xref: /aosp_15_r20/external/mbedtls/library/dhm.c (revision 62c56f9862f102b96d72393aff6076c951fb8148)
1*62c56f98SSadaf Ebrahimi /*
2*62c56f98SSadaf Ebrahimi  *  Diffie-Hellman-Merkle key exchange
3*62c56f98SSadaf Ebrahimi  *
4*62c56f98SSadaf Ebrahimi  *  Copyright The Mbed TLS Contributors
5*62c56f98SSadaf Ebrahimi  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
6*62c56f98SSadaf Ebrahimi  */
7*62c56f98SSadaf Ebrahimi /*
8*62c56f98SSadaf Ebrahimi  *  The following sources were referenced in the design of this implementation
9*62c56f98SSadaf Ebrahimi  *  of the Diffie-Hellman-Merkle algorithm:
10*62c56f98SSadaf Ebrahimi  *
11*62c56f98SSadaf Ebrahimi  *  [1] Handbook of Applied Cryptography - 1997, Chapter 12
12*62c56f98SSadaf Ebrahimi  *      Menezes, van Oorschot and Vanstone
13*62c56f98SSadaf Ebrahimi  *
14*62c56f98SSadaf Ebrahimi  */
15*62c56f98SSadaf Ebrahimi 
16*62c56f98SSadaf Ebrahimi #include "common.h"
17*62c56f98SSadaf Ebrahimi 
18*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_DHM_C)
19*62c56f98SSadaf Ebrahimi 
20*62c56f98SSadaf Ebrahimi #include "mbedtls/dhm.h"
21*62c56f98SSadaf Ebrahimi #include "mbedtls/platform_util.h"
22*62c56f98SSadaf Ebrahimi #include "mbedtls/error.h"
23*62c56f98SSadaf Ebrahimi 
24*62c56f98SSadaf Ebrahimi #include <string.h>
25*62c56f98SSadaf Ebrahimi 
26*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_PEM_PARSE_C)
27*62c56f98SSadaf Ebrahimi #include "mbedtls/pem.h"
28*62c56f98SSadaf Ebrahimi #endif
29*62c56f98SSadaf Ebrahimi 
30*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_ASN1_PARSE_C)
31*62c56f98SSadaf Ebrahimi #include "mbedtls/asn1.h"
32*62c56f98SSadaf Ebrahimi #endif
33*62c56f98SSadaf Ebrahimi 
34*62c56f98SSadaf Ebrahimi #include "mbedtls/platform.h"
35*62c56f98SSadaf Ebrahimi 
36*62c56f98SSadaf Ebrahimi #if !defined(MBEDTLS_DHM_ALT)
37*62c56f98SSadaf Ebrahimi 
38*62c56f98SSadaf Ebrahimi /*
39*62c56f98SSadaf Ebrahimi  * helper to validate the mbedtls_mpi size and import it
40*62c56f98SSadaf Ebrahimi  */
dhm_read_bignum(mbedtls_mpi * X,unsigned char ** p,const unsigned char * end)41*62c56f98SSadaf Ebrahimi static int dhm_read_bignum(mbedtls_mpi *X,
42*62c56f98SSadaf Ebrahimi                            unsigned char **p,
43*62c56f98SSadaf Ebrahimi                            const unsigned char *end)
44*62c56f98SSadaf Ebrahimi {
45*62c56f98SSadaf Ebrahimi     int ret, n;
46*62c56f98SSadaf Ebrahimi 
47*62c56f98SSadaf Ebrahimi     if (end - *p < 2) {
48*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
49*62c56f98SSadaf Ebrahimi     }
50*62c56f98SSadaf Ebrahimi 
51*62c56f98SSadaf Ebrahimi     n = ((*p)[0] << 8) | (*p)[1];
52*62c56f98SSadaf Ebrahimi     (*p) += 2;
53*62c56f98SSadaf Ebrahimi 
54*62c56f98SSadaf Ebrahimi     if ((int) (end - *p) < n) {
55*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
56*62c56f98SSadaf Ebrahimi     }
57*62c56f98SSadaf Ebrahimi 
58*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_mpi_read_binary(X, *p, n)) != 0) {
59*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PARAMS_FAILED, ret);
60*62c56f98SSadaf Ebrahimi     }
61*62c56f98SSadaf Ebrahimi 
62*62c56f98SSadaf Ebrahimi     (*p) += n;
63*62c56f98SSadaf Ebrahimi 
64*62c56f98SSadaf Ebrahimi     return 0;
65*62c56f98SSadaf Ebrahimi }
66*62c56f98SSadaf Ebrahimi 
67*62c56f98SSadaf Ebrahimi /*
68*62c56f98SSadaf Ebrahimi  * Verify sanity of parameter with regards to P
69*62c56f98SSadaf Ebrahimi  *
70*62c56f98SSadaf Ebrahimi  * Parameter should be: 2 <= public_param <= P - 2
71*62c56f98SSadaf Ebrahimi  *
72*62c56f98SSadaf Ebrahimi  * This means that we need to return an error if
73*62c56f98SSadaf Ebrahimi  *              public_param < 2 or public_param > P-2
74*62c56f98SSadaf Ebrahimi  *
75*62c56f98SSadaf Ebrahimi  * For more information on the attack, see:
76*62c56f98SSadaf Ebrahimi  *  http://www.cl.cam.ac.uk/~rja14/Papers/psandqs.pdf
77*62c56f98SSadaf Ebrahimi  *  http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2005-2643
78*62c56f98SSadaf Ebrahimi  */
dhm_check_range(const mbedtls_mpi * param,const mbedtls_mpi * P)79*62c56f98SSadaf Ebrahimi static int dhm_check_range(const mbedtls_mpi *param, const mbedtls_mpi *P)
80*62c56f98SSadaf Ebrahimi {
81*62c56f98SSadaf Ebrahimi     mbedtls_mpi U;
82*62c56f98SSadaf Ebrahimi     int ret = 0;
83*62c56f98SSadaf Ebrahimi 
84*62c56f98SSadaf Ebrahimi     mbedtls_mpi_init(&U);
85*62c56f98SSadaf Ebrahimi 
86*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(&U, P, 2));
87*62c56f98SSadaf Ebrahimi 
88*62c56f98SSadaf Ebrahimi     if (mbedtls_mpi_cmp_int(param, 2) < 0 ||
89*62c56f98SSadaf Ebrahimi         mbedtls_mpi_cmp_mpi(param, &U) > 0) {
90*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
91*62c56f98SSadaf Ebrahimi     }
92*62c56f98SSadaf Ebrahimi 
93*62c56f98SSadaf Ebrahimi cleanup:
94*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&U);
95*62c56f98SSadaf Ebrahimi     return ret;
96*62c56f98SSadaf Ebrahimi }
97*62c56f98SSadaf Ebrahimi 
mbedtls_dhm_init(mbedtls_dhm_context * ctx)98*62c56f98SSadaf Ebrahimi void mbedtls_dhm_init(mbedtls_dhm_context *ctx)
99*62c56f98SSadaf Ebrahimi {
100*62c56f98SSadaf Ebrahimi     memset(ctx, 0, sizeof(mbedtls_dhm_context));
101*62c56f98SSadaf Ebrahimi }
102*62c56f98SSadaf Ebrahimi 
mbedtls_dhm_get_bitlen(const mbedtls_dhm_context * ctx)103*62c56f98SSadaf Ebrahimi size_t mbedtls_dhm_get_bitlen(const mbedtls_dhm_context *ctx)
104*62c56f98SSadaf Ebrahimi {
105*62c56f98SSadaf Ebrahimi     return mbedtls_mpi_bitlen(&ctx->P);
106*62c56f98SSadaf Ebrahimi }
107*62c56f98SSadaf Ebrahimi 
mbedtls_dhm_get_len(const mbedtls_dhm_context * ctx)108*62c56f98SSadaf Ebrahimi size_t mbedtls_dhm_get_len(const mbedtls_dhm_context *ctx)
109*62c56f98SSadaf Ebrahimi {
110*62c56f98SSadaf Ebrahimi     return mbedtls_mpi_size(&ctx->P);
111*62c56f98SSadaf Ebrahimi }
112*62c56f98SSadaf Ebrahimi 
mbedtls_dhm_get_value(const mbedtls_dhm_context * ctx,mbedtls_dhm_parameter param,mbedtls_mpi * dest)113*62c56f98SSadaf Ebrahimi int mbedtls_dhm_get_value(const mbedtls_dhm_context *ctx,
114*62c56f98SSadaf Ebrahimi                           mbedtls_dhm_parameter param,
115*62c56f98SSadaf Ebrahimi                           mbedtls_mpi *dest)
116*62c56f98SSadaf Ebrahimi {
117*62c56f98SSadaf Ebrahimi     const mbedtls_mpi *src = NULL;
118*62c56f98SSadaf Ebrahimi     switch (param) {
119*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_P:
120*62c56f98SSadaf Ebrahimi             src = &ctx->P;
121*62c56f98SSadaf Ebrahimi             break;
122*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_G:
123*62c56f98SSadaf Ebrahimi             src = &ctx->G;
124*62c56f98SSadaf Ebrahimi             break;
125*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_X:
126*62c56f98SSadaf Ebrahimi             src = &ctx->X;
127*62c56f98SSadaf Ebrahimi             break;
128*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_GX:
129*62c56f98SSadaf Ebrahimi             src = &ctx->GX;
130*62c56f98SSadaf Ebrahimi             break;
131*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_GY:
132*62c56f98SSadaf Ebrahimi             src = &ctx->GY;
133*62c56f98SSadaf Ebrahimi             break;
134*62c56f98SSadaf Ebrahimi         case MBEDTLS_DHM_PARAM_K:
135*62c56f98SSadaf Ebrahimi             src = &ctx->K;
136*62c56f98SSadaf Ebrahimi             break;
137*62c56f98SSadaf Ebrahimi         default:
138*62c56f98SSadaf Ebrahimi             return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
139*62c56f98SSadaf Ebrahimi     }
140*62c56f98SSadaf Ebrahimi     return mbedtls_mpi_copy(dest, src);
141*62c56f98SSadaf Ebrahimi }
142*62c56f98SSadaf Ebrahimi 
143*62c56f98SSadaf Ebrahimi /*
144*62c56f98SSadaf Ebrahimi  * Parse the ServerKeyExchange parameters
145*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_read_params(mbedtls_dhm_context * ctx,unsigned char ** p,const unsigned char * end)146*62c56f98SSadaf Ebrahimi int mbedtls_dhm_read_params(mbedtls_dhm_context *ctx,
147*62c56f98SSadaf Ebrahimi                             unsigned char **p,
148*62c56f98SSadaf Ebrahimi                             const unsigned char *end)
149*62c56f98SSadaf Ebrahimi {
150*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
151*62c56f98SSadaf Ebrahimi 
152*62c56f98SSadaf Ebrahimi     if ((ret = dhm_read_bignum(&ctx->P,  p, end)) != 0 ||
153*62c56f98SSadaf Ebrahimi         (ret = dhm_read_bignum(&ctx->G,  p, end)) != 0 ||
154*62c56f98SSadaf Ebrahimi         (ret = dhm_read_bignum(&ctx->GY, p, end)) != 0) {
155*62c56f98SSadaf Ebrahimi         return ret;
156*62c56f98SSadaf Ebrahimi     }
157*62c56f98SSadaf Ebrahimi 
158*62c56f98SSadaf Ebrahimi     if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
159*62c56f98SSadaf Ebrahimi         return ret;
160*62c56f98SSadaf Ebrahimi     }
161*62c56f98SSadaf Ebrahimi 
162*62c56f98SSadaf Ebrahimi     return 0;
163*62c56f98SSadaf Ebrahimi }
164*62c56f98SSadaf Ebrahimi 
165*62c56f98SSadaf Ebrahimi /*
166*62c56f98SSadaf Ebrahimi  * Pick a random R in the range [2, M-2] for blinding or key generation.
167*62c56f98SSadaf Ebrahimi  */
dhm_random_below(mbedtls_mpi * R,const mbedtls_mpi * M,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)168*62c56f98SSadaf Ebrahimi static int dhm_random_below(mbedtls_mpi *R, const mbedtls_mpi *M,
169*62c56f98SSadaf Ebrahimi                             int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
170*62c56f98SSadaf Ebrahimi {
171*62c56f98SSadaf Ebrahimi     int ret;
172*62c56f98SSadaf Ebrahimi 
173*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_random(R, 3, M, f_rng, p_rng));
174*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_sub_int(R, R, 1));
175*62c56f98SSadaf Ebrahimi 
176*62c56f98SSadaf Ebrahimi cleanup:
177*62c56f98SSadaf Ebrahimi     return ret;
178*62c56f98SSadaf Ebrahimi }
179*62c56f98SSadaf Ebrahimi 
dhm_make_common(mbedtls_dhm_context * ctx,int x_size,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)180*62c56f98SSadaf Ebrahimi static int dhm_make_common(mbedtls_dhm_context *ctx, int x_size,
181*62c56f98SSadaf Ebrahimi                            int (*f_rng)(void *, unsigned char *, size_t),
182*62c56f98SSadaf Ebrahimi                            void *p_rng)
183*62c56f98SSadaf Ebrahimi {
184*62c56f98SSadaf Ebrahimi     int ret = 0;
185*62c56f98SSadaf Ebrahimi 
186*62c56f98SSadaf Ebrahimi     if (mbedtls_mpi_cmp_int(&ctx->P, 0) == 0) {
187*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
188*62c56f98SSadaf Ebrahimi     }
189*62c56f98SSadaf Ebrahimi     if (x_size < 0) {
190*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
191*62c56f98SSadaf Ebrahimi     }
192*62c56f98SSadaf Ebrahimi 
193*62c56f98SSadaf Ebrahimi     if ((unsigned) x_size < mbedtls_mpi_size(&ctx->P)) {
194*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_fill_random(&ctx->X, x_size, f_rng, p_rng));
195*62c56f98SSadaf Ebrahimi     } else {
196*62c56f98SSadaf Ebrahimi         /* Generate X as large as possible ( <= P - 2 ) */
197*62c56f98SSadaf Ebrahimi         ret = dhm_random_below(&ctx->X, &ctx->P, f_rng, p_rng);
198*62c56f98SSadaf Ebrahimi         if (ret == MBEDTLS_ERR_MPI_NOT_ACCEPTABLE) {
199*62c56f98SSadaf Ebrahimi             return MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED;
200*62c56f98SSadaf Ebrahimi         }
201*62c56f98SSadaf Ebrahimi         if (ret != 0) {
202*62c56f98SSadaf Ebrahimi             return ret;
203*62c56f98SSadaf Ebrahimi         }
204*62c56f98SSadaf Ebrahimi     }
205*62c56f98SSadaf Ebrahimi 
206*62c56f98SSadaf Ebrahimi     /*
207*62c56f98SSadaf Ebrahimi      * Calculate GX = G^X mod P
208*62c56f98SSadaf Ebrahimi      */
209*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->GX, &ctx->G, &ctx->X,
210*62c56f98SSadaf Ebrahimi                                         &ctx->P, &ctx->RP));
211*62c56f98SSadaf Ebrahimi 
212*62c56f98SSadaf Ebrahimi     if ((ret = dhm_check_range(&ctx->GX, &ctx->P)) != 0) {
213*62c56f98SSadaf Ebrahimi         return ret;
214*62c56f98SSadaf Ebrahimi     }
215*62c56f98SSadaf Ebrahimi 
216*62c56f98SSadaf Ebrahimi cleanup:
217*62c56f98SSadaf Ebrahimi     return ret;
218*62c56f98SSadaf Ebrahimi }
219*62c56f98SSadaf Ebrahimi 
220*62c56f98SSadaf Ebrahimi /*
221*62c56f98SSadaf Ebrahimi  * Setup and write the ServerKeyExchange parameters
222*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_make_params(mbedtls_dhm_context * ctx,int x_size,unsigned char * output,size_t * olen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)223*62c56f98SSadaf Ebrahimi int mbedtls_dhm_make_params(mbedtls_dhm_context *ctx, int x_size,
224*62c56f98SSadaf Ebrahimi                             unsigned char *output, size_t *olen,
225*62c56f98SSadaf Ebrahimi                             int (*f_rng)(void *, unsigned char *, size_t),
226*62c56f98SSadaf Ebrahimi                             void *p_rng)
227*62c56f98SSadaf Ebrahimi {
228*62c56f98SSadaf Ebrahimi     int ret;
229*62c56f98SSadaf Ebrahimi     size_t n1, n2, n3;
230*62c56f98SSadaf Ebrahimi     unsigned char *p;
231*62c56f98SSadaf Ebrahimi 
232*62c56f98SSadaf Ebrahimi     ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
233*62c56f98SSadaf Ebrahimi     if (ret != 0) {
234*62c56f98SSadaf Ebrahimi         goto cleanup;
235*62c56f98SSadaf Ebrahimi     }
236*62c56f98SSadaf Ebrahimi 
237*62c56f98SSadaf Ebrahimi     /*
238*62c56f98SSadaf Ebrahimi      * Export P, G, GX. RFC 5246 §4.4 states that "leading zero octets are
239*62c56f98SSadaf Ebrahimi      * not required". We omit leading zeros for compactness.
240*62c56f98SSadaf Ebrahimi      */
241*62c56f98SSadaf Ebrahimi #define DHM_MPI_EXPORT(X, n)                                          \
242*62c56f98SSadaf Ebrahimi     do {                                                                \
243*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary((X),               \
244*62c56f98SSadaf Ebrahimi                                                  p + 2,               \
245*62c56f98SSadaf Ebrahimi                                                  (n)));           \
246*62c56f98SSadaf Ebrahimi         *p++ = MBEDTLS_BYTE_1(n);                                     \
247*62c56f98SSadaf Ebrahimi         *p++ = MBEDTLS_BYTE_0(n);                                     \
248*62c56f98SSadaf Ebrahimi         p += (n);                                                     \
249*62c56f98SSadaf Ebrahimi     } while (0)
250*62c56f98SSadaf Ebrahimi 
251*62c56f98SSadaf Ebrahimi     n1 = mbedtls_mpi_size(&ctx->P);
252*62c56f98SSadaf Ebrahimi     n2 = mbedtls_mpi_size(&ctx->G);
253*62c56f98SSadaf Ebrahimi     n3 = mbedtls_mpi_size(&ctx->GX);
254*62c56f98SSadaf Ebrahimi 
255*62c56f98SSadaf Ebrahimi     p = output;
256*62c56f98SSadaf Ebrahimi     DHM_MPI_EXPORT(&ctx->P, n1);
257*62c56f98SSadaf Ebrahimi     DHM_MPI_EXPORT(&ctx->G, n2);
258*62c56f98SSadaf Ebrahimi     DHM_MPI_EXPORT(&ctx->GX, n3);
259*62c56f98SSadaf Ebrahimi 
260*62c56f98SSadaf Ebrahimi     *olen = p - output;
261*62c56f98SSadaf Ebrahimi 
262*62c56f98SSadaf Ebrahimi cleanup:
263*62c56f98SSadaf Ebrahimi     if (ret != 0 && ret > -128) {
264*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED, ret);
265*62c56f98SSadaf Ebrahimi     }
266*62c56f98SSadaf Ebrahimi     return ret;
267*62c56f98SSadaf Ebrahimi }
268*62c56f98SSadaf Ebrahimi 
269*62c56f98SSadaf Ebrahimi /*
270*62c56f98SSadaf Ebrahimi  * Set prime modulus and generator
271*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_set_group(mbedtls_dhm_context * ctx,const mbedtls_mpi * P,const mbedtls_mpi * G)272*62c56f98SSadaf Ebrahimi int mbedtls_dhm_set_group(mbedtls_dhm_context *ctx,
273*62c56f98SSadaf Ebrahimi                           const mbedtls_mpi *P,
274*62c56f98SSadaf Ebrahimi                           const mbedtls_mpi *G)
275*62c56f98SSadaf Ebrahimi {
276*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
277*62c56f98SSadaf Ebrahimi 
278*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_mpi_copy(&ctx->P, P)) != 0 ||
279*62c56f98SSadaf Ebrahimi         (ret = mbedtls_mpi_copy(&ctx->G, G)) != 0) {
280*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_SET_GROUP_FAILED, ret);
281*62c56f98SSadaf Ebrahimi     }
282*62c56f98SSadaf Ebrahimi 
283*62c56f98SSadaf Ebrahimi     return 0;
284*62c56f98SSadaf Ebrahimi }
285*62c56f98SSadaf Ebrahimi 
286*62c56f98SSadaf Ebrahimi /*
287*62c56f98SSadaf Ebrahimi  * Import the peer's public value G^Y
288*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_read_public(mbedtls_dhm_context * ctx,const unsigned char * input,size_t ilen)289*62c56f98SSadaf Ebrahimi int mbedtls_dhm_read_public(mbedtls_dhm_context *ctx,
290*62c56f98SSadaf Ebrahimi                             const unsigned char *input, size_t ilen)
291*62c56f98SSadaf Ebrahimi {
292*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
293*62c56f98SSadaf Ebrahimi 
294*62c56f98SSadaf Ebrahimi     if (ilen < 1 || ilen > mbedtls_dhm_get_len(ctx)) {
295*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
296*62c56f98SSadaf Ebrahimi     }
297*62c56f98SSadaf Ebrahimi 
298*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_mpi_read_binary(&ctx->GY, input, ilen)) != 0) {
299*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_READ_PUBLIC_FAILED, ret);
300*62c56f98SSadaf Ebrahimi     }
301*62c56f98SSadaf Ebrahimi 
302*62c56f98SSadaf Ebrahimi     return 0;
303*62c56f98SSadaf Ebrahimi }
304*62c56f98SSadaf Ebrahimi 
305*62c56f98SSadaf Ebrahimi /*
306*62c56f98SSadaf Ebrahimi  * Create own private value X and export G^X
307*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_make_public(mbedtls_dhm_context * ctx,int x_size,unsigned char * output,size_t olen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)308*62c56f98SSadaf Ebrahimi int mbedtls_dhm_make_public(mbedtls_dhm_context *ctx, int x_size,
309*62c56f98SSadaf Ebrahimi                             unsigned char *output, size_t olen,
310*62c56f98SSadaf Ebrahimi                             int (*f_rng)(void *, unsigned char *, size_t),
311*62c56f98SSadaf Ebrahimi                             void *p_rng)
312*62c56f98SSadaf Ebrahimi {
313*62c56f98SSadaf Ebrahimi     int ret;
314*62c56f98SSadaf Ebrahimi 
315*62c56f98SSadaf Ebrahimi     if (olen < 1 || olen > mbedtls_dhm_get_len(ctx)) {
316*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
317*62c56f98SSadaf Ebrahimi     }
318*62c56f98SSadaf Ebrahimi 
319*62c56f98SSadaf Ebrahimi     ret = dhm_make_common(ctx, x_size, f_rng, p_rng);
320*62c56f98SSadaf Ebrahimi     if (ret == MBEDTLS_ERR_DHM_MAKE_PARAMS_FAILED) {
321*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED;
322*62c56f98SSadaf Ebrahimi     }
323*62c56f98SSadaf Ebrahimi     if (ret != 0) {
324*62c56f98SSadaf Ebrahimi         goto cleanup;
325*62c56f98SSadaf Ebrahimi     }
326*62c56f98SSadaf Ebrahimi 
327*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->GX, output, olen));
328*62c56f98SSadaf Ebrahimi 
329*62c56f98SSadaf Ebrahimi cleanup:
330*62c56f98SSadaf Ebrahimi     if (ret != 0 && ret > -128) {
331*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_MAKE_PUBLIC_FAILED, ret);
332*62c56f98SSadaf Ebrahimi     }
333*62c56f98SSadaf Ebrahimi     return ret;
334*62c56f98SSadaf Ebrahimi }
335*62c56f98SSadaf Ebrahimi 
336*62c56f98SSadaf Ebrahimi 
337*62c56f98SSadaf Ebrahimi /*
338*62c56f98SSadaf Ebrahimi  * Use the blinding method and optimisation suggested in section 10 of:
339*62c56f98SSadaf Ebrahimi  *  KOCHER, Paul C. Timing attacks on implementations of Diffie-Hellman, RSA,
340*62c56f98SSadaf Ebrahimi  *  DSS, and other systems. In : Advances in Cryptology-CRYPTO'96. Springer
341*62c56f98SSadaf Ebrahimi  *  Berlin Heidelberg, 1996. p. 104-113.
342*62c56f98SSadaf Ebrahimi  */
dhm_update_blinding(mbedtls_dhm_context * ctx,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)343*62c56f98SSadaf Ebrahimi static int dhm_update_blinding(mbedtls_dhm_context *ctx,
344*62c56f98SSadaf Ebrahimi                                int (*f_rng)(void *, unsigned char *, size_t), void *p_rng)
345*62c56f98SSadaf Ebrahimi {
346*62c56f98SSadaf Ebrahimi     int ret;
347*62c56f98SSadaf Ebrahimi     mbedtls_mpi R;
348*62c56f98SSadaf Ebrahimi 
349*62c56f98SSadaf Ebrahimi     mbedtls_mpi_init(&R);
350*62c56f98SSadaf Ebrahimi 
351*62c56f98SSadaf Ebrahimi     /*
352*62c56f98SSadaf Ebrahimi      * Don't use any blinding the first time a particular X is used,
353*62c56f98SSadaf Ebrahimi      * but remember it to use blinding next time.
354*62c56f98SSadaf Ebrahimi      */
355*62c56f98SSadaf Ebrahimi     if (mbedtls_mpi_cmp_mpi(&ctx->X, &ctx->pX) != 0) {
356*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_copy(&ctx->pX, &ctx->X));
357*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vi, 1));
358*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_lset(&ctx->Vf, 1));
359*62c56f98SSadaf Ebrahimi 
360*62c56f98SSadaf Ebrahimi         return 0;
361*62c56f98SSadaf Ebrahimi     }
362*62c56f98SSadaf Ebrahimi 
363*62c56f98SSadaf Ebrahimi     /*
364*62c56f98SSadaf Ebrahimi      * Ok, we need blinding. Can we re-use existing values?
365*62c56f98SSadaf Ebrahimi      * If yes, just update them by squaring them.
366*62c56f98SSadaf Ebrahimi      */
367*62c56f98SSadaf Ebrahimi     if (mbedtls_mpi_cmp_int(&ctx->Vi, 1) != 0) {
368*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vi, &ctx->Vi, &ctx->Vi));
369*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vi, &ctx->Vi, &ctx->P));
370*62c56f98SSadaf Ebrahimi 
371*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &ctx->Vf));
372*62c56f98SSadaf Ebrahimi         MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
373*62c56f98SSadaf Ebrahimi 
374*62c56f98SSadaf Ebrahimi         return 0;
375*62c56f98SSadaf Ebrahimi     }
376*62c56f98SSadaf Ebrahimi 
377*62c56f98SSadaf Ebrahimi     /*
378*62c56f98SSadaf Ebrahimi      * We need to generate blinding values from scratch
379*62c56f98SSadaf Ebrahimi      */
380*62c56f98SSadaf Ebrahimi 
381*62c56f98SSadaf Ebrahimi     /* Vi = random( 2, P-2 ) */
382*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(dhm_random_below(&ctx->Vi, &ctx->P, f_rng, p_rng));
383*62c56f98SSadaf Ebrahimi 
384*62c56f98SSadaf Ebrahimi     /* Vf = Vi^-X mod P
385*62c56f98SSadaf Ebrahimi      * First compute Vi^-1 = R * (R Vi)^-1, (avoiding leaks from inv_mod),
386*62c56f98SSadaf Ebrahimi      * then elevate to the Xth power. */
387*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(dhm_random_below(&R, &ctx->P, f_rng, p_rng));
388*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vi, &R));
389*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
390*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_inv_mod(&ctx->Vf, &ctx->Vf, &ctx->P));
391*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->Vf, &ctx->Vf, &R));
392*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->Vf, &ctx->Vf, &ctx->P));
393*62c56f98SSadaf Ebrahimi 
394*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->Vf, &ctx->Vf, &ctx->X, &ctx->P, &ctx->RP));
395*62c56f98SSadaf Ebrahimi 
396*62c56f98SSadaf Ebrahimi cleanup:
397*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&R);
398*62c56f98SSadaf Ebrahimi 
399*62c56f98SSadaf Ebrahimi     return ret;
400*62c56f98SSadaf Ebrahimi }
401*62c56f98SSadaf Ebrahimi 
402*62c56f98SSadaf Ebrahimi /*
403*62c56f98SSadaf Ebrahimi  * Derive and export the shared secret (G^Y)^X mod P
404*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_calc_secret(mbedtls_dhm_context * ctx,unsigned char * output,size_t output_size,size_t * olen,int (* f_rng)(void *,unsigned char *,size_t),void * p_rng)405*62c56f98SSadaf Ebrahimi int mbedtls_dhm_calc_secret(mbedtls_dhm_context *ctx,
406*62c56f98SSadaf Ebrahimi                             unsigned char *output, size_t output_size, size_t *olen,
407*62c56f98SSadaf Ebrahimi                             int (*f_rng)(void *, unsigned char *, size_t),
408*62c56f98SSadaf Ebrahimi                             void *p_rng)
409*62c56f98SSadaf Ebrahimi {
410*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
411*62c56f98SSadaf Ebrahimi     mbedtls_mpi GYb;
412*62c56f98SSadaf Ebrahimi 
413*62c56f98SSadaf Ebrahimi     if (f_rng == NULL) {
414*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
415*62c56f98SSadaf Ebrahimi     }
416*62c56f98SSadaf Ebrahimi 
417*62c56f98SSadaf Ebrahimi     if (output_size < mbedtls_dhm_get_len(ctx)) {
418*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_BAD_INPUT_DATA;
419*62c56f98SSadaf Ebrahimi     }
420*62c56f98SSadaf Ebrahimi 
421*62c56f98SSadaf Ebrahimi     if ((ret = dhm_check_range(&ctx->GY, &ctx->P)) != 0) {
422*62c56f98SSadaf Ebrahimi         return ret;
423*62c56f98SSadaf Ebrahimi     }
424*62c56f98SSadaf Ebrahimi 
425*62c56f98SSadaf Ebrahimi     mbedtls_mpi_init(&GYb);
426*62c56f98SSadaf Ebrahimi 
427*62c56f98SSadaf Ebrahimi     /* Blind peer's value */
428*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(dhm_update_blinding(ctx, f_rng, p_rng));
429*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&GYb, &ctx->GY, &ctx->Vi));
430*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&GYb, &GYb, &ctx->P));
431*62c56f98SSadaf Ebrahimi 
432*62c56f98SSadaf Ebrahimi     /* Do modular exponentiation */
433*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_exp_mod(&ctx->K, &GYb, &ctx->X,
434*62c56f98SSadaf Ebrahimi                                         &ctx->P, &ctx->RP));
435*62c56f98SSadaf Ebrahimi 
436*62c56f98SSadaf Ebrahimi     /* Unblind secret value */
437*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mul_mpi(&ctx->K, &ctx->K, &ctx->Vf));
438*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_mod_mpi(&ctx->K, &ctx->K, &ctx->P));
439*62c56f98SSadaf Ebrahimi 
440*62c56f98SSadaf Ebrahimi     /* Output the secret without any leading zero byte. This is mandatory
441*62c56f98SSadaf Ebrahimi      * for TLS per RFC 5246 §8.1.2. */
442*62c56f98SSadaf Ebrahimi     *olen = mbedtls_mpi_size(&ctx->K);
443*62c56f98SSadaf Ebrahimi     MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&ctx->K, output, *olen));
444*62c56f98SSadaf Ebrahimi 
445*62c56f98SSadaf Ebrahimi cleanup:
446*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&GYb);
447*62c56f98SSadaf Ebrahimi 
448*62c56f98SSadaf Ebrahimi     if (ret != 0) {
449*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_CALC_SECRET_FAILED, ret);
450*62c56f98SSadaf Ebrahimi     }
451*62c56f98SSadaf Ebrahimi 
452*62c56f98SSadaf Ebrahimi     return 0;
453*62c56f98SSadaf Ebrahimi }
454*62c56f98SSadaf Ebrahimi 
455*62c56f98SSadaf Ebrahimi /*
456*62c56f98SSadaf Ebrahimi  * Free the components of a DHM key
457*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_free(mbedtls_dhm_context * ctx)458*62c56f98SSadaf Ebrahimi void mbedtls_dhm_free(mbedtls_dhm_context *ctx)
459*62c56f98SSadaf Ebrahimi {
460*62c56f98SSadaf Ebrahimi     if (ctx == NULL) {
461*62c56f98SSadaf Ebrahimi         return;
462*62c56f98SSadaf Ebrahimi     }
463*62c56f98SSadaf Ebrahimi 
464*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->pX);
465*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->Vf);
466*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->Vi);
467*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->RP);
468*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->K);
469*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->GY);
470*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->GX);
471*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->X);
472*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->G);
473*62c56f98SSadaf Ebrahimi     mbedtls_mpi_free(&ctx->P);
474*62c56f98SSadaf Ebrahimi 
475*62c56f98SSadaf Ebrahimi     mbedtls_platform_zeroize(ctx, sizeof(mbedtls_dhm_context));
476*62c56f98SSadaf Ebrahimi }
477*62c56f98SSadaf Ebrahimi 
478*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_ASN1_PARSE_C)
479*62c56f98SSadaf Ebrahimi /*
480*62c56f98SSadaf Ebrahimi  * Parse DHM parameters
481*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_parse_dhm(mbedtls_dhm_context * dhm,const unsigned char * dhmin,size_t dhminlen)482*62c56f98SSadaf Ebrahimi int mbedtls_dhm_parse_dhm(mbedtls_dhm_context *dhm, const unsigned char *dhmin,
483*62c56f98SSadaf Ebrahimi                           size_t dhminlen)
484*62c56f98SSadaf Ebrahimi {
485*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
486*62c56f98SSadaf Ebrahimi     size_t len;
487*62c56f98SSadaf Ebrahimi     unsigned char *p, *end;
488*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_PEM_PARSE_C)
489*62c56f98SSadaf Ebrahimi     mbedtls_pem_context pem;
490*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_PEM_PARSE_C */
491*62c56f98SSadaf Ebrahimi 
492*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_PEM_PARSE_C)
493*62c56f98SSadaf Ebrahimi     mbedtls_pem_init(&pem);
494*62c56f98SSadaf Ebrahimi 
495*62c56f98SSadaf Ebrahimi     /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
496*62c56f98SSadaf Ebrahimi     if (dhminlen == 0 || dhmin[dhminlen - 1] != '\0') {
497*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
498*62c56f98SSadaf Ebrahimi     } else {
499*62c56f98SSadaf Ebrahimi         ret = mbedtls_pem_read_buffer(&pem,
500*62c56f98SSadaf Ebrahimi                                       "-----BEGIN DH PARAMETERS-----",
501*62c56f98SSadaf Ebrahimi                                       "-----END DH PARAMETERS-----",
502*62c56f98SSadaf Ebrahimi                                       dhmin, NULL, 0, &dhminlen);
503*62c56f98SSadaf Ebrahimi     }
504*62c56f98SSadaf Ebrahimi 
505*62c56f98SSadaf Ebrahimi     if (ret == 0) {
506*62c56f98SSadaf Ebrahimi         /*
507*62c56f98SSadaf Ebrahimi          * Was PEM encoded
508*62c56f98SSadaf Ebrahimi          */
509*62c56f98SSadaf Ebrahimi         dhminlen = pem.buflen;
510*62c56f98SSadaf Ebrahimi     } else if (ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT) {
511*62c56f98SSadaf Ebrahimi         goto exit;
512*62c56f98SSadaf Ebrahimi     }
513*62c56f98SSadaf Ebrahimi 
514*62c56f98SSadaf Ebrahimi     p = (ret == 0) ? pem.buf : (unsigned char *) dhmin;
515*62c56f98SSadaf Ebrahimi #else
516*62c56f98SSadaf Ebrahimi     p = (unsigned char *) dhmin;
517*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_PEM_PARSE_C */
518*62c56f98SSadaf Ebrahimi     end = p + dhminlen;
519*62c56f98SSadaf Ebrahimi 
520*62c56f98SSadaf Ebrahimi     /*
521*62c56f98SSadaf Ebrahimi      *  DHParams ::= SEQUENCE {
522*62c56f98SSadaf Ebrahimi      *      prime              INTEGER,  -- P
523*62c56f98SSadaf Ebrahimi      *      generator          INTEGER,  -- g
524*62c56f98SSadaf Ebrahimi      *      privateValueLength INTEGER OPTIONAL
525*62c56f98SSadaf Ebrahimi      *  }
526*62c56f98SSadaf Ebrahimi      */
527*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_asn1_get_tag(&p, end, &len,
528*62c56f98SSadaf Ebrahimi                                     MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {
529*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
530*62c56f98SSadaf Ebrahimi         goto exit;
531*62c56f98SSadaf Ebrahimi     }
532*62c56f98SSadaf Ebrahimi 
533*62c56f98SSadaf Ebrahimi     end = p + len;
534*62c56f98SSadaf Ebrahimi 
535*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_asn1_get_mpi(&p, end, &dhm->P)) != 0 ||
536*62c56f98SSadaf Ebrahimi         (ret = mbedtls_asn1_get_mpi(&p, end, &dhm->G)) != 0) {
537*62c56f98SSadaf Ebrahimi         ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
538*62c56f98SSadaf Ebrahimi         goto exit;
539*62c56f98SSadaf Ebrahimi     }
540*62c56f98SSadaf Ebrahimi 
541*62c56f98SSadaf Ebrahimi     if (p != end) {
542*62c56f98SSadaf Ebrahimi         /* This might be the optional privateValueLength.
543*62c56f98SSadaf Ebrahimi          * If so, we can cleanly discard it */
544*62c56f98SSadaf Ebrahimi         mbedtls_mpi rec;
545*62c56f98SSadaf Ebrahimi         mbedtls_mpi_init(&rec);
546*62c56f98SSadaf Ebrahimi         ret = mbedtls_asn1_get_mpi(&p, end, &rec);
547*62c56f98SSadaf Ebrahimi         mbedtls_mpi_free(&rec);
548*62c56f98SSadaf Ebrahimi         if (ret != 0) {
549*62c56f98SSadaf Ebrahimi             ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT, ret);
550*62c56f98SSadaf Ebrahimi             goto exit;
551*62c56f98SSadaf Ebrahimi         }
552*62c56f98SSadaf Ebrahimi         if (p != end) {
553*62c56f98SSadaf Ebrahimi             ret = MBEDTLS_ERROR_ADD(MBEDTLS_ERR_DHM_INVALID_FORMAT,
554*62c56f98SSadaf Ebrahimi                                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);
555*62c56f98SSadaf Ebrahimi             goto exit;
556*62c56f98SSadaf Ebrahimi         }
557*62c56f98SSadaf Ebrahimi     }
558*62c56f98SSadaf Ebrahimi 
559*62c56f98SSadaf Ebrahimi     ret = 0;
560*62c56f98SSadaf Ebrahimi 
561*62c56f98SSadaf Ebrahimi exit:
562*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_PEM_PARSE_C)
563*62c56f98SSadaf Ebrahimi     mbedtls_pem_free(&pem);
564*62c56f98SSadaf Ebrahimi #endif
565*62c56f98SSadaf Ebrahimi     if (ret != 0) {
566*62c56f98SSadaf Ebrahimi         mbedtls_dhm_free(dhm);
567*62c56f98SSadaf Ebrahimi     }
568*62c56f98SSadaf Ebrahimi 
569*62c56f98SSadaf Ebrahimi     return ret;
570*62c56f98SSadaf Ebrahimi }
571*62c56f98SSadaf Ebrahimi 
572*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_FS_IO)
573*62c56f98SSadaf Ebrahimi /*
574*62c56f98SSadaf Ebrahimi  * Load all data from a file into a given buffer.
575*62c56f98SSadaf Ebrahimi  *
576*62c56f98SSadaf Ebrahimi  * The file is expected to contain either PEM or DER encoded data.
577*62c56f98SSadaf Ebrahimi  * A terminating null byte is always appended. It is included in the announced
578*62c56f98SSadaf Ebrahimi  * length only if the data looks like it is PEM encoded.
579*62c56f98SSadaf Ebrahimi  */
load_file(const char * path,unsigned char ** buf,size_t * n)580*62c56f98SSadaf Ebrahimi static int load_file(const char *path, unsigned char **buf, size_t *n)
581*62c56f98SSadaf Ebrahimi {
582*62c56f98SSadaf Ebrahimi     FILE *f;
583*62c56f98SSadaf Ebrahimi     long size;
584*62c56f98SSadaf Ebrahimi 
585*62c56f98SSadaf Ebrahimi     if ((f = fopen(path, "rb")) == NULL) {
586*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
587*62c56f98SSadaf Ebrahimi     }
588*62c56f98SSadaf Ebrahimi     /* The data loaded here is public, so don't bother disabling buffering. */
589*62c56f98SSadaf Ebrahimi 
590*62c56f98SSadaf Ebrahimi     fseek(f, 0, SEEK_END);
591*62c56f98SSadaf Ebrahimi     if ((size = ftell(f)) == -1) {
592*62c56f98SSadaf Ebrahimi         fclose(f);
593*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
594*62c56f98SSadaf Ebrahimi     }
595*62c56f98SSadaf Ebrahimi     fseek(f, 0, SEEK_SET);
596*62c56f98SSadaf Ebrahimi 
597*62c56f98SSadaf Ebrahimi     *n = (size_t) size;
598*62c56f98SSadaf Ebrahimi 
599*62c56f98SSadaf Ebrahimi     if (*n + 1 == 0 ||
600*62c56f98SSadaf Ebrahimi         (*buf = mbedtls_calloc(1, *n + 1)) == NULL) {
601*62c56f98SSadaf Ebrahimi         fclose(f);
602*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_ALLOC_FAILED;
603*62c56f98SSadaf Ebrahimi     }
604*62c56f98SSadaf Ebrahimi 
605*62c56f98SSadaf Ebrahimi     if (fread(*buf, 1, *n, f) != *n) {
606*62c56f98SSadaf Ebrahimi         fclose(f);
607*62c56f98SSadaf Ebrahimi 
608*62c56f98SSadaf Ebrahimi         mbedtls_zeroize_and_free(*buf, *n + 1);
609*62c56f98SSadaf Ebrahimi 
610*62c56f98SSadaf Ebrahimi         return MBEDTLS_ERR_DHM_FILE_IO_ERROR;
611*62c56f98SSadaf Ebrahimi     }
612*62c56f98SSadaf Ebrahimi 
613*62c56f98SSadaf Ebrahimi     fclose(f);
614*62c56f98SSadaf Ebrahimi 
615*62c56f98SSadaf Ebrahimi     (*buf)[*n] = '\0';
616*62c56f98SSadaf Ebrahimi 
617*62c56f98SSadaf Ebrahimi     if (strstr((const char *) *buf, "-----BEGIN ") != NULL) {
618*62c56f98SSadaf Ebrahimi         ++*n;
619*62c56f98SSadaf Ebrahimi     }
620*62c56f98SSadaf Ebrahimi 
621*62c56f98SSadaf Ebrahimi     return 0;
622*62c56f98SSadaf Ebrahimi }
623*62c56f98SSadaf Ebrahimi 
624*62c56f98SSadaf Ebrahimi /*
625*62c56f98SSadaf Ebrahimi  * Load and parse DHM parameters
626*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_parse_dhmfile(mbedtls_dhm_context * dhm,const char * path)627*62c56f98SSadaf Ebrahimi int mbedtls_dhm_parse_dhmfile(mbedtls_dhm_context *dhm, const char *path)
628*62c56f98SSadaf Ebrahimi {
629*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
630*62c56f98SSadaf Ebrahimi     size_t n;
631*62c56f98SSadaf Ebrahimi     unsigned char *buf;
632*62c56f98SSadaf Ebrahimi 
633*62c56f98SSadaf Ebrahimi     if ((ret = load_file(path, &buf, &n)) != 0) {
634*62c56f98SSadaf Ebrahimi         return ret;
635*62c56f98SSadaf Ebrahimi     }
636*62c56f98SSadaf Ebrahimi 
637*62c56f98SSadaf Ebrahimi     ret = mbedtls_dhm_parse_dhm(dhm, buf, n);
638*62c56f98SSadaf Ebrahimi 
639*62c56f98SSadaf Ebrahimi     mbedtls_zeroize_and_free(buf, n);
640*62c56f98SSadaf Ebrahimi 
641*62c56f98SSadaf Ebrahimi     return ret;
642*62c56f98SSadaf Ebrahimi }
643*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_FS_IO */
644*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_ASN1_PARSE_C */
645*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_DHM_ALT */
646*62c56f98SSadaf Ebrahimi 
647*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_SELF_TEST)
648*62c56f98SSadaf Ebrahimi 
649*62c56f98SSadaf Ebrahimi #if defined(MBEDTLS_PEM_PARSE_C)
650*62c56f98SSadaf Ebrahimi static const char mbedtls_test_dhm_params[] =
651*62c56f98SSadaf Ebrahimi     "-----BEGIN DH PARAMETERS-----\r\n"
652*62c56f98SSadaf Ebrahimi     "MIGHAoGBAJ419DBEOgmQTzo5qXl5fQcN9TN455wkOL7052HzxxRVMyhYmwQcgJvh\r\n"
653*62c56f98SSadaf Ebrahimi     "1sa18fyfR9OiVEMYglOpkqVoGLN7qd5aQNNi5W7/C+VBdHTBJcGZJyyP5B3qcz32\r\n"
654*62c56f98SSadaf Ebrahimi     "9mLJKudlVudV0Qxk5qUJaPZ/xupz0NyoVpviuiBOI1gNi8ovSXWzAgEC\r\n"
655*62c56f98SSadaf Ebrahimi     "-----END DH PARAMETERS-----\r\n";
656*62c56f98SSadaf Ebrahimi #else /* MBEDTLS_PEM_PARSE_C */
657*62c56f98SSadaf Ebrahimi static const char mbedtls_test_dhm_params[] = {
658*62c56f98SSadaf Ebrahimi     0x30, 0x81, 0x87, 0x02, 0x81, 0x81, 0x00, 0x9e, 0x35, 0xf4, 0x30, 0x44,
659*62c56f98SSadaf Ebrahimi     0x3a, 0x09, 0x90, 0x4f, 0x3a, 0x39, 0xa9, 0x79, 0x79, 0x7d, 0x07, 0x0d,
660*62c56f98SSadaf Ebrahimi     0xf5, 0x33, 0x78, 0xe7, 0x9c, 0x24, 0x38, 0xbe, 0xf4, 0xe7, 0x61, 0xf3,
661*62c56f98SSadaf Ebrahimi     0xc7, 0x14, 0x55, 0x33, 0x28, 0x58, 0x9b, 0x04, 0x1c, 0x80, 0x9b, 0xe1,
662*62c56f98SSadaf Ebrahimi     0xd6, 0xc6, 0xb5, 0xf1, 0xfc, 0x9f, 0x47, 0xd3, 0xa2, 0x54, 0x43, 0x18,
663*62c56f98SSadaf Ebrahimi     0x82, 0x53, 0xa9, 0x92, 0xa5, 0x68, 0x18, 0xb3, 0x7b, 0xa9, 0xde, 0x5a,
664*62c56f98SSadaf Ebrahimi     0x40, 0xd3, 0x62, 0xe5, 0x6e, 0xff, 0x0b, 0xe5, 0x41, 0x74, 0x74, 0xc1,
665*62c56f98SSadaf Ebrahimi     0x25, 0xc1, 0x99, 0x27, 0x2c, 0x8f, 0xe4, 0x1d, 0xea, 0x73, 0x3d, 0xf6,
666*62c56f98SSadaf Ebrahimi     0xf6, 0x62, 0xc9, 0x2a, 0xe7, 0x65, 0x56, 0xe7, 0x55, 0xd1, 0x0c, 0x64,
667*62c56f98SSadaf Ebrahimi     0xe6, 0xa5, 0x09, 0x68, 0xf6, 0x7f, 0xc6, 0xea, 0x73, 0xd0, 0xdc, 0xa8,
668*62c56f98SSadaf Ebrahimi     0x56, 0x9b, 0xe2, 0xba, 0x20, 0x4e, 0x23, 0x58, 0x0d, 0x8b, 0xca, 0x2f,
669*62c56f98SSadaf Ebrahimi     0x49, 0x75, 0xb3, 0x02, 0x01, 0x02
670*62c56f98SSadaf Ebrahimi };
671*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_PEM_PARSE_C */
672*62c56f98SSadaf Ebrahimi 
673*62c56f98SSadaf Ebrahimi static const size_t mbedtls_test_dhm_params_len = sizeof(mbedtls_test_dhm_params);
674*62c56f98SSadaf Ebrahimi 
675*62c56f98SSadaf Ebrahimi /*
676*62c56f98SSadaf Ebrahimi  * Checkup routine
677*62c56f98SSadaf Ebrahimi  */
mbedtls_dhm_self_test(int verbose)678*62c56f98SSadaf Ebrahimi int mbedtls_dhm_self_test(int verbose)
679*62c56f98SSadaf Ebrahimi {
680*62c56f98SSadaf Ebrahimi     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
681*62c56f98SSadaf Ebrahimi     mbedtls_dhm_context dhm;
682*62c56f98SSadaf Ebrahimi 
683*62c56f98SSadaf Ebrahimi     mbedtls_dhm_init(&dhm);
684*62c56f98SSadaf Ebrahimi 
685*62c56f98SSadaf Ebrahimi     if (verbose != 0) {
686*62c56f98SSadaf Ebrahimi         mbedtls_printf("  DHM parameter load: ");
687*62c56f98SSadaf Ebrahimi     }
688*62c56f98SSadaf Ebrahimi 
689*62c56f98SSadaf Ebrahimi     if ((ret = mbedtls_dhm_parse_dhm(&dhm,
690*62c56f98SSadaf Ebrahimi                                      (const unsigned char *) mbedtls_test_dhm_params,
691*62c56f98SSadaf Ebrahimi                                      mbedtls_test_dhm_params_len)) != 0) {
692*62c56f98SSadaf Ebrahimi         if (verbose != 0) {
693*62c56f98SSadaf Ebrahimi             mbedtls_printf("failed\n");
694*62c56f98SSadaf Ebrahimi         }
695*62c56f98SSadaf Ebrahimi 
696*62c56f98SSadaf Ebrahimi         ret = 1;
697*62c56f98SSadaf Ebrahimi         goto exit;
698*62c56f98SSadaf Ebrahimi     }
699*62c56f98SSadaf Ebrahimi 
700*62c56f98SSadaf Ebrahimi     if (verbose != 0) {
701*62c56f98SSadaf Ebrahimi         mbedtls_printf("passed\n\n");
702*62c56f98SSadaf Ebrahimi     }
703*62c56f98SSadaf Ebrahimi 
704*62c56f98SSadaf Ebrahimi exit:
705*62c56f98SSadaf Ebrahimi     mbedtls_dhm_free(&dhm);
706*62c56f98SSadaf Ebrahimi 
707*62c56f98SSadaf Ebrahimi     return ret;
708*62c56f98SSadaf Ebrahimi }
709*62c56f98SSadaf Ebrahimi 
710*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_SELF_TEST */
711*62c56f98SSadaf Ebrahimi 
712*62c56f98SSadaf Ebrahimi #endif /* MBEDTLS_DHM_C */
713