Turns out SHA1 runs faster than SHA. I kind of figured the reverse. I ran a 94 megabyte file through the program below on a single processor 1Ghz PIII SLT2 and got...

#include <openssl/sha.h>
#include <stdio.h>
#include <stdlib.h>

#define BUFSIZE   1024*16
#define SHA 1

/* Dumps out a SHA string
 */
void pt(unsigned char *md)
{
   int i;

   for (i=0; i<SHA_DIGEST_LENGTH; i++)
   {  printf("%02x",md[i]);
   }
   printf("\n");
}


long do_fp_test(FILE *f, char* result, int SHA1mode)
{
   SHA_CTX c;
   int fd;
   int i;
   long bytesRead = 0;
   unsigned char buf[BUFSIZE];

   fd=fileno(f);

   if (SHA1mode)
   {  SHA1_Init(&c);
   }
   else
   {  SHA_Init(&c);
   }

   for (;;)
   {
      i=read(fd,buf,BUFSIZE);
      bytesRead += i;
      if (i <= 0) break;
      if (SHA1mode)
      {  SHA1_Update(&c,buf,(unsigned long)i);
      }
      else
      {  SHA_Update(&c,buf,(unsigned long)i);
      }
   }

   if (SHA1mode)
   {  SHA1_Final(&(result[0]),&c);
   }
   else
   {  SHA_Final(&(result[0]),&c);
   }

   return bytesRead;
}

int main(int argc, char **argv)
{
   FILE* myFile;
   unsigned char md[SHA_DIGEST_LENGTH];
   struct timeval start, end;
   double total_time;
   long bytesProcessed = 0;
   float processingRate = 0;

   int doSHA1 = 1;

   if (argc < 2)
   {
      printf("usage: shatest <filename> [SHA] (SHA1 by default)\n");
   }
   else
   {
      if (argc > 2)
      {  if (!strcmp(argv[2], "SHA"))
         {  doSHA1 = 0;
         }
      }

      printf("Computing %s for %s...",
         (doSHA1 ? "SHA1" : "SHA"), argv[1]);

      myFile = fopen(argv[1], "r");
      if (myFile)
      {

   /* start the timer
    */
         gettimeofday(&start, NULL);
         bytesProcessed = do_fp_test(myFile, md, doSHA1);
         gettimeofday(&end, NULL);

         printf("OK!\n");
         pt(md);

         total_time =
            (end.tv_sec   +   (end.tv_usec * 0.000001)) -
            (start.tv_sec +   (start.tv_usec * 0.000001));
         processingRate = ((float)bytesProcessed / total_time)/1000000;
         printf("Total time for test:  %f\n", total_time);
         printf("Bytes processed:  %d\n", bytesProcessed);
         printf("Processing Speed: %f MB/s\n", processingRate);

      }
      else
      {  printf("FAILED! Can't open file.\n");
      }
   }
}

OPENSSLDIR = /usr/local/ssl # openSSL directory


INCLUDE = -I$(OPENSSLDIR)/crypto/sha

LIB = $(OPENSSLDIR)/libcrypto.a $(OPENSSLDIR)/libssl.a

shatest: shatest.c
       gcc -o shatest shatest.c ${INCLUDE} ${LIB} -static

clean:
   rm *.o core

-- MattWalsh - 09 Feb 2002