totp

commit ca676107d5735204b3b420f1524dd6e9c8556967
parent 5b2d51ff64270788966fc59436ab71f498c42a44
Author: Santtu Lakkala <santtu.lakkala@digital14.com>
Date:   Wed, 13 Sep 2023 13:28:29 +0300

Cleanup struct bytes usage

Diffstat:
M
token.c
 | 
29
++++++++++++++---------------
M
util.c
 | 
11
++++++-----
M
util.h
 | 
16
+++++++++++++++-

3 files changed, 35 insertions(+), 21 deletions(-)
diff --git a/token.c b/token.c
@@ -13,9 +13,8 @@ const char *digest_names[] = {
 	"SHA512",
 };
 
-static inline char dehex(const char *s)
+static inline uint8_t dehex(const uint8_t *s)
 {
-	const uint8_t *u = (const uint8_t *)s;
 	static const uint8_t vals[256] = {
 		['0'] = 1, ['1'] = 2, ['2'] = 3, ['3'] = 4, ['4'] = 5,
 		['5'] = 6, ['6'] = 7, ['7'] = 8, ['8'] = 9, ['9'] = 10,
@@ -24,18 +23,18 @@ static inline char dehex(const char *s)
 		['e'] = 15, ['f'] = 16,
 	};
 
-	if (!vals[u[0]] || !vals[u[1]])
+	if (!vals[s[0]] || !vals[s[1]])
 		return 0;
 
-	return (vals[u[0]] - 1) << 4 |
-	       (vals[u[1]] - 1);
+	return (vals[s[0]] - 1) << 4 |
+	       (vals[s[1]] - 1);
 }
 
 static struct bytes uridecode(struct bytes data, bool getarg)
 {
-	char *w = (char *)data.data;
-	char *end = w + data.len;
-	const char *r = w;
+	uint8_t *w = data.data;
+	uint8_t *end = w + data.len;
+	const uint8_t *r = w;
 
 	while (r < end) {
 		if (*r == '%') {
@@ -52,7 +51,7 @@ static struct bytes uridecode(struct bytes data, bool getarg)
 			*w++ = *r++;
 	}
 
-	return (struct bytes){ data.data, w - (char *)data.data };
+	return (struct bytes){ data.data, w - data.data };
 }
 
 
@@ -92,11 +91,11 @@ struct token token_parse_uri(char *data) {
 	if (!i)
 		return rv;
 
-	rv.desc = uridecode((struct bytes){ (uint8_t *)str, i - str }, false);
+	rv.desc = uridecode(bytesnc(str, i - str), false);
 
 	if ((v = memchr(rv.desc.data, ':', rv.desc.len))) {
-		rv.issuer = (struct bytes){ rv.desc.data, v++ - (char *)rv.desc.data };
-		rv.desc = (struct bytes){ (void *)v, i - v };
+		rv.issuer = (struct bytes){ rv.desc.data, pdiff(rv.desc.data, v++) };
+		rv.desc = bytesnc(v, i - v);
 	}
 
 	while (*i++) {
@@ -104,7 +103,7 @@ struct token token_parse_uri(char *data) {
 			if (rv.key.len)
 				croak("Multiple secrets in URI");
 			i = v + strcspn(v, "&");
-			rv.key = debase32(v, i - v);
+			rv.key = debase32(bytesnc(v, i - v));
 		} else if ((v = if_prefix(i, "digits="))) {
 			if (!(rv.digits = strtou8(v, &i)))
 				return rv;
@@ -113,9 +112,9 @@ struct token token_parse_uri(char *data) {
 				return rv;
 		} else if ((v = if_prefix(i, "issuer="))) {
 			i = v + strcspn(v, "&");
-			struct bytes newiss = uridecode((struct bytes){ (void *)v, i - v }, true);
+			struct bytes newiss = uridecode(bytesnc(v, i - v), true);
 			if (rv.issuer.len && (newiss.len != rv.issuer.len ||
-					      memcmp(rv.issuer.data, newiss.data, newiss.len))) {
+					      !bytesequal(rv.issuer, newiss))) {
 				errno = EINVAL;
 				return rv;
 			}
diff --git a/util.c b/util.c
@@ -133,10 +133,10 @@ void croak(const char *fmt, ...)
 	exit(1);
 }
 
-struct bytes debase32(char *buffer, size_t len)
+struct bytes debase32(struct bytes data)
 {
-	uint8_t *wp = (uint8_t *)buffer;
-	const uint8_t *rp = (const uint8_t *)buffer;
+	uint8_t *wp = data.data;
+	const uint8_t *rp;
 	uint16_t v = 0;
 	size_t b = 0;
 
@@ -155,7 +155,7 @@ struct bytes debase32(char *buffer, size_t len)
 		['5'] = 30, ['6'] = 31, ['7'] = 32
 	};
 
-	for (rp = (uint8_t *)buffer; (char *)rp - buffer < (ptrdiff_t)len && *rp && *rp != '='; rp++) {
+	for (rp = data.data; rp < data.data + data.len && *rp && *rp != '='; rp++) {
 		uint8_t c = val[*rp];
 		if (!c)
 			return (struct bytes){ 0 };
@@ -166,7 +166,8 @@ struct bytes debase32(char *buffer, size_t len)
 			b -= 8;
 		}
 	}
-	return (struct bytes){ (void *)buffer, (char *)wp - buffer };
+
+	return (struct bytes){ data.data, wp - data.data };
 }
 
 void randmem(void *mem, size_t n)
diff --git a/util.h b/util.h
@@ -84,6 +84,11 @@ static inline void *mempushb(void *dst, struct bytes data)
 	return mempush(dst, data.data, data.len);
 }
 
+static inline int bytesequal(struct bytes a, struct bytes b)
+{
+	return a.len == b.len && !memcmp(a.data, b.data, a.len);
+}
+
 static inline char *if_prefix(const char *s, const char *prefix)
 {
 	while (*prefix)
@@ -93,6 +98,15 @@ static inline char *if_prefix(const char *s, const char *prefix)
 }
 
 void croak(const char *fmt, ...);
-struct bytes debase32(char *buffer, size_t len);
+struct bytes debase32(struct bytes data);
+
+static inline ptrdiff_t pdiff(const void *a, const void *b) {
+	return (const char *)b - (const char *)a;
+}
+
+static inline struct bytes bytesnc(char *data, size_t len)
+{
+	return (struct bytes){ (void *)data, len };
+}
 
 #endif