static int x509_write_extension( unsigned char **p, unsigned char *start,
mbedtls_asn1_named_data *ext )
{
int ret;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, ext->val.p + 1,
ext->val.len - 1 ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, ext->val.len - 1 ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OCTET_STRING ) );
if( ext->val.p[0] != 0 )
{
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_bool( p, start, 1 ) );
}
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, ext->oid.p,
ext->oid.len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, ext->oid.len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_OID ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
return( (int) 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 );
}
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 );
}
/*
* RelativeDistinguishedName ::=
* SET OF AttributeTypeAndValue
*
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue }
*
* AttributeType ::= OBJECT IDENTIFIER
*
* AttributeValue ::= ANY DEFINED BY AttributeType
*/
static int x509_write_name( unsigned char **p, unsigned char *start, mbedtls_asn1_named_data* cur_name)
{
int ret;
size_t len = 0;
const char *oid = (const char*)cur_name->oid.p;
size_t oid_len = cur_name->oid.len;
const unsigned char *name = cur_name->val.p;
size_t name_len = cur_name->val.len;
// Write correct string tag and value
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tagged_string( p, start,
cur_name->val.tag,
(const char *) name,
name_len ) );
// Write OID
//
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid,
oid_len ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SET ) );
return( (int) len );
}
int mbedtls_asn1_write_mpi( unsigned char **p, unsigned char *start, const mbedtls_mpi *X )
{
int ret;
size_t len = 0;
// Write the MPI
//
len = mbedtls_mpi_size( X );
if( *p < start || (size_t)( *p - start ) < len )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
(*p) -= len;
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( X, *p, len ) );
// DER format assumes 2s complement for numbers, so the leftmost bit
// should be 0 for positive numbers and 1 for negative numbers.
//
if( X->s ==1 && **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
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_INTEGER ) );
ret = (int) len;
cleanup:
return( ret );
}
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 );
}
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
{
int ret;
size_t len = 0;
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len += 1;
*--(*p) = val;
if( val > 0 && **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
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_INTEGER ) );
return( (int) len );
}
int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t bits )
{
int ret;
size_t len = 0, size;
size = ( bits / 8 ) + ( ( bits % 8 ) ? 1 : 0 );
// Calculate byte length
//
if( *p < start || (size_t)( *p - start ) < size + 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = size + 1;
(*p) -= size;
memcpy( *p, buf, size );
// Write unused bits
//
*--(*p) = (unsigned char) (size * 8 - bits);
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_BIT_STRING ) );
return( (int) len );
}
int mbedtls_asn1_write_bitstring( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t bits )
{
int ret;
size_t len = 0;
size_t unused_bits, byte_len;
byte_len = ( bits + 7 ) / 8;
unused_bits = ( byte_len * 8 ) - bits;
if( *p < start || (size_t)( *p - start ) < byte_len + 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = byte_len + 1;
/* Write the bitstring. Ensure the unused bits are zeroed */
if( byte_len > 0 )
{
byte_len--;
*--( *p ) = buf[byte_len] & ~( ( 0x1 << unused_bits ) - 1 );
( *p ) -= byte_len;
memcpy( *p, buf, byte_len );
}
/* Write unused bits */
*--( *p ) = (unsigned char)unused_bits;
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_BIT_STRING ) );
return( (int) len );
}
int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val )
{
int ret;
size_t len = 0;
// DER format assumes 2s complement for numbers, so the leftmost bit
// should be 0 for positive numbers and 1 for negative numbers.
//
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len += 1;
*--(*p) = val;
if( val > 0 && **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
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_INTEGER ) );
return( (int) len );
}
int mbedtls_ecies_write_hmac(unsigned char **p, unsigned char *start,
mbedtls_md_type_t hmac_type, const unsigned char *hmac, size_t hmac_len)
{
int result = 0;
size_t len = 0;
size_t par_len = 0;
const char *oid = NULL;
size_t oid_len = 0;
if (hmac_type == MBEDTLS_MD_NONE || hmac == NULL || hmac_len == 0)
{
return MBEDTLS_ERR_ECIES_BAD_INPUT_DATA;
}
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_octet_string(p, start, hmac, hmac_len)
);
ACCUMULATE_AND_CHECK(result, par_len,
mbedtls_asn1_write_null(p, start)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_oid_by_md(hmac_type, &oid, &oid_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, par_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_len(p, start, len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)
);
return (int)len;
}
int mbedtls_x509_write_sig( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len,
unsigned char *sig, size_t size )
{
int ret;
size_t len = 0;
if( *p - start < (int) size + 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = size;
(*p) -= len;
memcpy( *p, sig, len );
*--(*p) = 0;
len += 1;
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_BIT_STRING ) );
// Write OID
//
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( p, start, oid,
oid_len, 0 ) );
return( (int) len );
}
int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
{
int ret;
unsigned char *c;
size_t len = 0, par_len = 0, oid_len;
const char *oid;
c = buf + size;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) );
if( c - buf < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
/*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING }
*/
*--c = 0;
len += 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_BIT_STRING ) );
if( ( ret = mbedtls_oid_get_oid_by_pk_alg( mbedtls_pk_get_type( key ),
&oid, &oid_len ) ) != 0 )
{
return( ret );
}
#if defined(MBEDTLS_ECP_C)
if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_ECKEY )
{
MBEDTLS_ASN1_CHK_ADD( par_len, pk_write_ec_param( &c, buf, mbedtls_pk_ec( *key ) ) );
}
#endif
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_algorithm_identifier( &c, buf, oid, oid_len,
par_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 );
}
int mbedtls_asn1_write_null( unsigned char **p, unsigned char *start )
{
int ret;
size_t len = 0;
// Write NULL
//
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, 0) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start, MBEDTLS_ASN1_NULL ) );
return( (int) len );
}
int mbedtls_ecies_write_envelope(unsigned char **p, unsigned char *start, size_t len)
{
int result = 0;
size_t asn_len = 0;
ACCUMULATE_AND_CHECK(result, asn_len,
mbedtls_asn1_write_len(p, start, len)
);
ACCUMULATE_AND_CHECK(result, asn_len,
mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)
);
return (int)asn_len;
}
int mbedtls_ecies_write_content_info(unsigned char **p, unsigned char *start,
mbedtls_cipher_type_t cipher_type, const unsigned char *iv, size_t iv_len,
size_t data_len)
{
int result = 0;
size_t len = data_len;
size_t par_len = 0;
const char *oid = NULL;
size_t oid_len = 0;
if (cipher_type == MBEDTLS_CIPHER_NONE || iv == NULL || iv_len == 0)
{
return MBEDTLS_ERR_ECIES_BAD_INPUT_DATA;
}
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_len(p, start, data_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_OCTET_STRING)
);
ACCUMULATE_AND_CHECK(result, par_len,
mbedtls_asn1_write_octet_string(p, start, iv, iv_len)
);
INVOKE_AND_CHECK(result,
mbedtls_oid_get_oid_by_cipher_alg(cipher_type, &oid, &oid_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_algorithm_identifier(p, start, oid, oid_len, par_len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_len(p, start, len)
);
ACCUMULATE_AND_CHECK(result, len,
mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)
);
return (int)len;
}
int mbedtls_asn1_write_octet_string( unsigned char **p, unsigned char *start,
const unsigned char *buf, size_t size )
{
int ret;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start, buf, 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_OCTET_STRING ) );
return( (int) len );
}
int mbedtls_asn1_write_oid( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len )
{
int ret;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
(const unsigned char *) oid, oid_len ) );
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_OID ) );
return( (int) len );
}
int mbedtls_asn1_write_ia5_string( unsigned char **p, unsigned char *start,
const char *text, size_t text_len )
{
int ret;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_raw_buffer( p, start,
(const unsigned char *) text, text_len ) );
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_IA5_STRING ) );
return( (int) len );
}
/*
* RelativeDistinguishedName ::=
* SET OF AttributeTypeAndValue
*
* AttributeTypeAndValue ::= SEQUENCE {
* type AttributeType,
* value AttributeValue }
*
* AttributeType ::= OBJECT IDENTIFIER
*
* AttributeValue ::= ANY DEFINED BY AttributeType
*/
static int x509_write_name( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len,
const unsigned char *name, size_t name_len )
{
int ret;
size_t len = 0;
// Write PrintableString for all except MBEDTLS_OID_PKCS9_EMAIL
//
if( MBEDTLS_OID_SIZE( MBEDTLS_OID_PKCS9_EMAIL ) == oid_len &&
memcmp( oid, MBEDTLS_OID_PKCS9_EMAIL, oid_len ) == 0 )
{
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_ia5_string( p, start,
(const char *) name,
name_len ) );
}
else
{
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_printable_string( p, start,
(const char *) name,
name_len ) );
}
// Write OID
//
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SET ) );
return( (int) len );
}
/*
* RSAPublicKey ::= SEQUENCE {
* modulus INTEGER, -- n
* publicExponent INTEGER -- e
* }
*/
static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
mbedtls_rsa_context *rsa )
{
int ret;
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->E ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( p, start, &rsa->N ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
int mbedtls_asn1_write_bool( unsigned char **p, unsigned char *start, int boolean )
{
int ret;
size_t len = 0;
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = (boolean) ? 255 : 0;
len++;
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_BOOLEAN ) );
return( (int) len );
}
int mbedtls_x509_write_names( unsigned char **p, unsigned char *start,
mbedtls_asn1_named_data *first )
{
int ret;
size_t len = 0;
mbedtls_asn1_named_data *cur = first;
while( cur != NULL )
{
MBEDTLS_ASN1_CHK_ADD( len, x509_write_name( p, start, cur ) );
cur = cur->next;
}
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_CONSTRUCTED |
MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
/*
* Simultaneously convert and move raw MPI from the beginning of a buffer
* to an ASN.1 MPI at the end of the buffer.
* See also mbedtls_asn1_write_mpi().
*
* p: pointer to the end of the output buffer
* start: start of the output buffer, and also of the mpi to write at the end
* n_len: length of the mpi to read from start
*/
static int asn1_write_mpibuf( unsigned char **p, unsigned char *start,
size_t n_len )
{
int ret;
size_t len = 0;
if( (size_t)( *p - start ) < n_len )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
len = n_len;
*p -= len;
memmove( *p, start, len );
/* ASN.1 DER encoding requires minimal length, so skip leading 0s.
* Neither r nor s should be 0, but as a failsafe measure, still detect
* that rather than overflowing the buffer in case of a PSA error. */
while( len > 0 && **p == 0x00 )
{
++(*p);
--len;
}
/* this is only reached if the signature was invalid */
if( len == 0 )
return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
/* if the msb is 1, ASN.1 requires that we prepend a 0.
* Neither r nor s can be 0, so we can assume len > 0 at all times. */
if( **p & 0x80 )
{
if( *p - start < 1 )
return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
*--(*p) = 0x00;
len += 1;
}
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_INTEGER ) );
return( (int) len );
}
/*
* Convert a signature (given by context) to ASN.1
*/
static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
unsigned char *sig, size_t *slen )
{
int ret;
unsigned char buf[MBEDTLS_ECDSA_MAX_LEN];
unsigned char *p = buf + sizeof( buf );
size_t len = 0;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, s ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_mpi( &p, buf, r ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
memcpy( sig, p, len );
*slen = len;
return( 0 );
}
int mbedtls_asn1_write_algorithm_identifier( unsigned char **p, unsigned char *start,
const char *oid, size_t oid_len,
size_t par_len )
{
int ret;
size_t len = 0;
if( par_len == 0 )
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_null( p, start ) );
else
len += par_len;
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( p, start, oid, oid_len ) );
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_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
return( (int) len );
}
/* Transcode signature from PSA format to ASN.1 sequence.
* See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
* MPIs, and in-place.
*
* [in/out] sig: the signature pre- and post-transcoding
* [in/out] sig_len: signature length pre- and post-transcoding
* [int] buf_len: the available size the in/out buffer
*/
static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len,
size_t buf_len )
{
int ret;
size_t len = 0;
const size_t rs_len = *sig_len / 2;
unsigned char *p = sig + buf_len;
MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) );
MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig,
MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
memmove( sig, p, len );
*sig_len = len;
return( 0 );
}
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_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 );
}
int mbedtls_x509write_csr_der( mbedtls_x509write_csr *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 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 );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
if( len )
{
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_CONSTRUCTED |
MBEDTLS_ASN1_SET ) );
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( &c, tmp_buf, MBEDTLS_OID_PKCS9_CSR_EXT_REQ,
MBEDTLS_OID_SIZE( MBEDTLS_OID_PKCS9_CSR_EXT_REQ ) ) );
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_CONSTRUCTED |
MBEDTLS_ASN1_CONTEXT_SPECIFIC ) );
MBEDTLS_ASN1_CHK_ADD( pub_len, mbedtls_pk_write_pubkey_der( ctx->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 ) );
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_int( &c, tmp_buf, 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 ) );
/*
* Prepare signature
*/
mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash );
pk_alg = mbedtls_pk_get_type( ctx->key );
if( pk_alg == MBEDTLS_PK_ECKEY )
pk_alg = MBEDTLS_PK_ECDSA;
if( ( ret = mbedtls_pk_sign( ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
f_rng, p_rng ) ) != 0 ||
( ret = mbedtls_oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
&sig_oid, &sig_oid_len ) ) != 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 ) );
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 );
}
