1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_CERT_ASN1_UTIL_H_ 6 #define NET_CERT_ASN1_UTIL_H_ 7 8 #include <vector> 9 10 #include "base/strings/string_piece.h" 11 #include "net/base/net_export.h" 12 13 namespace net { 14 15 namespace asn1 { 16 17 // These are the DER encodings of the tag byte for ASN.1 objects. 18 static const unsigned kBOOLEAN = 0x01; 19 static const unsigned kINTEGER = 0x02; 20 static const unsigned kBITSTRING = 0x03; 21 static const unsigned kOCTETSTRING = 0x04; 22 static const unsigned kOID = 0x06; 23 static const unsigned kENUMERATED = 0x0A; 24 static const unsigned kSEQUENCE = 0x30; 25 26 // These are flags that can be ORed with the above tag numbers. 27 static const unsigned kContextSpecific = 0x80; 28 static const unsigned kConstructed = 0x20; 29 30 // kAny matches any tag value; 31 static const unsigned kAny = 0x10000; 32 // kOptional denotes an optional element. 33 static const unsigned kOptional = 0x20000; 34 35 // ParseElement parses a DER encoded ASN1 element from |in|, requiring that 36 // it have the given |tag_value|. It returns true on success. The following 37 // limitations are imposed: 38 // 1) tag numbers > 31 are not permitted. 39 // 2) lengths > 65535 are not permitted. 40 // On successful return: 41 // |in| is advanced over the element 42 // |out| contains the element, including the tag and length bytes. 43 // |out_header_len| contains the length of the tag and length bytes in |out|. 44 // 45 // If |tag_value & kOptional| is true then *out_header_len can be zero after a 46 // true return value if the element was not found. 47 bool ParseElement(base::StringPiece* in, 48 unsigned tag_value, 49 base::StringPiece* out, 50 unsigned *out_header_len); 51 52 // GetElement performs the same actions as ParseElement, except that the header 53 // bytes are not included in the output. 54 // 55 // If |tag_value & kOptional| is true then this function cannot distinguish 56 // between a missing optional element and an empty one. 57 NET_EXPORT_PRIVATE bool GetElement(base::StringPiece* in, 58 unsigned tag_value, 59 base::StringPiece* out); 60 61 // ExtractSPKIFromDERCert parses the DER encoded certificate in |cert| and 62 // extracts the bytes of the SubjectPublicKeyInfo. On successful return, 63 // |spki_out| is set to contain the SPKI, pointing into |cert|. 64 NET_EXPORT_PRIVATE bool ExtractSPKIFromDERCert(base::StringPiece cert, 65 base::StringPiece* spki_out); 66 67 // ExtractSubjectPublicKeyFromSPKI parses the DER encoded SubjectPublicKeyInfo 68 // in |spki| and extracts the bytes of the SubjectPublicKey. On successful 69 // return, |spk_out| is set to contain the public key, pointing into |spki|. 70 NET_EXPORT_PRIVATE bool ExtractSubjectPublicKeyFromSPKI( 71 base::StringPiece spki, 72 base::StringPiece* spk_out); 73 74 // ExtractCRLURLsFromDERCert parses the DER encoded certificate in |cert| and 75 // extracts the URL of each CRL. On successful return, the elements of 76 // |urls_out| point into |cert|. 77 // 78 // CRLs that only cover a subset of the reasons are omitted as the spec 79 // requires that at least one CRL be included that covers all reasons. 80 // 81 // CRLs that use an alternative issuer are also omitted. 82 // 83 // The nested set of GeneralNames is flattened into a single list because 84 // having several CRLs with one location is equivalent to having one CRL with 85 // several locations as far as a CRL filter is concerned. 86 NET_EXPORT_PRIVATE bool ExtractCRLURLsFromDERCert( 87 base::StringPiece cert, 88 std::vector<base::StringPiece>* urls_out); 89 90 } // namespace asn1 91 92 } // namespace net 93 94 #endif // NET_CERT_ASN1_UTIL_H_ 95
