mbed TLS Build
Dependents: Encrypt_Decrypt1 mbed_blink_tls encrypt encrypt
Diff: library/x509write_crt.c
- Revision:
- 0:cdf462088d13
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/library/x509write_crt.c Thu Jan 05 00:18:44 2017 +0000 @@ -0,0 +1,459 @@ +/* + * X.509 certificate writing + * + * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * This file is part of mbed TLS (https://tls.mbed.org) + */ +/* + * References: + * - certificates: RFC 5280, updated by RFC 6818 + * - CSRs: PKCS#10 v1.7 aka RFC 2986 + * - attributes: PKCS#9 v2.0 aka RFC 2985 + */ + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#if defined(MBEDTLS_X509_CRT_WRITE_C) + +#include "mbedtls/x509_crt.h" +#include "mbedtls/oid.h" +#include "mbedtls/asn1write.h" +#include "mbedtls/sha1.h" + +#include <string.h> + +#if defined(MBEDTLS_PEM_WRITE_C) +#include "mbedtls/pem.h" +#endif /* MBEDTLS_PEM_WRITE_C */ + +/* Implementation that should never be optimized out by the compiler */ +static void mbedtls_zeroize( void *v, size_t n ) { + volatile unsigned char *p = v; while( n-- ) *p++ = 0; +} + +void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx ) +{ + memset( ctx, 0, sizeof(mbedtls_x509write_cert) ); + + mbedtls_mpi_init( &ctx->serial ); + ctx->version = MBEDTLS_X509_CRT_VERSION_3; +} + +void mbedtls_x509write_crt_free( mbedtls_x509write_cert *ctx ) +{ + mbedtls_mpi_free( &ctx->serial ); + + mbedtls_asn1_free_named_data_list( &ctx->subject ); + mbedtls_asn1_free_named_data_list( &ctx->issuer ); + mbedtls_asn1_free_named_data_list( &ctx->extensions ); + + mbedtls_zeroize( ctx, sizeof(mbedtls_x509write_cert) ); +} + +void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx, int version ) +{ + ctx->version = version; +} + +void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx, mbedtls_md_type_t md_alg ) +{ + ctx->md_alg = md_alg; +} + +void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) +{ + ctx->subject_key = key; +} + +void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx, mbedtls_pk_context *key ) +{ + ctx->issuer_key = key; +} + +int mbedtls_x509write_crt_set_subject_name( mbedtls_x509write_cert *ctx, + const char *subject_name ) +{ + return mbedtls_x509_string_to_names( &ctx->subject, subject_name ); +} + +int mbedtls_x509write_crt_set_issuer_name( mbedtls_x509write_cert *ctx, + const char *issuer_name ) +{ + return mbedtls_x509_string_to_names( &ctx->issuer, issuer_name ); +} + +int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx, const mbedtls_mpi *serial ) +{ + int ret; + + if( ( ret = mbedtls_mpi_copy( &ctx->serial, serial ) ) != 0 ) + return( ret ); + + return( 0 ); +} + +int mbedtls_x509write_crt_set_validity( mbedtls_x509write_cert *ctx, const char *not_before, + const char *not_after ) +{ + if( strlen( not_before ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 || + strlen( not_after ) != MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1 ) + { + return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); + } + strncpy( ctx->not_before, not_before, MBEDTLS_X509_RFC5280_UTC_TIME_LEN ); + strncpy( ctx->not_after , not_after , MBEDTLS_X509_RFC5280_UTC_TIME_LEN ); + ctx->not_before[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z'; + ctx->not_after[MBEDTLS_X509_RFC5280_UTC_TIME_LEN - 1] = 'Z'; + + return( 0 ); +} + +int mbedtls_x509write_crt_set_extension( mbedtls_x509write_cert *ctx, + const char *oid, size_t oid_len, + int critical, + const unsigned char *val, size_t val_len ) +{ + return mbedtls_x509_set_extension( &ctx->extensions, oid, oid_len, + critical, val, val_len ); +} + +int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx, + int is_ca, int max_pathlen ) +{ + int ret; + unsigned char buf[9]; + unsigned char *c = buf + sizeof(buf); + size_t len = 0; + + memset( buf, 0, sizeof(buf) ); + + if( is_ca && max_pathlen > 127 ) + return( MBEDTLS_ERR_X509_BAD_INPUT_DATA ); + + if( is_ca ) + { + if( max_pathlen >= 0 ) + { + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, buf, max_pathlen ) ); + } + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( &c, buf, 1 ) ); + } + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + + return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_BASIC_CONSTRAINTS, + MBEDTLS_OID_SIZE( MBEDTLS_OID_BASIC_CONSTRAINTS ), + 0, buf + sizeof(buf) - len, len ); +} + +#if defined(MBEDTLS_SHA1_C) +int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx ) +{ + int ret; + unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */ + unsigned char *c = buf + sizeof(buf); + size_t len = 0; + + memset( buf, 0, sizeof(buf) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->subject_key ) ); + + mbedtls_sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 ); + c = buf + sizeof(buf) - 20; + len = 20; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_OCTET_STRING ) ); + + return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER, + MBEDTLS_OID_SIZE( MBEDTLS_OID_SUBJECT_KEY_IDENTIFIER ), + 0, buf + sizeof(buf) - len, len ); +} + +int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx ) +{ + int ret; + unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */ + unsigned char *c = buf + sizeof(buf); + size_t len = 0; + + memset( buf, 0, sizeof(buf) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, ctx->issuer_key ) ); + + mbedtls_sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 ); + c = buf + sizeof(buf) - 20; + len = 20; + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | 0 ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + + return mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER, + MBEDTLS_OID_SIZE( MBEDTLS_OID_AUTHORITY_KEY_IDENTIFIER ), + 0, buf + sizeof(buf) - len, len ); +} +#endif /* MBEDTLS_SHA1_C */ + +int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx, + unsigned int key_usage ) +{ + unsigned char buf[4], ku; + unsigned char *c; + int ret; + + /* We currently only support 7 bits, from 0x80 to 0x02 */ + if( ( key_usage & ~0xfe ) != 0 ) + return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE ); + + c = buf + 4; + ku = (unsigned char) key_usage; + + if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ku, 7 ) ) != 4 ) + return( ret ); + + ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE, + MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ), + 1, buf, 4 ); + if( ret != 0 ) + return( ret ); + + return( 0 ); +} + +int mbedtls_x509write_crt_set_ns_cert_type( mbedtls_x509write_cert *ctx, + unsigned char ns_cert_type ) +{ + unsigned char buf[4]; + unsigned char *c; + int ret; + + c = buf + 4; + + if( ( ret = mbedtls_asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 ) + return( ret ); + + ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE, + MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ), + 0, buf, 4 ); + if( ret != 0 ) + return( ret ); + + return( 0 ); +} + +static int x509_write_time( unsigned char **p, unsigned char *start, + const char *time, size_t size ) +{ + int ret; + size_t len = 0; + + /* + * write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter) + */ + if( time[0] == '2' && time[1] == '0' && time [2] < '5' ) + { + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, + (const unsigned char *) time + 2, + size - 2 ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_UTC_TIME ) ); + } + else + { + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, + (const unsigned char *) time, + size ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_GENERALIZED_TIME ) ); + } + + return( (int) len ); +} + +int mbedtls_x509write_crt_der( mbedtls_x509write_cert *ctx, unsigned char *buf, size_t size, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + const char *sig_oid; + size_t sig_oid_len = 0; + unsigned char *c, *c2; + unsigned char hash[64]; + unsigned char sig[MBEDTLS_MPI_MAX_SIZE]; + unsigned char tmp_buf[2048]; + size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len; + size_t len = 0; + mbedtls_pk_type_t pk_alg; + + /* + * Prepare data to be signed in tmp_buf + */ + c = tmp_buf + sizeof( tmp_buf ); + + /* Signature algorithm needed in TBS, and later for actual signature */ + pk_alg = mbedtls_pk_get_type( ctx->issuer_key ); + if( pk_alg == MBEDTLS_PK_ECKEY ) + pk_alg = MBEDTLS_PK_ECDSA; + + if( ( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg, + &sig_oid, &sig_oid_len ) ) != 0 ) + { + return( ret ); + } + + /* + * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension + */ + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | + MBEDTLS_ASN1_CONSTRUCTED | 3 ) ); + + /* + * SubjectPublicKeyInfo + */ + MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->subject_key, + tmp_buf, c - tmp_buf ) ); + c -= pub_len; + len += pub_len; + + /* + * Subject ::= Name + */ + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->subject ) ); + + /* + * Validity ::= SEQUENCE { + * notBefore Time, + * notAfter Time } + */ + sub_len = 0; + + MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after, + MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); + + MBEDTLS_ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before, + MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) ); + + len += sub_len; + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + + /* + * Issuer ::= Name + */ + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, tmp_buf, ctx->issuer ) ); + + /* + * Signature ::= AlgorithmIdentifier + */ + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, tmp_buf, + sig_oid, strlen( sig_oid ), 0 ) ); + + /* + * Serial ::= INTEGER + */ + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, tmp_buf, &ctx->serial ) ); + + /* + * Version ::= INTEGER { v1(0), v2(1), v3(2) } + */ + sub_len = 0; + MBEDTLS_ASN1_CHK_ADD( sub_len, mbedtls_asn1_write_int( &c, tmp_buf, ctx->version ) ); + len += sub_len; + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, sub_len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONTEXT_SPECIFIC | + MBEDTLS_ASN1_CONSTRUCTED | 0 ) ); + + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, tmp_buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c, tmp_buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + + /* + * Make signature + */ + mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash ); + + if( ( ret = mbedtls_pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len, + f_rng, p_rng ) ) != 0 ) + { + return( ret ); + } + + /* + * Write data to output buffer + */ + c2 = buf + size; + MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, buf, + sig_oid, sig_oid_len, sig, sig_len ) ); + + if( len > (size_t)( c2 - buf ) ) + return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL ); + + c2 -= len; + memcpy( c2, c, len ); + + len += sig_and_oid_len; + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c2, buf, len ) ); + MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &c2, buf, MBEDTLS_ASN1_CONSTRUCTED | + MBEDTLS_ASN1_SEQUENCE ) ); + + return( (int) len ); +} + +#define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n" +#define PEM_END_CRT "-----END CERTIFICATE-----\n" + +#if defined(MBEDTLS_PEM_WRITE_C) +int mbedtls_x509write_crt_pem( mbedtls_x509write_cert *crt, unsigned char *buf, size_t size, + int (*f_rng)(void *, unsigned char *, size_t), + void *p_rng ) +{ + int ret; + unsigned char output_buf[4096]; + size_t olen = 0; + + if( ( ret = mbedtls_x509write_crt_der( crt, output_buf, sizeof(output_buf), + f_rng, p_rng ) ) < 0 ) + { + return( ret ); + } + + if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT, + output_buf + sizeof(output_buf) - ret, + ret, buf, size, &olen ) ) != 0 ) + { + return( ret ); + } + + return( 0 ); +} +#endif /* MBEDTLS_PEM_WRITE_C */ + +#endif /* MBEDTLS_X509_CRT_WRITE_C */