2 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 /* Dispatch functions for gcm mode */
12 #include "cipher_locl.h"
13 #include "internal/ciphers/cipher_gcm.h"
14 #include "internal/providercommonerr.h"
15 #include "internal/rand_int.h"
16 #include "internal/provider_ctx.h"
18 static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len);
19 static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv,
21 static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen,
22 const unsigned char *in, size_t len);
23 static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out,
24 size_t *padlen, const unsigned char *in,
27 void gcm_initctx(void *provctx, PROV_GCM_CTX *ctx, size_t keybits,
28 const PROV_GCM_HW *hw, size_t ivlen_min)
31 ctx->mode = EVP_CIPH_GCM_MODE;
33 ctx->tls_aad_len = -1;
34 ctx->ivlen_min = ivlen_min;
35 ctx->ivlen = (EVP_GCM_TLS_FIXED_IV_LEN + EVP_GCM_TLS_EXPLICIT_IV_LEN);
36 ctx->keylen = keybits / 8;
38 ctx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
41 void gcm_deinitctx(PROV_GCM_CTX *ctx)
43 OPENSSL_cleanse(ctx->iv, sizeof(ctx->iv));
46 static int gcm_init(void *vctx, const unsigned char *key, size_t keylen,
47 const unsigned char *iv, size_t ivlen, int enc)
49 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
54 if (ivlen < ctx->ivlen_min || ivlen > sizeof(ctx->iv)) {
55 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
59 memcpy(ctx->iv, iv, ctx->ivlen);
60 ctx->iv_state = IV_STATE_BUFFERED;
64 if (keylen != ctx->keylen) {
65 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
68 return ctx->hw->setkey(ctx, key, ctx->keylen);
73 int gcm_einit(void *vctx, const unsigned char *key, size_t keylen,
74 const unsigned char *iv, size_t ivlen)
76 return gcm_init(vctx, key, keylen, iv, ivlen, 1);
79 int gcm_dinit(void *vctx, const unsigned char *key, size_t keylen,
80 const unsigned char *iv, size_t ivlen)
82 return gcm_init(vctx, key, keylen, iv, ivlen, 0);
85 int gcm_get_ctx_params(void *vctx, OSSL_PARAM params[])
87 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
91 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
92 if (p != NULL && !OSSL_PARAM_set_int(p, ctx->ivlen)) {
93 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
96 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN);
97 if (p != NULL && !OSSL_PARAM_set_int(p, ctx->keylen)) {
98 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
102 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
104 if (ctx->iv_gen != 1 && ctx->iv_gen_rand != 1)
106 if (ctx->ivlen != (int)p->data_size) {
107 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
110 if (!OSSL_PARAM_set_octet_string(p, ctx->iv, ctx->ivlen)) {
111 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
116 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD);
117 if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->tls_aad_pad_sz)) {
118 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
121 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAG);
124 if (sz == 0 || sz > EVP_GCM_TLS_TAG_LEN || !ctx->enc || ctx->taglen < 0) {
125 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
128 if (!OSSL_PARAM_set_octet_string(p, ctx->buf, sz)) {
129 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
136 int gcm_set_ctx_params(void *vctx, const OSSL_PARAM params[])
138 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
143 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG);
146 if (!OSSL_PARAM_get_octet_string(p, &vp, EVP_GCM_TLS_TAG_LEN, &sz)) {
147 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
150 if (sz == 0 || ctx->enc) {
151 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
157 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN);
159 if (!OSSL_PARAM_get_size_t(p, &sz)) {
160 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
163 if (sz == 0 || sz > sizeof(ctx->iv)) {
164 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
170 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD);
172 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
173 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
176 sz = gcm_tls_init(ctx, p->data, p->data_size);
178 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_AAD);
181 ctx->tls_aad_pad_sz = sz;
184 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED);
186 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
187 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
190 if (gcm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) {
191 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
197 * TODO(3.0) Temporary solution to address fuzz test crash, which will be
198 * reworked once the discussion in PR #9510 is resolved. i.e- We need a
199 * general solution for handling missing parameters inside set_params and
200 * get_params methods.
202 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN);
206 if (!OSSL_PARAM_get_int(p, &keylen)) {
207 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
210 /* The key length can not be modified for gcm mode */
211 if (keylen != (int)ctx->keylen)
218 int gcm_stream_update(void *vctx, unsigned char *out, size_t *outl,
219 size_t outsize, const unsigned char *in, size_t inl)
221 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
224 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
228 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0) {
229 ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
235 int gcm_stream_final(void *vctx, unsigned char *out, size_t *outl,
238 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
241 i = gcm_cipher_internal(ctx, out, outl, NULL, 0);
249 int gcm_cipher(void *vctx,
250 unsigned char *out, size_t *outl, size_t outsize,
251 const unsigned char *in, size_t inl)
253 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
256 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
260 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0)
268 * See SP800-38D (GCM) Section 8 "Uniqueness requirement on IVS and keys"
270 * See also 8.2.2 RBG-based construction.
271 * Random construction consists of a free field (which can be NULL) and a
272 * random field which will use a DRBG that can return at least 96 bits of
273 * entropy strength. (The DRBG must be seeded by the FIPS module).
275 static int gcm_iv_generate(PROV_GCM_CTX *ctx, int offset)
277 int sz = ctx->ivlen - offset;
279 /* Must be at least 96 bits */
280 if (sz <= 0 || ctx->ivlen < GCM_IV_DEFAULT_SIZE)
283 /* Use DRBG to generate random iv */
284 if (rand_bytes_ex(ctx->libctx, ctx->iv + offset, sz) <= 0)
286 ctx->iv_state = IV_STATE_BUFFERED;
287 ctx->iv_gen_rand = 1;
291 static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out,
292 size_t *padlen, const unsigned char *in,
297 const PROV_GCM_HW *hw = ctx->hw;
299 if (ctx->tls_aad_len >= 0)
300 return gcm_tls_cipher(ctx, out, padlen, in, len);
302 if (!ctx->key_set || ctx->iv_state == IV_STATE_FINISHED)
306 * FIPS requires generation of AES-GCM IV's inside the FIPS module.
307 * The IV can still be set externally (the security policy will state that
308 * this is not FIPS compliant). There are some applications
309 * where setting the IV externally is the only option available.
311 if (ctx->iv_state == IV_STATE_UNINITIALISED) {
312 if (!ctx->enc || !gcm_iv_generate(ctx, 0))
316 if (ctx->iv_state == IV_STATE_BUFFERED) {
317 if (!hw->setiv(ctx, ctx->iv, ctx->ivlen))
319 ctx->iv_state = IV_STATE_COPIED;
323 /* The input is AAD if out is NULL */
325 if (!hw->aadupdate(ctx, in, len))
328 /* The input is ciphertext OR plaintext */
329 if (!hw->cipherupdate(ctx, in, len, out))
333 /* Finished when in == NULL */
334 if (!hw->cipherfinal(ctx, ctx->buf))
336 ctx->iv_state = IV_STATE_FINISHED; /* Don't reuse the IV */
347 static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len)
352 if (aad_len != EVP_AEAD_TLS1_AAD_LEN)
355 /* Save the aad for later use. */
357 memcpy(buf, aad, aad_len);
358 dat->tls_aad_len = aad_len;
359 dat->tls_enc_records = 0;
361 len = buf[aad_len - 2] << 8 | buf[aad_len - 1];
362 /* Correct length for explicit iv. */
363 if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN)
365 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
367 /* If decrypting correct for tag too. */
369 if (len < EVP_GCM_TLS_TAG_LEN)
371 len -= EVP_GCM_TLS_TAG_LEN;
373 buf[aad_len - 2] = (unsigned char)(len >> 8);
374 buf[aad_len - 1] = (unsigned char)(len & 0xff);
375 /* Extra padding: tag appended to record. */
376 return EVP_GCM_TLS_TAG_LEN;
379 static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv,
382 /* Special case: -1 length restores whole IV */
383 if (len == (size_t)-1) {
384 memcpy(ctx->iv, iv, ctx->ivlen);
386 ctx->iv_state = IV_STATE_BUFFERED;
389 /* Fixed field must be at least 4 bytes and invocation field at least 8 */
390 if ((len < EVP_GCM_TLS_FIXED_IV_LEN)
391 || (ctx->ivlen - (int)len) < EVP_GCM_TLS_EXPLICIT_IV_LEN)
394 memcpy(ctx->iv, iv, len);
396 && rand_bytes_ex(ctx->libctx, ctx->iv + len, ctx->ivlen - len) <= 0)
399 ctx->iv_state = IV_STATE_BUFFERED;
403 /* increment counter (64-bit int) by 1 */
404 static void ctr64_inc(unsigned char *counter)
420 * Handle TLS GCM packet format. This consists of the last portion of the IV
421 * followed by the payload and finally the tag. On encrypt generate IV,
422 * encrypt payload and write the tag. On verify retrieve IV, decrypt payload
425 static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen,
426 const unsigned char *in, size_t len)
428 int rv = 0, arg = EVP_GCM_TLS_EXPLICIT_IV_LEN;
430 unsigned char *tag = NULL;
435 /* Encrypt/decrypt must be performed in place */
436 if (out != in || len < (EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN))
440 * Check for too many keys as per FIPS 140-2 IG A.5 "Key/IV Pair Uniqueness
441 * Requirements from SP 800-38D". The requirements is for one party to the
442 * communication to fail after 2^64 - 1 keys. We do this on the encrypting
445 if (ctx->enc && ++ctx->tls_enc_records == 0) {
446 ERR_raise(ERR_LIB_PROV, EVP_R_TOO_MANY_RECORDS);
450 if (ctx->iv_gen == 0)
453 * Set IV from start of buffer or generate IV and write to start of
457 if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
459 if (arg > ctx->ivlen)
461 memcpy(out, ctx->iv + ctx->ivlen - arg, arg);
463 * Invocation field will be at least 8 bytes in size and so no need
464 * to check wrap around or increment more than last 8 bytes.
466 ctr64_inc(ctx->iv + ctx->ivlen - 8);
468 memcpy(ctx->iv + ctx->ivlen - arg, out, arg);
469 if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
472 ctx->iv_state = IV_STATE_COPIED;
474 /* Fix buffer and length to point to payload */
475 in += EVP_GCM_TLS_EXPLICIT_IV_LEN;
476 out += EVP_GCM_TLS_EXPLICIT_IV_LEN;
477 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
479 tag = ctx->enc ? out + len : (unsigned char *)in + len;
480 if (!ctx->hw->oneshot(ctx, ctx->buf, ctx->tls_aad_len, in, len, out, tag,
481 EVP_GCM_TLS_TAG_LEN)) {
483 OPENSSL_cleanse(out, len);
487 plen = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
493 ctx->iv_state = IV_STATE_FINISHED;
494 ctx->tls_aad_len = -1;