--- /dev/null
+/*
+ * Privacy Enhanced Mail (PEM) decoding
+ *
+ * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * 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.
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PEM_PARSE_C) || defined(MBEDTLS_PEM_WRITE_C)
+
+#include "mbedtls/pem.h"
+#include "mbedtls/base64.h"
+#include "mbedtls/des.h"
+#include "mbedtls/aes.h"
+#include "mbedtls/md5.h"
+#include "mbedtls/cipher.h"
+#include "mbedtls/platform_util.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc calloc
+#define mbedtls_free free
+#endif
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+void mbedtls_pem_init( mbedtls_pem_context *ctx )
+{
+ memset( ctx, 0, sizeof( mbedtls_pem_context ) );
+}
+
+#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
+ ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_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( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
+
+ k = ( ( i & 1 ) != 0 ) ? j : j << 4;
+
+ iv[i >> 1] = (unsigned char)( iv[i >> 1] | k );
+ }
+
+ return( 0 );
+}
+
+static int pem_pbkdf1( unsigned char *key, size_t keylen,
+ unsigned char *iv,
+ const unsigned char *pwd, size_t pwdlen )
+{
+ mbedtls_md5_context md5_ctx;
+ unsigned char md5sum[16];
+ size_t use_len;
+ int ret;
+
+ mbedtls_md5_init( &md5_ctx );
+
+ /*
+ * key[ 0..15] = MD5(pwd || IV)
+ */
+ if( ( ret = mbedtls_md5_starts_ret( &md5_ctx ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_finish_ret( &md5_ctx, md5sum ) ) != 0 )
+ goto exit;
+
+ if( keylen <= 16 )
+ {
+ memcpy( key, md5sum, keylen );
+ goto exit;
+ }
+
+ memcpy( key, md5sum, 16 );
+
+ /*
+ * key[16..23] = MD5(key[ 0..15] || pwd || IV])
+ */
+ if( ( ret = mbedtls_md5_starts_ret( &md5_ctx ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_update_ret( &md5_ctx, md5sum, 16 ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_update_ret( &md5_ctx, pwd, pwdlen ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_update_ret( &md5_ctx, iv, 8 ) ) != 0 )
+ goto exit;
+ if( ( ret = mbedtls_md5_finish_ret( &md5_ctx, md5sum ) ) != 0 )
+ goto exit;
+
+ use_len = 16;
+ if( keylen < 32 )
+ use_len = keylen - 16;
+
+ memcpy( key + 16, md5sum, use_len );
+
+exit:
+ mbedtls_md5_free( &md5_ctx );
+ mbedtls_platform_zeroize( md5sum, 16 );
+
+ return( ret );
+}
+
+#if defined(MBEDTLS_DES_C)
+/*
+ * Decrypt with DES-CBC, using PBKDF1 for key derivation
+ */
+static int pem_des_decrypt( unsigned char des_iv[8],
+ unsigned char *buf, size_t buflen,
+ const unsigned char *pwd, size_t pwdlen )
+{
+ mbedtls_des_context des_ctx;
+ unsigned char des_key[8];
+ int ret;
+
+ mbedtls_des_init( &des_ctx );
+
+ if( ( ret = pem_pbkdf1( des_key, 8, des_iv, pwd, pwdlen ) ) != 0 )
+ goto exit;
+
+ if( ( ret = mbedtls_des_setkey_dec( &des_ctx, des_key ) ) != 0 )
+ goto exit;
+ ret = mbedtls_des_crypt_cbc( &des_ctx, MBEDTLS_DES_DECRYPT, buflen,
+ des_iv, buf, buf );
+
+exit:
+ mbedtls_des_free( &des_ctx );
+ mbedtls_platform_zeroize( des_key, 8 );
+
+ return( ret );
+}
+
+/*
+ * Decrypt with 3DES-CBC, using PBKDF1 for key derivation
+ */
+static int pem_des3_decrypt( unsigned char des3_iv[8],
+ unsigned char *buf, size_t buflen,
+ const unsigned char *pwd, size_t pwdlen )
+{
+ mbedtls_des3_context des3_ctx;
+ unsigned char des3_key[24];
+ int ret;
+
+ mbedtls_des3_init( &des3_ctx );
+
+ if( ( ret = pem_pbkdf1( des3_key, 24, des3_iv, pwd, pwdlen ) ) != 0 )
+ goto exit;
+
+ if( ( ret = mbedtls_des3_set3key_dec( &des3_ctx, des3_key ) ) != 0 )
+ goto exit;
+ ret = mbedtls_des3_crypt_cbc( &des3_ctx, MBEDTLS_DES_DECRYPT, buflen,
+ des3_iv, buf, buf );
+
+exit:
+ mbedtls_des3_free( &des3_ctx );
+ mbedtls_platform_zeroize( des3_key, 24 );
+
+ return( ret );
+}
+#endif /* MBEDTLS_DES_C */
+
+#if defined(MBEDTLS_AES_C)
+/*
+ * Decrypt with AES-XXX-CBC, using PBKDF1 for key derivation
+ */
+static int pem_aes_decrypt( unsigned char aes_iv[16], unsigned int keylen,
+ unsigned char *buf, size_t buflen,
+ const unsigned char *pwd, size_t pwdlen )
+{
+ mbedtls_aes_context aes_ctx;
+ unsigned char aes_key[32];
+ int ret;
+
+ mbedtls_aes_init( &aes_ctx );
+
+ if( ( ret = pem_pbkdf1( aes_key, keylen, aes_iv, pwd, pwdlen ) ) != 0 )
+ goto exit;
+
+ if( ( ret = mbedtls_aes_setkey_dec( &aes_ctx, aes_key, keylen * 8 ) ) != 0 )
+ goto exit;
+ ret = mbedtls_aes_crypt_cbc( &aes_ctx, MBEDTLS_AES_DECRYPT, buflen,
+ aes_iv, buf, buf );
+
+exit:
+ mbedtls_aes_free( &aes_ctx );
+ mbedtls_platform_zeroize( aes_key, keylen );
+
+ return( ret );
+}
+#endif /* MBEDTLS_AES_C */
+
+#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
+ ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
+
+int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const 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(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
+ ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
+ unsigned char pem_iv[16];
+ mbedtls_cipher_type_t enc_alg = MBEDTLS_CIPHER_NONE;
+#else
+ ((void) pwd);
+ ((void) pwdlen);
+#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
+ ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
+
+ if( ctx == NULL )
+ return( MBEDTLS_ERR_PEM_BAD_INPUT_DATA );
+
+ s1 = (unsigned char *) strstr( (const char *) data, header );
+
+ if( s1 == NULL )
+ return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
+
+ s2 = (unsigned char *) strstr( (const char *) data, footer );
+
+ if( s2 == NULL || s2 <= s1 )
+ return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
+
+ s1 += strlen( header );
+ if( *s1 == ' ' ) s1++;
+ if( *s1 == '\r' ) s1++;
+ if( *s1 == '\n' ) s1++;
+ else return( MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT );
+
+ end = s2;
+ end += strlen( footer );
+ if( *end == ' ' ) end++;
+ if( *end == '\r' ) end++;
+ if( *end == '\n' ) end++;
+ *use_len = end - data;
+
+ enc = 0;
+
+ if( s2 - s1 >= 22 && memcmp( s1, "Proc-Type: 4,ENCRYPTED", 22 ) == 0 )
+ {
+#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
+ ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
+ enc++;
+
+ s1 += 22;
+ if( *s1 == '\r' ) s1++;
+ if( *s1 == '\n' ) s1++;
+ else return( MBEDTLS_ERR_PEM_INVALID_DATA );
+
+
+#if defined(MBEDTLS_DES_C)
+ if( s2 - s1 >= 23 && memcmp( s1, "DEK-Info: DES-EDE3-CBC,", 23 ) == 0 )
+ {
+ enc_alg = MBEDTLS_CIPHER_DES_EDE3_CBC;
+
+ s1 += 23;
+ if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8 ) != 0 )
+ return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
+
+ s1 += 16;
+ }
+ else if( s2 - s1 >= 18 && memcmp( s1, "DEK-Info: DES-CBC,", 18 ) == 0 )
+ {
+ enc_alg = MBEDTLS_CIPHER_DES_CBC;
+
+ s1 += 18;
+ if( s2 - s1 < 16 || pem_get_iv( s1, pem_iv, 8) != 0 )
+ return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
+
+ s1 += 16;
+ }
+#endif /* MBEDTLS_DES_C */
+
+#if defined(MBEDTLS_AES_C)
+ if( s2 - s1 >= 14 && memcmp( s1, "DEK-Info: AES-", 14 ) == 0 )
+ {
+ if( s2 - s1 < 22 )
+ return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
+ else if( memcmp( s1, "DEK-Info: AES-128-CBC,", 22 ) == 0 )
+ enc_alg = MBEDTLS_CIPHER_AES_128_CBC;
+ else if( memcmp( s1, "DEK-Info: AES-192-CBC,", 22 ) == 0 )
+ enc_alg = MBEDTLS_CIPHER_AES_192_CBC;
+ else if( memcmp( s1, "DEK-Info: AES-256-CBC,", 22 ) == 0 )
+ enc_alg = MBEDTLS_CIPHER_AES_256_CBC;
+ else
+ return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
+
+ s1 += 22;
+ if( s2 - s1 < 32 || pem_get_iv( s1, pem_iv, 16 ) != 0 )
+ return( MBEDTLS_ERR_PEM_INVALID_ENC_IV );
+
+ s1 += 32;
+ }
+#endif /* MBEDTLS_AES_C */
+
+ if( enc_alg == MBEDTLS_CIPHER_NONE )
+ return( MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG );
+
+ if( *s1 == '\r' ) s1++;
+ if( *s1 == '\n' ) s1++;
+ else return( MBEDTLS_ERR_PEM_INVALID_DATA );
+#else
+ return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
+#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
+ ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
+ }
+
+ if( s1 >= s2 )
+ return( MBEDTLS_ERR_PEM_INVALID_DATA );
+
+ ret = mbedtls_base64_decode( NULL, 0, &len, s1, s2 - s1 );
+
+ if( ret == MBEDTLS_ERR_BASE64_INVALID_CHARACTER )
+ return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
+
+ if( ( buf = mbedtls_calloc( 1, len ) ) == NULL )
+ return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
+
+ if( ( ret = mbedtls_base64_decode( buf, len, &len, s1, s2 - s1 ) ) != 0 )
+ {
+ mbedtls_platform_zeroize( buf, len );
+ mbedtls_free( buf );
+ return( MBEDTLS_ERR_PEM_INVALID_DATA + ret );
+ }
+
+ if( enc != 0 )
+ {
+#if defined(MBEDTLS_MD5_C) && defined(MBEDTLS_CIPHER_MODE_CBC) && \
+ ( defined(MBEDTLS_DES_C) || defined(MBEDTLS_AES_C) )
+ if( pwd == NULL )
+ {
+ mbedtls_platform_zeroize( buf, len );
+ mbedtls_free( buf );
+ return( MBEDTLS_ERR_PEM_PASSWORD_REQUIRED );
+ }
+
+ ret = 0;
+
+#if defined(MBEDTLS_DES_C)
+ if( enc_alg == MBEDTLS_CIPHER_DES_EDE3_CBC )
+ ret = pem_des3_decrypt( pem_iv, buf, len, pwd, pwdlen );
+ else if( enc_alg == MBEDTLS_CIPHER_DES_CBC )
+ ret = pem_des_decrypt( pem_iv, buf, len, pwd, pwdlen );
+#endif /* MBEDTLS_DES_C */
+
+#if defined(MBEDTLS_AES_C)
+ if( enc_alg == MBEDTLS_CIPHER_AES_128_CBC )
+ ret = pem_aes_decrypt( pem_iv, 16, buf, len, pwd, pwdlen );
+ else if( enc_alg == MBEDTLS_CIPHER_AES_192_CBC )
+ ret = pem_aes_decrypt( pem_iv, 24, buf, len, pwd, pwdlen );
+ else if( enc_alg == MBEDTLS_CIPHER_AES_256_CBC )
+ ret = pem_aes_decrypt( pem_iv, 32, buf, len, pwd, pwdlen );
+#endif /* MBEDTLS_AES_C */
+
+ if( ret != 0 )
+ {
+ mbedtls_free( buf );
+ return( ret );
+ }
+
+ /*
+ * The result will be ASN.1 starting with a SEQUENCE tag, with 1 to 3
+ * length bytes (allow 4 to be sure) in all known use cases.
+ *
+ * Use that as a heuristic to try to detect password mismatches.
+ */
+ if( len <= 2 || buf[0] != 0x30 || buf[1] > 0x83 )
+ {
+ mbedtls_platform_zeroize( buf, len );
+ mbedtls_free( buf );
+ return( MBEDTLS_ERR_PEM_PASSWORD_MISMATCH );
+ }
+#else
+ mbedtls_platform_zeroize( buf, len );
+ mbedtls_free( buf );
+ return( MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE );
+#endif /* MBEDTLS_MD5_C && MBEDTLS_CIPHER_MODE_CBC &&
+ ( MBEDTLS_AES_C || MBEDTLS_DES_C ) */
+ }
+
+ ctx->buf = buf;
+ ctx->buflen = len;
+
+ return( 0 );
+}
+
+void mbedtls_pem_free( mbedtls_pem_context *ctx )
+{
+ if( ctx->buf != NULL )
+ mbedtls_platform_zeroize( ctx->buf, ctx->buflen );
+ mbedtls_free( ctx->buf );
+ mbedtls_free( ctx->info );
+
+ mbedtls_platform_zeroize( ctx, sizeof( mbedtls_pem_context ) );
+}
+#endif /* MBEDTLS_PEM_PARSE_C */
+
+#if defined(MBEDTLS_PEM_WRITE_C)
+int mbedtls_pem_write_buffer( const char *header, const char *footer,
+ const unsigned char *der_data, size_t der_len,
+ unsigned char *buf, size_t buf_len, size_t *olen )
+{
+ int ret;
+ unsigned char *encode_buf = NULL, *c, *p = buf;
+ size_t len = 0, use_len, add_len = 0;
+
+ mbedtls_base64_encode( NULL, 0, &use_len, der_data, der_len );
+ add_len = strlen( header ) + strlen( footer ) + ( use_len / 64 ) + 1;
+
+ if( use_len + add_len > buf_len )
+ {
+ *olen = use_len + add_len;
+ return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
+ }
+
+ if( use_len != 0 &&
+ ( ( encode_buf = mbedtls_calloc( 1, use_len ) ) == NULL ) )
+ return( MBEDTLS_ERR_PEM_ALLOC_FAILED );
+
+ if( ( ret = mbedtls_base64_encode( encode_buf, use_len, &use_len, der_data,
+ der_len ) ) != 0 )
+ {
+ mbedtls_free( encode_buf );
+ return( ret );
+ }
+
+ memcpy( p, header, strlen( header ) );
+ p += strlen( header );
+ c = encode_buf;
+
+ while( use_len )
+ {
+ len = ( use_len > 64 ) ? 64 : use_len;
+ memcpy( p, c, len );
+ use_len -= len;
+ p += len;
+ c += len;
+ *p++ = '\n';
+ }
+
+ memcpy( p, footer, strlen( footer ) );
+ p += strlen( footer );
+
+ *p++ = '\0';
+ *olen = p - buf;
+
+ mbedtls_free( encode_buf );
+ return( 0 );
+}
+#endif /* MBEDTLS_PEM_WRITE_C */
+#endif /* MBEDTLS_PEM_PARSE_C || MBEDTLS_PEM_WRITE_C */
projects / proxmark3-svn / blobdiff