PolarSSL v1.3.1
x509write_crt.c
Go to the documentation of this file.
1 /*
2  * X.509 certificate writing
3  *
4  * Copyright (C) 2006-2013, Brainspark B.V.
5  *
6  * This file is part of PolarSSL (http://www.polarssl.org)
7  * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
8  *
9  * All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License along
22  * with this program; if not, write to the Free Software Foundation, Inc.,
23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24  */
25 /*
26  * References:
27  * - certificates: RFC 5280, updated by RFC 6818
28  * - CSRs: PKCS#10 v1.7 aka RFC 2986
29  * - attributes: PKCS#9 v2.0 aka RFC 2985
30  */
31 
32 #include "polarssl/config.h"
33 
34 #if defined(POLARSSL_X509_CRT_WRITE_C)
35 
36 #include "polarssl/x509_crt.h"
37 #include "polarssl/oid.h"
38 #include "polarssl/asn1write.h"
39 #include "polarssl/sha1.h"
40 
41 #if defined(POLARSSL_PEM_WRITE_C)
42 #include "polarssl/pem.h"
43 #endif /* POLARSSL_PEM_WRITE_C */
44 
46 {
47  memset( ctx, 0, sizeof(x509write_cert) );
48 
49  mpi_init( &ctx->serial );
51 }
52 
54 {
55  mpi_free( &ctx->serial );
56 
60 
61  memset( ctx, 0, sizeof(x509write_cert) );
62 }
63 
64 void x509write_crt_set_version( x509write_cert *ctx, int version )
65 {
66  ctx->version = version;
67 }
68 
70 {
71  ctx->md_alg = md_alg;
72 }
73 
75 {
76  ctx->subject_key = key;
77 }
78 
80 {
81  ctx->issuer_key = key;
82 }
83 
84 int x509write_crt_set_subject_name( x509write_cert *ctx, char *subject_name )
85 {
86  return x509_string_to_names( &ctx->subject, subject_name );
87 }
88 
89 int x509write_crt_set_issuer_name( x509write_cert *ctx, char *issuer_name )
90 {
91  return x509_string_to_names( &ctx->issuer, issuer_name );
92 }
93 
94 int x509write_crt_set_serial( x509write_cert *ctx, const mpi *serial )
95 {
96  int ret;
97 
98  if( ( ret = mpi_copy( &ctx->serial, serial ) ) != 0 )
99  return( ret );
100 
101  return( 0 );
102 }
103 
104 int x509write_crt_set_validity( x509write_cert *ctx, char *not_before,
105  char *not_after )
106 {
107  if( strlen(not_before) != X509_RFC5280_UTC_TIME_LEN - 1 ||
108  strlen(not_after) != X509_RFC5280_UTC_TIME_LEN - 1 )
109  {
111  }
112  strncpy( ctx->not_before, not_before, X509_RFC5280_UTC_TIME_LEN );
113  strncpy( ctx->not_after , not_after , X509_RFC5280_UTC_TIME_LEN );
114  ctx->not_before[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
115  ctx->not_after[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
116 
117  return( 0 );
118 }
119 
121  const char *oid, size_t oid_len,
122  int critical,
123  const unsigned char *val, size_t val_len )
124 {
125  return x509_set_extension( &ctx->extensions, oid, oid_len,
126  critical, val, val_len );
127 }
128 
130  int is_ca, int max_pathlen )
131 {
132  int ret;
133  unsigned char buf[9];
134  unsigned char *c = buf + sizeof(buf);
135  size_t len = 0;
136 
137  memset( buf, 0, sizeof(buf) );
138 
139  if( is_ca && max_pathlen > 127 )
141 
142  if( is_ca )
143  {
144  if( max_pathlen >= 0 )
145  {
146  ASN1_CHK_ADD( len, asn1_write_int( &c, buf, max_pathlen ) );
147  }
148  ASN1_CHK_ADD( len, asn1_write_bool( &c, buf, 1 ) );
149  }
150 
151  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
153 
156  0, buf + sizeof(buf) - len, len );
157 }
158 
160 {
161  int ret;
162  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
163  unsigned char *c = buf + sizeof(buf);
164  size_t len = 0;
165 
166  memset( buf, 0, sizeof(buf));
167  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->subject_key ) );
168 
169  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
170  c = buf + sizeof(buf) - 20;
171  len = 20;
172 
173  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
174  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_OCTET_STRING ) );
175 
178  0, buf + sizeof(buf) - len, len );
179 }
180 
182 {
183  int ret;
184  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
185  unsigned char *c = buf + sizeof(buf);
186  size_t len = 0;
187 
188  memset( buf, 0, sizeof(buf));
189  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->issuer_key ) );
190 
191  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
192  c = buf + sizeof(buf) - 20;
193  len = 20;
194 
195  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
196  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONTEXT_SPECIFIC | 0 ) );
197 
198  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
200 
203  0, buf + sizeof(buf) - len, len );
204 }
205 
206 int x509write_crt_set_key_usage( x509write_cert *ctx, unsigned char key_usage )
207 {
208  unsigned char buf[4];
209  unsigned char *c;
210  int ret;
211 
212  c = buf + 4;
213 
214  if( ( ret = asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
215  return( ret );
216 
219  1, buf, 4 );
220  if( ret != 0 )
221  return( ret );
222 
223  return( 0 );
224 }
225 
227  unsigned char ns_cert_type )
228 {
229  unsigned char buf[4];
230  unsigned char *c;
231  int ret;
232 
233  c = buf + 4;
234 
235  if( ( ret = asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
236  return( ret );
237 
240  0, buf, 4 );
241  if( ret != 0 )
242  return( ret );
243 
244  return( 0 );
245 }
246 
247 static int x509_write_time( unsigned char **p, unsigned char *start,
248  const char *time, size_t size )
249 {
250  int ret;
251  size_t len = 0;
252 
253  /*
254  * write ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
255  */
256  if( time[0] == '2' && time[1] == '0' && time [2] < '5' )
257  {
258  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
259  (const unsigned char *) time + 2,
260  size - 2 ) );
261  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
262  ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_UTC_TIME ) );
263  }
264  else
265  {
266  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
267  (const unsigned char *) time,
268  size ) );
269  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
271  }
272 
273  return( (int) len );
274 }
275 
276 int x509write_crt_der( x509write_cert *ctx, unsigned char *buf, size_t size,
277  int (*f_rng)(void *, unsigned char *, size_t),
278  void *p_rng )
279 {
280  int ret;
281  const char *sig_oid;
282  size_t sig_oid_len = 0;
283  unsigned char *c, *c2;
284  unsigned char hash[64];
285  unsigned char sig[POLARSSL_MPI_MAX_SIZE];
286  unsigned char tmp_buf[2048];
287  size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
288  size_t len = 0;
289  pk_type_t pk_alg;
290 
291  /*
292  * Prepare data to be signed in tmp_buf
293  */
294  c = tmp_buf + sizeof( tmp_buf );
295 
296  /* Signature algorithm needed in TBS, and later for actual signature */
297  pk_alg = pk_get_type( ctx->issuer_key );
298  if( pk_alg == POLARSSL_PK_ECKEY )
299  pk_alg = POLARSSL_PK_ECDSA;
300 
301  if( ( ret = oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
302  &sig_oid, &sig_oid_len ) ) != 0 )
303  {
304  return( ret );
305  }
306 
307  /*
308  * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
309  */
310  ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
311  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
312  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
313  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
315 
316  /*
317  * SubjectPublicKeyInfo
318  */
320  tmp_buf, c - tmp_buf ) );
321  c -= pub_len;
322  len += pub_len;
323 
324  /*
325  * Subject ::= Name
326  */
327  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->subject ) );
328 
329  /*
330  * Validity ::= SEQUENCE {
331  * notBefore Time,
332  * notAfter Time }
333  */
334  sub_len = 0;
335 
336  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after,
338 
339  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before,
341 
342  len += sub_len;
343  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
344  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
345 
346  /*
347  * Issuer ::= Name
348  */
349  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->issuer ) );
350 
351  /*
352  * Signature ::= AlgorithmIdentifier
353  */
355  sig_oid, strlen( sig_oid ), 0 ) );
356 
357  /*
358  * Serial ::= INTEGER
359  */
360  ASN1_CHK_ADD( len, asn1_write_mpi( &c, tmp_buf, &ctx->serial ) );
361 
362  /*
363  * Version ::= INTEGER { v1(0), v2(1), v3(2) }
364  */
365  sub_len = 0;
366  ASN1_CHK_ADD( sub_len, asn1_write_int( &c, tmp_buf, ctx->version ) );
367  len += sub_len;
368  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
370 
371  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
372  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
373 
374  /*
375  * Make signature
376  */
377  md( md_info_from_type( ctx->md_alg ), c, len, hash );
378 
379  if( ( ret = pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len,
380  f_rng, p_rng ) ) != 0 )
381  {
382  return( ret );
383  }
384 
385  /*
386  * Write data to output buffer
387  */
388  c2 = buf + size;
389  ASN1_CHK_ADD( sig_and_oid_len, x509_write_sig( &c2, buf,
390  sig_oid, sig_oid_len, sig, sig_len ) );
391 
392  c2 -= len;
393  memcpy( c2, c, len );
394 
395  len += sig_and_oid_len;
396  ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
398 
399  return( (int) len );
400 }
401 
402 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
403 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
404 
405 #if defined(POLARSSL_PEM_WRITE_C)
406 int x509write_crt_pem( x509write_cert *crt, unsigned char *buf, size_t size,
407  int (*f_rng)(void *, unsigned char *, size_t),
408  void *p_rng )
409 {
410  int ret;
411  unsigned char output_buf[4096];
412  size_t olen = 0;
413 
414  if( ( ret = x509write_crt_der( crt, output_buf, sizeof(output_buf),
415  f_rng, p_rng ) ) < 0 )
416  {
417  return( ret );
418  }
419 
420  if( ( ret = pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
421  output_buf + sizeof(output_buf) - ret,
422  ret, buf, size, &olen ) ) != 0 )
423  {
424  return( ret );
425  }
426 
427  return( 0 );
428 }
429 #endif /* POLARSSL_PEM_WRITE_C */
430 
431 #endif /* POLARSSL_X509_CRT_WRITE_C */
int md(const md_info_t *md_info, const unsigned char *input, size_t ilen, unsigned char *output)
Output = message_digest( input buffer )
void x509write_crt_set_version(x509write_cert *ctx, int version)
Set the verion for a Certificate Default: X509_CRT_VERSION_3.
int x509write_crt_der(x509write_cert *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
Write a built up certificate to a X509 DER structure Note: data is written at the end of the buffer! ...
int x509_set_extension(asn1_named_data **head, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len)
#define ASN1_UTC_TIME
Definition: asn1.h:83
#define ASN1_GENERALIZED_TIME
Definition: asn1.h:84
char not_after[X509_RFC5280_UTC_TIME_LEN+1]
Definition: x509_crt.h:117
#define POLARSSL_MPI_MAX_SIZE
Maximum number of bytes for usable MPIs.
Definition: bignum.h:87
void sha1(const unsigned char *input, size_t ilen, unsigned char output[20])
Output = SHA-1( input buffer )
asn1_named_data * extensions
Definition: x509_crt.h:118
#define ASN1_SEQUENCE
Definition: asn1.h:78
int x509write_crt_set_validity(x509write_cert *ctx, char *not_before, char *not_after)
Set the validity period for a Certificate Timestamps should be in string format for UTC timezone i...
Configuration options (set of defines)
#define ASN1_CONSTRUCTED
Definition: asn1.h:88
pk_context * subject_key
Definition: x509_crt.h:111
void x509write_crt_set_md_alg(x509write_cert *ctx, md_type_t md_alg)
Set the MD algorithm to use for the signature (e.g.
MPI structure.
Definition: bignum.h:168
pk_type_t pk_get_type(const pk_context *ctx)
Get the key type.
void mpi_init(mpi *X)
Initialize one MPI.
Object Identifier (OID) database.
#define OID_SIZE(x)
Returns the size of the binary string, without the trailing \0.
Definition: asn1.h:94
md_type_t
Definition: md.h:51
int asn1_write_len(unsigned char **p, unsigned char *start, size_t len)
Write a length field in ASN.1 format Note: function works backwards in data buffer.
int x509write_crt_set_issuer_name(x509write_cert *ctx, char *issuer_name)
Set the issuer name for a Certificate Issuer names should contain a comma-separated list of OID types...
int x509_write_names(unsigned char **p, unsigned char *start, asn1_named_data *first)
const md_info_t * md_info_from_type(md_type_t md_type)
Returns the message digest information associated with the given digest type.
int pk_write_pubkey(unsigned char **p, unsigned char *start, const pk_context *key)
Write a subjectPublicKey to ASN.1 data Note: function works backwards in data buffer.
int x509write_crt_set_key_usage(x509write_cert *ctx, unsigned char key_usage)
Set the Key Usage Extension flags (e.g.
void x509write_crt_free(x509write_cert *ctx)
Free the contents of a CRT write context.
Privacy Enhanced Mail (PEM) decoding.
#define X509_CRT_VERSION_3
Definition: x509_crt.h:99
int x509write_crt_set_subject_key_identifier(x509write_cert *ctx)
Set the subjectKeyIdentifier extension for a CRT Requires that x509write_crt_set_subject_key() has be...
char not_before[X509_RFC5280_UTC_TIME_LEN+1]
Definition: x509_crt.h:116
int asn1_write_raw_buffer(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t size)
Write raw buffer data Note: function works backwards in data buffer.
int x509write_crt_set_extension(x509write_cert *ctx, const char *oid, size_t oid_len, int critical, const unsigned char *val, size_t val_len)
Generic function to add to or replace an extension in the CRT.
#define OID_AUTHORITY_KEY_IDENTIFIER
id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 }
Definition: oid.h:116
void mpi_free(mpi *X)
Unallocate one MPI.
int x509_write_extensions(unsigned char **p, unsigned char *start, asn1_named_data *first)
asn1_named_data * issuer
Definition: x509_crt.h:114
#define OID_BASIC_CONSTRAINTS
id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 }
Definition: oid.h:124
X.509 certificate parsing and writing.
void x509write_crt_set_issuer_key(x509write_cert *ctx, pk_context *key)
Set the issuer key used for signing the certificate.
pk_type_t
Public key types.
Definition: pk.h:90
int x509write_crt_set_serial(x509write_cert *ctx, const mpi *serial)
Set the serial number for a Certificate.
int pk_write_pubkey_der(pk_context *key, unsigned char *buf, size_t size)
Write a public key to a SubjectPublicKeyInfo DER structure Note: data is written at the end of the bu...
#define ASN1_CONTEXT_SPECIFIC
Definition: asn1.h:89
int asn1_write_mpi(unsigned char **p, unsigned char *start, mpi *X)
Write a big number (ASN1_INTEGER) in ASN.1 format Note: function works backwards in data buffer...
int x509write_crt_set_authority_key_identifier(x509write_cert *ctx)
Set the authorityKeyIdentifier extension for a CRT Requires that x509write_crt_set_issuer_key() has b...
int x509write_crt_set_subject_name(x509write_cert *ctx, char *subject_name)
Set the subject name for a Certificate Subject names should contain a comma-separated list of OID typ...
int x509write_crt_set_ns_cert_type(x509write_cert *ctx, unsigned char ns_cert_type)
Set the Netscape Cert Type flags (e.g.
int asn1_write_bitstring(unsigned char **p, unsigned char *start, const unsigned char *buf, size_t bits)
Write a bitstring tag (ASN1_BIT_STRING) and value in ASN.1 format Note: function works backwards in d...
Container for writing a certificate (CRT)
Definition: x509_crt.h:107
int asn1_write_int(unsigned char **p, unsigned char *start, int val)
Write an int tag (ASN1_INTEGER) and value in ASN.1 format Note: function works backwards in data buff...
#define OID_SUBJECT_KEY_IDENTIFIER
id-ce-subjectKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 14 }
Definition: oid.h:117
void asn1_free_named_data_list(asn1_named_data **head)
Free all entries in a asn1_named_data list Head will be set to NULL.
#define ASN1_CHK_ADD(g, f)
Definition: asn1write.h:32
int asn1_write_algorithm_identifier(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, size_t par_len)
Write an AlgorithmIdentifier sequence in ASN.1 format Note: function works backwards in data buffer...
int pk_sign(pk_context *ctx, md_type_t md_alg, const unsigned char *hash, size_t hash_len, unsigned char *sig, size_t *sig_len, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
Make signature.
SHA-1 cryptographic hash function.
int x509write_crt_set_basic_constraints(x509write_cert *ctx, int is_ca, int max_pathlen)
Set the basicConstraints extension for a CRT.
int mpi_copy(mpi *X, const mpi *Y)
Copy the contents of Y into X.
md_type_t md_alg
Definition: x509_crt.h:115
pk_context * issuer_key
Definition: x509_crt.h:112
int asn1_write_bool(unsigned char **p, unsigned char *start, int boolean)
Write a boolean tag (ASN1_BOOLEAN) and value in ASN.1 format Note: function works backwards in data b...
int x509_write_sig(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len, unsigned char *sig, size_t size)
ASN.1 buffer writing functionality.
#define ASN1_OCTET_STRING
Definition: asn1.h:74
void x509write_crt_init(x509write_cert *ctx)
Initialize a CRT writing context.
#define POLARSSL_ERR_X509_BAD_INPUT_DATA
Input invalid.
Definition: x509.h:63
int asn1_write_tag(unsigned char **p, unsigned char *start, unsigned char tag)
Write a ASN.1 tag in ASN.1 format Note: function works backwards in data buffer.
void x509write_crt_set_subject_key(x509write_cert *ctx, pk_context *key)
Set the subject public key for the certificate.
#define OID_NS_CERT_TYPE
Definition: oid.h:136
int x509write_crt_pem(x509write_cert *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
Write a built up certificate to a X509 PEM string.
#define X509_RFC5280_UTC_TIME_LEN
Definition: x509_crt.h:102
Public key container.
Definition: pk.h:177
int x509_string_to_names(asn1_named_data **head, char *name)
int oid_get_oid_by_sig_alg(pk_type_t pk_alg, md_type_t md_alg, const char **oid, size_t *olen)
Translate md_type and pk_type into SignatureAlgorithm OID.
asn1_named_data * subject
Definition: x509_crt.h:113
#define OID_KEY_USAGE
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
Definition: oid.h:118