123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522 |
- /*
- * 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 "mbedtls/platform_util.h"
- #include <string.h>
- #if defined(MBEDTLS_PEM_WRITE_C)
- #include "mbedtls/pem.h"
- #endif /* MBEDTLS_PEM_WRITE_C */
- /*
- * For the currently used signature algorithms the buffer to store any signature
- * must be at least of size MAX(MBEDTLS_ECDSA_MAX_LEN, MBEDTLS_MPI_MAX_SIZE)
- */
- #if MBEDTLS_ECDSA_MAX_LEN > MBEDTLS_MPI_MAX_SIZE
- #define SIGNATURE_MAX_SIZE MBEDTLS_ECDSA_MAX_LEN
- #else
- #define SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
- #endif
- 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_platform_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 ) );
- ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len,
- buf + sizeof( buf ) - 20 );
- if( ret != 0 )
- return( ret );
- 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 ) );
- ret = mbedtls_sha1_ret( buf + sizeof( buf ) - len, len,
- buf + sizeof( buf ) - 20 );
- if( ret != 0 )
- return( ret );
- 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 */
- static size_t crt_get_unused_bits_for_named_bitstring( unsigned char bitstring,
- size_t bit_offset )
- {
- size_t unused_bits;
- /* Count the unused bits removing trailing 0s */
- for( unused_bits = bit_offset; unused_bits < 8; unused_bits++ )
- if( ( ( bitstring >> unused_bits ) & 0x1 ) != 0 )
- break;
- return( unused_bits );
- }
- 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;
- size_t unused_bits;
- const unsigned int allowed_bits = MBEDTLS_X509_KU_DIGITAL_SIGNATURE |
- MBEDTLS_X509_KU_NON_REPUDIATION |
- MBEDTLS_X509_KU_KEY_ENCIPHERMENT |
- MBEDTLS_X509_KU_DATA_ENCIPHERMENT |
- MBEDTLS_X509_KU_KEY_AGREEMENT |
- MBEDTLS_X509_KU_KEY_CERT_SIGN |
- MBEDTLS_X509_KU_CRL_SIGN;
- /* Check that nothing other than the allowed flags is set */
- if( ( key_usage & ~allowed_bits ) != 0 )
- return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
- c = buf + 4;
- ku = (unsigned char)key_usage;
- unused_bits = crt_get_unused_bits_for_named_bitstring( ku, 1 );
- ret = mbedtls_asn1_write_bitstring( &c, buf, &ku, 8 - unused_bits );
- if( ret < 0 )
- return( ret );
- else if( ret < 3 || ret > 4 )
- return( MBEDTLS_ERR_X509_INVALID_FORMAT );
- ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_KEY_USAGE,
- MBEDTLS_OID_SIZE( MBEDTLS_OID_KEY_USAGE ),
- 1, c, (size_t)ret );
- 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;
- size_t unused_bits;
- int ret;
- c = buf + 4;
- unused_bits = crt_get_unused_bits_for_named_bitstring( ns_cert_type, 0 );
- ret = mbedtls_asn1_write_bitstring( &c,
- buf,
- &ns_cert_type,
- 8 - unused_bits );
- if( ret < 3 || ret > 4 )
- return( ret );
- ret = mbedtls_x509write_crt_set_extension( ctx, MBEDTLS_OID_NS_CERT_TYPE,
- MBEDTLS_OID_SIZE( MBEDTLS_OID_NS_CERT_TYPE ),
- 0, c, (size_t)ret );
- if( ret != 0 )
- return( ret );
- return( 0 );
- }
- static int x509_write_time( unsigned char **p, unsigned char *start,
- const char *t, size_t size )
- {
- int ret;
- size_t len = 0;
- /*
- * write MBEDTLS_ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
- */
- if( t[0] == '2' && t[1] == '0' && t[2] < '5' )
- {
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
- (const unsigned char *) t + 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 *) t,
- 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[SIGNATURE_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 */
- /* There's no direct way of extracting a signature algorithm
- * (represented as an element of mbedtls_pk_type_t) from a PK instance. */
- if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_RSA ) )
- pk_alg = MBEDTLS_PK_RSA;
- else if( mbedtls_pk_can_do( ctx->issuer_key, MBEDTLS_PK_ECDSA ) )
- pk_alg = MBEDTLS_PK_ECDSA;
- else
- return( MBEDTLS_ERR_X509_INVALID_ALG );
- 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
- */
- /* Only for v3 */
- if( ctx->version == MBEDTLS_X509_CRT_VERSION_3 )
- {
- 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) }
- */
- /* Can be omitted for v1 */
- if( ctx->version != MBEDTLS_X509_CRT_VERSION_1 )
- {
- 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
- */
- if( ( ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c,
- len, hash ) ) != 0 )
- {
- return( ret );
- }
- 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 */
|