checksum tools: implement -c

Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>

crypt.h

@@ -6,6 +6,7 @@ struct crypt_ops {
 	void *s;
 };
 
+int cryptcheck(char *, int, char **, struct crypt_ops *, uint8_t *, size_t);
 int cryptmain(int, char **, struct crypt_ops *, uint8_t *, size_t);
 int cryptsum(struct crypt_ops *, FILE *, const char *, uint8_t *);
 void mdprint(const uint8_t *, const char *, size_t);

md5sum.c

@@ -24,13 +24,17 @@ int
 main(int argc, char *argv[])
 {
 	uint8_t md[MD5_DIGEST_LENGTH];
+	char *checkfile = NULL;
 
 	ARGBEGIN {
 	case 'c':
-		eprintf("not implemented\n");
+		checkfile = EARGF(usage());
+		break;
 	default:
 		usage();
 	} ARGEND;
 
+	if(checkfile)
+		return cryptcheck(checkfile, argc, argv, &md5_ops, md, sizeof(md));
 	return cryptmain(argc, argv, &md5_ops, md, sizeof(md));
 }

sha1sum.c

@@ -24,13 +24,16 @@ int
 main(int argc, char *argv[])
 {
 	uint8_t md[SHA1_DIGEST_LENGTH];
+	char *checkfile = NULL;
 
 	ARGBEGIN {
 	case 'c':
-		eprintf("not implemented\n");
+		checkfile = EARGF(usage());
 	default:
 		usage();
 	} ARGEND;
 
+	if(checkfile)
+		return cryptcheck(checkfile, argc, argv, &sha1_ops, md, sizeof(md));
 	return cryptmain(argc, argv, &sha1_ops, md, sizeof(md));
 }

sha256sum.c

@@ -24,13 +24,16 @@ int
 main(int argc, char *argv[])
 {
 	uint8_t md[SHA256_DIGEST_LENGTH];
+	char *checkfile = NULL;
 
 	ARGBEGIN {
 	case 'c':
-		eprintf("not implemented\n");
+		checkfile = EARGF(usage());
 	default:
 		usage();
 	} ARGEND;
 
+	if(checkfile)
+		return cryptcheck(checkfile, argc, argv, &sha256_ops, md, sizeof(md));
 	return cryptmain(argc, argv, &sha256_ops, md, sizeof(md));
 }

sha512sum.c

@@ -24,13 +24,16 @@ int
 main(int argc, char *argv[])
 {
 	uint8_t md[SHA512_DIGEST_LENGTH];
+	char *checkfile = NULL;
 
 	ARGBEGIN {
 	case 'c':
-		eprintf("not implemented\n");
+		checkfile = EARGF(usage());
 	default:
 		usage();
 	} ARGEND;
 
+	if(checkfile)
+		return cryptcheck(checkfile, argc, argv, &sha512_ops, md, sizeof(md));
 	return cryptmain(argc, argv, &sha512_ops, md, sizeof(md));
 }

util/crypt.c

@@ -2,9 +2,96 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <string.h>
 #include "../util.h"
+#include "../text.h"
 #include "../crypt.h"
 
+static int
+hexdec(int c) {
+	if(c >= '0' && c <= '9')
+		return c - '0';
+	else if(c >= 'A' && c <= 'F')
+		return c - 'A' + 10;
+	else if(c >= 'a' && c <= 'f')
+		return c - 'a' + 10;
+	return -1; /* unknown character */
+}
+
+static int
+mdcheckline(const char *s, uint8_t *md, size_t sz) {
+	size_t i;
+	int b1, b2;
+
+	for(i = 0; i < sz; i++) {
+		if(!*s || (b1 = hexdec(*s++)) < 0)
+			return -1; /* invalid format */
+		if(!*s || (b2 = hexdec(*s++)) < 0)
+			return -1; /* invalid format */
+		if((uint8_t)((b1 << 4) | b2) != md[i])
+			return 0; /* value mismatch */
+	}
+	return (i == sz) ? 1 : 0;
+}
+
+int
+cryptcheck(char *sumfile, int argc, char *argv[],
+	  struct crypt_ops *ops, uint8_t *md, size_t sz)
+{
+	FILE *cfp, *fp;
+	char *buf = NULL, *line, *file, *p;
+	int r, nonmatch = 0, formatsucks = 0, noread = 0, ret = EXIT_SUCCESS;
+	size_t bufsiz = 0;
+
+	if(!(cfp = fopen(sumfile, "r")))
+		eprintf("fopen %s:", sumfile);
+
+	while((line = afgets(&buf, &bufsiz, cfp))) {
+		if(!(file = strstr(line, "  "))) {
+			formatsucks++;
+			continue;
+		}
+		if((file - line) / 2 != sz) {
+			formatsucks++; /* checksum length mismatch */
+			continue;
+		}
+		*file = '\0';
+		file += 2;
+		for(p = file; *p && *p != '\n' && *p != '\r'; p++); /* strip newline */
+		*p = '\0';
+		if(!(fp = fopen(file, "r"))) {
+			weprintf("fopen %s:", file);
+			noread++;
+			continue;
+		}
+		cryptsum(ops, fp, file, md);
+		r = mdcheckline(line, md, sz);
+		if(r == 1) {
+			printf("%s: OK\n", file);
+		} else if(r == 0) {
+			printf("%s: FAILED\n", file);
+			nonmatch++;
+		} else {
+			formatsucks++;
+		}
+		fclose(fp);
+	}
+	fclose(cfp);
+	if(formatsucks > 0) {
+		weprintf("WARNING: %d lines are improperly formatted\n", formatsucks);
+		ret = EXIT_FAILURE;
+	}
+	if(noread > 0) {
+		weprintf("WARNING: %d listed file could not be read\n", noread);
+		ret = EXIT_FAILURE;
+	}
+	if(nonmatch > 0) {
+		weprintf("WARNING: %d computed checksums did NOT match\n", nonmatch);
+		ret = EXIT_FAILURE;
+	}
+	return ret;
+}
+
 int
 cryptmain(int argc, char *argv[],
 	  struct crypt_ops *ops, uint8_t *md, size_t sz)