088d13 206 int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer,
markrad 0:cdf462088d13 207 const unsigned char *data, const unsigned char *pwd,
markrad 0:cdf462088d13 208 size_t pwdlen, size_t *use_len )
markrad 0:cdf462088d13 209 {
markrad 0:cdf462088d13 210 int ret, enc;
markrad 0:cdf462088d13 211 size_t len;
markrad 0:cdf462088d13 212 unsigned char *buf;
markrad 0:cdf462088d13 213 const unsigned char *s1, *s2, *end;
markrad 0:cdf462088d13 214 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
markrad 0:cdf462088d13 215 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
markrad 0:cdf462088d13 216 unsigned char pem_iv[16];
markrad 0:cdf462088d13 217 mbedtls_cipher_type_t enc_alg = MBEDTLS_CIPHER_NONE;
markrad 0:cdf462088d13 218 #else
markrad 0:cdf462088d13 219 ((void) pwd);
markrad 0:cdf462088d13 220 ((void) pwdlen);
markrad 0:cdf462088d13 221 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
markrad 0:cdf462088d13 222 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
markrad 0:cdf462088d13 223
markrad 0:cdf462088d13 224 if( ctx == NULL )
markrad 0:cdf462088d13 225 return( MBEDTLS_ERR_PEM_BAD_INPUT_DATA );
markrad 0:cdf462088d13 226
markrad 0:cdf462088d13 227 s1 = (unsigned char *) strstr( (const char *) data, header );
markrad 0:cdf462088d13 228
markrad 0:cdf462088d13 229 if( s1 == NULL )
markrad 0:cdf462088d13 230 return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
markrad 0:cdf462088d13 231
markrad 0:cdf462088d13 232 s2 = (unsigned char *) strstr( (const char *) data, footer );
markrad 0:cdf462088d13 233
markrad 0:cdf462088d13 234 if( s2 == NULL || s2 <= s1 )
markrad 0:cdf462088d13 235 return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
markrad 0:cdf462088d13 236
markrad 0:cdf462088d13 237 s1 += strlen( header );
markrad 0:cdf462088d13 238 if( *s1 == ' ' ) s1++;
markrad 0:cdf462088d13 239 if( *s1 == '\r' ) s1++;
markrad 0:cdf462088d13 240 if( *s1 == '\n' ) s1++;
markrad 0:cdf462088d13 241 else return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
markrad 0:cdf462088d13 242
markrad 0:cdf462088d13 243 end = s2;
markrad 0:cdf462088d13 244 end += strlen( footer );
markrad 0:cdf462088d13 245 if( *end == ' ' ) end++;
markrad 0:cdf462088d13 246 if( *end == '\r' ) end++;
markrad 0:cdf462088d13 247 if( *end == '\n' ) end++;
markrad 0:cdf462088d13 248 *use_len = end - data;
markrad 0:cdf462088d13 249
markrad 0:cdf462088d13 250 enc = 0;
markrad 0:cdf462088d13 251
markrad 0:cdf462088d13 252 if( memcmp( s1, "Proc-Type: 4,ENCRYPTED", 22 ) == 0 )
markrad 0:cdf462088d13 253 {
markrad 0:cdf462088d13 254 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
markrad 0:cdf462088d13 255 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
markrad 0:cdf462088d13 256 enc++;
markrad 0:cdf462088d13 257
markrad 0:cdf462088d13 258 s1 += 22;
markrad 0:cdf462088d13 259 if( *s1 == '\r' ) s1++;
markrad 0:cdf462088d13 260 if( *s1 == '\n' ) s1++;
markrad 0:cdf462088d13 261 else return( MBEDTLS_ERR_PEM_INVALID_DATA );
markrad 0:cdf462088d13 262
markrad 0:cdf462088d13 263
markrad 0:cdf462088d13 264 #if defined(MBEDTLS_DES_C)
markrad 0:cdf462088d13 265 if( memcmp( s1, "DEK-Info: DES-EDE3-CBC,", 23 ) == 0 )
markrad 0:cdf462088d13 266 {
markrad 0:cdf462088d13 267 enc_alg = MBEDTLS_CIPHER_DES_EDE3_CBC;
markrad 0:cdf462088d13 268
markrad 0:cdf462088d13 269 s1 += 23;
markrad 0:cdf462088d13 270 if( pem_get_iv( s1, pem_iv, 8 ) != 0 )
markrad 0:cdf462088d13 271 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
markrad 0:cdf462088d13 272
markrad 0:cdf462088d13 273 s1 += 16;
markrad 0:cdf462088d13 274 }
markrad 0:cdf462088d13 275 else if( memcmp( s1, "DEK-Info: DES-CBC,", 18 ) == 0 )
markrad 0:cdf462088d13 276 {
markrad 0:cdf462088d13 277 enc_alg = MBEDTLS_CIPHER_DES_CBC;
markrad 0:cdf462088d13 278
markrad 0:cdf462088d13 279 s1 += 18;
markrad 0:cdf462088d13 280 if( pem_get_iv( s1, pem_iv, 8) != 0 )
markrad 0:cdf462088d13 281 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
markrad 0:cdf462088d13 282
markrad 0:cdf462088d13 283 s1 += 16;
markrad 0:cdf462088d13 284 }
markrad 0:cdf462088d13 285 #endif /* MBEDTLS_DES_C */
markrad 0:cdf462088d13 286
markrad 0:cdf462088d13 287 #if defined(MBEDTLS_AES_C)
markrad 0:cdf462088d13 288 if( memcmp( s1, "DEK-Info: AES-", 14 ) == 0 )
markrad 0:cdf462088d13 289 {
markrad 0:cdf462088d13 290 if( memcmp( s1, "DEK-Info: AES-128-CBC,", 22 ) == 0 )
markrad 0:cdf462088d13 291 enc_alg = MBEDTLS_CIPHER_AES_128_CBC;
markrad 0:cdf462088d13 292 else if( memcmp( s1, "DEK-Info: AES-192-CBC,", 22 ) == 0 )
markrad 0:cdf462088d13 293 enc_alg = MBEDTLS_CIPHER_AES_192_CBC;
markrad 0:cdf462088d13 294 else if( memcmp( s1, "DEK-Info: AES-256-CBC,", 22 ) == 0 )
markrad 0:cdf462088d13 295 enc_alg = MBEDTLS_CIPHER_AES_256_CBC;
markrad 0:cdf462088d13 296 else
markrad 0:cdf462088d13 297 return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
markrad 0:cdf462088d13 298
markrad 0:cdf462088d13 299 s1 += 22;
markrad 0:cdf462088d13 300 if( pem_get_iv( s1, pem_iv, 16 ) != 0 )
markrad 0:cdf462088d13 301 return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
markrad 0:cdf462088d13 302
markrad 0:cdf462088d13 303 s1 += 32;
markrad 0:cdf462088d13 304 }
markrad 0:cdf462088d13 305 #endif /* MBEDTLS_AES_C */
markrad 0:cdf462088d13 306
markrad 0:cdf462088d13 307 if( enc_alg == MBEDTLS_CIPHER_NONE )
markrad 0:cdf462088d13 308 return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
markrad 0:cdf462088d13 309
markrad 0:cdf462088d13 310 if( *s1 == '\r' ) s1++;
markrad 0:cdf462088d13 311 if( *s1 == '\n' ) s1++;
markrad 0:cdf462088d13 312 else return( MBEDTLS_ERR_PEM_INVALID_DATA );
markrad 0:cdf462088d13 313 #else
markrad 0:cdf462088d13 314 return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
markrad 0:cdf462088d13 315 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
markrad 0:cdf462088d13 316 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
markrad 0:cdf462088d13 317 }
markrad 0:cdf462088d13 318
markrad 0:cdf462088d13 319 if( s1 == s2 )
markrad 0:cdf462088d13 320 return( MBEDTLS_ERR_PEM_INVALID_DATA );
markrad 0:cdf462088d13 321
markrad 0:cdf462088d13 322 ret = mbedtls_base64_decode( NULL, 0, &len, s1, s2 - s1 );
markrad 0:cdf462088d13 323
markrad 0:cdf462088d13 324 if( ret == MBEDTLS_ERR_BASE64_INVALID_CHARACTER )
markrad 0:cdf462088d13 325 return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
markrad 0:cdf462088d13 326
markrad 0:cdf462088d13 327 if( ( buf = mbedtls_calloc( 1, len ) ) == NULL )
markrad 0:cdf462088d13 328 return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
markrad 0:cdf462088d13 329
markrad 0:cdf462088d13 330 if( ( ret = mbedtls_base64_decode( buf, len, &len, s1, s2 - s1 ) ) != 0 )
markrad 0:cdf462088d13 331 {
markrad 0:cdf462088d13 332 mbedtls_free( buf );
markrad 0:cdf462088d13 333 return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
markrad 0:cdf462088d13 334 }
markrad 0:cdf462088d13 335
markrad 0:cdf462088d13 336 if( enc != 0 )
markrad 0:cdf462088d13 337 {
markrad 0:cdf462088d13 338 #if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
markrad 0:cdf462088d13 339 ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
markrad 0:cdf462088d13 340 if( pwd == NULL )
markrad 0:cdf462088d13 341 {
markrad 0:cdf462088d13 342 mbedtls_free( buf );
markrad 0:cdf462088d13 343 return( MBEDTLS_ERR_PEM_PASSWORD_REQUIRED );
markrad 0:cdf462088d13 344 }
markrad 0:cdf462088d13 345
markrad 0:cdf462088d13 346 #if defined(MBEDTLS_DES_C)
markrad 0:cdf462088d13 347 if( enc_alg == MBEDTLS_CIPHER_DES_EDE3_CBC )
markrad 0:cdf462088d13 348 pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen );
markrad 0:cdf462088d13 349 else if( enc_alg == MBEDTLS_CIPHER_DES_CBC )
markrad 0:cdf462088d13 350 pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen );
markrad 0:cdf462088d13 351 #endif /* MBEDTLS_DES_C */
markrad 0:cdf462088d13 352
markrad 0:cdf462088d13 353 #if defined(MBEDTLS_AES_C)
markrad 0:cdf462088d13 354 if( enc_alg == MBEDTLS_CIPHER_AES_128_CBC )
markrad 0:cdf462088d13 355 pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen );
markrad 0:cdf462088d13 356 else if( enc_alg == MBEDTLS_CIPHER_AES_192_CBC )
markrad 0:cdf462088d13 357 pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen );
markrad 0:cdf462088d13 358 else if( enc_alg == MBEDTLS_CIPHER_AES_256_CBC )
markrad 0:cdf462088d13 359 pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen );
markrad 0:cdf462088d13 360 #endif /* MBEDTLS_AES_C */
markrad 0:cdf462088d13 361
markrad 0:cdf462088d13 362 /*
markrad 0:cdf462088d13 363 * The result will be ASN.1 starting with a SEQUENCE tag, with 1 to 3
markrad 0:cdf462088d13 364 * length bytes (allow 4 to be sure) in all known use cases.
markrad 0:cdf462088d13 365 *
markrad 0:cdf462088d13 366 * Use that as heurisitic to try detecting password mismatchs.
markrad 0:cdf462088d13 367 */
markrad 0:cdf462088d13 368 if( len <= 2 || buf[0] != 0x30 || buf[1] > 0x83 )
markrad 0:cdf462088d13 369 {
markrad 0:cdf462088d13 370 mbedtls_free( buf );
markrad 0:cdf462088d13 371 return( MBEDTLS_ERR_PEM_PASSWORD_MISMATCH );
markrad 0:cdf462088d13 372 }
markrad 0:cdf462088d13 373 #else
markrad 0:cdf462088d13 374 mbedtls_free( buf );
markrad 0:cdf462088d13 375 return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
markrad 0:cdf462088d13 376 #endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
markrad 0:cdf462088d13 377 ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
markrad 0:cdf462088d13 378 }
markrad 0:cdf462088d13 379
markrad 0:cdf462088d13 380 ctx->buf = buf;
markrad 0:cdf462088d13 381 ctx->buflen = len;
markrad 0:cdf462088d13 382
markrad 0:cdf462088d13 383 return( 0 );
markrad 0:cdf462088d13 384 }
markrad 0:cdf462088d13 385
markrad 0:cdf462088d13 386 void mbedtls_pem_free( mbedtls_pem_context *ctx )
markrad 0:cdf462088d13 387 {
markrad 0:cdf462088d13 388 mbedtls_free( ctx->buf );
markrad 0:cdf462088d13 389 mbedtls_free( ctx->info );
markrad 0:cdf462088d13 390
markrad 0:cdf462088d13 391 mbedtls_zeroize( ctx, sizeof( mbedtls_pem_context ) );
markrad 0:cdf462088d13 392 }
markrad 0:cdf462088d13 393 #endif /* MBEDTLS_PEM_PARSE_C */
markrad 0:cdf462088d13 394
markrad 0:cdf462088d13 395 #if defined(MBEDTLS_PEM_WRITE_C)
markrad 0:cdf462088d13 396 int mbedtls_pem_write_buffer( const char *header, const char *footer,
markrad 0:cdf462088d13 397 const unsigned char *der_data, size_t der_len,
markrad 0:cdf462088d13 398 unsigned char *buf, size_t buf_len, size_t *olen )
markrad 0:cdf462088d13 399 {
markrad 0:cdf462088d13 400 int ret;
markrad 0:cdf462088d13 401 unsigned char *encode_buf, *c, *p = buf;
markrad 0:cdf462088d13 402 size_t len = 0, use_len, add_len = 0;
markrad 0:cdf462088d13 403
markrad 0:cdf462088d13 404 mbedtls_base64_encode( NULL, 0, &use_len, der_data, der_len );
markrad 0:cdf462088d13 405 add_len = strlen( header ) + strlen( footer ) + ( use_len / 64 ) + 1;
markrad 0:cdf462088d13 406
markrad 0:cdf462088d13 407 if( use_len + add_len > buf_len )
markrad 0:cdf462088d13 408 {
markrad 0:cdf462088d13 409 *olen = use_len + add_len;
markrad 0:cdf462088d13 410 return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
markrad 0:cdf462088d13 411 }
markrad 0:cdf462088d13 412
markrad 0:cdf462088d13 413 if( ( encode_buf = mbedtls_calloc( 1, use_len ) ) == NULL )
markrad 0:cdf462088d13 414 return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
markrad 0:cdf462088d13 415
markrad 0:cdf462088d13 416 if( ( ret = mbedtls_base64_encode( encode_buf, use_len, &use_len, der_data,
markrad 0:cdf462088d13 417 der_len ) ) != 0 )
markrad 0:cdf462088d13 418 {
markrad 0:cdf462088d13 419 mbedtls_free( encode_buf );
markrad 0:cdf462088d13 420 return( ret );
markrad 0:cdf462088d13 421 }
markrad 0:cdf462088d13 422
markrad 0:cdf462088d13 423 memcpy( p, header, strlen( header ) );
markrad 0:cdf462088d13 424 p += strlen( header );
markrad 0:cdf462088d13 425 c = encode_buf;
markrad 0:cdf462088d13 426
markrad 0:cdf462088d13 427 while( use_len )
markrad 0:cdf462088d13 428 {
markrad 0:cdf462088d13 429 len = ( use_len > 64 ) ? 64 : use_len;
markrad 0:cdf462088d13 430 memcpy( p, c, len );
markrad 0:cdf462088d13 431 use_len -= len;
markrad 0:cdf462088d13 432 p += len;
markrad 0:cdf462088d13 433 c += len;
markrad 0:cdf462088d13 434 *p++ = '\n';
markrad 0:cdf462088d13 435 }
markrad 0:cdf462088d13 436
markrad 0:cdf462088d13 437 memcpy( p, footer, strlen( footer ) );
markrad 0:cdf462088d13 438 p += strlen( footer );
markrad 0:cdf462088d13 439
markrad 0:cdf462088d13 440 *p++ = '\0';
markrad 0:cdf462088d13 441 *olen = p - buf;
markrad 0:cdf462088d13 442
markrad 0:cdf462088d13 443 mbedtls_free( encode_buf );
markrad 0:cdf462088d13 444 return( 0 );
markrad 0:cdf462088d13 445 }
markrad 0:cdf462088d13 446 #endif /* MBEDTLS_PEM_WRITE_C */
markrad 0:cdf462088d13 447 #endif /* MBEDTLS_PEM_PARSE_C || MBEDTLS_PEM_WRITE_C */