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cosmopolitan/third_party/mbedtls/x509write_crt.c
Justine Tunney 957c61cbbf
Release Cosmopolitan v3.3 
This change upgrades to GCC 12.3 and GNU binutils 2.42. The GNU linker
appears to have changed things so that only a single de-duplicated str
table is present in the binary, and it gets placed wherever the linker
wants, regardless of what the linker script says. To cope with that we
need to stop using .ident to embed licenses. As such, this change does
significant work to revamp how third party licenses are defined in the
codebase, using `.section .notice,"aR",@progbits`.

This new GCC 12.3 toolchain has support for GNU indirect functions. It
lets us support __target_clones__ for the first time. This is used for
optimizing the performance of libc string functions such as strlen and
friends so far on x86, by ensuring AVX systems favor a second codepath
that uses VEX encoding. It shaves some latency off certain operations.
It's a useful feature to have for scientific computing for the reasons
explained by the test/libcxx/openmp_test.cc example which compiles for
fifteen different microarchitectures. Thanks to the upgrades, it's now
also possible to use newer instruction sets, such as AVX512FP16, VNNI.

Cosmo now uses the %gs register on x86 by default for TLS. Doing it is
helpful for any program that links `cosmo_dlopen()`. Such programs had
to recompile their binaries at startup to change the TLS instructions.
That's not great, since it means every page in the executable needs to
be faulted. The work of rewriting TLS-related x86 opcodes, is moved to
fixupobj.com instead. This is great news for MacOS x86 users, since we
previously needed to morph the binary every time for that platform but
now that's no longer necessary. The only platforms where we need fixup
of TLS x86 opcodes at runtime are now Windows, OpenBSD, and NetBSD. On
Windows we morph TLS to point deeper into the TIB, based on a TlsAlloc
assignment, and on OpenBSD/NetBSD we morph %gs back into %fs since the
kernels do not allow us to specify a value for the %gs register.

OpenBSD users are now required to use APE Loader to run Cosmo binaries
and assimilation is no longer possible. OpenBSD kernel needs to change
to allow programs to specify a value for the %gs register, or it needs
to stop marking executable pages loaded by the kernel as mimmutable().

This release fixes __constructor__, .ctor, .init_array, and lastly the
.preinit_array so they behave the exact same way as glibc.

We no longer use hex constants to define math.h symbols like M_PI.
2024-02-20 13:27:59 -08:00

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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:4;tab-width:4;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright The Mbed TLS Contributors │
│ │
│ 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. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "third_party/mbedtls/asn1write.h"
#include "third_party/mbedtls/common.h"
#include "third_party/mbedtls/error.h"
#include "third_party/mbedtls/oid.h"
#include "third_party/mbedtls/pem.h"
#include "third_party/mbedtls/platform.h"
#include "third_party/mbedtls/sha1.h"
#include "third_party/mbedtls/x509_crt.h"
__static_yoink("mbedtls_notice");
/*
* X.509 certificate writing
*
* Copyright The Mbed TLS Contributors
* 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.
*/
/*
* 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_X509_CRT_WRITE_C)
/**
* \brief Initialize a CRT writing context
*
* \param ctx CRT context to initialize
*/
void mbedtls_x509write_crt_init( mbedtls_x509write_cert *ctx )
{
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_x509write_cert ) );
mbedtls_mpi_init( &ctx->serial );
ctx->version = MBEDTLS_X509_CRT_VERSION_3;
}
/**
* \brief Free the contents of a CRT write context
*
* \param ctx CRT context to free
*/
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 ) );
}
/**
* \brief Set the verion for a Certificate
* Default: MBEDTLS_X509_CRT_VERSION_3
*
* \param ctx CRT context to use
* \param version version to set (MBEDTLS_X509_CRT_VERSION_1, MBEDTLS_X509_CRT_VERSION_2 or
* MBEDTLS_X509_CRT_VERSION_3)
*/
void mbedtls_x509write_crt_set_version( mbedtls_x509write_cert *ctx,
int version )
{
ctx->version = version;
}
/**
* \brief Set the MD algorithm to use for the signature
* (e.g. MBEDTLS_MD_SHA1)
*
* \param ctx CRT context to use
* \param md_alg MD algorithm to use
*/
void mbedtls_x509write_crt_set_md_alg( mbedtls_x509write_cert *ctx,
mbedtls_md_type_t md_alg )
{
ctx->md_alg = md_alg;
}
/**
* \brief Set the subject public key for the certificate
*
* \param ctx CRT context to use
* \param key public key to include
*/
void mbedtls_x509write_crt_set_subject_key( mbedtls_x509write_cert *ctx,
mbedtls_pk_context *key )
{
ctx->subject_key = key;
}
/**
* \brief Set the issuer key used for signing the certificate
*
* \param ctx CRT context to use
* \param key private key to sign with
*/
void mbedtls_x509write_crt_set_issuer_key( mbedtls_x509write_cert *ctx,
mbedtls_pk_context *key )
{
ctx->issuer_key = key;
}
/**
* \brief Set the subject name for a Certificate
* Subject names should contain a comma-separated list
* of OID types and values:
* e.g. "C=UK,O=ARM,CN=mbed TLS Server 1"
*
* \param ctx CRT context to use
* \param subject_name subject name to set
*
* \return 0 if subject name was parsed successfully, or
* a specific error code
*/
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 );
}
/**
* \brief Set the issuer name for a Certificate
* Issuer names should contain a comma-separated list
* of OID types and values:
* e.g. "C=UK,O=ARM,CN=mbed TLS CA"
*
* \param ctx CRT context to use
* \param issuer_name issuer name to set
*
* \return 0 if issuer name was parsed successfully, or
* a specific error code
*/
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 );
}
/**
* \brief Set the serial number for a Certificate.
*
* \param ctx CRT context to use
* \param serial serial number to set
*
* \return 0 if successful
*/
int mbedtls_x509write_crt_set_serial( mbedtls_x509write_cert *ctx,
const mbedtls_mpi *serial )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
if( ( ret = mbedtls_mpi_copy( &ctx->serial, serial ) ) != 0 )
return( ret );
return( 0 );
}
/**
* \brief Set the validity period for a Certificate
* Timestamps should be in string format for UTC timezone
* i.e. "YYYYMMDDhhmmss"
* e.g. "20131231235959" for December 31st 2013
* at 23:59:59
*
* \param ctx CRT context to use
* \param not_before not_before timestamp
* \param not_after not_after timestamp
*
* \return 0 if timestamp was parsed successfully, or
* a specific error code
*/
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 );
}
/**
* \brief Generic function to add to or replace an extension in the
* CRT
*
* \param ctx CRT context to use
* \param oid OID of the extension
* \param oid_len length of the OID
* \param critical if the extension is critical (per the RFC's definition)
* \param val value of the extension OCTET STRING
* \param val_len length of the value data
*
* \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
*/
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 ) );
}
/**
* \brief Set the basicConstraints extension for a CRT
*
* \param ctx CRT context to use
* \param is_ca is this a CA certificate
* \param max_pathlen maximum length of certificate chains below this
* certificate (only for CA certificates, -1 is
* inlimited)
*
* \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
*/
int mbedtls_x509write_crt_set_basic_constraints( mbedtls_x509write_cert *ctx,
int is_ca, int max_pathlen )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
unsigned char buf[9];
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
mbedtls_platform_zeroize( buf, 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 ),
is_ca, buf + sizeof(buf) - len, len ) );
}
#if defined(MBEDTLS_SHA1_C)
/**
* \brief Set the subjectKeyIdentifier extension for a CRT
* Requires that mbedtls_x509write_crt_set_subject_key() has been
* called before
*
* \param ctx CRT context to use
*
* \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
*/
int mbedtls_x509write_crt_set_subject_key_identifier( mbedtls_x509write_cert *ctx )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof(buf);
size_t len = 0;
mbedtls_platform_zeroize( buf, 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 );
}
/**
* \brief Set the authorityKeyIdentifier extension for a CRT
* Requires that mbedtls_x509write_crt_set_issuer_key() has been
* called before
*
* \param ctx CRT context to use
*
* \return 0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
*/
int mbedtls_x509write_crt_set_authority_key_identifier( mbedtls_x509write_cert *ctx )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
unsigned char buf[MBEDTLS_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
unsigned char *c = buf + sizeof( buf );
size_t len = 0;
mbedtls_platform_zeroize( buf, 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 */
/**
* \brief Set the Key Usage Extension flags
* (e.g. MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_KEY_CERT_SIGN)
*
* \param ctx CRT context to use
* \param key_usage key usage flags to set
*
* \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
*/
int mbedtls_x509write_crt_set_key_usage( mbedtls_x509write_cert *ctx,
unsigned int key_usage )
{
unsigned char buf[5], ku[2];
unsigned char *c;
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
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 |
MBEDTLS_X509_KU_ENCIPHER_ONLY |
MBEDTLS_X509_KU_DECIPHER_ONLY;
/* Check that nothing other than the allowed flags is set */
if( ( key_usage & ~allowed_bits ) != 0 )
return( MBEDTLS_ERR_X509_FEATURE_UNAVAILABLE );
c = buf + 5;
ku[0] = (unsigned char)( key_usage );
ku[1] = (unsigned char)( key_usage >> 8 );
ret = mbedtls_asn1_write_named_bitstring( &c, buf, ku, 9 );
if( ret < 0 )
return( ret );
else if( ret < 3 || ret > 5 )
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 );
}
/**
* \brief Set the Netscape Cert Type flags
* (e.g. MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT | MBEDTLS_X509_NS_CERT_TYPE_EMAIL)
*
* \param ctx CRT context to use
* \param ns_cert_type Netscape Cert Type flags to set
*
* \return 0 if successful, or MBEDTLS_ERR_X509_ALLOC_FAILED
*/
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 = MBEDTLS_ERR_THIS_CORRUPTION;
c = buf + 4;
ret = mbedtls_asn1_write_named_bitstring( &c, buf, &ns_cert_type, 8 );
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 );
}
/**
* Writes Extended Key Usage section to certificate.
*
* @see mbedtls_x509write_crt_set_ns_cert_type()
* @see RFC5280 §4.2.1.12
*/
int mbedtls_x509write_crt_set_ext_key_usage(mbedtls_x509write_cert *ctx,
int ns_cert_type) {
int ret;
size_t len;
unsigned char buf[256];
unsigned char *c;
if (!ns_cert_type) return 0;
if (ns_cert_type & ~(MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT |
MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER |
MBEDTLS_X509_NS_CERT_TYPE_EMAIL)) {
return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
}
len = 0;
c = buf + sizeof(buf);
mbedtls_platform_zeroize(buf, sizeof(buf));
if (ns_cert_type & MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT) {
MBEDTLS_ASN1_CHK_ADD(
len, mbedtls_asn1_write_oid(&c, buf, MBEDTLS_OID_CLIENT_AUTH,
MBEDTLS_OID_SIZE(MBEDTLS_OID_CLIENT_AUTH)));
}
if (ns_cert_type & MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER) {
MBEDTLS_ASN1_CHK_ADD(
len, mbedtls_asn1_write_oid(&c, buf, MBEDTLS_OID_SERVER_AUTH,
MBEDTLS_OID_SIZE(MBEDTLS_OID_SERVER_AUTH)));
}
if (ns_cert_type & MBEDTLS_X509_NS_CERT_TYPE_EMAIL) {
MBEDTLS_ASN1_CHK_ADD(
len,
mbedtls_asn1_write_oid(&c, buf, MBEDTLS_OID_EMAIL_PROTECTION,
MBEDTLS_OID_SIZE(MBEDTLS_OID_EMAIL_PROTECTION)));
}
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_EXTENDED_KEY_USAGE,
MBEDTLS_OID_SIZE(MBEDTLS_OID_EXTENDED_KEY_USAGE), false,
buf + sizeof(buf) - len, len);
}
static int x509_write_time( unsigned char **p, unsigned char *start,
const char *t, size_t size )
{
int ret = MBEDTLS_ERR_THIS_CORRUPTION;
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 );
}
/**
* \brief Write a built up certificate to a X509 DER structure
* Note: data is written at the end of the buffer! Use the
* return value to determine where you should start
* using the buffer
*
* \param ctx certificate to write away
* \param buf buffer to write to
* \param size size of the buffer
* \param f_rng RNG function (for signature, see note)
* \param p_rng RNG parameter
*
* \return length of data written if successful, or a specific
* error code
*
* \note f_rng may be NULL if RSA is used for signature and the
* signature is made offline (otherwise f_rng is desirable
* for countermeasures against timing attacks).
* ECDSA signatures always require a non-NULL f_rng.
*/
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 = MBEDTLS_ERR_THIS_CORRUPTION;
const char *sig_oid;
size_t sig_oid_len = 0;
unsigned char *c, *c2;
unsigned char hash[64];
unsigned char sig[MBEDTLS_PK_SIGNATURE_MAX_SIZE];
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 at the end of the target buffer
*/
c = buf + size;
/* 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,
buf, ctx->extensions ) );
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 ) );
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 |
MBEDTLS_ASN1_CONSTRUCTED | 3 ) );
}
/*
* SubjectPublicKeyInfo
*/
MBEDTLS_ASN1_CHK_ADD( pub_len,
mbedtls_pk_write_pubkey_der( ctx->subject_key,
buf, c - buf ) );
c -= pub_len;
len += pub_len;
/*
* Subject ::= Name
*/
MBEDTLS_ASN1_CHK_ADD( len,
mbedtls_x509_write_names( &c, buf,
ctx->subject ) );
/*
* Validity ::= SEQUENCE {
* notBefore Time,
* notAfter Time }
*/
sub_len = 0;
MBEDTLS_ASN1_CHK_ADD( sub_len,
x509_write_time( &c, buf, ctx->not_after,
MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
MBEDTLS_ASN1_CHK_ADD( sub_len,
x509_write_time( &c, buf, ctx->not_before,
MBEDTLS_X509_RFC5280_UTC_TIME_LEN ) );
len += sub_len;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &c, buf, sub_len ) );
MBEDTLS_ASN1_CHK_ADD( len,
mbedtls_asn1_write_tag( &c, buf,
MBEDTLS_ASN1_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
/*
* Issuer ::= Name
*/
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_names( &c, buf,
ctx->issuer ) );
/*
* Signature ::= AlgorithmIdentifier
*/
MBEDTLS_ASN1_CHK_ADD( len,
mbedtls_asn1_write_algorithm_identifier( &c, buf,
sig_oid, strlen( sig_oid ), 0 ) );
/*
* Serial ::= INTEGER
*/
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &c, 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, buf, ctx->version ) );
len += sub_len;
MBEDTLS_ASN1_CHK_ADD( len,
mbedtls_asn1_write_len( &c, buf, sub_len ) );
MBEDTLS_ASN1_CHK_ADD( len,
mbedtls_asn1_write_tag( &c, buf,
MBEDTLS_ASN1_CONTEXT_SPECIFIC |
MBEDTLS_ASN1_CONSTRUCTED | 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 ) );
/*
* Make signature
*/
/* Compute hash of CRT. */
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 );
}
/* Move CRT to the front of the buffer to have space
* for the signature. */
memmove( buf, c, len );
c = buf + len;
/* Add signature at the end of the buffer,
* making sure that it doesn't underflow
* into the CRT buffer. */
c2 = buf + size;
MBEDTLS_ASN1_CHK_ADD( sig_and_oid_len, mbedtls_x509_write_sig( &c2, c,
sig_oid, sig_oid_len, sig, sig_len ) );
/*
* Memory layout after this step:
*
* buf c=buf+len c2 buf+size
* [CRT0,...,CRTn, UNUSED, ..., UNUSED, SIG0, ..., SIGm]
*/
/* Move raw CRT to just before the signature. */
c = c2 - len;
memmove( c, buf, len );
len += sig_and_oid_len;
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( (int) len );
}
#define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
#define PEM_END_CRT "-----END CERTIFICATE-----\n"
/**
* \brief Write a built up certificate to a X509 PEM string
*
* \param ctx certificate to write away
* \param buf buffer to write to
* \param size size of the buffer
* \param f_rng RNG function (for signature, see note)
* \param p_rng RNG parameter
*
* \return 0 if successful, or a specific error code
*
* \note f_rng may be NULL if RSA is used for signature and the
* signature is made offline (otherwise f_rng is desirable
* for countermeasures against timing attacks).
* ECDSA signatures always require a non-NULL f_rng.
*/
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 = MBEDTLS_ERR_THIS_CORRUPTION;
size_t olen;
if( ( ret = mbedtls_x509write_crt_der( crt, buf, size,
f_rng, p_rng ) ) < 0 )
{
return( ret );
}
if( ( ret = mbedtls_pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
buf + size - ret, ret,
buf, size, &olen ) ) != 0 )
{
return( ret );
}
return( 0 );
}
#endif /* MBEDTLS_X509_CRT_WRITE_C */
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