Add simple algorithm for converting result hash to password

Makefile.in

@@ -51,6 +51,7 @@ binPROGRAMS_INSTALL = $(INSTALL_PROGRAM)
 PROGRAMS = $(bin_PROGRAMS)
 am_scrypt_OBJECTS = scrypt-main.$(OBJEXT) \
 	scrypt-readpass.$(OBJEXT) scrypt-warn.$(OBJEXT) \
+	scrypt-hashtopass.$(OBJEXT) \
 	scrypt-genpass.$(OBJEXT) \
 	scrypt-sha256.$(OBJEXT) \
 	scrypt-crypto_scrypt-@SCRYPTVER@.$(OBJEXT)
@@ -175,6 +176,7 @@ AUTOMAKE_OPTIONS = foreign
 dist_man_MANS = $(scrypt_man_MANS)
 scrypt_SOURCES = main.c				\
 			lib/util/readpass.c		\
+			lib/util/hashtopass.c \
 			lib/util/warn.c			\
 			lib/genpass/genpass.c	\
 			lib/crypto/sha256.c		\
@@ -274,6 +276,7 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-crypto_scrypt-@SCRYPTVER@.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-main.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-readpass.Po@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-hashtopass.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-genpass.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-sha256.Po@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/scrypt-warn.Po@am__quote@
@@ -319,6 +322,21 @@ scrypt-readpass.obj: lib/util/readpass.c
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	source='lib/util/readpass.c' object='scrypt-readpass.obj' libtool=no @AMDEPBACKSLASH@
 @AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
 @am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -c -o scrypt-readpass.obj `if test -f 'lib/util/readpass.c'; then $(CYGPATH_W) 'lib/util/readpass.c'; else $(CYGPATH_W) '$(srcdir)/lib/util/readpass.c'; fi`
+scrypt-readpass.o: lib/util/readpass.c
+
+scrypt-hashtopass.o: lib/util/hashtopass.c
+@am__fastdepCC_TRUE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -MT scrypt-hashtopass.o -MD -MP -MF $(DEPDIR)/scrypt-hashtopass.Tpo -c -o scrypt-hashtopass.o `test -f 'lib/util/hashtopass.c' || echo '$(srcdir)/'`lib/util/hashtopass.c
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/scrypt-hashtopass.Tpo $(DEPDIR)/scrypt-hashtopass.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='lib/util/hashtopass.c' object='scrypt-hashtopass.o' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -c -o scrypt-hashtopass.o `test -f 'lib/util/hashtopass.c' || echo '$(srcdir)/'`lib/util/hashtopass.c
+
+scrypt-hashtopass.obj: lib/util/hashtopass.c
+@am__fastdepCC_TRUE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -MT scrypt-hashtopass.obj -MD -MP -MF $(DEPDIR)/scrypt-hashtopass.Tpo -c -o scrypt-hashtopass.obj `if test -f 'lib/util/hashtopass.c'; then $(CYGPATH_W) 'lib/util/hashtopass.c'; else $(CYGPATH_W) '$(srcdir)/lib/util/hashtopass.c'; fi`
+@am__fastdepCC_TRUE@	mv -f $(DEPDIR)/scrypt-hashtopass.Tpo $(DEPDIR)/scrypt-hashtopass.Po
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	source='lib/util/hashtopass.c' object='scrypt-hashtopass.obj' libtool=no @AMDEPBACKSLASH@
+@AMDEP_TRUE@@am__fastdepCC_FALSE@	DEPDIR=$(DEPDIR) $(CCDEPMODE) $(depcomp) @AMDEPBACKSLASH@
+@am__fastdepCC_FALSE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -c -o scrypt-hashtopass.obj `if test -f 'lib/util/hashtopass.c'; then $(CYGPATH_W) 'lib/util/hashtopass.c'; else $(CYGPATH_W) '$(srcdir)/lib/util/hashtopass.c'; fi`
 
 scrypt-warn.o: lib/util/warn.c
 @am__fastdepCC_TRUE@	$(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(scrypt_CFLAGS) $(CFLAGS) -MT scrypt-warn.o -MD -MP -MF $(DEPDIR)/scrypt-warn.Tpo -c -o scrypt-warn.o `test -f 'lib/util/warn.c' || echo '$(srcdir)/'`lib/util/warn.c

lib/util/hashtopass.c

@@ -0,0 +1,18 @@
+#include "hashtopass.h"
+
+void hashtopass(char* p, size_t len, uint8_t* key)
+{
+	char* lowers = "abcdefghijklmnopqrstuvwxyz";
+	char* uppers = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+	char* numerals = "0123456789";
+	char* allchars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+
+	p[0] = lowers[key[0] % 26];
+	p[1] = numerals[key[1] % 10];
+	p[2] = uppers[key[2] % 26];
+
+	size_t i;
+	for (i = 3; i < len; i++)
+		p[i] = allchars[key[i] % (26 + 26 + 10)];
+	p[len] = '\0';
+}

lib/util/hashtopass.h

@@ -0,0 +1,12 @@
+#include "scrypt_platform.h"
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "warn.h"
+
+void hashtopass(char* p, size_t len, uint8_t* key);

main.c

@@ -41,7 +41,7 @@ usage(void)
 {
 
 	fprintf(stderr,
-	    "usage: scrypt-genpass [-m MAXMEM] [-o MAXOPS] [-k KEYFILE] [-p PASS] <site>\n");
+	    "usage: scrypt-genpass [-l LEN] [-m MAXMEM] [-o MAXOPS] [-k KEYFILE] [-p PASS] <site>\n");
 	fprintf(stderr,
 			"       scrypt-genpass -t\n");
 	exit(1);
@@ -75,6 +75,7 @@ main(int argc, char *argv[])
 	FILE * outfile = stdout;
 	int dec = 0;
 	size_t passwdlen = 0;
+	size_t outputlength = 12;
 	uint32_t maxmem = 1000;
 	uint32_t megaops = 32;
 	char ch;
@@ -90,11 +91,13 @@ main(int argc, char *argv[])
 		usage();
 
 	/* Parse arguments. */
-	while ((ch = getopt(argc, argv, "htk:m:o:p:")) != -1) {
+	while ((ch = getopt(argc, argv, "htk:l:m:o:p:")) != -1) {
 		switch (ch) {
 		case 'k':
 			keyfile = strdup(optarg);
 			break;
+		case 'l':
+			outputlength = atoi(optarg);
 		case 'm':
 			maxmem = atoi(optarg);
 			break;
@@ -177,6 +180,15 @@ main(int argc, char *argv[])
 	bintohex(buf, 64, dk);
 	printf("Pass hex: %s\n", buf);
 
+	if ((outputlength < 3)||(outputlength > 64)) {
+		warn("Unable to generate password for output length %lu", outputlength);
+		exit(1);
+	}
+
+	char output[outputlength + 1];
+	hashtopass(output, outputlength, dk);
+	printf("Generated password: %s\n", output);
+
 	/* If we failed, print the right error message and exit. */
 	if (rc != 0) {
 		switch (rc) {

test/test.bash

@@ -7,5 +7,8 @@ $PROG -t > $RESULTS 2>&1
 $PROG -h >> $RESULTS 2>&1
 $PROG -p b a >> $RESULTS 2>&1
 $PROG -k test/keyfile1.dat -p abc ghi >> $RESULTS 2>&1
+$PROG -l 2 -p a a >> $RESULTS 2>&1
+$PROG -l 65 -p a a >> $RESULTS 2>&1
+$PROG -l 64 -p a a >> $RESULTS 2>&1
 
 diff $RESULTS test/test_results.reference

test/test_results.reference

@@ -1,9 +1,23 @@
 All internal tests pass
-usage: scrypt-genpass [-m MAXMEM] [-o MAXOPS] [-k KEYFILE] [-p PASS] <site>
+usage: scrypt-genpass [-l LEN] [-m MAXMEM] [-o MAXOPS] [-k KEYFILE] [-p PASS] <site>
        scrypt-genpass -t
 Master hex: 3e23e8160039594a33894f6564e1b1348bbd7a0088d42c4acb73eeaed59c009d
 Site hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
 Pass hex: 0160b45a147d0a0f5b6976a7ab698554a41c06c5f77cc9d77b06304265d1646fdc8e3119474748778ab3b68a39d0a67b3a92b41a8ddb45d4bb6ebec20a5f4a57
+Generated password: b6YCubkpDR4R
 Master hex: bef57ec7f53a6d40beb640a780a639c83bc29ac8a9816f1fc6c5c6dcd93c4721
 Site hex: 50ae61e841fac4e8f9e40baf2ad36ec868922ea48368c18f9535e47db56dd7fb
 Pass hex: a46a99d8d0ed2388d48cc3ddd33efe0b635790176c4f84387c0b02b589d2db9703db2fa3d41d5ee1d670ba0ddd1cfd1520a0d1a7394db5ff5eaa8b290aa80ebd
+Generated password: i6XEwZJmAqjJ
+scrypt-genpass: Unable to generate password for output length 2: Undefined error: 0
+Master hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Site hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Pass hex: 4394a3d67ecf5faa9ee733225147a7b58be00c497d990ad0ff4a5c63c608f843160924503886964e275867c1885cf73e072ebbed617088ae8f864d672e656097
+scrypt-genpass: Unable to generate password for output length 65: Undefined error: 0
+Master hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Site hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Pass hex: fcd149fda370967694b85b3e29edba64c68a0fe3b679770aec240b3cf460222c9d259f8b38064c1f07628dc2050a205cf52d498b300aa3851a9d0de5d0a27aa8
+Master hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Site hex: ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb
+Pass hex: fcd149fda370967694b85b3e29edba64c68a0fe3b679770aec240b3cf460222c9d259f8b38064c1f07628dc2050a205cf52d498b300aa3851a9d0de5d0a27aa8
+Generated password: s9VfNYA4y8DaPZaMmopP675kYKl86IISHLJp4goFhKrifkGE7TlpWkNjAHnRwM8S