Add support for Keccak, SHA3, SHAKE, and RawSHAKE via libkeccak>=1.3 (this version introduced zerocopy)

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

1 files changed, 127 insertions, 2 deletions

diff --git a/libhashsum_init_hasher_from_string.c b/libhashsum_init_hasher_from_string.c
index e41c8b1..30526da 100644
--- a/libhashsum_init_hasher_from_string.c
+++ b/libhashsum_init_hasher_from_string.c
@@ -8,7 +8,7 @@ __attribute__((__pure__))
 static int
 equiv(const char *a, const char *b)
 {
-	while (*a && *b) {
+	while (*a && *b && *b != '[') {
 		if (tolower(*a) == tolower(*b)) {
 			a++;
 			b++;
@@ -18,7 +18,102 @@ equiv(const char *a, const char *b)
 			return 0;
 		}
 	}
-	return !*a && !*b;
+	return !*a && (!*b || *b == '[');
+}
+
+
+static int
+with_n(int (*initfunc)(struct libhashsum_hasher *, size_t), struct libhashsum_hasher *this, const char *algorithm)
+{
+	const char *p;
+	size_t n = 0, digit;
+
+	p = strchr(algorithm, '[');
+	if (!p || *++p == ']')
+		return initfunc(this, 0);
+
+	if ((*p++ != 'n' && *p++ != 'N'))
+		goto einval;
+	if (*p++ != '=' || !('1' <= *p && *p <= '9'))
+		goto einval;
+
+	while (isdigit(*p)) {
+		digit = (size_t)(*p++ & 15);
+		if (n > (SIZE_MAX - digit) / 10U)
+			goto einval;
+		n = n * 10U + digit;
+	}
+
+	if (*p++ != ']' || *p)
+		goto einval;
+
+	return initfunc(this, n);
+
+einval:
+	errno = EINVAL;
+	return -1;
+}
+
+
+static int
+parse_value(size_t *valp, const char *p, const char **end_out)
+{
+	size_t digit;
+	if (*valp)
+		return -1;
+	p++;
+	if (*p++ != '=' || !('1' <= *p && *p <= '9'))
+		return -1;
+	while (isdigit(*p)) {
+		digit = (size_t)(*p++ & 15);
+		if (*valp > (SIZE_MAX - digit) / 10U)
+			return -1;
+		*valp = *valp * 10U + digit;
+	}
+	*end_out = p;
+	return 0;
+}
+
+
+static int
+with_rcn(int (*initfunc)(struct libhashsum_hasher *, size_t, size_t, size_t),
+         struct libhashsum_hasher *this, const char *algorithm)
+{
+	const char *p;
+	size_t r = 0, c = 0, n = 0;
+
+	p = strchr(algorithm, '[');
+	if (!p || *++p == ']')
+		return initfunc(this, 0, 0, 0);
+
+	for (;;) {
+		if (*p == 'r' || *p == 'R') {
+			if (parse_value(&r, p, &p))
+				goto einval;
+		} else if (*p == 'c' || *p == 'C') {
+			if (parse_value(&c, p, &p))
+				goto einval;
+		} else if (*p == 'n' || *p == 'N') {
+			if (parse_value(&n, p, &p))
+				goto einval;
+		} else if (*p == ']') {
+			break;
+		} else {
+			goto einval;
+		}
+		if (*p == ']')
+			break;
+		if (*p++ != ',')
+			goto einval;
+	}
+	if (p[1])
+		goto einval;
+
+	return initfunc(this, r, c, n);
+
+einval:
+	errno = EINVAL;
+	return -1;
 }
 
 
@@ -55,6 +150,36 @@ libhashsum_init_hasher_from_string(struct libhashsum_hasher *this, const char *a
 		return libhashsum_init_sha_512_224_hasher(this);
 	if (equiv(algorithm, "SHA-512/256") || !strcasecmp(algorithm, "SHA2-512/256"))
 		return libhashsum_init_sha_512_256_hasher(this);
+	if (equiv(algorithm, "Keccak-224"))
+		return libhashsum_init_keccak_224_hasher(this);
+	if (equiv(algorithm, "Keccak-256"))
+		return libhashsum_init_keccak_256_hasher(this);
+	if (equiv(algorithm, "Keccak-384"))
+		return libhashsum_init_keccak_384_hasher(this);
+	if (equiv(algorithm, "Keccak-512"))
+		return libhashsum_init_keccak_512_hasher(this);
+	if (!strcasecmp(algorithm, "SHA3-224"))
+		return libhashsum_init_sha3_224_hasher(this);
+	if (!strcasecmp(algorithm, "SHA3-256"))
+		return libhashsum_init_sha3_256_hasher(this);
+	if (!strcasecmp(algorithm, "SHA3-384"))
+		return libhashsum_init_sha3_384_hasher(this);
+	if (!strcasecmp(algorithm, "SHA3-512"))
+		return libhashsum_init_sha3_512_hasher(this);
+	if (equiv(algorithm, "SHAKE-128["))
+		return with_n(&libhashsum_init_shake128_hasher, this, algorithm);
+	if (equiv(algorithm, "SHAKE-256["))
+		return with_n(&libhashsum_init_shake256_hasher, this, algorithm);
+	if (equiv(algorithm, "SHAKE-512["))
+		return with_n(&libhashsum_init_shake512_hasher, this, algorithm);
+	if (equiv(algorithm, "RawSHAKE-128["))
+		return with_n(&libhashsum_init_rawshake128_hasher, this, algorithm);
+	if (equiv(algorithm, "RawSHAKE-256["))
+		return with_n(&libhashsum_init_rawshake256_hasher, this, algorithm);
+	if (equiv(algorithm, "RawSHAKE-512["))
+		return with_n(&libhashsum_init_rawshake512_hasher, this, algorithm);
+	if (equiv(algorithm, "Keccak["))
+		return with_rcn(&libhashsum_init_keccak_hasher, this, algorithm);
 
 	errno = EINVAL;
 	return -1;