1 // SPDX-License-Identifier: GPL-2.0-only
14  * asn1_encode_integer() - encode positive integer to ASN.1
19  * This is a simplified encoder: it only currently does
27 	int data_len = end_data - data;  in asn1_encode_integer()
33 		 "BUG: integer encode only supports positive integers"))  in asn1_encode_integer()
34 		return ERR_PTR(-EINVAL);  in asn1_encode_integer()
41 		return ERR_PTR(-EINVAL);  in asn1_encode_integer()
44 	data_len -= 2;  in asn1_encode_integer()
52 	for (i = sizeof(integer); i > 0 ; i--) {  in asn1_encode_integer()
53 		int byte = integer >> (8 * (i - 1));  in asn1_encode_integer()
70 			data_len--;  in asn1_encode_integer()
75 			return ERR_PTR(-EINVAL);  in asn1_encode_integer()
78 		data_len--;  in asn1_encode_integer()
82 	data[1] = d - data - 2;  in asn1_encode_integer()
96 		return -EINVAL;  in asn1_encode_oid_digit()
101 		(*data_len)--;  in asn1_encode_oid_digit()
106 		start -= 7;  in asn1_encode_oid_digit()
112 		oid = oid - (byte << start);  in asn1_encode_oid_digit()
113 		start -= 7;  in asn1_encode_oid_digit()
116 		(*data_len)--;  in asn1_encode_oid_digit()
121 		(*data_len)--;  in asn1_encode_oid_digit()
123 		ret = -EINVAL;  in asn1_encode_oid_digit()
132  * asn1_encode_oid() - encode an oid to ASN.1
144 	int data_len = end_data - data;  in asn1_encode_oid()
149 		return ERR_PTR(-EINVAL);  in asn1_encode_oid()
152 		return ERR_PTR(-EINVAL);  in asn1_encode_oid()
160 		return ERR_PTR(-EINVAL);  in asn1_encode_oid()
165 	data_len -= 3;  in asn1_encode_oid()
173 	data[1] = d - data - 2;  in asn1_encode_oid()
180  * asn1_encode_length() - encode a length to follow an ASN.1 tag
181  * @data: pointer to encode at
183  * @len: length to encode
185  * This routine can encode lengths up to 65535 using the ASN.1 rules.
189  * sequence will be re-encoded when the length is known.
194 		return -EINVAL;  in asn1_encode_length()
198 		(*data_len)--;  in asn1_encode_length()
204 		(*data_len)--;  in asn1_encode_length()
209 		return -EINVAL;  in asn1_encode_length()
214 		*data_len -= 2;  in asn1_encode_length()
219 		return -EINVAL;  in asn1_encode_length()
225 		*data_len -= 3;  in asn1_encode_length()
230 		return -EINVAL;  in asn1_encode_length()
233 		return -EINVAL;  in asn1_encode_length()
238 	*data_len -= 4;  in asn1_encode_length()
244  * asn1_encode_tag() - add a tag for optional or explicit value
251  * Note this currently only handles short form tags < 31.
259  * To encode in place pass a NULL @string and -1 for @len and the
266  * expects to be called with @data pointing to where the first encode
273 	int data_len = end_data - data;  in asn1_encode_tag()
277 		return ERR_PTR(-EINVAL);  in asn1_encode_tag()
281 		return ERR_PTR(-EINVAL);  in asn1_encode_tag()
292 		data -= 2;  in asn1_encode_tag()
297 		return ERR_PTR(-EINVAL);  in asn1_encode_tag()
300 	data_len--;  in asn1_encode_tag()
309 		return ERR_PTR(-EINVAL);  in asn1_encode_tag()
319  * asn1_encode_octet_string() - encode an ASN.1 OCTET STRING
320  * @data:	pointer to encode at
332 	int data_len = end_data - data;  in asn1_encode_octet_string()
340 		return ERR_PTR(-EINVAL);  in asn1_encode_octet_string()
343 	data_len--;  in asn1_encode_octet_string()
350 		return ERR_PTR(-EINVAL);  in asn1_encode_octet_string()
360  * asn1_encode_sequence() - wrap a byte stream in an ASN.1 SEQUENCE
361  * @data:	pointer to encode at
366  * Fill in a sequence.  To encode in place, pass NULL for @seq and -1
370  * where the first encode placed it.
376 	int data_len = end_data - data;  in asn1_encode_sequence()
381 		return ERR_PTR(-EINVAL);  in asn1_encode_sequence()
392 		data -= 2;  in asn1_encode_sequence()
397 		return ERR_PTR(-EINVAL);  in asn1_encode_sequence()
400 	data_len--;  in asn1_encode_sequence()
410 		return ERR_PTR(-EINVAL);  in asn1_encode_sequence()
420  * asn1_encode_boolean() - encode a boolean value to ASN.1
421  * @data:	pointer to encode at
429 	int data_len = end_data - data;  in asn1_encode_boolean()
436 		return ERR_PTR(-EINVAL);  in asn1_encode_boolean()
439 	data_len--;  in asn1_encode_boolean()