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/*
* libjingle
* Copyright 2004, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef TALK_BASE_MESSAGEDIGEST_H_
#define TALK_BASE_MESSAGEDIGEST_H_
#include <string>
namespace talk_base {
// Definitions for the digest algorithms.
extern const char DIGEST_MD5[];
extern const char DIGEST_SHA_1[];
extern const char DIGEST_SHA_224[];
extern const char DIGEST_SHA_256[];
extern const char DIGEST_SHA_384[];
extern const char DIGEST_SHA_512[];
// A general class for computing hashes.
class MessageDigest {
public:
enum { kMaxSize = 64 }; // Maximum known size (SHA-512)
virtual ~MessageDigest() {}
// Returns the digest output size (e.g. 16 bytes for MD5).
virtual size_t Size() const = 0;
// Updates the digest with |len| bytes from |buf|.
virtual void Update(const void* buf, size_t len) = 0;
// Outputs the digest value to |buf| with length |len|.
// Returns the number of bytes written, i.e., Size().
virtual size_t Finish(void* buf, size_t len) = 0;
};
// A factory class for creating digest objects.
class MessageDigestFactory {
public:
static MessageDigest* Create(const std::string& alg);
};
// Functions to create hashes.
// Computes the hash of |in_len| bytes of |input|, using the |digest| hash
// implementation, and outputs the hash to the buffer |output|, which is
// |out_len| bytes long. Returns the number of bytes written to |output| if
// successful, or 0 if |out_len| was too small.
size_t ComputeDigest(MessageDigest* digest, const void* input, size_t in_len,
void* output, size_t out_len);
// Like the previous function, but creates a digest implementation based on
// the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns 0 if there is no
// digest with the given name.
size_t ComputeDigest(const std::string& alg, const void* input, size_t in_len,
void* output, size_t out_len);
// Computes the hash of |input| using the |digest| hash implementation, and
// returns it as a hex-encoded string.
std::string ComputeDigest(MessageDigest* digest, const std::string& input);
// Like the previous function, but creates a digest implementation based on
// the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns empty string if
// there is no digest with the given name.
std::string ComputeDigest(const std::string& alg, const std::string& input);
// Like the previous function, but returns an explicit result code.
bool ComputeDigest(const std::string& alg, const std::string& input,
std::string* output);
// Shorthand way to compute a hex-encoded hash using MD5.
inline std::string MD5(const std::string& input) {
return ComputeDigest(DIGEST_MD5, input);
}
// Functions to compute RFC 2104 HMACs.
// Computes the HMAC of |in_len| bytes of |input|, using the |digest| hash
// implementation and |key_len| bytes of |key| to key the HMAC, and outputs
// the HMAC to the buffer |output|, which is |out_len| bytes long. Returns the
// number of bytes written to |output| if successful, or 0 if |out_len| was too
// small.
size_t ComputeHmac(MessageDigest* digest, const void* key, size_t key_len,
const void* input, size_t in_len,
void* output, size_t out_len);
// Like the previous function, but creates a digest implementation based on
// the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns 0 if there is no
// digest with the given name.
size_t ComputeHmac(const std::string& alg, const void* key, size_t key_len,
const void* input, size_t in_len,
void* output, size_t out_len);
// Computes the HMAC of |input| using the |digest| hash implementation and |key|
// to key the HMAC, and returns it as a hex-encoded string.
std::string ComputeHmac(MessageDigest* digest, const std::string& key,
const std::string& input);
// Like the previous function, but creates a digest implementation based on
// the desired digest name |alg|, e.g. DIGEST_SHA_1. Returns empty string if
// there is no digest with the given name.
std::string ComputeHmac(const std::string& alg, const std::string& key,
const std::string& input);
// Like the previous function, but returns an explicit result code.
bool ComputeHmac(const std::string& alg, const std::string& key,
const std::string& input, std::string* output);
} // namespace talk_base
#endif // TALK_BASE_MESSAGEDIGEST_H_