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Diffstat (limited to 'ent/entest.c')
| -rw-r--r-- | ent/entest.c | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/ent/entest.c b/ent/entest.c new file mode 100644 index 0000000..9a38bee --- /dev/null +++ b/ent/entest.c @@ -0,0 +1,270 @@ +/* + ENT -- Entropy calculation and analysis of putative + random sequences. + + Designed and implemented by John "Random" Walker in May 1985. + + Multiple analyses of random sequences added in December 1985. + + Bit stream analysis added in September 1997. + + Terse mode output, getopt() command line processing, + optional stdin input, and HTML documentation added in + October 1998. + + Documentation for the -t (terse output) option added + in July 2006. + + Replaced table look-up for chi square to probability + conversion with algorithmic computation in January 2008. + + Hacked for haveged test April 2009 + + For additional information and the latest version, + see http://www.fourmilab.ch/random/ + +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <math.h> +#include "getopt.h" +#ifdef _WIN32 +#include <fcntl.h> +#include <io.h> +#else +#include <unistd.h> +#endif + +#include "iso8859.h" +#include "randtest.h" + +#define UPDATE "January 28th, 2008" + +#define FALSE 0 +#define TRUE 1 + +#ifdef M_PI +#define PI M_PI +#else +#define PI 3.14159265358979323846 +#endif + +extern double pochisq(const double ax, const int df); + +struct pparams { + double chisqr; + double entropy; + double mean; + double pi; + double seq; + double xtreme; +}; + +static struct pparams defaults = { + .chisqr = 1, // bounds - should be >1% and <99% + .entropy = 7.5, // minimum - should be close to 8 + .mean = 127.0, // minimum - should be close to 127.5 + .pi = 0.5, // maximum - error deviation in percent + .seq = 0.8, // minimum - should be close to 1 + .xtreme = 0.00001 // maximum - result deviation +}; +struct pparams *params = &defaults; + +static int check(long totalc, double ent, double chip, double mean, double montepi, double scc) +{ +char failures[512]; +int offs=0; +double p; +double p0 = params->chisqr; +double p1 = 100-p0; +if (ent<params->entropy) { + sprintf(failures+offs,"entropy:%f<%f ",ent,params->entropy); + offs=strlen(failures); +} +chip *= 100; +if (chip<p0||chip>p1) { + sprintf(failures+offs,"chisqr:%f%% not in %f-%f ",chip,p0,p1); + offs=strlen(failures); +} +if (mean<params->mean) { + sprintf(failures+offs,"mean:%f<%f ",mean,params->mean); + offs=strlen(failures); +} +p = 100*(montepi-PI)/PI; +if (fabs(p)>params->pi) { + sprintf(failures+offs,"pi:%f %f>%f ",montepi,p,params->pi); + offs=strlen(failures); +} +if (scc>params->seq) { + sprintf(failures+offs,"sequence:%f>%f ",scc,params->seq); + offs=strlen(failures); +} +if (offs) { + printf("Check Fail: %s\n",failures); + return -1; +} +printf("Sample looks good!\n"); +return 0; +} + +/* Who checks the checker? The ent self-test test the various options by collecting the output + * of the various options on a given input in a text and then doing a diff with the expected + * output. IMHO the text comparison is pretty cheezy since doubles are involved. We make the + * same check but do not require equality on the quantities involved + */ + +static int checkSelf(long totalc, double ent, double chisq, double mean, double montepi, double scc) +{ +double ref[6] = {11619,7.787095,6567.223255,110.000258,3.392562,0.098324}; +double tst[6] = {totalc,ent,chisq,mean,montepi,scc}; +int i;double f; +for(i=0;i<6;i++) { + f=fabs(tst[i]-ref[i])/ref[i]; + if (f > params->xtreme) { + printf("Self-test(%d) failed:%f?",i,f); + return -1; + } + } +printf("Self-test good!\n"); +return 0; +} + +/* HELP -- Print information on how to call */ + +static void help(void) +{ + printf("entest -- Test the havege RNG."); + printf("\n"); + printf("\n Options: -c<min> Chi Square Threshold"); + printf("\n -e<min> Min entropy/char"); + printf("\n -f<file> File"); + printf("\n -m<min> Min arithmetic mean"); + printf("\n -p<max> Max error in pi"); + printf("\n -s<min> Min serial coeficient"); + printf("\n -t Self test"); + printf("\n -u Print this message\n"); + printf("\n -v Verbose - show the stats"); + printf("\nAdapted from the work of John Walker"); + printf("\n http://www.fourmilab.ch/\n\n"); +} + + +/* Main program */ + +int main(int argc, char *argv[]) +{ + int oc, opt; + long ccount[256]; /* Bins to count occurrences of values */ + long totalc = 0; /* Total character count */ + double montepi, chip, + scc, ent, mean, chisq; + FILE *fp = stdin; + int fold = FALSE, /* Fold upper to lower */ + binary = FALSE, /* Treat input as a bitstream */ + stest = FALSE, + verbose = FALSE; + char *filename=""; + + while ((opt = getopt(argc, argv, "?c:e:f:m:p:s:t:v")) != -1) { + switch (toISOlower(opt)) { + case 'c': + params->chisqr = atof(optarg); + break; + + case 'e': + params->entropy = atof(optarg); + break; + + case 'f': + filename = optarg; + break; + + case 'm': + params->mean = atof(optarg); + break; + + case 'p': + params->pi = atof(optarg); + break; + + case 's': + params->seq = atof(optarg); + break; + + case 't': + filename = optarg; +/* filename = "entitle.gif"; */ + stest = TRUE; + break; + + case 'v': + verbose = TRUE; + break; + + default: + help(); + return -1; + } + } + if (!strlen(filename)) { + printf("Need input file\n"); + help(); + return 2; + } + if ((fp = fopen(filename, "rb")) == NULL) { + printf("Cannot open file %s\n", filename); + return 2; + } + memset(ccount, 0, sizeof ccount); + + /* Initialise for calculations */ + + rt_init(binary); + + /* Scan input file and count character occurrences */ + + while ((oc = fgetc(fp)) != EOF) { + unsigned char ocb; + + if (fold && isISOalpha(oc) && isISOupper(oc)) { + oc = toISOlower(oc); + } + ocb = (unsigned char) oc; + totalc += binary ? 8 : 1; + if (binary) { + int b; + unsigned char ob = ocb; + + for (b = 0; b < 8; b++) { + ccount[ob & 1]++; + ob >>= 1; + } + } else { + ccount[ocb]++; /* Update counter for this bin */ + } + rt_add(&ocb, 1); + } + fclose(fp); + + /* Complete calculation and return sequence metrics */ + + rt_end(&ent, &chisq, &mean, &montepi, &scc); + chip = pochisq(chisq, (binary ? 1 : 255)); + + if (verbose) + printf("\nTest Results\n" + "Sample: %ld bytes\n" + "Entropy: %f bits\n" + "Chi-Square: %f(%f%%)\n" + "Mean: %f\n" + "PI: %f(%f%%)\n" + "Correlation: %f\n", + totalc, ent, chisq, chip*100, mean, montepi,100*(montepi-PI)/PI,scc); + + if (stest) + return checkSelf(totalc, ent, chisq, mean, montepi, scc); + return check(totalc, ent, chip, mean, montepi, scc); +} |