Misc

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 89 insertions, 13 deletions

diff --git a/argon2/make_settings.c b/argon2/make_settings.c
index 94ee5ae..66ac3d6 100644
--- a/argon2/make_settings.c
+++ b/argon2/make_settings.c
@@ -2,11 +2,17 @@
 #include "../common.h"
 #ifndef TEST
 
+#include <libar2.h>
+
 
 static ssize_t
 make_settings(char *out_buffer, size_t size, const char *algorithm, size_t memcost, uintmax_t timecost,
               int gensalt, ssize_t (*rng)(void *out, size_t n, void *user), void *user)
 {
+	const char *p, *version = "19";
+	size_t algolen, ret, min, len, i;
+	int r;
+
 	/* Use default RNG if NULL is specified */
 	if (!rng)
 		rng = &librecrypt_rng_;
@@ -17,22 +23,90 @@ make_settings(char *out_buffer, size_t size, const char *algorithm, size_t memco
 		memcost = (size_t)4096u; /* 4 MiB */
 	} else {
 		/* Function takes bytes as memcost, algorithm takes kilobytes */
-		int memcost_round_up = memcost % 1024u >= 512u;
+		size_t memcost_round_up = (memcost >> 9) & 1u;
 		memcost >>= 10;
-		memcost += memcost_round_up ? 1u : 0u;
-		memcost = memcost ? memcost : 1u;
+		memcost += memcost_round_up;
 	}
+	memcost = memcost < LIBAR2_MIN_M_COST ? LIBAR2_MIN_M_COST : memcost;
+	memcost = memcost > LIBAR2_MAX_M_COST ? LIBAR2_MAX_M_COST : memcost;
 
-	/* TODO implement */
-	(void) out_buffer;
-	(void) size;
-	(void) algorithm;
-	(void) memcost;
-	(void) timecost;
-	(void) gensalt;
-	(void) rng;
-	(void) user;
-	return 0;
+	/* Adjust `timecost` for algorithm */
+	if (!timecost) {
+		/* Use default timecost if 0 was specified:
+		 * default m_cost (4096) multiple by default t_cost (10) */
+		timecost = 40960u;
+	}
+	timecost /= memcost;
+	timecost = timecost < LIBAR2_MIN_T_COST ? LIBAR2_MIN_T_COST : timecost;
+	timecost = timecost > LIBAR2_MAX_T_COST ? LIBAR2_MAX_T_COST : timecost;
+
+	/* Get version */
+	p = algorithm;
+	if (*p++ != '$')
+		abort();
+	p = strchr(p, '$');
+	algolen = p ? (size_t)(p - algorithm) : strlen(algorithm);
+	if (algolen > 64) /* just some small value absolute will fit all variants */
+		abort();
+	if (p++ && *p++ == 'v') {
+		if (!strncmp(p, "=16", 3u) && (!p[3u] || p[3u] == '$'))
+			version = "16";
+		else if (!strncmp(p, "=19", 3u) && (!p[3u] || p[3u] == '$'))
+			version = "19";
+		else
+			goto enosys;
+	}
+
+	/* Write algorithm and parameters */
+	r = snprintf(out_buffer, size, "%.*s$v=%s$m=%zu,t=%llu,p=1$",
+	             (int)algolen, algorithm, version,
+	             memcost, (unsigned long long int)timecost);
+	if (r < (int)sizeof("$argon2_$v=__$m=_,t=_,p=1$") - 1)
+		abort();
+	ret = (size_t)r;
+	min = size ? ret < size - 1u ? ret : size - 1u : 0u;
+	out_buffer = &out_buffer[min];
+	size -= min;
+
+	/* Add 16 bytes of salt */
+	if (gensalt) {
+		/* 16 bytes is 128 bits, and 128 = 21*6+2, so that is
+		 * 21 full base-64 characeters and 1 that only use 2 bits */
+		ret += len = 22u;
+		min = size ? len < size - 1u ? len : size - 1u : 0u;
+		if (librecrypt_fill_with_random_(out_buffer, min, rng, user))
+			return -1;
+		if (min == len)
+			out_buffer[len - 1u] = (char)((unsigned char)out_buffer[len - 1u] & ~15u);
+		for (i = 0u; i < min; i++)
+			out_buffer[i] = librecrypt_common_rfc4848s4_encoding_lut_[((unsigned char *)out_buffer)[i]];
+	} else {
+		ret += len = sizeof("*16") - 1u;
+		min = size ? len < size - 1u ? len : size - 1u : 0u;
+		memcpy(out_buffer, "*16", min);
+	}
+	out_buffer = &out_buffer[min];
+	size -= min;
+
+	/* Add tag size (size of hash result) */
+	ret += len = sizeof("$*32") - 1u;
+	min = size ? len < size - 1u ? len : size - 1u : 0u;
+	memcpy(out_buffer, "$*32", min);
+	out_buffer = &out_buffer[min];
+	size -= min;
+
+	/* NUL terminate */
+	if (size) {
+		/* We were careful to make sure size is positive at
+		 * the end if it was when the function was called */
+		*out_buffer = '\0';
+	}
+
+	return (ssize_t)ret;
+
+enosys:
+	errno = ENOSYS;
+	return -1;
 }
 
 
@@ -59,7 +133,9 @@ CONST int
 main(void)
 {
 	SET_UP_ALARM();
+	INIT_RESOURCE_TEST();
 
+	STOP_RESOURCE_TEST();
 	return 0;
 }