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Diffstat (limited to 'rsa.c')
-rw-r--r--rsa.c96
1 files changed, 95 insertions, 1 deletions
diff --git a/rsa.c b/rsa.c
index e6d70db..86c891a 100644
--- a/rsa.c
+++ b/rsa.c
@@ -733,7 +733,7 @@ hal_error_t hal_rsa_private_key_to_der(const hal_rsa_key_t * const key,
return HAL_OK;
}
-size_t hal_rsa_key_to_der_len(const hal_rsa_key_t * const key)
+size_t hal_rsa_private_key_to_der_len(const hal_rsa_key_t * const key)
{
size_t len = 0;
return hal_rsa_private_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0;
@@ -775,6 +775,100 @@ hal_error_t hal_rsa_private_key_from_der(hal_rsa_key_t **key_,
}
/*
+ * ASN.1 public keys in SubjectPublicKeyInfo form, see RFCs 2313, 4055, and 5280.
+ */
+
+static const uint8_t oid_rsaEncryption[] = { 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01 };
+
+hal_error_t hal_rsa_public_key_to_der(const hal_rsa_key_t * const key,
+ uint8_t *der, size_t *der_len, const size_t der_max)
+{
+ if (key == NULL || (key->type != HAL_KEY_TYPE_RSA_PRIVATE &&
+ key->type != HAL_KEY_TYPE_RSA_PUBLIC))
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ size_t hlen, n_len, e_len;
+ hal_error_t err;
+
+ if ((err = hal_asn1_encode_integer(key->n, NULL, &n_len, 0)) != HAL_OK ||
+ (err = hal_asn1_encode_integer(key->e, NULL, &e_len, 0)) != HAL_OK)
+ return err;
+
+ const size_t vlen = n_len + e_len;
+
+ if ((err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)) != HAL_OK)
+ return err;
+
+ if (der != NULL) {
+ uint8_t * const n_out = der + hlen;
+ uint8_t * const e_out = n_out + n_len;
+
+ if ((err = hal_asn1_encode_integer(key->n, n_out, NULL, der + der_max - n_out)) != HAL_OK ||
+ (err = hal_asn1_encode_integer(key->e, e_out, NULL, der + der_max - e_out)) != HAL_OK)
+ return err;
+ }
+
+ return hal_asn1_encode_spki(oid_rsaEncryption, sizeof(oid_rsaEncryption),
+ NULL, 0, der, hlen + vlen,
+ der, der_len, der_max);
+
+}
+
+size_t hal_rsa_public_key_to_der_len(const hal_rsa_key_t * const key)
+{
+ size_t len = 0;
+ return hal_rsa_public_key_to_der(key, NULL, &len, 0) == HAL_OK ? len : 0;
+}
+
+hal_error_t hal_rsa_public_key_from_der(hal_rsa_key_t **key_,
+ void *keybuf, const size_t keybuf_len,
+ const uint8_t * const der, const size_t der_len)
+{
+ hal_rsa_key_t *key = keybuf;
+
+ if (key_ == NULL || key == NULL || keybuf_len < sizeof(*key) || der == NULL)
+ return HAL_ERROR_BAD_ARGUMENTS;
+
+ memset(keybuf, 0, keybuf_len);
+
+ key->type = HAL_KEY_TYPE_RSA_PUBLIC;
+
+ const uint8_t *alg_oid = NULL, *null = NULL, *pubkey = NULL;
+ size_t alg_oid_len, null_len, pubkey_len;
+ hal_error_t err;
+
+ if ((err = hal_asn1_decode_spki(&alg_oid, &alg_oid_len, &null, &null_len, &pubkey, &pubkey_len, der, der_len)) != HAL_OK)
+ return err;
+
+ if (null != NULL || null_len != 0 || alg_oid == NULL ||
+ alg_oid_len != sizeof(oid_rsaEncryption) || memcmp(alg_oid, oid_rsaEncryption, alg_oid_len) != 0)
+ return HAL_ERROR_ASN1_PARSE_FAILED;
+
+ size_t len, hlen, vlen;
+
+ if ((err = hal_asn1_decode_header(ASN1_SEQUENCE, pubkey, pubkey_len, &hlen, &vlen)) != HAL_OK)
+ return err;
+
+ const uint8_t * const pubkey_end = pubkey + hlen + vlen;
+ const uint8_t *d = pubkey + hlen;
+
+ if ((err = hal_asn1_decode_integer(key->n, d, &len, pubkey_end - d)) != HAL_OK)
+ return err;
+ d += len;
+
+ if ((err = hal_asn1_decode_integer(key->e, d, &len, pubkey_end - d)) != HAL_OK)
+ return err;
+ d += len;
+
+ if (d != pubkey_end)
+ return HAL_ERROR_ASN1_PARSE_FAILED;
+
+ *key_ = key;
+
+ return HAL_OK;
+}
+
+/*
* Local variables:
* indent-tabs-mode: nil
* End: