1 /* 2 * libjingle 3 * Copyright 2004, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef TALK_BASE_MESSAGEDIGEST_H_ 29 #define TALK_BASE_MESSAGEDIGEST_H_ 30 31 #include <string> 32 33 namespace talk_base { 34 35 // Definitions for the digest algorithms. 36 extern const char DIGEST_MD5[]; 37 extern const char DIGEST_SHA_1[]; 38 extern const char DIGEST_SHA_224[]; 39 extern const char DIGEST_SHA_256[]; 40 extern const char DIGEST_SHA_384[]; 41 extern const char DIGEST_SHA_512[]; 42 43 // A general class for computing hashes. 44 class MessageDigest { 45 public: 46 enum { kMaxSize = 64 }; // Maximum known size (SHA-512) 47 virtual ~MessageDigest() {} 48 // Returns the digest output size (e.g. 16 bytes for MD5). 49 virtual size_t Size() const = 0; 50 // Updates the digest with |len| bytes from |buf|. 51 virtual void Update(const void* buf, size_t len) = 0; 52 // Outputs the digest value to |buf| with length |len|. 53 // Returns the number of bytes written, i.e., Size(). 54 virtual size_t Finish(void* buf, size_t len) = 0; 55 }; 56 57 // A factory class for creating digest objects. 58 class MessageDigestFactory { 59 public: 60 static MessageDigest* Create(const std::string& alg); 61 }; 62 63 // Functions to create hashes. 64 65 // Computes the hash of |in_len| bytes of |input|, using the |digest| hash 66 // implementation, and outputs the hash to the buffer |output|, which is 67 // |out_len| bytes long. Returns the number of bytes written to |output| if 68 // successful, or 0 if |out_len| was too small. 69 size_t ComputeDigest(MessageDigest* digest, const void* input, size_t in_len, 70 void* output, size_t out_len); 71 // Like the previous function, but creates a digest implementation based on 72 // the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns 0 if there is no 73 // digest with the given name. 74 size_t ComputeDigest(const std::string& alg, const void* input, size_t in_len, 75 void* output, size_t out_len); 76 // Computes the hash of |input| using the |digest| hash implementation, and 77 // returns it as a hex-encoded string. 78 std::string ComputeDigest(MessageDigest* digest, const std::string& input); 79 // Like the previous function, but creates a digest implementation based on 80 // the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns empty string if 81 // there is no digest with the given name. 82 std::string ComputeDigest(const std::string& alg, const std::string& input); 83 // Like the previous function, but returns an explicit result code. 84 bool ComputeDigest(const std::string& alg, const std::string& input, 85 std::string* output); 86 87 // Shorthand way to compute a hex-encoded hash using MD5. 88 inline std::string MD5(const std::string& input) { 89 return ComputeDigest(DIGEST_MD5, input); 90 } 91 92 // Functions to compute RFC 2104 HMACs. 93 94 // Computes the HMAC of |in_len| bytes of |input|, using the |digest| hash 95 // implementation and |key_len| bytes of |key| to key the HMAC, and outputs 96 // the HMAC to the buffer |output|, which is |out_len| bytes long. Returns the 97 // number of bytes written to |output| if successful, or 0 if |out_len| was too 98 // small. 99 size_t ComputeHmac(MessageDigest* digest, const void* key, size_t key_len, 100 const void* input, size_t in_len, 101 void* output, size_t out_len); 102 // Like the previous function, but creates a digest implementation based on 103 // the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns 0 if there is no 104 // digest with the given name. 105 size_t ComputeHmac(const std::string& alg, const void* key, size_t key_len, 106 const void* input, size_t in_len, 107 void* output, size_t out_len); 108 // Computes the HMAC of |input| using the |digest| hash implementation and |key| 109 // to key the HMAC, and returns it as a hex-encoded string. 110 std::string ComputeHmac(MessageDigest* digest, const std::string& key, 111 const std::string& input); 112 // Like the previous function, but creates a digest implementation based on 113 // the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns empty string if 114 // there is no digest with the given name. 115 std::string ComputeHmac(const std::string& alg, const std::string& key, 116 const std::string& input); 117 // Like the previous function, but returns an explicit result code. 118 bool ComputeHmac(const std::string& alg, const std::string& key, 119 const std::string& input, std::string* output); 120 121 } // namespace talk_base 122 123 #endif // TALK_BASE_MESSAGEDIGEST_H_ 124
