PolarSSL v1.3.9
x509write_crt.c
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1 /*
2  * X.509 certificate writing
3  *
4  * Copyright (C) 2006-2014, 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 #if !defined(POLARSSL_CONFIG_FILE)
33 #include "polarssl/config.h"
34 #else
35 #include POLARSSL_CONFIG_FILE
36 #endif
37 
38 #if defined(POLARSSL_X509_CRT_WRITE_C)
39 
40 #include "polarssl/x509_crt.h"
41 #include "polarssl/oid.h"
42 #include "polarssl/asn1write.h"
43 #include "polarssl/sha1.h"
44 
45 #if defined(POLARSSL_PEM_WRITE_C)
46 #include "polarssl/pem.h"
47 #endif /* POLARSSL_PEM_WRITE_C */
48 
49 /* Implementation that should never be optimized out by the compiler */
50 static void polarssl_zeroize( void *v, size_t n ) {
51  volatile unsigned char *p = v; while( n-- ) *p++ = 0;
52 }
53 
55 {
56  memset( ctx, 0, sizeof(x509write_cert) );
57 
58  mpi_init( &ctx->serial );
60 }
61 
63 {
64  mpi_free( &ctx->serial );
65 
69 
70  polarssl_zeroize( ctx, sizeof(x509write_cert) );
71 }
72 
73 void x509write_crt_set_version( x509write_cert *ctx, int version )
74 {
75  ctx->version = version;
76 }
77 
79 {
80  ctx->md_alg = md_alg;
81 }
82 
84 {
85  ctx->subject_key = key;
86 }
87 
89 {
90  ctx->issuer_key = key;
91 }
92 
94  const char *subject_name )
95 {
96  return x509_string_to_names( &ctx->subject, subject_name );
97 }
98 
100  const char *issuer_name )
101 {
102  return x509_string_to_names( &ctx->issuer, issuer_name );
103 }
104 
105 int x509write_crt_set_serial( x509write_cert *ctx, const mpi *serial )
106 {
107  int ret;
108 
109  if( ( ret = mpi_copy( &ctx->serial, serial ) ) != 0 )
110  return( ret );
111 
112  return( 0 );
113 }
114 
115 int x509write_crt_set_validity( x509write_cert *ctx, const char *not_before,
116  const char *not_after )
117 {
118  if( strlen( not_before ) != X509_RFC5280_UTC_TIME_LEN - 1 ||
119  strlen( not_after ) != X509_RFC5280_UTC_TIME_LEN - 1 )
120  {
122  }
123  strncpy( ctx->not_before, not_before, X509_RFC5280_UTC_TIME_LEN );
124  strncpy( ctx->not_after , not_after , X509_RFC5280_UTC_TIME_LEN );
125  ctx->not_before[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
126  ctx->not_after[X509_RFC5280_UTC_TIME_LEN - 1] = 'Z';
127 
128  return( 0 );
129 }
130 
132  const char *oid, size_t oid_len,
133  int critical,
134  const unsigned char *val, size_t val_len )
135 {
136  return x509_set_extension( &ctx->extensions, oid, oid_len,
137  critical, val, val_len );
138 }
139 
141  int is_ca, int max_pathlen )
142 {
143  int ret;
144  unsigned char buf[9];
145  unsigned char *c = buf + sizeof(buf);
146  size_t len = 0;
147 
148  memset( buf, 0, sizeof(buf) );
149 
150  if( is_ca && max_pathlen > 127 )
152 
153  if( is_ca )
154  {
155  if( max_pathlen >= 0 )
156  {
157  ASN1_CHK_ADD( len, asn1_write_int( &c, buf, max_pathlen ) );
158  }
159  ASN1_CHK_ADD( len, asn1_write_bool( &c, buf, 1 ) );
160  }
161 
162  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
164  ASN1_SEQUENCE ) );
165 
168  0, buf + sizeof(buf) - len, len );
169 }
170 
171 #if defined(POLARSSL_SHA1_C)
173 {
174  int ret;
175  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
176  unsigned char *c = buf + sizeof(buf);
177  size_t len = 0;
178 
179  memset( buf, 0, sizeof(buf) );
180  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->subject_key ) );
181 
182  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
183  c = buf + sizeof(buf) - 20;
184  len = 20;
185 
186  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
187  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_OCTET_STRING ) );
188 
191  0, buf + sizeof(buf) - len, len );
192 }
193 
195 {
196  int ret;
197  unsigned char buf[POLARSSL_MPI_MAX_SIZE * 2 + 20]; /* tag, length + 2xMPI */
198  unsigned char *c = buf + sizeof(buf);
199  size_t len = 0;
200 
201  memset( buf, 0, sizeof(buf) );
202  ASN1_CHK_ADD( len, pk_write_pubkey( &c, buf, ctx->issuer_key ) );
203 
204  sha1( buf + sizeof(buf) - len, len, buf + sizeof(buf) - 20 );
205  c = buf + sizeof(buf) - 20;
206  len = 20;
207 
208  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
209  ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONTEXT_SPECIFIC | 0 ) );
210 
211  ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
213  ASN1_SEQUENCE ) );
214 
217  0, buf + sizeof(buf) - len, len );
218 }
219 #endif /* POLARSSL_SHA1_C */
220 
221 int x509write_crt_set_key_usage( x509write_cert *ctx, unsigned char key_usage )
222 {
223  unsigned char buf[4];
224  unsigned char *c;
225  int ret;
226 
227  c = buf + 4;
228 
229  if( ( ret = asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
230  return( ret );
231 
234  1, buf, 4 );
235  if( ret != 0 )
236  return( ret );
237 
238  return( 0 );
239 }
240 
242  unsigned char ns_cert_type )
243 {
244  unsigned char buf[4];
245  unsigned char *c;
246  int ret;
247 
248  c = buf + 4;
249 
250  if( ( ret = asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
251  return( ret );
252 
255  0, buf, 4 );
256  if( ret != 0 )
257  return( ret );
258 
259  return( 0 );
260 }
261 
262 static int x509_write_time( unsigned char **p, unsigned char *start,
263  const char *time, size_t size )
264 {
265  int ret;
266  size_t len = 0;
267 
268  /*
269  * write ASN1_UTC_TIME if year < 2050 (2 bytes shorter)
270  */
271  if( time[0] == '2' && time[1] == '0' && time [2] < '5' )
272  {
273  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
274  (const unsigned char *) time + 2,
275  size - 2 ) );
276  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
277  ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_UTC_TIME ) );
278  }
279  else
280  {
281  ASN1_CHK_ADD( len, asn1_write_raw_buffer( p, start,
282  (const unsigned char *) time,
283  size ) );
284  ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
286  }
287 
288  return( (int) len );
289 }
290 
291 int x509write_crt_der( x509write_cert *ctx, unsigned char *buf, size_t size,
292  int (*f_rng)(void *, unsigned char *, size_t),
293  void *p_rng )
294 {
295  int ret;
296  const char *sig_oid;
297  size_t sig_oid_len = 0;
298  unsigned char *c, *c2;
299  unsigned char hash[64];
300  unsigned char sig[POLARSSL_MPI_MAX_SIZE];
301  unsigned char tmp_buf[2048];
302  size_t sub_len = 0, pub_len = 0, sig_and_oid_len = 0, sig_len;
303  size_t len = 0;
304  pk_type_t pk_alg;
305 
306  /*
307  * Prepare data to be signed in tmp_buf
308  */
309  c = tmp_buf + sizeof( tmp_buf );
310 
311  /* Signature algorithm needed in TBS, and later for actual signature */
312  pk_alg = pk_get_type( ctx->issuer_key );
313  if( pk_alg == POLARSSL_PK_ECKEY )
314  pk_alg = POLARSSL_PK_ECDSA;
315 
316  if( ( ret = oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
317  &sig_oid, &sig_oid_len ) ) != 0 )
318  {
319  return( ret );
320  }
321 
322  /*
323  * Extensions ::= SEQUENCE SIZE (1..MAX) OF Extension
324  */
325  ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
326  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
327  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
328  ASN1_SEQUENCE ) );
329  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
331  ASN1_CONSTRUCTED | 3 ) );
332 
333  /*
334  * SubjectPublicKeyInfo
335  */
337  tmp_buf, c - tmp_buf ) );
338  c -= pub_len;
339  len += pub_len;
340 
341  /*
342  * Subject ::= Name
343  */
344  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->subject ) );
345 
346  /*
347  * Validity ::= SEQUENCE {
348  * notBefore Time,
349  * notAfter Time }
350  */
351  sub_len = 0;
352 
353  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_after,
355 
356  ASN1_CHK_ADD( sub_len, x509_write_time( &c, tmp_buf, ctx->not_before,
358 
359  len += sub_len;
360  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
361  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
362  ASN1_SEQUENCE ) );
363 
364  /*
365  * Issuer ::= Name
366  */
367  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->issuer ) );
368 
369  /*
370  * Signature ::= AlgorithmIdentifier
371  */
373  sig_oid, strlen( sig_oid ), 0 ) );
374 
375  /*
376  * Serial ::= INTEGER
377  */
378  ASN1_CHK_ADD( len, asn1_write_mpi( &c, tmp_buf, &ctx->serial ) );
379 
380  /*
381  * Version ::= INTEGER { v1(0), v2(1), v3(2) }
382  */
383  sub_len = 0;
384  ASN1_CHK_ADD( sub_len, asn1_write_int( &c, tmp_buf, ctx->version ) );
385  len += sub_len;
386  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
388  ASN1_CONSTRUCTED | 0 ) );
389 
390  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
391  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED |
392  ASN1_SEQUENCE ) );
393 
394  /*
395  * Make signature
396  */
397  md( md_info_from_type( ctx->md_alg ), c, len, hash );
398 
399  if( ( ret = pk_sign( ctx->issuer_key, ctx->md_alg, hash, 0, sig, &sig_len,
400  f_rng, p_rng ) ) != 0 )
401  {
402  return( ret );
403  }
404 
405  /*
406  * Write data to output buffer
407  */
408  c2 = buf + size;
409  ASN1_CHK_ADD( sig_and_oid_len, x509_write_sig( &c2, buf,
410  sig_oid, sig_oid_len, sig, sig_len ) );
411 
412  c2 -= len;
413  memcpy( c2, c, len );
414 
415  len += sig_and_oid_len;
416  ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
417  ASN1_CHK_ADD( len, asn1_write_tag( &c2, buf, ASN1_CONSTRUCTED |
418  ASN1_SEQUENCE ) );
419 
420  return( (int) len );
421 }
422 
423 #define PEM_BEGIN_CRT "-----BEGIN CERTIFICATE-----\n"
424 #define PEM_END_CRT "-----END CERTIFICATE-----\n"
425 
426 #if defined(POLARSSL_PEM_WRITE_C)
427 int x509write_crt_pem( x509write_cert *crt, unsigned char *buf, size_t size,
428  int (*f_rng)(void *, unsigned char *, size_t),
429  void *p_rng )
430 {
431  int ret;
432  unsigned char output_buf[4096];
433  size_t olen = 0;
434 
435  if( ( ret = x509write_crt_der( crt, output_buf, sizeof(output_buf),
436  f_rng, p_rng ) ) < 0 )
437  {
438  return( ret );
439  }
440 
441  if( ( ret = pem_write_buffer( PEM_BEGIN_CRT, PEM_END_CRT,
442  output_buf + sizeof(output_buf) - ret,
443  ret, buf, size, &olen ) ) != 0 )
444  {
445  return( ret );
446  }
447 
448  return( 0 );
449 }
450 #endif /* POLARSSL_PEM_WRITE_C */
451 
452 #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:87
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:88
char not_after[X509_RFC5280_UTC_TIME_LEN+1]
Definition: x509_crt.h:122
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:123
#define ASN1_SEQUENCE
Definition: asn1.h:82
Configuration options (set of defines)
#define ASN1_CONSTRUCTED
Definition: asn1.h:92
pk_context * subject_key
Definition: x509_crt.h:116
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:182
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:98
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.
#define POLARSSL_MPI_MAX_SIZE
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:104
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:121
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:133
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:119
#define OID_BASIC_CONSTRAINTS
id-ce-basicConstraints OBJECT IDENTIFIER ::= { id-ce 19 }
Definition: oid.h:141
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:95
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:93
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:112
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:134
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, including padding if relevant.
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:120
pk_context * issuer_key
Definition: x509_crt.h:117
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:78
void x509write_crt_init(x509write_cert *ctx)
Initialize a CRT writing context.
#define POLARSSL_ERR_X509_BAD_INPUT_DATA
Input invalid.
Definition: x509.h:67
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:153
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:107
Public key container.
Definition: pk.h:194
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:118
#define OID_KEY_USAGE
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
Definition: oid.h:135