PolarSSL v1.3.8
oid.c
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1 
28 #if !defined(POLARSSL_CONFIG_FILE)
29 #include "polarssl/config.h"
30 #else
31 #include POLARSSL_CONFIG_FILE
32 #endif
33 
34 #if defined(POLARSSL_OID_C)
35 
36 #include "polarssl/oid.h"
37 #include "polarssl/rsa.h"
38 
39 #if defined(POLARSSL_X509_USE_C) || defined(POLARSSL_X509_CREATE_C)
40 #include "polarssl/x509.h"
41 #endif
42 
43 #include <stdio.h>
44 
45 /*
46  * Macro to automatically add the size of #define'd OIDs
47  */
48 #define ADD_LEN(s) s, OID_SIZE(s)
49 
50 /*
51  * Macro to generate an internal function for oid_XXX_from_asn1() (used by
52  * the other functions)
53  */
54 #define FN_OID_TYPED_FROM_ASN1( TYPE_T, NAME, LIST ) \
55 static const TYPE_T * oid_ ## NAME ## _from_asn1( const asn1_buf *oid ) \
56 { \
57  const TYPE_T *p = LIST; \
58  const oid_descriptor_t *cur = (const oid_descriptor_t *) p; \
59  if( p == NULL || oid == NULL ) return( NULL ); \
60  while( cur->asn1 != NULL ) { \
61  if( cur->asn1_len == oid->len && \
62  memcmp( cur->asn1, oid->p, oid->len ) == 0 ) { \
63  return( p ); \
64  } \
65  p++; \
66  cur = (const oid_descriptor_t *) p; \
67  } \
68  return( NULL ); \
69 }
70 
71 /*
72  * Macro to generate a function for retrieving a single attribute from the
73  * descriptor of an oid_descriptor_t wrapper.
74  */
75 #define FN_OID_GET_DESCRIPTOR_ATTR1(FN_NAME, TYPE_T, TYPE_NAME, ATTR1_TYPE, ATTR1) \
76 int FN_NAME( const asn1_buf *oid, ATTR1_TYPE * ATTR1 ) \
77 { \
78  const TYPE_T *data = oid_ ## TYPE_NAME ## _from_asn1( oid ); \
79  if( data == NULL ) return( POLARSSL_ERR_OID_NOT_FOUND ); \
80  *ATTR1 = data->descriptor.ATTR1; \
81  return( 0 ); \
82 }
83 
84 /*
85  * Macro to generate a function for retrieving a single attribute from an
86  * oid_descriptor_t wrapper.
87  */
88 #define FN_OID_GET_ATTR1(FN_NAME, TYPE_T, TYPE_NAME, ATTR1_TYPE, ATTR1) \
89 int FN_NAME( const asn1_buf *oid, ATTR1_TYPE * ATTR1 ) \
90 { \
91  const TYPE_T *data = oid_ ## TYPE_NAME ## _from_asn1( oid ); \
92  if( data == NULL ) return( POLARSSL_ERR_OID_NOT_FOUND ); \
93  *ATTR1 = data->ATTR1; \
94  return( 0 ); \
95 }
96 
97 /*
98  * Macro to generate a function for retrieving two attributes from an
99  * oid_descriptor_t wrapper.
100  */
101 #define FN_OID_GET_ATTR2(FN_NAME, TYPE_T, TYPE_NAME, ATTR1_TYPE, ATTR1, \
102  ATTR2_TYPE, ATTR2) \
103 int FN_NAME( const asn1_buf *oid, ATTR1_TYPE * ATTR1, ATTR2_TYPE * ATTR2 ) \
104 { \
105  const TYPE_T *data = oid_ ## TYPE_NAME ## _from_asn1( oid ); \
106  if( data == NULL ) return( POLARSSL_ERR_OID_NOT_FOUND ); \
107  *ATTR1 = data->ATTR1; \
108  *ATTR2 = data->ATTR2; \
109  return( 0 ); \
110 }
111 
112 /*
113  * Macro to generate a function for retrieving the OID based on a single
114  * attribute from a oid_descriptor_t wrapper.
115  */
116 #define FN_OID_GET_OID_BY_ATTR1(FN_NAME, TYPE_T, LIST, ATTR1_TYPE, ATTR1) \
117 int FN_NAME( ATTR1_TYPE ATTR1, const char **oid, size_t *olen ) \
118 { \
119  const TYPE_T *cur = LIST; \
120  while( cur->descriptor.asn1 != NULL ) { \
121  if( cur->ATTR1 == ATTR1 ) { \
122  *oid = cur->descriptor.asn1; \
123  *olen = cur->descriptor.asn1_len; \
124  return( 0 ); \
125  } \
126  cur++; \
127  } \
128  return( POLARSSL_ERR_OID_NOT_FOUND ); \
129 }
130 
131 /*
132  * Macro to generate a function for retrieving the OID based on two
133  * attributes from a oid_descriptor_t wrapper.
134  */
135 #define FN_OID_GET_OID_BY_ATTR2(FN_NAME, TYPE_T, LIST, ATTR1_TYPE, ATTR1, \
136  ATTR2_TYPE, ATTR2) \
137 int FN_NAME( ATTR1_TYPE ATTR1, ATTR2_TYPE ATTR2, const char **oid , \
138  size_t *olen ) \
139 { \
140  const TYPE_T *cur = LIST; \
141  while( cur->descriptor.asn1 != NULL ) { \
142  if( cur->ATTR1 == ATTR1 && cur->ATTR2 == ATTR2 ) { \
143  *oid = cur->descriptor.asn1; \
144  *olen = cur->descriptor.asn1_len; \
145  return( 0 ); \
146  } \
147  cur++; \
148  } \
149  return( POLARSSL_ERR_OID_NOT_FOUND ); \
150 }
151 
152 /*
153  * For X520 attribute types
154  */
155 typedef struct {
156  oid_descriptor_t descriptor;
157  const char *short_name;
158 } oid_x520_attr_t;
159 
160 static const oid_x520_attr_t oid_x520_attr_type[] =
161 {
162  {
163  { ADD_LEN( OID_AT_CN ), "id-at-commonName", "Common Name" },
164  "CN",
165  },
166  {
167  { ADD_LEN( OID_AT_COUNTRY ), "id-at-countryName", "Country" },
168  "C",
169  },
170  {
171  { ADD_LEN( OID_AT_LOCALITY ), "id-at-locality", "Locality" },
172  "L",
173  },
174  {
175  { ADD_LEN( OID_AT_STATE ), "id-at-state", "State" },
176  "ST",
177  },
178  {
179  { ADD_LEN( OID_AT_ORGANIZATION ),"id-at-organizationName", "Organization" },
180  "O",
181  },
182  {
183  { ADD_LEN( OID_AT_ORG_UNIT ), "id-at-organizationalUnitName", "Org Unit" },
184  "OU",
185  },
186  {
187  { ADD_LEN( OID_PKCS9_EMAIL ), "emailAddress", "E-mail address" },
188  "emailAddress",
189  },
190  {
191  { ADD_LEN( OID_AT_SERIAL_NUMBER ),"id-at-serialNumber", "Serial number" },
192  "serialNumber",
193  },
194  {
195  { ADD_LEN( OID_AT_POSTAL_ADDRESS ),"id-at-postalAddress", "Postal address" },
196  "postalAddress",
197  },
198  {
199  { ADD_LEN( OID_AT_POSTAL_CODE ), "id-at-postalCode", "Postal code" },
200  "postalCode",
201  },
202  {
203  { ADD_LEN( OID_AT_SUR_NAME ), "id-at-surName", "Surname" },
204  "SN",
205  },
206  {
207  { ADD_LEN( OID_AT_GIVEN_NAME ), "id-at-givenName", "Given name" },
208  "GN",
209  },
210  {
211  { ADD_LEN( OID_AT_INITIALS ), "id-at-initials", "Initials" },
212  "initials",
213  },
214  {
215  { ADD_LEN( OID_AT_GENERATION_QUALIFIER ), "id-at-generationQualifier", "Generation qualifier" },
216  "generationQualifier",
217  },
218  {
219  { ADD_LEN( OID_AT_TITLE ), "id-at-title", "Title" },
220  "title",
221  },
222  {
223  { ADD_LEN( OID_AT_DN_QUALIFIER ),"id-at-dnQualifier", "Distinguished Name qualifier" },
224  "dnQualifier",
225  },
226  {
227  { ADD_LEN( OID_AT_PSEUDONYM ), "id-at-pseudonym", "Pseudonym" },
228  "pseudonym",
229  },
230  {
231  { ADD_LEN( OID_DOMAIN_COMPONENT ), "id-domainComponent", "Domain component" },
232  "DC",
233  },
234  {
235  { NULL, 0, NULL, NULL },
236  NULL,
237  }
238 };
239 
240 FN_OID_TYPED_FROM_ASN1(oid_x520_attr_t, x520_attr, oid_x520_attr_type);
241 FN_OID_GET_ATTR1(oid_get_attr_short_name, oid_x520_attr_t, x520_attr, const char *, short_name);
242 
243 #if defined(POLARSSL_X509_USE_C) || defined(POLARSSL_X509_CREATE_C)
244 /*
245  * For X509 extensions
246  */
247 typedef struct {
248  oid_descriptor_t descriptor;
249  int ext_type;
250 } oid_x509_ext_t;
251 
252 static const oid_x509_ext_t oid_x509_ext[] =
253 {
254  {
255  { ADD_LEN( OID_BASIC_CONSTRAINTS ), "id-ce-basicConstraints", "Basic Constraints" },
257  },
258  {
259  { ADD_LEN( OID_KEY_USAGE ), "id-ce-keyUsage", "Key Usage" },
261  },
262  {
263  { ADD_LEN( OID_EXTENDED_KEY_USAGE ), "id-ce-keyUsage", "Extended Key Usage" },
265  },
266  {
267  { ADD_LEN( OID_SUBJECT_ALT_NAME ), "id-ce-subjectAltName", "Subject Alt Name" },
269  },
270  {
271  { ADD_LEN( OID_NS_CERT_TYPE ), "id-netscape-certtype", "Netscape Certificate Type" },
273  },
274  {
275  { NULL, 0, NULL, NULL },
276  0,
277  },
278 };
279 
280 FN_OID_TYPED_FROM_ASN1(oid_x509_ext_t, x509_ext, oid_x509_ext);
281 FN_OID_GET_ATTR1(oid_get_x509_ext_type, oid_x509_ext_t, x509_ext, int, ext_type);
282 
283 static const oid_descriptor_t oid_ext_key_usage[] =
284 {
285  { ADD_LEN( OID_SERVER_AUTH ), "id-kp-serverAuth", "TLS Web Server Authentication" },
286  { ADD_LEN( OID_CLIENT_AUTH ), "id-kp-clientAuth", "TLS Web Client Authentication" },
287  { ADD_LEN( OID_CODE_SIGNING ), "id-kp-codeSigning", "Code Signing" },
288  { ADD_LEN( OID_EMAIL_PROTECTION ), "id-kp-emailProtection", "E-mail Protection" },
289  { ADD_LEN( OID_TIME_STAMPING ), "id-kp-timeStamping", "Time Stamping" },
290  { ADD_LEN( OID_OCSP_SIGNING ), "id-kp-OCSPSigning", "OCSP Signing" },
291  { NULL, 0, NULL, NULL },
292 };
293 
294 FN_OID_TYPED_FROM_ASN1(oid_descriptor_t, ext_key_usage, oid_ext_key_usage);
295 FN_OID_GET_ATTR1(oid_get_extended_key_usage, oid_descriptor_t, ext_key_usage, const char *, description);
296 #endif /* POLARSSL_X509_USE_C || POLARSSL_X509_CREATE_C */
297 
298 #if defined(POLARSSL_MD_C)
299 /*
300  * For SignatureAlgorithmIdentifier
301  */
302 typedef struct {
303  oid_descriptor_t descriptor;
304  md_type_t md_alg;
305  pk_type_t pk_alg;
306 } oid_sig_alg_t;
307 
308 static const oid_sig_alg_t oid_sig_alg[] =
309 {
310  {
311  { ADD_LEN( OID_PKCS1_MD2 ), "md2WithRSAEncryption", "RSA with MD2" },
313  },
314  {
315  { ADD_LEN( OID_PKCS1_MD4 ), "md4WithRSAEncryption", "RSA with MD4" },
317  },
318  {
319  { ADD_LEN( OID_PKCS1_MD5 ), "md5WithRSAEncryption", "RSA with MD5" },
321  },
322  {
323  { ADD_LEN( OID_PKCS1_SHA1 ), "sha-1WithRSAEncryption", "RSA with SHA1" },
325  },
326  {
327  { ADD_LEN( OID_PKCS1_SHA224 ), "sha224WithRSAEncryption", "RSA with SHA-224" },
329  },
330  {
331  { ADD_LEN( OID_PKCS1_SHA256 ), "sha256WithRSAEncryption", "RSA with SHA-256" },
333  },
334  {
335  { ADD_LEN( OID_PKCS1_SHA384 ), "sha384WithRSAEncryption", "RSA with SHA-384" },
337  },
338  {
339  { ADD_LEN( OID_PKCS1_SHA512 ), "sha512WithRSAEncryption", "RSA with SHA-512" },
341  },
342  {
343  { ADD_LEN( OID_RSA_SHA_OBS ), "sha-1WithRSAEncryption", "RSA with SHA1" },
345  },
346  {
347  { ADD_LEN( OID_ECDSA_SHA1 ), "ecdsa-with-SHA1", "ECDSA with SHA1" },
349  },
350  {
351  { ADD_LEN( OID_ECDSA_SHA224 ), "ecdsa-with-SHA224", "ECDSA with SHA224" },
353  },
354  {
355  { ADD_LEN( OID_ECDSA_SHA256 ), "ecdsa-with-SHA256", "ECDSA with SHA256" },
357  },
358  {
359  { ADD_LEN( OID_ECDSA_SHA384 ), "ecdsa-with-SHA384", "ECDSA with SHA384" },
361  },
362  {
363  { ADD_LEN( OID_ECDSA_SHA512 ), "ecdsa-with-SHA512", "ECDSA with SHA512" },
365  },
366  {
367  { ADD_LEN( OID_RSASSA_PSS ), "RSASSA-PSS", "RSASSA-PSS" },
369  },
370  {
371  { NULL, 0, NULL, NULL },
372  0, 0,
373  },
374 };
375 
376 FN_OID_TYPED_FROM_ASN1(oid_sig_alg_t, sig_alg, oid_sig_alg);
377 FN_OID_GET_DESCRIPTOR_ATTR1(oid_get_sig_alg_desc, oid_sig_alg_t, sig_alg, const char *, description);
378 FN_OID_GET_ATTR2(oid_get_sig_alg, oid_sig_alg_t, sig_alg, md_type_t, md_alg, pk_type_t, pk_alg);
379 FN_OID_GET_OID_BY_ATTR2(oid_get_oid_by_sig_alg, oid_sig_alg_t, oid_sig_alg, pk_type_t, pk_alg, md_type_t, md_alg);
380 #endif /* POLARSSL_MD_C */
381 
382 /*
383  * For PublicKeyInfo (PKCS1, RFC 5480)
384  */
385 typedef struct {
386  oid_descriptor_t descriptor;
387  pk_type_t pk_alg;
388 } oid_pk_alg_t;
389 
390 static const oid_pk_alg_t oid_pk_alg[] =
391 {
392  {
393  { ADD_LEN( OID_PKCS1_RSA ), "rsaEncryption", "RSA" },
395  },
396  {
397  { ADD_LEN( OID_EC_ALG_UNRESTRICTED ), "id-ecPublicKey", "Generic EC key" },
399  },
400  {
401  { ADD_LEN( OID_EC_ALG_ECDH ), "id-ecDH", "EC key for ECDH" },
403  },
404  {
405  { NULL, 0, NULL, NULL },
406  0,
407  },
408 };
409 
410 FN_OID_TYPED_FROM_ASN1(oid_pk_alg_t, pk_alg, oid_pk_alg);
411 FN_OID_GET_ATTR1(oid_get_pk_alg, oid_pk_alg_t, pk_alg, pk_type_t, pk_alg);
412 FN_OID_GET_OID_BY_ATTR1(oid_get_oid_by_pk_alg, oid_pk_alg_t, oid_pk_alg, pk_type_t, pk_alg);
413 
414 #if defined(POLARSSL_ECP_C)
415 /*
416  * For namedCurve (RFC 5480)
417  */
418 typedef struct {
419  oid_descriptor_t descriptor;
420  ecp_group_id grp_id;
421 } oid_ecp_grp_t;
422 
423 static const oid_ecp_grp_t oid_ecp_grp[] =
424 {
425  {
426  { ADD_LEN( OID_EC_GRP_SECP192R1 ), "secp192r1", "secp192r1" },
428  },
429  {
430  { ADD_LEN( OID_EC_GRP_SECP224R1 ), "secp224r1", "secp224r1" },
432  },
433  {
434  { ADD_LEN( OID_EC_GRP_SECP256R1 ), "secp256r1", "secp256r1" },
436  },
437  {
438  { ADD_LEN( OID_EC_GRP_SECP384R1 ), "secp384r1", "secp384r1" },
440  },
441  {
442  { ADD_LEN( OID_EC_GRP_SECP521R1 ), "secp521r1", "secp521r1" },
444  },
445  {
446  { ADD_LEN( OID_EC_GRP_SECP192K1 ), "secp192k1", "secp192k1" },
448  },
449  {
450  { ADD_LEN( OID_EC_GRP_SECP224K1 ), "secp224k1", "secp224k1" },
452  },
453  {
454  { ADD_LEN( OID_EC_GRP_SECP256K1 ), "secp256k1", "secp256k1" },
456  },
457  {
458  { ADD_LEN( OID_EC_GRP_BP256R1 ), "brainpoolP256r1","brainpool256r1" },
460  },
461  {
462  { ADD_LEN( OID_EC_GRP_BP384R1 ), "brainpoolP384r1","brainpool384r1" },
464  },
465  {
466  { ADD_LEN( OID_EC_GRP_BP512R1 ), "brainpoolP512r1","brainpool512r1" },
468  },
469  {
470  { NULL, 0, NULL, NULL },
471  0,
472  },
473 };
474 
475 FN_OID_TYPED_FROM_ASN1(oid_ecp_grp_t, grp_id, oid_ecp_grp);
476 FN_OID_GET_ATTR1(oid_get_ec_grp, oid_ecp_grp_t, grp_id, ecp_group_id, grp_id);
477 FN_OID_GET_OID_BY_ATTR1(oid_get_oid_by_ec_grp, oid_ecp_grp_t, oid_ecp_grp, ecp_group_id, grp_id);
478 #endif /* POLARSSL_ECP_C */
479 
480 #if defined(POLARSSL_CIPHER_C)
481 /*
482  * For PKCS#5 PBES2 encryption algorithm
483  */
484 typedef struct {
485  oid_descriptor_t descriptor;
486  cipher_type_t cipher_alg;
487 } oid_cipher_alg_t;
488 
489 static const oid_cipher_alg_t oid_cipher_alg[] =
490 {
491  {
492  { ADD_LEN( OID_DES_CBC ), "desCBC", "DES-CBC" },
494  },
495  {
496  { ADD_LEN( OID_DES_EDE3_CBC ), "des-ede3-cbc", "DES-EDE3-CBC" },
498  },
499  {
500  { NULL, 0, NULL, NULL },
501  0,
502  },
503 };
504 
505 FN_OID_TYPED_FROM_ASN1(oid_cipher_alg_t, cipher_alg, oid_cipher_alg);
506 FN_OID_GET_ATTR1(oid_get_cipher_alg, oid_cipher_alg_t, cipher_alg, cipher_type_t, cipher_alg);
507 #endif /* POLARSSL_CIPHER_C */
508 
509 #if defined(POLARSSL_MD_C)
510 /*
511  * For digestAlgorithm
512  */
513 typedef struct {
514  oid_descriptor_t descriptor;
515  md_type_t md_alg;
516 } oid_md_alg_t;
517 
518 static const oid_md_alg_t oid_md_alg[] =
519 {
520  {
521  { ADD_LEN( OID_DIGEST_ALG_MD2 ), "id-md2", "MD2" },
523  },
524  {
525  { ADD_LEN( OID_DIGEST_ALG_MD4 ), "id-md4", "MD4" },
527  },
528  {
529  { ADD_LEN( OID_DIGEST_ALG_MD5 ), "id-md5", "MD5" },
531  },
532  {
533  { ADD_LEN( OID_DIGEST_ALG_SHA1 ), "id-sha1", "SHA-1" },
535  },
536  {
537  { ADD_LEN( OID_DIGEST_ALG_SHA224 ), "id-sha224", "SHA-224" },
539  },
540  {
541  { ADD_LEN( OID_DIGEST_ALG_SHA256 ), "id-sha256", "SHA-256" },
543  },
544  {
545  { ADD_LEN( OID_DIGEST_ALG_SHA384 ), "id-sha384", "SHA-384" },
547  },
548  {
549  { ADD_LEN( OID_DIGEST_ALG_SHA512 ), "id-sha512", "SHA-512" },
551  },
552  {
553  { NULL, 0, NULL, NULL },
554  0,
555  },
556 };
557 
558 FN_OID_TYPED_FROM_ASN1(oid_md_alg_t, md_alg, oid_md_alg);
559 FN_OID_GET_ATTR1(oid_get_md_alg, oid_md_alg_t, md_alg, md_type_t, md_alg);
560 FN_OID_GET_OID_BY_ATTR1(oid_get_oid_by_md, oid_md_alg_t, oid_md_alg, md_type_t, md_alg);
561 #endif /* POLARSSL_MD_C */
562 
563 #if defined(POLARSSL_PKCS12_C)
564 /*
565  * For PKCS#12 PBEs
566  */
567 typedef struct {
568  oid_descriptor_t descriptor;
569  md_type_t md_alg;
570  cipher_type_t cipher_alg;
571 } oid_pkcs12_pbe_alg_t;
572 
573 static const oid_pkcs12_pbe_alg_t oid_pkcs12_pbe_alg[] =
574 {
575  {
576  { ADD_LEN( OID_PKCS12_PBE_SHA1_DES3_EDE_CBC ), "pbeWithSHAAnd3-KeyTripleDES-CBC", "PBE with SHA1 and 3-Key 3DES" },
578  },
579  {
580  { ADD_LEN( OID_PKCS12_PBE_SHA1_DES2_EDE_CBC ), "pbeWithSHAAnd2-KeyTripleDES-CBC", "PBE with SHA1 and 2-Key 3DES" },
582  },
583  {
584  { NULL, 0, NULL, NULL },
585  0, 0,
586  },
587 };
588 
589 FN_OID_TYPED_FROM_ASN1(oid_pkcs12_pbe_alg_t, pkcs12_pbe_alg, oid_pkcs12_pbe_alg);
590 FN_OID_GET_ATTR2(oid_get_pkcs12_pbe_alg, oid_pkcs12_pbe_alg_t, pkcs12_pbe_alg, md_type_t, md_alg, cipher_type_t, cipher_alg);
591 #endif /* POLARSSL_PKCS12_C */
592 
593 #if defined(_MSC_VER) && !defined snprintf && !defined(EFIX64) && \
594  !defined(EFI32)
595 #include <stdarg.h>
596 
597 #if !defined vsnprintf
598 #define vsnprintf _vsnprintf
599 #endif // vsnprintf
600 
601 /*
602  * Windows _snprintf and _vsnprintf are not compatible to linux versions.
603  * Result value is not size of buffer needed, but -1 if no fit is possible.
604  *
605  * This fuction tries to 'fix' this by at least suggesting enlarging the
606  * size by 20.
607  */
608 static int compat_snprintf( char *str, size_t size, const char *format, ... )
609 {
610  va_list ap;
611  int res = -1;
612 
613  va_start( ap, format );
614 
615  res = vsnprintf( str, size, format, ap );
616 
617  va_end( ap );
618 
619  // No quick fix possible
620  if( res < 0 )
621  return( (int) size + 20 );
622 
623  return( res );
624 }
625 
626 #define snprintf compat_snprintf
627 #endif /* _MSC_VER && !snprintf && !EFIX64 && !EFI32 */
628 
629 #define SAFE_SNPRINTF() \
630 { \
631  if( ret == -1 ) \
632  return( POLARSSL_ERR_OID_BUF_TOO_SMALL ); \
633  \
634  if( (unsigned int) ret >= n ) { \
635  p[n - 1] = '\0'; \
636  return( POLARSSL_ERR_OID_BUF_TOO_SMALL ); \
637  } \
638  \
639  n -= (unsigned int) ret; \
640  p += (unsigned int) ret; \
641 }
642 
643 /* Return the x.y.z.... style numeric string for the given OID */
644 int oid_get_numeric_string( char *buf, size_t size,
645  const asn1_buf *oid )
646 {
647  int ret;
648  size_t i, n;
649  unsigned int value;
650  char *p;
651 
652  p = buf;
653  n = size;
654 
655  /* First byte contains first two dots */
656  if( oid->len > 0 )
657  {
658  ret = snprintf( p, n, "%d.%d", oid->p[0] / 40, oid->p[0] % 40 );
659  SAFE_SNPRINTF();
660  }
661 
662  value = 0;
663  for( i = 1; i < oid->len; i++ )
664  {
665  /* Prevent overflow in value. */
666  if( ( ( value << 7 ) >> 7 ) != value )
668 
669  value <<= 7;
670  value += oid->p[i] & 0x7F;
671 
672  if( !( oid->p[i] & 0x80 ) )
673  {
674  /* Last byte */
675  ret = snprintf( p, n, ".%d", value );
676  SAFE_SNPRINTF();
677  value = 0;
678  }
679  }
680 
681  return( (int) ( size - n ) );
682 }
683 
684 #endif /* POLARSSL_OID_C */