Revert "abuild-tar: embed checksum for symlinks"

Tar could not handle the headers.

This reverts parts of commit 8b1a5301.
Keep the usage fixes.

abuild-tar.c

@@ -42,8 +42,6 @@ struct tar_header {
 	char padding[12];   /* 500-512 */
 };
 
-#define MAX_MD_SIZE 20
-
 #define GET_OCTAL(s)	get_octal(s, sizeof(s))
 #define PUT_OCTAL(s,v)	put_octal(s, sizeof(s), v)
 
@@ -175,7 +173,7 @@ static int do_it(const EVP_MD *md, int cut)
 	struct tar_header hdr;
 	size_t size, aligned_size;
 	void *ptr;
-	int r;
+	int dohash = 0, r;
 	struct {
 		char id[4];
 		uint16_t nid;
@@ -195,34 +193,22 @@ static int do_it(const EVP_MD *md, int cut)
 		if (cut && hdr.name[0] == 0)
 			return 0;
 
-		ptr = NULL;
 		size = GET_OCTAL(hdr.size);
 		aligned_size = (size + 511) & ~511;
 
-		if (md != NULL &&
-		    (hdr.typeflag == '0' || hdr.typeflag == '2' ||
-		     hdr.typeflag == '7')) {
+		if (md != NULL)
+			dohash = (hdr.typeflag == '0' || hdr.typeflag == '7');
+		if (dohash) {
 			const unsigned char *src;
-			unsigned char csdata[MAX_MD_SIZE];
 			int chksum, i;
 
-			if (hdr.typeflag == '0' || hdr.typeflag == '7') {
-				ptr = malloc(aligned_size);
-				if (full_read(STDIN_FILENO, ptr, aligned_size)
-				    != aligned_size)
-					return 1;
-
-				memcpy(&hdr.linkname[3], &mdinfo, sizeof(mdinfo));
-				EVP_Digest(ptr, size, csdata, NULL, md, NULL);
-			} else {
-				EVP_Digest(hdr.linkname, strlen(hdr.linkname),
-					   csdata, NULL, md, NULL);
-			}
+			ptr = malloc(aligned_size);
+			if (full_read(STDIN_FILENO, ptr, aligned_size) != aligned_size)
+				return 1;
 
-			/* Embed to header */
-			memcpy(&hdr.devmajor, &mdinfo, sizeof(hdr.devmajor));
-			memcpy(&hdr.devminor, &csdata[0], sizeof(hdr.devminor));
-			memcpy(&hdr.padding,  &csdata[sizeof(hdr.devminor)], sizeof(hdr.padding));
+			memcpy(&hdr.linkname[3], &mdinfo, sizeof(mdinfo));
+			EVP_Digest(ptr, size, &hdr.linkname[3+sizeof(mdinfo)],
+				   NULL, md, NULL);
 
 			/* Recalculate checksum */
 			memset(hdr.chksum, ' ', sizeof(hdr.chksum));
@@ -235,7 +221,7 @@ static int do_it(const EVP_MD *md, int cut)
 		if (full_write(STDOUT_FILENO, &hdr, sizeof(hdr)) != sizeof(hdr))
 			return 2;
 
-		if (ptr != NULL) {
+		if (dohash) {
 			if (full_write(STDOUT_FILENO, ptr, aligned_size) != aligned_size)
 				return 2;
 			free(ptr);
@@ -285,10 +271,6 @@ int main(int argc, char **argv)
 		md = EVP_get_digestbyname(digest);
 		if (md == NULL)
 			return usage();
-		if (EVP_MD_size(md) > MAX_MD_SIZE) {
-			fprintf(stderr, "digest size is too large\n");
-			return -1;
-		}
 	}
 
 	return do_it(md, cut);