nssprivkeyinfocodec.h

//The following code is for for serializing and deserializing
// PKCS #8 PrivateKeyInfo and PublicKeyInfo

//This part of code is introduced from chromium, therefore the BSD license applies

#include <list>
#include <vector>

typedef unsigned int uint32;
typedef int int32;
typedef unsigned short uint16;
typedef short int16;
typedef unsigned char uint8;
typedef signed char int8;

struct SECKEYPrivateKeyStr;
struct SECKEYPublicKeyStr;

namespace AuthN {

  class PrivateKeyInfoCodec {
  public:

    // ASN.1 encoding of the AlgorithmIdentifier from PKCS #8.
    static const uint8 kRsaAlgorithmIdentifier[];

    // ASN.1 tags for some types we use.
    static const uint8 kBitStringTag = 0x03;
    static const uint8 kIntegerTag = 0x02;
    static const uint8 kNullTag = 0x05;
    static const uint8 kOctetStringTag = 0x04;
    static const uint8 kSequenceTag = 0x30;

    // |big_endian| here specifies the byte-significance of the integer components
    // that will be parsed & serialized (modulus(), etc...) during Import(),
    // Export() and ExportPublicKeyInfo() -- not the ASN.1 DER encoding of the
    // PrivateKeyInfo/PublicKeyInfo (which is always big-endian).
    explicit PrivateKeyInfoCodec(bool big_endian);

    ~PrivateKeyInfoCodec();

    // Exports the contents of the integer components to the ASN.1 DER encoding
    // of the PrivateKeyInfo structure to |output|.
    bool Export(std::vector<uint8>* output);

    // Exports the contents of the integer components to the ASN.1 DER encoding
    // of the PublicKeyInfo structure to |output|.
    bool ExportPublicKeyInfo(std::vector<uint8>* output);

    // Exports the contents of the integer components to the ASN.1 DER encoding
    // of the RSAPublicKey structure to |output|.
    bool ExportPublicKey(std::vector<uint8>* output);

    // Parses the ASN.1 DER encoding of the PrivateKeyInfo structure in |input|
    // and populates the integer components with |big_endian_| byte-significance.
    // IMPORTANT NOTE: This is currently *not* security-approved for importing
    // keys from unstrusted sources.
    bool Import(const std::vector<uint8>& input);

    // Accessors to the contents of the integer components of the PrivateKeyInfo structure.
    std::vector<uint8>* modulus() { return &modulus_; };
    std::vector<uint8>* public_exponent() { return &public_exponent_; };
    std::vector<uint8>* private_exponent() { return &private_exponent_; };
    std::vector<uint8>* prime1() { return &prime1_; };
    std::vector<uint8>* prime2() { return &prime2_; };
    std::vector<uint8>* exponent1() { return &exponent1_; };
    std::vector<uint8>* exponent2() { return &exponent2_; };
    std::vector<uint8>* coefficient() { return &coefficient_; };

  private:
    // Utility wrappers for PrependIntegerImpl that use the class's |big_endian_|
    // value.
    void PrependInteger(const std::vector<uint8>& in, std::list<uint8>* out);
    void PrependInteger(uint8* val, int num_bytes, std::list<uint8>* data);

    // Prepends the integer stored in |val| - |val + num_bytes| with |big_endian|
    // byte-significance into |data| as an ASN.1 integer.
    void PrependIntegerImpl(uint8* val,
                          int num_bytes,
                          std::list<uint8>* data,
                          bool big_endian);

    // Utility wrappers for ReadIntegerImpl that use the class's |big_endian_|
    // value.
    bool ReadInteger(uint8** pos, uint8* end, std::vector<uint8>* out);
    bool ReadIntegerWithExpectedSize(uint8** pos,
                                   uint8* end,
                                   size_t expected_size,
                                   std::vector<uint8>* out);

    // Reads an ASN.1 integer from |pos|, and stores the result into |out| with
    // |big_endian| byte-significance.
    bool ReadIntegerImpl(uint8** pos,
                       uint8* end,
                       std::vector<uint8>* out,
                       bool big_endian);

    // Prepends the integer stored in |val|, starting a index |start|, for
    // |num_bytes| bytes onto |data|.
    void PrependBytes(uint8* val,
                    int start,
                    int num_bytes,
                    std::list<uint8>* data);

    // Helper to prepend an ASN.1 length field.
    void PrependLength(size_t size, std::list<uint8>* data);

    // Helper to prepend an ASN.1 type header.
    void PrependTypeHeaderAndLength(uint8 type,
                                  uint32 length,
                                  std::list<uint8>* output);

    // Helper to prepend an ASN.1 bit string
    void PrependBitString(uint8* val, int num_bytes, std::list<uint8>* output);

    // Read an ASN.1 length field. This also checks that the length does not
    // extend beyond |end|.
    bool ReadLength(uint8** pos, uint8* end, uint32* result);

    // Read an ASN.1 type header and its length.
    bool ReadTypeHeaderAndLength(uint8** pos,
                               uint8* end,
                               uint8 expected_tag,
                               uint32* length);

    // Read an ASN.1 sequence declaration. This consumes the type header and
    // length field, but not the contents of the sequence.
    bool ReadSequence(uint8** pos, uint8* end);

    // Read the RSA AlgorithmIdentifier.
    bool ReadAlgorithmIdentifier(uint8** pos, uint8* end);

    // Read one of the two version fields in PrivateKeyInfo.
    bool ReadVersion(uint8** pos, uint8* end);

    // The byte-significance of the stored components (modulus, etc..).
    bool big_endian_;

    // Component integers of the PrivateKeyInfo
    std::vector<uint8> modulus_;
    std::vector<uint8> public_exponent_;
    std::vector<uint8> private_exponent_;
    std::vector<uint8> prime1_;
    std::vector<uint8> prime2_;
    std::vector<uint8> exponent1_;
    std::vector<uint8> exponent2_;
    std::vector<uint8> coefficient_;
  };

}

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