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From: James Prestwood <prestwoj@gmail.com>
To: ell@lists.linux.dev
Cc: James Prestwood <prestwoj@gmail.com>
Subject: [RFC 5/8] cert-crypto: refactor l_cert_pkcs5_pbkdf2
Date: Fri, 18 Nov 2022 13:16:21 -0800	[thread overview]
Message-ID: <20221118211624.19298-6-prestwoj@gmail.com> (raw)
In-Reply-To: <20221118211624.19298-1-prestwoj@gmail.com>

This makes the actual algorithm common to prepare for adding a
new variant which uses a key ID rather than password.
---
 ell/cert-crypto.c | 67 +++++++++++++++++++++++++++++------------------
 1 file changed, 41 insertions(+), 26 deletions(-)

diff --git a/ell/cert-crypto.c b/ell/cert-crypto.c
index e6e8876..bf748b0 100644
--- a/ell/cert-crypto.c
+++ b/ell/cert-crypto.c
@@ -103,44 +103,34 @@ LIB_EXPORT bool l_cert_pkcs5_pbkdf1(enum l_checksum_type type,
 	return !iter_count;
 }
 
-/* RFC8018 section 5.2 */
-LIB_EXPORT bool l_cert_pkcs5_pbkdf2(enum l_checksum_type type,
-					const char *password,
-					const uint8_t *salt, size_t salt_len,
-					unsigned int iter_count,
-					uint8_t *out_dk, size_t dk_len)
+static size_t cert_checksum_to_length(enum l_checksum_type type)
 {
-	size_t h_len;
-	struct l_checksum *checksum;
-	unsigned int i;
-
 	switch (type) {
 	case L_CHECKSUM_SHA1:
-		h_len = 20;
-		break;
+		return 20;
 	case L_CHECKSUM_SHA224:
-		h_len = 28;
-		break;
+		return 28;
 	case L_CHECKSUM_SHA256:
-		h_len = 32;
-		break;
+		return 32;
 	case L_CHECKSUM_SHA384:
-		h_len = 48;
-		break;
+		return 48;
 	case L_CHECKSUM_SHA512:
-		h_len = 64;
-		break;
+		return 64;
 	case L_CHECKSUM_NONE:
 	case L_CHECKSUM_MD4:
 	case L_CHECKSUM_MD5:
-		return false;
+		return 0;
 	default:
-		return false;
+		return 0;
 	}
+}
 
-	checksum = l_checksum_new_hmac(type, password, strlen(password));
-	if (!checksum)
-		return false;
+static bool cert_pkcs5_pbkdf2(struct l_checksum *checksum, const uint8_t *salt,
+				size_t salt_len, size_t h_len,
+				unsigned int iter_count, uint8_t *out_dk,
+				size_t dk_len)
+{
+	unsigned int i;
 
 	for (i = 1; dk_len; i++) {
 		unsigned int j, k;
@@ -180,9 +170,34 @@ LIB_EXPORT bool l_cert_pkcs5_pbkdf2(enum l_checksum_type type,
 		dk_len -= block_len;
 	}
 
+	return !dk_len;
+}
+
+/* RFC8018 section 5.2 */
+LIB_EXPORT bool l_cert_pkcs5_pbkdf2(enum l_checksum_type type,
+					const char *password,
+					const uint8_t *salt, size_t salt_len,
+					unsigned int iter_count,
+					uint8_t *out_dk, size_t dk_len)
+{
+	size_t h_len;
+	struct l_checksum *checksum;
+	bool r;
+
+	h_len = cert_checksum_to_length(type);
+	if (!h_len)
+		return false;
+
+	checksum = l_checksum_new_hmac(type, password, strlen(password));
+	if (!checksum)
+		return false;
+
+	r = cert_pkcs5_pbkdf2(checksum, salt, salt_len, h_len, iter_count,
+				out_dk, dk_len);
+
 	l_checksum_free(checksum);
 
-	return !dk_len;
+	return r;
 }
 
 /* RFC7292 Appendix B */
-- 
2.34.3


  parent reply	other threads:[~2022-11-18 21:16 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-18 21:16 [RFC 0/8] Crypto operations by key ID James Prestwood
2022-11-18 21:16 ` [RFC 1/8] key: add l_key_search James Prestwood
2022-11-22 16:43   ` Denis Kenzior
2022-11-22 17:16     ` James Prestwood
2022-11-22 17:09       ` Denis Kenzior
2022-11-22 18:34         ` James Prestwood
2022-11-18 21:16 ` [RFC 2/8] unit: add key search test James Prestwood
2022-11-18 21:16 ` [RFC 3/8] checksum: commonize checksum creation James Prestwood
2022-11-22 16:46   ` Denis Kenzior
2022-11-18 21:16 ` [RFC 4/8] checksum: add l_checksum_new_hmac_from_key_id James Prestwood
2022-11-22 16:53   ` Denis Kenzior
2022-11-18 21:16 ` James Prestwood [this message]
2022-11-22 17:00   ` [RFC 5/8] cert-crypto: refactor l_cert_pkcs5_pbkdf2 Denis Kenzior
2022-11-18 21:16 ` [RFC 6/8] cert: add l_cert_pkcs5_pbkdf2_from_key_id James Prestwood
2022-11-22 17:03   ` Denis Kenzior
2022-11-18 21:16 ` [RFC 7/8] cert: add explicit length to l_cert_pkcs5_pbkdf2 James Prestwood
2022-11-18 21:16 ` [RFC 8/8] unit: update test-pbkdf2 with API change James Prestwood

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