PolarSSL v1.3.3
x509write_crt.c
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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 
85  const char *subject_name )
86 {
87  return x509_string_to_names( &ctx->subject, subject_name );
88 }
89 
91  const char *issuer_name )
92 {
93  return x509_string_to_names( &ctx->issuer, issuer_name );
94 }
95 
96 int x509write_crt_set_serial( x509write_cert *ctx, const mpi *serial )
97 {
98  int ret;
99 
100  if( ( ret = mpi_copy( &ctx->serial, serial ) ) != 0 )
101  return( ret );
102 
103  return( 0 );
104 }
105 
106 int x509write_crt_set_validity( x509write_cert *ctx, const char *not_before,
107  const char *not_after )
108 {
109  if( strlen(not_before) != X509_RFC5280_UTC_TIME_LEN - 1 ||
110  strlen(not_after) != X509_RFC5280_UTC_TIME_LEN - 1 )
111  {
113  }
114  strncpy( ctx->not_before, not_before, X509_RFC5280_UTC_TIME_LEN );
115  strncpy( ctx->not_after , not_after , X509_RFC5280_UTC_TIME_LEN );
116  ctx->not_before[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
117  ctx->not_after[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
118 
119  return( 0 );
120 }
121 
123  const char *oid, size_t oid_len,
124  int critical,
125  const unsigned char *val, size_t val_len )
126 {
127  return x509_set_extension( &ctx->extensions, oid, oid_len,
128  critical, val, val_len );
129 }
130 
132  int is_ca, int max_pathlen )
133 {
134  int ret;
135  unsigned char buf[9];
136  unsigned char *c = buf + sizeof(buf);
137  size_t len = 0;
138 
139  memset( buf, 0, sizeof(buf) );
140 
141  if( is_ca && max_pathlen > 127 )
143 
144  if( is_ca )
145  {
146  if( max_pathlen >= 0 )
147  {
148  ASN1_CHK_ADD( len, asn1_write_int( &c, buf, max_pathlen ) );
149  }
150  ASN1_CHK_ADD( len, asn1_write_bool( &c, buf, 1 ) );
151  }
152 
153  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
155 
158  0, buf + sizeof(buf) - len, len );
159 }
160 
161 #if defined(POLARSSL_SHA1_C)
163 {
164  int ret;
165  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
166  unsigned char *c = buf + sizeof(buf);
167  size_t len = 0;
168 
169  memset( buf, 0, sizeof(buf));
170  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->subject_key ) );
171 
172  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
173  c = buf + sizeof(buf) - 20;
174  len = 20;
175 
176  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
177  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_OCTET_STRING ) );
178 
181  0, buf + sizeof(buf) - len, len );
182 }
183 
185 {
186  int ret;
187  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
188  unsigned char *c = buf + sizeof(buf);
189  size_t len = 0;
190 
191  memset( buf, 0, sizeof(buf));
192  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->issuer_key ) );
193 
194  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
195  c = buf + sizeof(buf) - 20;
196  len = 20;
197 
198  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
199  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONTEXT_SPECIFIC | 0 ) );
200 
201  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
203 
206  0, buf + sizeof(buf) - len, len );
207 }
208 #endif /* POLARSSL_SHA1_C */
209 
210 int x509write_crt_set_key_usage( x509write_cert *ctx, unsigned char key_usage )
211 {
212  unsigned char buf[4];
213  unsigned char *c;
214  int ret;
215 
216  c = buf + 4;
217 
218  if( ( ret = asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
219  return( ret );
220 
223  1, buf, 4 );
224  if( ret != 0 )
225  return( ret );
226 
227  return( 0 );
228 }
229 
231  unsigned char ns_cert_type )
232 {
233  unsigned char buf[4];
234  unsigned char *c;
235  int ret;
236 
237  c = buf + 4;
238 
239  if( ( ret = asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
240  return( ret );
241 
244  0, buf, 4 );
245  if( ret != 0 )
246  return( ret );
247 
248  return( 0 );
249 }
250 
251 static int x509_write_time( unsigned char **p, unsigned char *start,
252  const char *time, size_t size )
253 {
254  int ret;
255  size_t len = 0;
256 
257  /*
258  * write ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
259  */
260  if( time[0] == '2' && time[1] == '0' && time [2] < '5' )
261  {
262  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
263  (const unsigned char *) time + 2,
264  size - 2 ) );
265  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
266  ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_UTC_TIME ) );
267  }
268  else
269  {
270  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
271  (const unsigned char *) time,
272  size ) );
273  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
275  }
276 
277  return( (int) len );
278 }
279 
280 int x509write_crt_der( x509write_cert *ctx, unsigned char *buf, size_t size,
281  int (*f_rng)(void *, unsigned char *, size_t),
282  void *p_rng )
283 {
284  int ret;
285  const char *sig_oid;
286  size_t sig_oid_len = 0;
287  unsigned char *c, *c2;
288  unsigned char hash[64];
289  unsigned char sig[POLARSSL_MPI_MAX_SIZE];
290  unsigned char tmp_buf[2048];
291  size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
292  size_t len = 0;
293  pk_type_t pk_alg;
294 
295  /*
296  * Prepare data to be signed in tmp_buf
297  */
298  c = tmp_buf + sizeof( tmp_buf );
299 
300  /* Signature algorithm needed in TBS, and later for actual signature */
301  pk_alg = pk_get_type( ctx->issuer_key );
302  if( pk_alg == POLARSSL_PK_ECKEY )
303  pk_alg = POLARSSL_PK_ECDSA;
304 
305  if( ( ret = oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
306  &sig_oid, &sig_oid_len ) ) != 0 )
307  {
308  return( ret );
309  }
310 
311  /*
312  * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
313  */
314  ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
315  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
316  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
317  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
319 
320  /*
321  * SubjectPublicKeyInfo
322  */
324  tmp_buf, c - tmp_buf ) );
325  c -= pub_len;
326  len += pub_len;
327 
328  /*
329  * Subject ::= Name
330  */
331  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->subject ) );
332 
333  /*
334  * Validity ::= SEQUENCE {
335  * notBefore Time,
336  * notAfter Time }
337  */
338  sub_len = 0;
339 
340  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after,
342 
343  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before,
345 
346  len += sub_len;
347  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
348  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
349 
350  /*
351  * Issuer ::= Name
352  */
353  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->issuer ) );
354 
355  /*
356  * Signature ::= AlgorithmIdentifier
357  */
359  sig_oid, strlen( sig_oid ), 0 ) );
360 
361  /*
362  * Serial ::= INTEGER
363  */
364  ASN1_CHK_ADD( len, asn1_write_mpi( &c, tmp_buf, &ctx->serial ) );
365 
366  /*
367  * Version ::= INTEGER { v1(0), v2(1), v3(2) }
368  */
369  sub_len = 0;
370  ASN1_CHK_ADD( sub_len, asn1_write_int( &c, tmp_buf, ctx->version ) );
371  len += sub_len;
372  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
374 
375  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
376  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
377 
378  /*
379  * Make signature
380  */
381  md( md_info_from_type( ctx->md_alg ), c, len, hash );
382 
383  if( ( ret = pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len,
384  f_rng, p_rng ) ) != 0 )
385  {
386  return( ret );
387  }
388 
389  /*
390  * Write data to output buffer
391  */
392  c2 = buf + size;
393  ASN1_CHK_ADD( sig_and_oid_len, x509_write_sig( &c2, buf,
394  sig_oid, sig_oid_len, sig, sig_len ) );
395 
396  c2 -= len;
397  memcpy( c2, c, len );
398 
399  len += sig_and_oid_len;
400  ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
402 
403  return( (int) len );
404 }
405 
406 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
407 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
408 
409 #if defined(POLARSSL_PEM_WRITE_C)
410 int x509write_crt_pem( x509write_cert *crt, unsigned char *buf, size_t size,
411  int (*f_rng)(void *, unsigned char *, size_t),
412  void *p_rng )
413 {
414  int ret;
415  unsigned char output_buf[4096];
416  size_t olen = 0;
417 
418  if( ( ret = x509write_crt_der( crt, output_buf, sizeof(output_buf),
419  f_rng, p_rng ) ) < 0 )
420  {
421  return( ret );
422  }
423 
424  if( ( ret = pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
425  output_buf + sizeof(output_buf) - ret,
426  ret, buf, size, &olen ) ) != 0 )
427  {
428  return( ret );
429  }
430 
431  return( 0 );
432 }
433 #endif /* POLARSSL_PEM_WRITE_C */
434 
435 #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)
int x509_string_to_names(asn1_named_data **head, const char *name)
#define ASN1_UTC_TIME
Definition: asn1.h:83
int x509write_crt_set_validity(x509write_cert *ctx, const char *not_before, const char *not_after)
Set the validity period for a Certificate Timestamps should be in string format for UTC timezone i...
#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
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:177
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 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 pk_write_pubkey_der(pk_context *ctx, 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...
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.
int x509write_crt_set_issuer_name(x509write_cert *ctx, const char *issuer_name)
Set the issuer name for a Certificate Issuer names should contain a comma-separated list of OID types...
#define OID_AUTHORITY_KEY_IDENTIFIER
id-ce-authorityKeyIdentifier OBJECT IDENTIFIER ::= { id-ce 35 }
Definition: oid.h:119
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:127
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.
#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_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:120
int x509write_crt_set_subject_name(x509write_cert *ctx, const char *subject_name)
Set the subject name for a Certificate Subject names should contain a comma-separated list of OID typ...
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:139
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 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:121