/**************************** sha.h ****************************/
/******************* See RFC 4634 for details ******************/
#ifndef _SHA_H_
#define _SHA_H_
/*
* Description:
* This file implements the Secure Hash Signature Standard
* algorithms as defined in the National Institute of Standards
* and Technology Federal Information Processing Standards
* Publication (FIPS PUB) 180-1 published on April 17, 1995, 180-2
* published on August 1, 2002, and the FIPS PUB 180-2 Change
* Notice published on February 28, 2004.
*
* A combined document showing all algorithms is available at
* http://csrc.nist.gov/publications/fips/
* fips180-2/fips180-2withchangenotice.pdf
*
* The five hashes are defined in these sizes:
* SHA-1 20 byte / 160 bit
* SHA-224 28 byte / 224 bit
* SHA-256 32 byte / 256 bit
* SHA-384 48 byte / 384 bit
* SHA-512 64 byte / 512 bit
*/
//#include <stdint.h>
/*
* If you do not have the ISO standard stdint.h header file, then you
* must typedef the following:
* name meaning
* uint64_t unsigned 64 bit integer
* uint32_t unsigned 32 bit integer
* uint8_t unsigned 8 bit integer (i.e., unsigned char)
* int32_t integer of >= 16 bits
*
*/
#ifndef _SHA_enum_
#define _SHA_enum_

#include "stdint.h"

/*
* All SHA functions return one of these values.
*/
enum {
    shaSuccess = 0,
    shaNull, /* Null pointer parameter */
    shaInputTooLong, /* input data too long */
    shaStateError, /* called Input after FinalBits or Result */
    shaBadParam /* passed a bad parameter */
};
#endif /* _SHA_enum_ */
/*
* These constants hold size information for each of the SHA
* hashing operations
*/
enum {
    SHA1_Message_Block_Size = 64, SHA224_Message_Block_Size = 64,
    SHA256_Message_Block_Size = 64, SHA384_Message_Block_Size = 128,
    SHA512_Message_Block_Size = 128,
    USHA_Max_Message_Block_Size = SHA512_Message_Block_Size,
    SHA1HashSize = 20, SHA224HashSize = 28, SHA256HashSize = 32,
    SHA384HashSize = 48, SHA512HashSize = 64,
    USHAMaxHashSize = SHA512HashSize,
    SHA1HashSizeBits = 160, SHA224HashSizeBits = 224,
    SHA256HashSizeBits = 256, SHA384HashSizeBits = 384,
    SHA512HashSizeBits = 512, USHAMaxHashSizeBits = SHA512HashSizeBits
};
/*
* These constants are used in the USHA (unified sha) functions.
*/
typedef enum SHAversion {
    SHA1, SHA224, SHA256, SHA384, SHA512
} SHAversion;

/*
* This structure will hold context information for the SHA-1
* hashing operation.
*/
typedef struct SHA1Context {
    uint32_t Intermediate_Hash[SHA1HashSize/4]; /* Message Digest */
    uint32_t Length_Low; /* Message length in bits */
    uint32_t Length_High; /* Message length in bits */
    int32_t Message_Block_Index; /* Message_Block array index */
    /* 512-bit message blocks */
    uint8_t Message_Block[SHA1_Message_Block_Size];
    int Computed; /* Is the digest computed? */
    int Corrupted; /* Is the digest corrupted? */
} SHA1Context;
/*
* This structure will hold context information for the SHA-256
* hashing operation.
*/
typedef struct SHA256Context {
    uint32_t Intermediate_Hash[SHA256HashSize/4]; /* Message Digest */
    uint32_t Length_Low; /* Message length in bits */
    uint32_t Length_High; /* Message length in bits */
    int32_t Message_Block_Index; /* Message_Block array index */
    /* 512-bit message blocks */
    uint8_t Message_Block[SHA256_Message_Block_Size];
    int Computed; /* Is the digest computed? */
    int Corrupted; /* Is the digest corrupted? */
} SHA256Context;

/*
* This structure will hold context information for the SHA-512
* hashing operation.
*/
typedef struct SHA512Context {
#ifdef USE_32BIT_ONLY
    uint32_t Intermediate_Hash[SHA512HashSize/4]; /* Message Digest */
    uint32_t Length[4]; /* Message length in bits */
#else /* !USE_32BIT_ONLY */
    uint64_t Intermediate_Hash[SHA512HashSize/8]; /* Message Digest */
    uint64_t Length_Low, Length_High; /* Message length in bits */
#endif /* USE_32BIT_ONLY */

    int32_t Message_Block_Index; /* Message_Block array index */
    /* 1024-bit message blocks */
    uint8_t Message_Block[SHA512_Message_Block_Size];
    int Computed; /* Is the digest computed?*/
    int Corrupted; /* Is the digest corrupted? */
} SHA512Context;
/*
* This structure will hold context information for the SHA-224
* hashing operation. It uses the SHA-256 structure for computation.
*/
typedef struct SHA256Context SHA224Context;
/*
* This structure will hold context information for the SHA-384
* hashing operation. It uses the SHA-512 structure for computation.
*/
typedef struct SHA512Context SHA384Context;
/*
* This structure holds context information for all SHA
* hashing operations.
*/
typedef struct USHAContext {
    int whichSha; /* which SHA is being used */
    union {
    SHA1Context sha1Context;
    SHA224Context sha224Context; SHA256Context sha256Context;
    SHA384Context sha384Context; SHA512Context sha512Context;
    } ctx;
} USHAContext;
/*
* This structure will hold context information for the HMAC
* keyed hashing operation.
*/
typedef struct HMACContext {
    int whichSha; /* which SHA is being used */
    int hashSize; /* hash size of SHA being used */
    int blockSize; /* block size of SHA being used */
    USHAContext shaContext; /* SHA context */
    unsigned char k_opad[USHA_Max_Message_Block_Size];
    /* outer padding - key XORd with opad */
} HMACContext;

/*
* Function Prototypes
*/
/* SHA-1 */
#ifdef __cplusplus
extern "C" {
#endif

extern int SHA1Reset(SHA1Context *);
extern int SHA1Input(SHA1Context *, const uint8_t *bytes, unsigned int bytecount);
extern int SHA1FinalBits(SHA1Context *, const uint8_t bits, unsigned int bitcount);
extern int SHA1Result(SHA1Context *, uint8_t Message_Digest[SHA1HashSize]);
/* SHA-224 */
extern int SHA224Reset(SHA224Context *);
extern int SHA224Input(SHA224Context *, const uint8_t *bytes, unsigned int bytecount);
extern int SHA224FinalBits(SHA224Context *, const uint8_t bits, unsigned int bitcount);
extern int SHA224Result(SHA224Context *, uint8_t Message_Digest[SHA224HashSize]);
/* SHA-256 */
extern int SHA256Reset(SHA256Context *);
extern int SHA256Input(SHA256Context *, const uint8_t *bytes, unsigned int bytecount);
extern int SHA256FinalBits(SHA256Context *, const uint8_t bits, unsigned int bitcount);
extern int SHA256Result(SHA256Context *, uint8_t Message_Digest[SHA256HashSize]);
/* SHA-384 */
extern int SHA384Reset(SHA384Context *);
extern int SHA384Input(SHA384Context *, const uint8_t *bytes, unsigned int bytecount);
extern int SHA384FinalBits(SHA384Context *, const uint8_t bits, unsigned int bitcount);
extern int SHA384Result(SHA384Context *, uint8_t Message_Digest[SHA384HashSize]);
/* SHA-512 */
extern int SHA512Reset(SHA512Context *);
extern int SHA512Input(SHA512Context *, const uint8_t *bytes, unsigned int bytecount);
extern int SHA512FinalBits(SHA512Context *, const uint8_t bits,unsigned int bitcount);
extern int SHA512Result(SHA512Context *, uint8_t Message_Digest[SHA512HashSize]);

/* Unified SHA functions, chosen by whichSha */
extern int USHAReset(USHAContext *, SHAversion whichSha);
extern int USHAInput(USHAContext *, const uint8_t *bytes, unsigned int bytecount);
extern int USHAFinalBits(USHAContext *, const uint8_t bits, unsigned int bitcount);
extern int USHAResult(USHAContext *, uint8_t Message_Digest[USHAMaxHashSize]);
extern int USHABlockSize(enum SHAversion whichSha);
extern int USHAHashSize(enum SHAversion whichSha);
extern int USHAHashSizeBits(enum SHAversion whichSha);
/*
* HMAC Keyed-Hashing for Message Authentication, RFC2104,
* for all SHAs.
* This interface allows a fixed-length text input to be used.
*/
extern int hmac(SHAversion whichSha, /* which SHA algorithm to use */
                const unsigned char *text, /* pointer to data stream */
                int text_len, /* length of data stream */
                const unsigned char *key, /* pointer to authentication key */
                int key_len, /* length of authentication key */
                uint8_t digest[USHAMaxHashSize]); /* caller digest to fill in */
/*
* HMAC Keyed-Hashing for Message Authentication, RFC2104,
* for all SHAs.
* This interface allows any length of text input to be used.
*/
extern int hmacReset(HMACContext *ctx, enum SHAversion whichSha, const unsigned char *key, int key_len);
extern int hmacInput(HMACContext *ctx, const unsigned char *text, int text_len);
extern int hmacFinalBits(HMACContext *ctx, const uint8_t bits, unsigned int bitcount);
extern int hmacResult(HMACContext *ctx, uint8_t digest[USHAMaxHashSize]);

#ifdef __cplusplus
}
#endif

#endif /* _SHA_H_ */
