PolarSSL v1.3.1
x509write_csr.c
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1 /*
2  * X.509 Certificate Signing Request 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  * - CSRs: PKCS#10 v1.7 aka RFC 2986
28  * - attributes: PKCS#9 v2.0 aka RFC 2985
29  */
30 
31 #include "polarssl/config.h"
32 
33 #if defined(POLARSSL_X509_CSR_WRITE_C)
34 
35 #include "polarssl/x509_csr.h"
36 #include "polarssl/oid.h"
37 #include "polarssl/asn1write.h"
38 
39 #if defined(POLARSSL_PEM_WRITE_C)
40 #include "polarssl/pem.h"
41 #endif
42 
43 #include <string.h>
44 #include <stdlib.h>
45 
47 {
48  memset( ctx, 0, sizeof(x509write_csr) );
49 }
50 
52 {
55 
56  memset( ctx, 0, sizeof(x509write_csr) );
57 }
58 
60 {
61  ctx->md_alg = md_alg;
62 }
63 
65 {
66  ctx->key = key;
67 }
68 
69 int x509write_csr_set_subject_name( x509write_csr *ctx, char *subject_name )
70 {
71  return x509_string_to_names( &ctx->subject, subject_name );
72 }
73 
75  const char *oid, size_t oid_len,
76  const unsigned char *val, size_t val_len )
77 {
78  return x509_set_extension( &ctx->extensions, oid, oid_len,
79  0, val, val_len );
80 }
81 
82 int x509write_csr_set_key_usage( x509write_csr *ctx, unsigned char key_usage )
83 {
84  unsigned char buf[4];
85  unsigned char *c;
86  int ret;
87 
88  c = buf + 4;
89 
90  if( ( ret = asn1_write_bitstring( &c, buf, &key_usage, 7 ) ) != 4 )
91  return( ret );
92 
95  buf, 4 );
96  if( ret != 0 )
97  return( ret );
98 
99  return( 0 );
100 }
101 
103  unsigned char ns_cert_type )
104 {
105  unsigned char buf[4];
106  unsigned char *c;
107  int ret;
108 
109  c = buf + 4;
110 
111  if( ( ret = asn1_write_bitstring( &c, buf, &ns_cert_type, 8 ) ) != 4 )
112  return( ret );
113 
116  buf, 4 );
117  if( ret != 0 )
118  return( ret );
119 
120  return( 0 );
121 }
122 
123 int x509write_csr_der( x509write_csr *ctx, unsigned char *buf, size_t size,
124  int (*f_rng)(void *, unsigned char *, size_t),
125  void *p_rng )
126 {
127  int ret;
128  const char *sig_oid;
129  size_t sig_oid_len = 0;
130  unsigned char *c, *c2;
131  unsigned char hash[64];
132  unsigned char sig[POLARSSL_MPI_MAX_SIZE];
133  unsigned char tmp_buf[2048];
134  size_t pub_len = 0, sig_and_oid_len = 0, sig_len;
135  size_t len = 0;
136  pk_type_t pk_alg;
137 
138  /*
139  * Prepare data to be signed in tmp_buf
140  */
141  c = tmp_buf + sizeof( tmp_buf );
142 
143  ASN1_CHK_ADD( len, x509_write_extensions( &c, tmp_buf, ctx->extensions ) );
144 
145  if( len )
146  {
147  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
148  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
149 
150  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
151  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SET ) );
152 
155 
156  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
157  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
158  }
159 
160  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
162 
163  ASN1_CHK_ADD( pub_len, pk_write_pubkey_der( ctx->key,
164  tmp_buf, c - tmp_buf ) );
165  c -= pub_len;
166  len += pub_len;
167 
168  /*
169  * Subject ::= Name
170  */
171  ASN1_CHK_ADD( len, x509_write_names( &c, tmp_buf, ctx->subject ) );
172 
173  /*
174  * Version ::= INTEGER { v1(0), v2(1), v3(2) }
175  */
176  ASN1_CHK_ADD( len, asn1_write_int( &c, tmp_buf, 0 ) );
177 
178  ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
179  ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
180 
181  /*
182  * Prepare signature
183  */
184  md( md_info_from_type( ctx->md_alg ), c, len, hash );
185 
186  pk_alg = pk_get_type( ctx->key );
187  if( pk_alg == POLARSSL_PK_ECKEY )
188  pk_alg = POLARSSL_PK_ECDSA;
189 
190  if( ( ret = pk_sign( ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
191  f_rng, p_rng ) ) != 0 ||
192  ( ret = oid_get_oid_by_sig_alg( pk_alg, ctx->md_alg,
193  &sig_oid, &sig_oid_len ) ) != 0 )
194  {
195  return( ret );
196  }
197 
198  /*
199  * Write data to output buffer
200  */
201  c2 = buf + size;
202  ASN1_CHK_ADD( sig_and_oid_len, x509_write_sig( &c2, buf,
203  sig_oid, sig_oid_len, sig, sig_len ) );
204 
205  c2 -= len;
206  memcpy( c2, c, len );
207 
208  len += sig_and_oid_len;
209  ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
211 
212  return( (int) len );
213 }
214 
215 #define PEM_BEGIN_CSR "-----BEGIN CERTIFICATE REQUEST-----\n"
216 #define PEM_END_CSR "-----END CERTIFICATE REQUEST-----\n"
217 
218 #if defined(POLARSSL_PEM_WRITE_C)
219 int x509write_csr_pem( x509write_csr *ctx, unsigned char *buf, size_t size,
220  int (*f_rng)(void *, unsigned char *, size_t),
221  void *p_rng )
222 {
223  int ret;
224  unsigned char output_buf[4096];
225  size_t olen = 0;
226 
227  if( ( ret = x509write_csr_der( ctx, output_buf, sizeof(output_buf),
228  f_rng, p_rng ) ) < 0 )
229  {
230  return( ret );
231  }
232 
233  if( ( ret = pem_write_buffer( PEM_BEGIN_CSR, PEM_END_CSR,
234  output_buf + sizeof(output_buf) - ret,
235  ret, buf, size, &olen ) ) != 0 )
236  {
237  return( ret );
238  }
239 
240  return( 0 );
241 }
242 #endif /* POLARSSL_PEM_WRITE_C */
243 
244 #endif /* POLARSSL_X509_CSR_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_csr_free(x509write_csr *ctx)
Free the contents of a CSR context.
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 POLARSSL_MPI_MAX_SIZE
Maximum number of bytes for usable MPIs.
Definition: bignum.h:87
int x509write_csr_der(x509write_csr *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
Write a CSR (Certificate Signing Request) to a DER structure Note: data is written at the end of the ...
int x509write_csr_set_extension(x509write_csr *ctx, const char *oid, size_t oid_len, const unsigned char *val, size_t val_len)
Generic function to add to or replace an extension in the CSR.
void x509write_csr_set_md_alg(x509write_csr *ctx, md_type_t md_alg)
Set the MD algorithm to use for the signature (e.g.
int x509write_csr_set_ns_cert_type(x509write_csr *ctx, unsigned char ns_cert_type)
Set the Netscape Cert Type flags (e.g.
#define ASN1_SEQUENCE
Definition: asn1.h:78
Configuration options (set of defines)
int x509write_csr_pem(x509write_csr *ctx, unsigned char *buf, size_t size, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng)
Write a CSR (Certificate Signing Request) to a PEM string.
#define ASN1_CONSTRUCTED
Definition: asn1.h:88
pk_type_t pk_get_type(const pk_context *ctx)
Get the key type.
#define OID_PKCS9_CSR_EXT_REQ
extensionRequest OBJECT IDENTIFIER ::= {pkcs-9 14}
Definition: oid.h:235
int x509write_csr_set_key_usage(x509write_csr *ctx, unsigned char key_usage)
Set the Key Usage Extension flags (e.g.
md_type_t md_alg
Definition: x509_csr.h:76
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.
#define ASN1_SET
Definition: asn1.h:79
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.
Privacy Enhanced Mail (PEM) decoding.
asn1_named_data * subject
Definition: x509_csr.h:75
X.509 certificate signing request parsing and writing.
int x509_write_extensions(unsigned char **p, unsigned char *start, asn1_named_data *first)
void x509write_csr_init(x509write_csr *ctx)
Initialize a CSR context.
pk_type_t
Public key types.
Definition: pk.h:90
pk_context * key
Definition: x509_csr.h:74
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
void x509write_csr_set_key(x509write_csr *ctx, pk_context *key)
Set the key for a CSR (public key will be included, private key used to sign the CSR when writing it)...
int x509write_csr_set_subject_name(x509write_csr *ctx, char *subject_name)
Set the subject name for a CSR Subject names should contain a comma-separated list of OID types and v...
asn1_named_data * extensions
Definition: x509_csr.h:77
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...
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...
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 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.
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.
int asn1_write_oid(unsigned char **p, unsigned char *start, const char *oid, size_t oid_len)
Write an OID tag (ASN1_OID) and data in ASN.1 format Note: function works backwards in data buffer...
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.
#define OID_NS_CERT_TYPE
Definition: oid.h:136
Public key container.
Definition: pk.h:177
int x509_string_to_names(asn1_named_data **head, char *name)
Container for writing a CSR.
Definition: x509_csr.h:72
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.
#define OID_KEY_USAGE
id-ce-keyUsage OBJECT IDENTIFIER ::= { id-ce 15 }
Definition: oid.h:118