Add support for salt for BLAKE

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

1 files changed, 64 insertions, 9 deletions

diff --git a/libhashsum_init_hasher_from_string.c b/libhashsum_init_hasher_from_string.c
index 9a53864..1bdc70d 100644
--- a/libhashsum_init_hasher_from_string.c
+++ b/libhashsum_init_hasher_from_string.c
@@ -32,7 +32,7 @@ with_n(int (*initfunc)(struct libhashsum_hasher *, size_t), struct libhashsum_ha
 	if (!p || *++p == ']')
 		return initfunc(this, 0);
 
-	if ((*p++ != 'n' && *p++ != 'N'))
+	if (*p++ != 'n' && *p++ != 'N')
 		goto einval;
 	if (*p++ != '=' || !('1' <= *p && *p <= '9'))
 		goto einval;
@@ -117,6 +117,61 @@ einval:
 }
 
 
+static int
+with_salt(int (*initfunc)(struct libhashsum_hasher *, const void *),
+          struct libhashsum_hasher *this, const char *algorithm, size_t saltbytes)
+{
+	const char *p;
+	uint8_t a, b, salt[32];
+	size_t salti = 0;
+
+	p = strchr(algorithm, '[');
+	if (!p || *++p == ']')
+		return initfunc(this, NULL);
+
+	if (*p++ != 's' && *p++ != 'S')
+		goto einval;
+	if (*p++ != 'a' && *p++ != 'A')
+		goto einval;
+	if (*p++ != 'l' && *p++ != 'L')
+		goto einval;
+	if (*p++ != 't' && *p++ != 'T')
+		goto einval;
+	if (*p++ != '=')
+		goto einval;
+
+	if (p[0] == '0' && (p[1] == 'x' || p[1] == 'X'))
+		p = &p[2];
+
+	for (;;) {
+		if (isxdigit(p[0]) && isxdigit(p[1])) {
+			if (!saltbytes)
+				goto einval;
+			saltbytes--;
+		} else if (isxdigit(p[0])) {
+			goto einval;
+		} else if (saltbytes) {
+			goto einval;
+		} else {
+			break;
+		}
+
+		a = (uint8_t)(((*p & 15) + (*p > '9' ? 9 : 0)) << 4);
+		b = (uint8_t)(((*p & 15) + (*p > '9' ? 9 : 0)) << 0);
+		salt[salti++] = (uint8_t)(a | b);
+	}
+
+	if (*p++ != ']' || *p)
+		goto einval;
+
+	return initfunc(this, salt);
+
+einval:
+	errno = EINVAL;
+	return -1;
+}
+
+
 int
 libhashsum_init_hasher_from_string(struct libhashsum_hasher *this, const char *algorithm)
 {
@@ -180,14 +235,14 @@ libhashsum_init_hasher_from_string(struct libhashsum_hasher *this, const char *a
 		return with_n(&libhashsum_init_rawshake512_hasher, this, algorithm);
 	if (equiv(algorithm, "Keccak["))
 		return with_rcn(&libhashsum_init_keccak_hasher, this, algorithm);
-	if (equiv(algorithm, "BLAKE-224"))
-		return libhashsum_init_blake224_hasher(this);
-	if (equiv(algorithm, "BLAKE-256"))
-		return libhashsum_init_blake256_hasher(this);
-	if (equiv(algorithm, "BLAKE-384"))
-		return libhashsum_init_blake384_hasher(this);
-	if (equiv(algorithm, "BLAKE-512"))
-		return libhashsum_init_blake512_hasher(this);
+	if (equiv(algorithm, "BLAKE-224["))
+		return with_salt(&libhashsum_init_blake224_hasher, this, algorithm, 16U);
+	if (equiv(algorithm, "BLAKE-256["))
+		return with_salt(&libhashsum_init_blake256_hasher, this, algorithm, 16U);
+	if (equiv(algorithm, "BLAKE-384["))
+		return with_salt(&libhashsum_init_blake384_hasher, this, algorithm, 32U);
+	if (equiv(algorithm, "BLAKE-512["))
+		return with_salt(&libhashsum_init_blake512_hasher, this, algorithm, 32U);
 
 	errno = EINVAL;
 	return -1;