aescrypt.c

来自「linux下完成任意文件的AES加密. 口令可变,加密稳定迅速.」· C语言 代码 · 共 1,135 行 · 第 1/3 页

        memcpy(buffer2, tail, 16);
        tail += 16;
        if (tail == (buffer + 64))
        {
            tail = buffer;
        }
        memcpy(buffer2+16, tail, 16);
    }
    else
    {
        memcpy(buffer2, tail+1, 15);
        tail += 16;
        if (tail == (buffer + 64))
        {
            tail = buffer;
        }
        memcpy(buffer2+15, tail, 16);
        tail += 16;
        if (tail == (buffer + 64))
        {
            tail = buffer;
        }
        memcpy(buffer2+31, tail, 1);
    }

    if (memcmp(digest, buffer2, 32))
    {
        if (aeshdr.version == 0x00)
        {
            fprintf(stderr, "Error: Message has been altered or password is incorrect\n");
        }
        else
        {
            fprintf(stderr, "Error: Message has been altered and should not be trusted\n");
        }

        return -1;
    }

    return 0;
}

/*
 *  usage
 *
 *  Displays the program usage to the user.
 */
void usage(const char *progname)
{
    const char* progname_real; //contains the real name of the program (without path)

    progname_real = rindex(progname, '/');
    if (progname_real == NULL) //no path in progname: use progname
    {
        progname_real = progname;
    }
    else
    {
        progname_real++;
    }

    fprintf(stderr, "\nusage: %s {-e|-d} [-p <password>] { [-o <output filename>] <file> | <file> [<file> ...] }\n\n",
            progname_real);
}

/*
 *  version
 *
 *  Displays the program version to the user.
 */
void version(const char *progname)
{
    const char* progname_real; //contains the real name of the program (without path)

    progname_real = rindex(progname, '/');
    if (progname_real == NULL) //no path in progname: use progname
    {
        progname_real = progname;
    }
    else
    {
        progname_real++;
    }

    fprintf(stderr, "\n%s version %s (%s)\n\n",
            progname_real, PROG_VERSION, PROG_DATE);
}

/*
 *  cleanup
 *
 *  Removes output files that are not fully and properly created.
 */
void cleanup(const char *outfile)
{
    if (strcmp(outfile,"-") && outfile[0] != '\0')
    {
        unlink(outfile);
    }
}

int main(int argc, char *argv[])
{
    int rc=0, passlen=0;
    FILE *infp = NULL;
    FILE *outfp = NULL;
    encryptmode_t mode=UNINIT;
    char *infile = NULL,
         pass_input[MAX_PASSWD_LEN+1],
         pass[MAX_PASSWD_LEN+1];
    int file_count = 0;
    char outfile[1024];
    iconv_t condesc;

    // Initialize the output filename
    outfile[0] = '\0';
    
    while ((rc = getopt(argc, argv, "vhdep:o:")) != -1)
    {
        switch (rc)
        {
            case 'h':
                usage(argv[0]);
                return 0;
            case 'v':
                version(argv[0]);
                return 0;
            case 'd':
                if (mode != UNINIT)
                {
                    fprintf(stderr, "Error: only specify one of -d or -e\n");
                    cleanup(outfile);
                    return -1;
                }
                mode = DEC;
                break;
            case 'e':
                if (mode != UNINIT)
                {
                    fprintf(stderr, "Error: only specify one of -d or -e\n");
                    cleanup(outfile);
                    return -1;
                }
                mode = ENC;
                break;
            case 'p':
                if (optarg != 0)
                {
                    passlen = passwd_to_utf16(  optarg,
                                                strlen(optarg),
                                                MAX_PASSWD_LEN+1,
                                                pass);
                    if (passlen < 0)
                    {
                        cleanup(outfile);
                        return -1;
                    }
                }
                break;
            case 'o':
                // outfile argument
                if (!strncmp("-", optarg, 2))
                {
                    // if '-' is outfile name then out to stdout
                    outfp = stdout;
                }
                else if ((outfp = fopen(optarg, "w")) == NULL)
                {
                    fprintf(stderr, "Error opening output file %s:", optarg);
                    perror("");
                    cleanup(outfile);
                    return  -1;
                }
                strncpy(outfile, optarg, 1024);
                outfile[1023] = '\0';
                break;
            default:
                fprintf(stderr, "Error: Unknown option '%c'\n", rc);
        }
    }
    
    if (optind >= argc)
    {
        fprintf(stderr, "Error: No file argument specified\n");
        usage(argv[0]);
        cleanup(outfile);
        return -1;
    }

    if (mode == UNINIT)
    {
        fprintf(stderr, "Error: -e or -d not specified\n");
        usage(argv[0]);
        cleanup(outfile);
        return -1;
    }

    // Prompt for password if not provided on the command line
    if (passlen == 0)
    {
        passlen = read_password(pass_input, mode);

        switch (passlen)
        {
            case 0: //no password in input
                fprintf(stderr, "Error: No password supplied.\n");
                cleanup(outfile);
                return -1;
            case AESCRYPT_READPWD_FOPEN:
            case AESCRYPT_READPWD_FILENO:
            case AESCRYPT_READPWD_TCGETATTR:
            case AESCRYPT_READPWD_TCSETATTR:
            case AESCRYPT_READPWD_FGETC:
            case AESCRYPT_READPWD_TOOLONG:
                fprintf(stderr, "Error in read_password: %s.\n",
                        read_password_error(passlen));
                cleanup(outfile);
                return -1;
            case AESCRYPT_READPWD_NOMATCH:
                fprintf(stderr, "Error: Passwords don't match.\n", passlen);
                cleanup(outfile);
                return -1;
        }

        passlen = passwd_to_utf16(  pass_input,
                                    strlen(pass_input),
                                    MAX_PASSWD_LEN+1,
                                    pass);
        if (passlen < 0)
        {
            cleanup(outfile);
            // For security reasons, erase the password
            memset(pass, 0, passlen);
            return -1;
        }
    }

    file_count = argc - optind;
    if ((file_count > 1) && (outfp != NULL))
    {
        if (outfp != stdout)
        {
            fclose(outfp);
        }
        fprintf(stderr, "Error: A single output file may not be specified with multiple input files.\n");
        usage(argv[0]);
        cleanup(outfile);
        // For security reasons, erase the password
        memset(pass, 0, passlen);
        return -1;
    }

    while (optind < argc)
    {
        infile = argv[optind++];

        if ((outfp != NULL) ||
            ((outfp == NULL) && (strncmp("-", infile, 2))))
        {
            printf("%s: %s\n",
                   (mode == ENC) ? "Encrypting" : "Decrypting",
                   strncmp(infile,"-",2) ? infile : "STDIN");
        }

        if(!strncmp("-", infile, 2))
        {
            if (file_count > 1)
            {
                if ((outfp != stdout) && (outfp != NULL))
                {
                    fclose(outfp);
                }
                fprintf(stderr, "Error: STDIN may not be specified with multiple input files.\n");
                usage(argv[0]);
                cleanup(outfile);
                // For security reasons, erase the password
                memset(pass, 0, passlen);
                return -1;
            }
            infp = stdin;
            if (outfp == NULL)
            {
                outfp = stdout;
            }
        }
        else if ((infp = fopen(infile, "r")) == NULL)
        {
            if ((outfp != stdout) && (outfp != NULL))
            {
                fclose(outfp);
            }
            fprintf(stderr, "Error opening input file %s : ", infile);
            perror("");
            cleanup(outfile);
            // For security reasons, erase the password
            memset(pass, 0, passlen);
            return  -1;
        }
        
        if (mode == ENC)
        {
            if (outfp == NULL)
            {
                snprintf(outfile, 1024, "%s.aes", infile);
                if ((outfp = fopen(outfile, "w")) == NULL)
                {
                    if ((infp != stdin) && (infp != NULL))
                    {
                        fclose(infp);
                    }
                    fprintf(stderr, "Error opening output file %s : ", outfile);
                    perror("");
                    cleanup(outfile);
                    // For security reasons, erase the password
                    memset(pass, 0, passlen);
                    return  -1;
                }
            }
            
            rc = encrypt_stream(infp, outfp, pass, passlen);
        }
        else if (mode == DEC)
        {
            if (outfp == NULL)
            {
                // assume .aes extension
                strncpy(outfile, infile, strlen(infile)-4);
                outfile[strlen(infile)-4] = '\0';
                if ((outfp = fopen(outfile, "w")) == NULL)
                {
                    if ((infp != stdin) && (infp != NULL))
                    {
                        fclose(infp);
                    }
                    fprintf(stderr, "Error opening output file %s : ", outfile);
                    perror("");
                    cleanup(outfile);
                    // For security reasons, erase the password
                    memset(pass, 0, passlen);
                    return  -1;
                }
            }
            
            // should probably test against ascii, utf-16le, and utf-16be encodings
            rc = decrypt_stream(infp, outfp, pass, passlen);
        }
        
        if ((infp != stdin) && (infp != NULL))
        {
            fclose(infp);
        }
        if ((outfp != stdout) && (outfp != NULL))
        {
            fclose(outfp);
        }

        // If there was an error, remove the output file
        if (rc)
        {
            cleanup(outfile);
            // For security reasons, erase the password
            memset(pass, 0, passlen);
            return -1;
        }

        // Reset input/output file names and desriptors
        outfile[0] = '\0';
        infp = NULL;
        outfp = NULL;
    }

    // For security reasons, erase the password
    memset(pass, 0, passlen);
    
    return rc;
}