/*

    File:       DigestTool.cpp

        Contains:   simple utility to demonstrate use of libCdsaCrypt used digest (hash) computation        

        Copyright:  © Copyright 2002 Apple Computer, Inc. All rights reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

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                        copyrights in this original Apple software (the "Apple Software"), to use,

                        reproduce, modify and redistribute the Apple Software, with or without

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                        this notice and the following text and disclaimers in all such redistributions of

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                        Apple Software without specific prior written permission from Apple.  Except as

                        expressly stated in this notice, no other rights or licenses, express or implied,

                        are granted by Apple herein, including but not limited to any patent rights that

                        may be infringed by your derivative works or by other works in which the Apple

                        Software may be incorporated.

                        The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

                        WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

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    Change History (most recent first):

                11/4/02     1.0d1

*/

#include <libCdsaCrypt/libCdsaCrypt.h>

#include <libCdsaCrypt/fileIo.h>

#include <unistd.h>

#include <fcntl.h>

#include <errno.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <strings.h>

static void usage(char **argv) 

{

    printf("usage:\n");

    printf("  %s inFile digestFile [s(taged)] [a=algorithm]\n", argv[0]);

    printf("  algorithm:\n");

    printf("     a  SHA1 (default if no algorithm specified)\n");

    printf("     5  MD5\n");

    exit(1);

}

#define IN_BUF_SIZE     256

static int stagedDigest(

    CSSM_CSP_HANDLE     cspHandle,

    CSSM_ALGORITHMS     digestAlg,

    const char          *inFileName,

    CSSM_DATA           *digestData)

{

    int                 inFileFd;

    unsigned char       inBuf[IN_BUF_SIZE];     // raw infile data

    CSSM_DATA           inData;

    ssize_t             thisMove;

    CSSM_RETURN         crtn;

    int                 rtn;

    CSSM_CC_HANDLE      ccHandle;

    /* open inFile for reading */

    inFileFd = open(inFileName, O_RDONLY, 0);

    if(inFileFd <= 0) {

        perror(inFileName);

        return -1;

    }

    rtn = lseek(inFileFd, 0, SEEK_SET);

    if(rtn < 0) {

        perror(inFileName);

        return -1;

    }

    /* obtain a digest context */

    crtn = cdsaStagedDigestInit(cspHandle, digestAlg, &ccHandle);

    if(crtn) {

        cssmPerror("cdsaStagedDigestInit", crtn);

        return -1;

    }

    for(;;) {

        /* read up to IN_BUF_SUZE bytes */

        thisMove = read(inFileFd, inBuf, IN_BUF_SIZE);

        if(thisMove < 0) {

            perror("read");

            return -1;

        }

        inData.Data   = inBuf;

        inData.Length = thisMove;

        /* digest - Assume "final" if we read less than we asked for */

        CSSM_BOOL final = (thisMove == IN_BUF_SIZE) ? CSSM_FALSE : CSSM_TRUE;

        crtn = cdsaStagedDigest(ccHandle,

            final,

            &inData,

            digestData);

        if(crtn) {

            cssmPerror("cdsaStagedDigest", crtn);

            return -1;

        }

        if(final) {

            break;

        }

    }

    close(inFileFd);

    return 0;

}

static int oneShotDigest(

    CSSM_CSP_HANDLE     cspHandle,

    CSSM_ALGORITHMS     digestAlg,

    const char          *inFileName,

    CSSM_DATA           *digestData)

{

    unsigned char       *inFile;            // raw infile data

    unsigned            inFileSize;         // in bytes

    int                 rtn;

    CSSM_DATA           inData;

    /* read inFile */

    rtn = readFile(inFileName, &inFile, &inFileSize);

    if(rtn) {

        printf("Error reading %s: %s\n", inFileName, strerror(rtn));

        return rtn;

    }

    inData.Data = inFile;

    inData.Length = inFileSize;

    /* calculate digest */

    CSSM_RETURN crtn = cdsaDigest(cspHandle,

        digestAlg,

        &inData, 

        digestData);

    if(crtn) {

        cssmPerror("Attach to CSP", crtn);

        return -1;

    }

    free(inFile);

    return 0;

}

int main(int argc, char **argv)

{

    int                 rtn;

    char                *inFileName;        // from cmd line

    char                *digestFileName;    // from cmd line

    CSSM_CSP_HANDLE     cspHandle;

    CSSM_RETURN         crtn;

    int                 doStaged = 0;

    CSSM_ALGORITHMS     digestAlg = CSSM_ALGID_SHA1;

    int                 arg;

    CSSM_DATA           digestData;

    if(argc < 3) {

        usage(argv);

    }

    /* gather up cmd line args */

    inFileName = argv[1];

    digestFileName = argv[2];

    for(arg=3; arg<argc; arg++) {

        switch(argv[arg][0]) {

            case 's':

                doStaged = 1;

                break;

            case 'a':

                switch(argv[arg][2]) {

                    case '5':

                        digestAlg  = CSSM_ALGID_MD5;

                        break;

                    case 's':

                        digestAlg  = CSSM_ALGID_SHA1;

                        break;

                    default:

                        usage(argv);

                }

                break;

            default:

                usage(argv);

        }

    }

    /* attach to CSP */

    crtn = cdsaCspAttach(&cspHandle);

    if(crtn) {

        cssmPerror("Attach to CSP", crtn);

        exit(1);

    }

    /* 

     * Do the digest calculation.

     */

    if(doStaged) {

        rtn = stagedDigest(cspHandle,

            digestAlg,

            inFileName,

            &digestData);

    }

    else {

        rtn = oneShotDigest(cspHandle,

            digestAlg,

            inFileName,

            &digestData);

    }

    if(rtn) {

        exit(1);

    }

    rtn = writeFile(digestFileName, digestData.Data, digestData.Length);

    if(rtn) {

        printf("Error writing %s: %s\n", digestFileName, strerror(rtn));

        exit(1);

    }

    else {

        printf("SUCCESS: wrote %u bytes of digest data\n",

            (unsigned)digestData.Length);

    }

    /* free resources */

    free(digestData.Data);

    cdsaCspDetach(cspHandle);

    return 0;

}