linux-master/crypto/ansi_cprng.c

81 static int _get_more_prng_bytes(struct prng_context *ctx, int cont_test)
89 		ctx);
91 	hexdump("Input DT: ", ctx->DT, DEFAULT_BLK_SZ);
92 	hexdump("Input I: ", ctx->I, DEFAULT_BLK_SZ);
93 	hexdump("Input V: ", ctx->V, DEFAULT_BLK_SZ);
106 			memcpy(tmp, ctx->DT, DEFAULT_BLK_SZ);
107 			output = ctx->I;
117 			xor_vectors(ctx->I, ctx->V, tmp, DEFAULT_BLK_SZ);
119 			output = ctx->rand_data;
126 			if (!memcmp(ctx->rand_data, ctx->last_rand_data,
130 						ctx);
134 					"ctx %p Failed repetition check!\n",
135 					ctx);
137 				ctx->flags |= PRNG_NEED_RESET;
140 			memcpy(ctx->last_rand_data, ctx->rand_data,
147 			xor_vectors(ctx->rand_data, ctx->I, tmp,
149 			output = ctx->V;
156 		crypto_cipher_encrypt_one(ctx->tfm, output, tmp);
164 		ctx->DT[i] += 1;
165 		if (ctx->DT[i] != 0)
169 	dbgprint("Returning new block for context %p\n", ctx);
170 	ctx->rand_data_valid = 0;
172 	hexdump("Output DT: ", ctx->DT, DEFAULT_BLK_SZ);
173 	hexdump("Output I: ", ctx->I, DEFAULT_BLK_SZ);
174 	hexdump("Output V: ", ctx->V, DEFAULT_BLK_SZ);
175 	hexdump("New Random Data: ", ctx->rand_data, DEFAULT_BLK_SZ);
181 static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx,
189 	spin_lock_bh(&ctx->prng_lock);
192 	if (ctx->flags & PRNG_NEED_RESET)
200 	if (ctx->flags & PRNG_FIXED_SIZE) {
213 		byte_count, ctx);
217 	if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
218 		if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
230 		while (ctx->rand_data_valid < DEFAULT_BLK_SZ) {
231 			*ptr = ctx->rand_data[ctx->rand_data_valid];
234 			ctx->rand_data_valid++;
244 		if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
245 			if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
251 		if (ctx->rand_data_valid > 0)
253 		memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
254 		ctx->rand_data_valid += DEFAULT_BLK_SZ;
265 	spin_unlock_bh(&ctx->prng_lock);
267 		err, ctx);
271 static void free_prng_context(struct prng_context *ctx)
273 	crypto_free_cipher(ctx->tfm);
276 static int reset_prng_context(struct prng_context *ctx,
283 	spin_lock_bh(&ctx->prng_lock);
284 	ctx->flags |= PRNG_NEED_RESET;
292 		memcpy(ctx->V, V, DEFAULT_BLK_SZ);
294 		memcpy(ctx->V, DEFAULT_V_SEED, DEFAULT_BLK_SZ);
297 		memcpy(ctx->DT, DT, DEFAULT_BLK_SZ);
299 		memset(ctx->DT, 0, DEFAULT_BLK_SZ);
301 	memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
302 	memset(ctx->last_rand_data, 0, DEFAULT_BLK_SZ);
304 	ctx->rand_data_valid = DEFAULT_BLK_SZ;
306 	ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
309 			crypto_cipher_get_flags(ctx->tfm));
314 	ctx->flags &= ~PRNG_NEED_RESET;
316 	spin_unlock_bh(&ctx->prng_lock);
322 	struct prng_context *ctx = crypto_tfm_ctx(tfm);
324 	spin_lock_init(&ctx->prng_lock);
325 	ctx->tfm = crypto_alloc_cipher("aes", 0, 0);
326 	if (IS_ERR(ctx->tfm)) {
328 				ctx);
329 		return PTR_ERR(ctx->tfm);
332 	if (reset_prng_context(ctx, NULL, DEFAULT_PRNG_KSZ, NULL, NULL) < 0)
340 	ctx->flags |= PRNG_NEED_RESET;