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Diffstat (limited to 'net/bluetooth/ecdh_helper.c')
-rw-r--r--net/bluetooth/ecdh_helper.c228
1 files changed, 116 insertions, 112 deletions
diff --git a/net/bluetooth/ecdh_helper.c b/net/bluetooth/ecdh_helper.c
index c7b1a9aee579..2155ce802877 100644
--- a/net/bluetooth/ecdh_helper.c
+++ b/net/bluetooth/ecdh_helper.c
@@ -23,7 +23,6 @@
#include "ecdh_helper.h"
#include <linux/scatterlist.h>
-#include <crypto/kpp.h>
#include <crypto/ecdh.h>
struct ecdh_completion {
@@ -50,55 +49,35 @@ static inline void swap_digits(u64 *in, u64 *out, unsigned int ndigits)
out[i] = __swab64(in[ndigits - 1 - i]);
}
-bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32],
- u8 secret[32])
+/* compute_ecdh_secret() - function assumes that the private key was
+ * already set.
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp().
+ * @public_key: pair's ecc public key.
+ * secret: memory where the ecdh computed shared secret will be saved.
+ *
+ * Return: zero on success; error code in case of error.
+ */
+int compute_ecdh_secret(struct crypto_kpp *tfm, const u8 public_key[64],
+ u8 secret[32])
{
- struct crypto_kpp *tfm;
struct kpp_request *req;
- struct ecdh p;
+ u8 *tmp;
struct ecdh_completion result;
struct scatterlist src, dst;
- u8 *tmp, *buf;
- unsigned int buf_len;
- int err = -ENOMEM;
+ int err;
tmp = kmalloc(64, GFP_KERNEL);
if (!tmp)
- return false;
+ return -ENOMEM;
- tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
- if (IS_ERR(tfm)) {
- pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",
- PTR_ERR(tfm));
+ req = kpp_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ err = -ENOMEM;
goto free_tmp;
}
- req = kpp_request_alloc(tfm, GFP_KERNEL);
- if (!req)
- goto free_kpp;
-
init_completion(&result.completion);
- /* Security Manager Protocol holds digits in litte-endian order
- * while ECC API expect big-endian data
- */
- swap_digits((u64 *)private_key, (u64 *)tmp, 4);
- p.key = (char *)tmp;
- p.key_size = 32;
- /* Set curve_id */
- p.curve_id = ECC_CURVE_NIST_P256;
- buf_len = crypto_ecdh_key_len(&p);
- buf = kmalloc(buf_len, GFP_KERNEL);
- if (!buf)
- goto free_req;
-
- crypto_ecdh_encode_key(buf, buf_len, &p);
-
- /* Set A private Key */
- err = crypto_kpp_set_secret(tfm, (void *)buf, buf_len);
- if (err)
- goto free_all;
-
swap_digits((u64 *)public_key, (u64 *)tmp, 4); /* x */
swap_digits((u64 *)&public_key[32], (u64 *)&tmp[32], 4); /* y */
@@ -123,104 +102,129 @@ bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32],
memcpy(secret, tmp, 32);
free_all:
- kzfree(buf);
-free_req:
kpp_request_free(req);
-free_kpp:
- crypto_free_kpp(tfm);
free_tmp:
- kfree(tmp);
- return (err == 0);
+ kzfree(tmp);
+ return err;
}
-bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32])
+/* set_ecdh_privkey() - set or generate ecc private key.
+ *
+ * Function generates an ecc private key in the crypto subsystem when receiving
+ * a NULL private key or sets the received key when not NULL.
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp().
+ * @private_key: user's ecc private key. When not NULL, the key is expected
+ * in little endian format.
+ *
+ * Return: zero on success; error code in case of error.
+ */
+int set_ecdh_privkey(struct crypto_kpp *tfm, const u8 private_key[32])
+{
+ u8 *buf, *tmp = NULL;
+ unsigned int buf_len;
+ int err;
+ struct ecdh p = {0};
+
+ p.curve_id = ECC_CURVE_NIST_P256;
+
+ if (private_key) {
+ tmp = kmalloc(32, GFP_KERNEL);
+ if (!tmp)
+ return -ENOMEM;
+ swap_digits((u64 *)private_key, (u64 *)tmp, 4);
+ p.key = tmp;
+ p.key_size = 32;
+ }
+
+ buf_len = crypto_ecdh_key_len(&p);
+ buf = kmalloc(buf_len, GFP_KERNEL);
+ if (!buf) {
+ err = -ENOMEM;
+ goto free_tmp;
+ }
+
+ err = crypto_ecdh_encode_key(buf, buf_len, &p);
+ if (err)
+ goto free_all;
+
+ err = crypto_kpp_set_secret(tfm, buf, buf_len);
+ /* fall through */
+free_all:
+ kzfree(buf);
+free_tmp:
+ kzfree(tmp);
+ return err;
+}
+
+/* generate_ecdh_public_key() - function assumes that the private key was
+ * already set.
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp().
+ * @public_key: memory where the computed ecc public key will be saved.
+ *
+ * Return: zero on success; error code in case of error.
+ */
+int generate_ecdh_public_key(struct crypto_kpp *tfm, u8 public_key[64])
{
- struct crypto_kpp *tfm;
struct kpp_request *req;
- struct ecdh p;
+ u8 *tmp;
struct ecdh_completion result;
struct scatterlist dst;
- u8 *tmp, *buf;
- unsigned int buf_len;
- int err = -ENOMEM;
- const unsigned short max_tries = 16;
- unsigned short tries = 0;
+ int err;
tmp = kmalloc(64, GFP_KERNEL);
if (!tmp)
- return false;
+ return -ENOMEM;
- tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);
- if (IS_ERR(tfm)) {
- pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",
- PTR_ERR(tfm));
+ req = kpp_request_alloc(tfm, GFP_KERNEL);
+ if (!req) {
+ err = -ENOMEM;
goto free_tmp;
}
- req = kpp_request_alloc(tfm, GFP_KERNEL);
- if (!req)
- goto free_kpp;
-
init_completion(&result.completion);
+ sg_init_one(&dst, tmp, 64);
+ kpp_request_set_input(req, NULL, 0);
+ kpp_request_set_output(req, &dst, 64);
+ kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ ecdh_complete, &result);
- /* Set curve_id */
- p.curve_id = ECC_CURVE_NIST_P256;
- p.key_size = 32;
- buf_len = crypto_ecdh_key_len(&p);
- buf = kmalloc(buf_len, GFP_KERNEL);
- if (!buf)
- goto free_req;
-
- do {
- if (tries++ >= max_tries)
- goto free_all;
-
- /* Set private Key */
- p.key = (char *)private_key;
- crypto_ecdh_encode_key(buf, buf_len, &p);
- err = crypto_kpp_set_secret(tfm, buf, buf_len);
- if (err)
- goto free_all;
-
- sg_init_one(&dst, tmp, 64);
- kpp_request_set_input(req, NULL, 0);
- kpp_request_set_output(req, &dst, 64);
- kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
- ecdh_complete, &result);
-
- err = crypto_kpp_generate_public_key(req);
-
- if (err == -EINPROGRESS) {
- wait_for_completion(&result.completion);
- err = result.err;
- }
-
- /* Private key is not valid. Regenerate */
- if (err == -EINVAL)
- continue;
-
- if (err < 0)
- goto free_all;
- else
- break;
-
- } while (true);
-
- /* Keys are handed back in little endian as expected by Security
- * Manager Protocol
+ err = crypto_kpp_generate_public_key(req);
+ if (err == -EINPROGRESS) {
+ wait_for_completion(&result.completion);
+ err = result.err;
+ }
+ if (err < 0)
+ goto free_all;
+
+ /* The public key is handed back in little endian as expected by
+ * the Security Manager Protocol.
*/
swap_digits((u64 *)tmp, (u64 *)public_key, 4); /* x */
swap_digits((u64 *)&tmp[32], (u64 *)&public_key[32], 4); /* y */
- swap_digits((u64 *)private_key, (u64 *)tmp, 4);
- memcpy(private_key, tmp, 32);
free_all:
- kzfree(buf);
-free_req:
kpp_request_free(req);
-free_kpp:
- crypto_free_kpp(tfm);
free_tmp:
kfree(tmp);
- return (err == 0);
+ return err;
+}
+
+/* generate_ecdh_keys() - generate ecc key pair.
+ *
+ * @tfm: KPP tfm handle allocated with crypto_alloc_kpp().
+ * @public_key: memory where the computed ecc public key will be saved.
+ *
+ * Return: zero on success; error code in case of error.
+ */
+int generate_ecdh_keys(struct crypto_kpp *tfm, u8 public_key[64])
+{
+ int err;
+
+ err = set_ecdh_privkey(tfm, NULL);
+ if (err)
+ return err;
+
+ return generate_ecdh_public_key(tfm, public_key);
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-08 01:03:33 +0300