diff --git a/coverage.sh b/coverage.sh
index d089ff6..a17c97d 100755
--- a/coverage.sh
+++ b/coverage.sh
@@ -32,7 +32,7 @@ fi
 ./sizes
 ./constants
 
-for i in $(./hashsum | tail -n +3 | awk '{print $1}' | sort); do echo -n "$i: " && ./hashsum $i testprof/test.key ; done > hashsum_tv.txt
+for i in $(for j in $(echo $(./hashsum -h | tail -n +3)); do echo $j; done | sort); do echo -n "$i: " && ./hashsum -a $i testprof/test.key ; done > hashsum_tv.txt
 difftroubles=$(diff -i -w -B hashsum_tv.txt notes/hashsum_tv.txt | grep '^<') || true
 if [ -n "$difftroubles" ]; then
   echo "FAILURE: hashsum_tv.tx"
diff --git a/demos/hashsum.c b/demos/hashsum.c
index 5625329..c3824d5 100644
--- a/demos/hashsum.c
+++ b/demos/hashsum.c
@@ -9,37 +9,232 @@
 
 #include <tomcrypt.h>
 
-int errno;
+#if _POSIX_C_SOURCE >= 200112L
+#include <libgen.h>
+#else
+#define basename(x) x
+#endif
 
-void register_algs(void);
+/* thanks http://stackoverflow.com/a/8198009 */
+#define _base(x) ((x >= '0' && x <= '9') ? '0' : \
+         (x >= 'a' && x <= 'f') ? 'a' - 10 : \
+         (x >= 'A' && x <= 'F') ? 'A' - 10 : \
+            '\255')
+#define HEXOF(x) (x - _base(x))
+
+static void register_algs(void);
+
+static char* hashsum;
+
+static void die(int status)
+{
+   unsigned long w, x;
+   FILE* o = status == EXIT_SUCCESS ? stdout : stderr;
+   fprintf(o, "usage: %s -a algorithm [-c] [file...]\n", hashsum);
+   fprintf(o, "Algorithms:\n");
+   w = 0;
+   for (x = 0; hash_descriptor[x].name != NULL; x++) {
+      w += fprintf(o, "%-14s", hash_descriptor[x].name);
+      if (w >= 70) {
+         fprintf(o, "\n");
+         w = 0;
+      }
+   }
+   if (w != 0) fprintf(o, "\n");
+   free(hashsum);
+   exit(status);
+}
+
+static void printf_hex(unsigned char* hash_buffer, unsigned long w)
+{
+   unsigned long x;
+   for (x = 0; x < w; x++) {
+       printf("%02x",hash_buffer[x]);
+   }
+}
+
+static void check_file(int argn, int argc, char **argv)
+{
+   int err, failed, invalid;
+   unsigned char is_buffer[MAXBLOCKSIZE], should_buffer[MAXBLOCKSIZE];
+   char buf[PATH_MAX + (MAXBLOCKSIZE * 3)];
+   /* iterate through all files */
+   while(argn < argc) {
+      char* s;
+      FILE* f = fopen(argv[argn], "rb");
+      if(f == NULL) {
+         int n = snprintf(buf, sizeof(buf), "%s: %s", hashsum, argv[argn]);
+         if (n > 0 && n < (int)sizeof(buf))
+            perror(buf);
+         else
+            perror(argv[argn]);
+         exit(EXIT_FAILURE);
+      }
+      failed = 0;
+      invalid = 0;
+      /* read the file line by line */
+      while((s = fgets(buf, sizeof(buf), f)) != NULL)
+      {
+         int tries, n;
+         unsigned long hash_len, w, x;
+         char* space = strstr(s, " ");
+         if (space == NULL) {
+            fprintf(stderr, "%s: no properly formatted checksum lines found\n", hashsum);
+            goto ERR;
+         }
+
+         hash_len = space - s;
+         hash_len /= 2;
+
+         /* convert the hex-string back to binary */
+         for (x = 0; x < hash_len; ++x) {
+            should_buffer[x] = HEXOF(s[x*2]) << 4 | HEXOF(s[x*2 + 1]);
+         }
+
+         space++;
+         if (*space != '*') {
+            fprintf(stderr, "%s: unsupported input mode '%c'\n", hashsum, *space);
+            goto ERR;
+         }
+         space++;
+
+         for (n = 0; n < (buf + sizeof(buf)) - space; ++n) {
+            if(iscntrl(space[n])) {
+               space[n] = '\0';
+               break;
+            }
+         }
+
+         /* try all hash algorithms that have the appropriate hash size */
+         tries = 0;
+         for (x = 0; hash_descriptor[x].name != NULL; ++x) {
+            if (hash_descriptor[x].hashsize == hash_len) {
+               tries++;
+               w = sizeof(is_buffer);
+               if ((err = hash_file(x, space, is_buffer, &w)) != CRYPT_OK) {
+                  fprintf(stderr, "%s: File hash error: %s: %s\n", hashsum, space, error_to_string(err));
+ERR:
+                  fclose(f);
+                  exit(EXIT_FAILURE);
+               }
+               if(XMEMCMP(should_buffer, is_buffer, w) == 0) {
+                  printf("%s: OK\n", space);
+                  break;
+               }
+            }
+         } /* for */
+         if (hash_descriptor[x].name == NULL) {
+            if(tries > 0) {
+               printf("%s: FAILED\n", space);
+               failed++;
+            }
+            else {
+               invalid++;
+            }
+         }
+      } /* while */
+      fclose(f);
+      if(invalid) {
+         fprintf(stderr, "%s: WARNING: %d %s is improperly formatted\n", hashsum, invalid, invalid > 1?"lines":"line");
+      }
+      if(failed) {
+         fprintf(stderr, "%s: WARNING: %d computed %s did NOT match\n", hashsum, failed, failed > 1?"checksums":"checksum");
+      }
+      argn++;
+   }
+   exit(EXIT_SUCCESS);
+}
 
 int main(int argc, char **argv)
 {
-   int idx, z;
+   int idx, check, z, err, argn;
    unsigned long w, x;
    unsigned char hash_buffer[MAXBLOCKSIZE];
 
+   hashsum = strdup(basename(argv[0]));
+
    /* You need to register algorithms before using them */
    register_algs();
-   if (argc < 2) {
-      printf("usage: ./hash algorithm file [file ...]\n");
-      printf("Algorithms:\n");
-      for (x = 0; hash_descriptor[x].name != NULL; x++) {
-         printf(" %s (%d)\n", hash_descriptor[x].name, hash_descriptor[x].ID);
+   if (argc > 1 && (strcmp("-h", argv[1]) == 0 || strcmp("--help", argv[1]) == 0)) {
+      die(EXIT_SUCCESS);
+   }
+   if (argc < 3) {
+      die(EXIT_FAILURE);
+   }
+
+   argn = 1;
+   check = 0;
+   idx = -2;
+
+   while(argn < argc){
+      if(strcmp("-a", argv[argn]) == 0) {
+         argn++;
+         if(argn < argc) {
+            idx = find_hash(argv[argn]);
+            if (idx == -1) {
+               struct {
+                  const char* is;
+                  const char* should;
+               } shasum_compat[] =
+                     {
+#ifdef LTC_SHA1
+                           { "1",        sha1_desc.name },
+#endif
+#ifdef LTC_SHA224
+                           { "224",      sha224_desc.name  },
+#endif
+#ifdef LTC_SHA256
+                           { "256",      sha256_desc.name  },
+#endif
+#ifdef LTC_SHA384
+                           { "384",      sha384_desc.name  },
+#endif
+#ifdef LTC_SHA512
+                           { "512",      sha512_desc.name  },
+#endif
+#ifdef LTC_SHA512_224
+                           { "512224",   sha512_224_desc.name  },
+#endif
+#ifdef LTC_SHA512_256
+                           { "512256",   sha512_256_desc.name  },
+#endif
+                           { NULL, NULL }
+                     };
+               for (x = 0; shasum_compat[x].is != NULL; ++x) {
+                  if(XSTRCMP(shasum_compat[x].is, argv[argn]) == 0) {
+                     idx = find_hash(shasum_compat[x].should);
+                     break;
+                  }
+               }
+            }
+            if (idx == -1) {
+               fprintf(stderr, "%s: Unrecognized algorithm\n", hashsum);
+               die(EXIT_FAILURE);
+            }
+            argn++;
+            continue;
+         }
+         else {
+            die(EXIT_FAILURE);
+         }
       }
-      exit(EXIT_SUCCESS);
+      if(strcmp("-c", argv[argn]) == 0) {
+         check = 1;
+         argn++;
+         continue;
+      }
+      break;
    }
 
-   idx = find_hash(argv[1]);
-   if (idx == -1) {
-      fprintf(stderr, "\nInvalid hash specified on command line.\n");
-      return -1;
+   if (check == 1) {
+      check_file(argn, argc, argv);
    }
 
-   if (argc == 2) {
+   if (argc == argn) {
       w = sizeof(hash_buffer);
-      if ((errno = hash_filehandle(idx, stdin, hash_buffer, &w)) != CRYPT_OK) {
-         printf("File hash error: %s\n", error_to_string(errno));
+      if ((err = hash_filehandle(idx, stdin, hash_buffer, &w)) != CRYPT_OK) {
+         fprintf(stderr, "%s: File hash error: %s\n", hashsum, error_to_string(err));
+         return EXIT_FAILURE;
       } else {
           for (x = 0; x < w; x++) {
               printf("%02x",hash_buffer[x]);
@@ -47,14 +242,13 @@ int main(int argc, char **argv)
           printf(" *-\n");
       }
    } else {
-      for (z = 2; z < argc; z++) {
+      for (z = 3; z < argc; z++) {
          w = sizeof(hash_buffer);
-         if ((errno = hash_file(idx,argv[z],hash_buffer,&w)) != CRYPT_OK) {
-            printf("File hash error: %s\n", error_to_string(errno));
+         if ((err = hash_file(idx,argv[z],hash_buffer,&w)) != CRYPT_OK) {
+            fprintf(stderr, "%s: File hash error: %s\n", hashsum, error_to_string(err));
+            return EXIT_FAILURE;
          } else {
-             for (x = 0; x < w; x++) {
-                 printf("%02x",hash_buffer[x]);
-             }
+             printf_hex(hash_buffer, w);
              printf(" *%s\n", argv[z]);
          }
       }
@@ -62,7 +256,7 @@ int main(int argc, char **argv)
    return EXIT_SUCCESS;
 }
 
-void register_algs(void)
+static void register_algs(void)
 {
   int err;
   LTC_UNUSED_PARAM(err);
diff --git a/notes/hashsum_tv.txt b/notes/hashsum_tv.txt
index c2a58b4..228d9f0 100644
--- a/notes/hashsum_tv.txt
+++ b/notes/hashsum_tv.txt
@@ -1,29 +1,29 @@
-blake2b-160: 684b540eb245ebba2cd66b7814fe6d787868a5bb  *testprof/test.key
-blake2b-256: 3aaa08120aa0174c105fd1f3412e3da30c3bbb9073569b0b8ae458b34de7780e  *testprof/test.key
-blake2b-384: c33f39ab19099d5dea6789479e23447857803a3f45361ea58dd69c7b8037c8697544b6a741e236215adcb8b38fa0cfc4  *testprof/test.key
-blake2b-512: a2daabae6996e3bbfb76c5d277fb881107037c756173f510d83a78f669cf0b70a5088b971e30ca2168381568ea3d30b80a7b500944a5e2e3294f25aed4c3a5f1  *testprof/test.key
-blake2s-128: 7e1f9b6de11a3c597308f9d8aacd7321  *testprof/test.key
-blake2s-160: 3d1c9ae1a0afe8a6ef8b61d5380de7b061cd353c  *testprof/test.key
-blake2s-224: 95dacd83d0421b2d69a52d92ee54143bb97c91a61450d917a88d4388  *testprof/test.key
-blake2s-256: 92ac6dc88b9ce4a75b2a54783435a37919303f713396db0e9ccd976d8c55f1cf  *testprof/test.key
-chc_hash: d50da1ea9b53c0b891c8bcb0a4c6e5e0  *testprof/test.key
-md2: 0b327a17a102580ccde8081c18f137c7  *testprof/test.key
-md4: 6df7b3c1f7fbcbf6b8246dc0046e9d6b  *testprof/test.key
-md5: 48fd9ed11c633069c3cf721611696a73  *testprof/test.key
-rmd128: a78170e11d56605eb0f5e05e6a218e61  *testprof/test.key
-rmd160: 56236b14cd15958c58136a295fa2b07c5edee009  *testprof/test.key
-rmd256: a0a658b25b8841f20be8151eb5e2c1229f085dd5cf7aa8bef4c8e07ea5738913  *testprof/test.key
-rmd320: 2ec15ca947f29dd8cef4782aeaeb4541ac00dc29e1649c4f5f4578ef0287091e513f9da423ce7319  *testprof/test.key
-sha1: c17a11eef02d7a2ad7250bc2ee22bdf37ed21f0f  *testprof/test.key
-sha224: b226daa069512c849d55866470c23543d87e1fb768171efdcc6ab59a  *testprof/test.key
-sha256: 76ec7faebdc42a4de35ca70024c2d273e9f7856ca61612e89f5f66350ba8cf5f  *testprof/test.key
-sha3-224: 09525d6410c462e00e72ccd4304290bc59ff2b1b8e5322dbc197e169  *testprof/test.key
-sha3-256: b9016fc9976545ad0183775d88f20df5295d40b31db00d85f6916333260b8ae2  *testprof/test.key
-sha3-384: 5452977763b602df4185bbe7cce193346b09ee20d4a45a780fd44237e335ceaa71b9da06242621e159d796db9043c9be  *testprof/test.key
-sha3-512: 1fadf63073c8613d38d5c944e2e3f7e086d94d93dceb2eec1e9693fd44158f3127c90cbaa8a13035cc9ff9b3572c9dce836bea15c92e8a78b036ec382caceb0f  *testprof/test.key
-sha384: 7cc080c662524617e56d5a49f1c185909e9b1858a86684161ddd97fc5426f693b53f59d779de16da25dcb1259df879e5  *testprof/test.key
-sha512: f90afe4d254716a9770fd2c4f29ca544f2975f961cbd7fa207117383e4e48f7a2e1ade4aac333a2cb8c227dd6af2fff4d87c31c2a3916ae24d507c7c94c21818  *testprof/test.key
-sha512-224: 64ec566b5c2de736eab1b4e8542dc110f736819ea7f8f48e3712fbad  *testprof/test.key
-sha512-256: db880bce4beb7246510febb961c7595aab57a15de6f90cd079f145e476b5d773  *testprof/test.key
-tiger: 97d713850e7affac30a642572c1ee7b18793d5b9e0ef5932  *testprof/test.key
-whirlpool: d7d41c755e0f28313f254cb198e0bfa42f56670595d97b80dceec754825d69938a9c11e5bf16e9a3809a62a09bddf021f3dbff4302ceec7ba46c88b41772b711  *testprof/test.key
+blake2b-160: 684b540eb245ebba2cd66b7814fe6d787868a5bb *testprof/test.key
+blake2b-256: 3aaa08120aa0174c105fd1f3412e3da30c3bbb9073569b0b8ae458b34de7780e *testprof/test.key
+blake2b-384: c33f39ab19099d5dea6789479e23447857803a3f45361ea58dd69c7b8037c8697544b6a741e236215adcb8b38fa0cfc4 *testprof/test.key
+blake2b-512: a2daabae6996e3bbfb76c5d277fb881107037c756173f510d83a78f669cf0b70a5088b971e30ca2168381568ea3d30b80a7b500944a5e2e3294f25aed4c3a5f1 *testprof/test.key
+blake2s-128: 7e1f9b6de11a3c597308f9d8aacd7321 *testprof/test.key
+blake2s-160: 3d1c9ae1a0afe8a6ef8b61d5380de7b061cd353c *testprof/test.key
+blake2s-224: 95dacd83d0421b2d69a52d92ee54143bb97c91a61450d917a88d4388 *testprof/test.key
+blake2s-256: 92ac6dc88b9ce4a75b2a54783435a37919303f713396db0e9ccd976d8c55f1cf *testprof/test.key
+chc_hash: d50da1ea9b53c0b891c8bcb0a4c6e5e0 *testprof/test.key
+md2: 0b327a17a102580ccde8081c18f137c7 *testprof/test.key
+md4: 6df7b3c1f7fbcbf6b8246dc0046e9d6b *testprof/test.key
+md5: 48fd9ed11c633069c3cf721611696a73 *testprof/test.key
+rmd128: a78170e11d56605eb0f5e05e6a218e61 *testprof/test.key
+rmd160: 56236b14cd15958c58136a295fa2b07c5edee009 *testprof/test.key
+rmd256: a0a658b25b8841f20be8151eb5e2c1229f085dd5cf7aa8bef4c8e07ea5738913 *testprof/test.key
+rmd320: 2ec15ca947f29dd8cef4782aeaeb4541ac00dc29e1649c4f5f4578ef0287091e513f9da423ce7319 *testprof/test.key
+sha1: c17a11eef02d7a2ad7250bc2ee22bdf37ed21f0f *testprof/test.key
+sha224: b226daa069512c849d55866470c23543d87e1fb768171efdcc6ab59a *testprof/test.key
+sha256: 76ec7faebdc42a4de35ca70024c2d273e9f7856ca61612e89f5f66350ba8cf5f *testprof/test.key
+sha3-224: 09525d6410c462e00e72ccd4304290bc59ff2b1b8e5322dbc197e169 *testprof/test.key
+sha3-256: b9016fc9976545ad0183775d88f20df5295d40b31db00d85f6916333260b8ae2 *testprof/test.key
+sha3-384: 5452977763b602df4185bbe7cce193346b09ee20d4a45a780fd44237e335ceaa71b9da06242621e159d796db9043c9be *testprof/test.key
+sha3-512: 1fadf63073c8613d38d5c944e2e3f7e086d94d93dceb2eec1e9693fd44158f3127c90cbaa8a13035cc9ff9b3572c9dce836bea15c92e8a78b036ec382caceb0f *testprof/test.key
+sha384: 7cc080c662524617e56d5a49f1c185909e9b1858a86684161ddd97fc5426f693b53f59d779de16da25dcb1259df879e5 *testprof/test.key
+sha512: f90afe4d254716a9770fd2c4f29ca544f2975f961cbd7fa207117383e4e48f7a2e1ade4aac333a2cb8c227dd6af2fff4d87c31c2a3916ae24d507c7c94c21818 *testprof/test.key
+sha512-224: 64ec566b5c2de736eab1b4e8542dc110f736819ea7f8f48e3712fbad *testprof/test.key
+sha512-256: db880bce4beb7246510febb961c7595aab57a15de6f90cd079f145e476b5d773 *testprof/test.key
+tiger: 97d713850e7affac30a642572c1ee7b18793d5b9e0ef5932 *testprof/test.key
+whirlpool: d7d41c755e0f28313f254cb198e0bfa42f56670595d97b80dceec754825d69938a9c11e5bf16e9a3809a62a09bddf021f3dbff4302ceec7ba46c88b41772b711 *testprof/test.key
diff --git a/src/hashes/helper/hash_filehandle.c b/src/hashes/helper/hash_filehandle.c
index e1d037e..f1f29c0 100644
--- a/src/hashes/helper/hash_filehandle.c
+++ b/src/hashes/helper/hash_filehandle.c
@@ -52,14 +52,15 @@ int hash_filehandle(int hash, FILE *in, unsigned char *out, unsigned long *outle
        goto LBL_ERR;
     }
 
-    *outlen = hash_descriptor[hash].hashsize;
     do {
         x = fread(buf, 1, LTC_FILE_READ_BUFSIZE, in);
         if ((err = hash_descriptor[hash].process(&md, buf, (unsigned long)x)) != CRYPT_OK) {
            goto LBL_CLEANBUF;
         }
     } while (x == LTC_FILE_READ_BUFSIZE);
-    err = hash_descriptor[hash].done(&md, out);
+    if ((err = hash_descriptor[hash].done(&md, out)) == CRYPT_OK) {
+       *outlen = hash_descriptor[hash].hashsize;
+    }
 
 LBL_CLEANBUF:
     zeromem(buf, LTC_FILE_READ_BUFSIZE);