1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
/**
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
#include <aws/cal/private/rsa.h>
#include <aws/cal/cal.h>
#include <aws/cal/hash.h>
#include <aws/cal/private/der.h>
typedef struct aws_rsa_key_pair *(
aws_rsa_key_pair_new_from_public_pkcs1_fn)(struct aws_allocator *allocator, struct aws_byte_cursor public_key);
typedef struct aws_rsa_key_pair *(
aws_rsa_key_pair_new_from_private_pkcs1_fn)(struct aws_allocator *allocator, struct aws_byte_cursor private_key);
#ifndef BYO_CRYPTO
extern struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_public_key_pkcs1_impl(
struct aws_allocator *allocator,
struct aws_byte_cursor public_key);
extern struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_private_key_pkcs1_impl(
struct aws_allocator *allocator,
struct aws_byte_cursor private_key);
#else /* BYO_CRYPTO */
struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_public_key_pkcs1_impl(
struct aws_allocator *allocator,
struct aws_byte_cursor public_key) {
(void)allocator;
(void)public_key;
abort();
}
struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_private_key_pkcs1_impl(
struct aws_allocator *allocator,
struct aws_byte_cursor private_key) {
(void)allocator;
(void)private_key;
abort();
}
#endif /* BYO_CRYPTO */
static aws_rsa_key_pair_new_from_public_pkcs1_fn *s_rsa_key_pair_new_from_public_key_pkcs1_fn =
aws_rsa_key_pair_new_from_public_key_pkcs1_impl;
static aws_rsa_key_pair_new_from_private_pkcs1_fn *s_rsa_key_pair_new_from_private_key_pkcs1_fn =
aws_rsa_key_pair_new_from_private_key_pkcs1_impl;
struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_public_key_pkcs1(
struct aws_allocator *allocator,
struct aws_byte_cursor public_key) {
return s_rsa_key_pair_new_from_public_key_pkcs1_fn(allocator, public_key);
}
struct aws_rsa_key_pair *aws_rsa_key_pair_new_from_private_key_pkcs1(
struct aws_allocator *allocator,
struct aws_byte_cursor private_key) {
return s_rsa_key_pair_new_from_private_key_pkcs1_fn(allocator, private_key);
}
void aws_rsa_key_pair_base_clean_up(struct aws_rsa_key_pair *key_pair) {
aws_byte_buf_clean_up_secure(&key_pair->priv);
aws_byte_buf_clean_up_secure(&key_pair->pub);
}
struct aws_rsa_key_pair *aws_rsa_key_pair_acquire(struct aws_rsa_key_pair *key_pair) {
return aws_ref_count_acquire(&key_pair->ref_count);
}
struct aws_rsa_key_pair *aws_rsa_key_pair_release(struct aws_rsa_key_pair *key_pair) {
if (key_pair != NULL) {
aws_ref_count_release(&key_pair->ref_count);
}
return NULL;
}
size_t aws_rsa_key_pair_max_encrypt_plaintext_size(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_encryption_algorithm algorithm) {
/*
* Per rfc8017, max size of plaintext for encrypt operation is as follows:
* PKCS1-v1_5: (key size in bytes) - 11
* OAEP: (key size in bytes) - 2 * (hash bytes) - 2
*/
size_t key_size_in_bytes = key_pair->key_size_in_bits / 8;
switch (algorithm) {
case AWS_CAL_RSA_ENCRYPTION_PKCS1_5:
return key_size_in_bytes - 11;
case AWS_CAL_RSA_ENCRYPTION_OAEP_SHA256:
return key_size_in_bytes - 2 * (256 / 8) - 2;
case AWS_CAL_RSA_ENCRYPTION_OAEP_SHA512:
return key_size_in_bytes - 2 * (512 / 8) - 2;
default:
AWS_FATAL_ASSERT("Unsupported RSA Encryption Algorithm");
}
return 0;
}
int aws_rsa_key_pair_encrypt(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_encryption_algorithm algorithm,
struct aws_byte_cursor plaintext,
struct aws_byte_buf *out) {
AWS_PRECONDITION(key_pair);
AWS_PRECONDITION(out);
if (AWS_UNLIKELY(aws_rsa_key_pair_max_encrypt_plaintext_size(key_pair, algorithm) < plaintext.len)) {
AWS_LOGF_ERROR(AWS_LS_CAL_RSA, "Unexpected buffer size. For RSA, ciphertext must not exceed block size");
return aws_raise_error(AWS_ERROR_CAL_BUFFER_TOO_LARGE_FOR_ALGORITHM);
}
return key_pair->vtable->encrypt(key_pair, algorithm, plaintext, out);
}
AWS_CAL_API int aws_rsa_key_pair_decrypt(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_encryption_algorithm algorithm,
struct aws_byte_cursor ciphertext,
struct aws_byte_buf *out) {
AWS_PRECONDITION(key_pair);
AWS_PRECONDITION(out);
if (AWS_UNLIKELY(ciphertext.len != (key_pair->key_size_in_bits / 8))) {
AWS_LOGF_ERROR(AWS_LS_CAL_RSA, "Unexpected buffer size. For RSA, ciphertext is expected to match block size.");
return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
}
return key_pair->vtable->decrypt(key_pair, algorithm, ciphertext, out);
}
int aws_rsa_key_pair_sign_message(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_signature_algorithm algorithm,
struct aws_byte_cursor digest,
struct aws_byte_buf *out) {
AWS_PRECONDITION(key_pair);
AWS_PRECONDITION(out);
AWS_FATAL_ASSERT(
algorithm == AWS_CAL_RSA_SIGNATURE_PKCS1_5_SHA256 || algorithm == AWS_CAL_RSA_SIGNATURE_PSS_SHA256);
if (digest.len > AWS_SHA256_LEN) {
AWS_LOGF_ERROR(
AWS_LS_CAL_RSA, "Unexpected digest size. For RSA, digest length is bound by max size of hash function");
return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
}
return key_pair->vtable->sign(key_pair, algorithm, digest, out);
}
int aws_rsa_key_pair_verify_signature(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_signature_algorithm algorithm,
struct aws_byte_cursor digest,
struct aws_byte_cursor signature) {
AWS_PRECONDITION(key_pair);
return key_pair->vtable->verify(key_pair, algorithm, digest, signature);
}
size_t aws_rsa_key_pair_block_length(const struct aws_rsa_key_pair *key_pair) {
AWS_PRECONDITION(key_pair);
return key_pair->key_size_in_bits / 8;
}
size_t aws_rsa_key_pair_signature_length(const struct aws_rsa_key_pair *key_pair) {
AWS_PRECONDITION(key_pair);
return key_pair->key_size_in_bits / 8;
}
int aws_rsa_key_pair_get_public_key(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_key_export_format format,
struct aws_byte_buf *out) {
(void)format; /* ignore format for now, since only pkcs1 is supported. */
AWS_PRECONDITION(key_pair);
AWS_PRECONDITION(out);
if (key_pair->pub.len == 0) {
return aws_raise_error(AWS_ERROR_PLATFORM_NOT_SUPPORTED);
}
aws_byte_buf_init_copy(out, key_pair->allocator, &key_pair->pub);
return AWS_OP_SUCCESS;
}
int aws_rsa_key_pair_get_private_key(
const struct aws_rsa_key_pair *key_pair,
enum aws_rsa_key_export_format format,
struct aws_byte_buf *out) {
(void)format; /* ignore format for now, since only pkcs1 is supported. */
AWS_PRECONDITION(key_pair);
AWS_PRECONDITION(out);
if (key_pair->priv.len == 0) {
return aws_raise_error(AWS_ERROR_PLATFORM_NOT_SUPPORTED);
}
aws_byte_buf_init_copy(out, key_pair->allocator, &key_pair->priv);
return AWS_OP_SUCCESS;
}
int aws_der_decoder_load_private_rsa_pkcs1(struct aws_der_decoder *decoder, struct aws_rsa_private_key_pkcs1 *out) {
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_type(decoder) != AWS_DER_SEQUENCE) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
struct aws_byte_cursor version_cur;
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &version_cur)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (version_cur.len != 1 || version_cur.ptr[0] != 0) {
return aws_raise_error(AWS_ERROR_CAL_UNSUPPORTED_KEY_FORMAT);
}
out->version = 0;
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &(out->modulus))) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->publicExponent)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->privateExponent)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->prime1)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->prime2)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->exponent1)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->exponent2)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->coefficient)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
return AWS_OP_SUCCESS;
}
int aws_der_decoder_load_public_rsa_pkcs1(struct aws_der_decoder *decoder, struct aws_rsa_public_key_pkcs1 *out) {
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_type(decoder) != AWS_DER_SEQUENCE) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &(out->modulus))) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
if (!aws_der_decoder_next(decoder) || aws_der_decoder_tlv_unsigned_integer(decoder, &out->publicExponent)) {
return aws_raise_error(AWS_ERROR_CAL_MALFORMED_ASN1_ENCOUNTERED);
}
return AWS_OP_SUCCESS;
}
int is_valid_rsa_key_size(size_t key_size_in_bits) {
if (key_size_in_bits < AWS_CAL_RSA_MIN_SUPPORTED_KEY_SIZE_IN_BITS ||
key_size_in_bits > AWS_CAL_RSA_MAX_SUPPORTED_KEY_SIZE_IN_BITS || key_size_in_bits % 8 != 0) {
return aws_raise_error(AWS_ERROR_INVALID_ARGUMENT);
}
return AWS_OP_SUCCESS;
}
|
