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/rand_int.h"
14 #include "internal/provider_ctx.h"
16 static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len);
17 static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv,
19 static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen,
20 const unsigned char *in, size_t len);
21 static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out,
22 size_t *padlen, const unsigned char *in,
25 void gcm_initctx(void *provctx, PROV_GCM_CTX *ctx, size_t keybits,
26 const PROV_GCM_HW *hw, size_t ivlen_min)
29 ctx->mode = EVP_CIPH_GCM_MODE;
31 ctx->tls_aad_len = -1;
32 ctx->ivlen_min = ivlen_min;
33 ctx->ivlen = (EVP_GCM_TLS_FIXED_IV_LEN + EVP_GCM_TLS_EXPLICIT_IV_LEN);
34 ctx->keylen = keybits / 8;
36 ctx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
39 void gcm_deinitctx(PROV_GCM_CTX *ctx)
41 OPENSSL_cleanse(ctx->iv, sizeof(ctx->iv));
44 static int gcm_init(void *vctx, const unsigned char *key, size_t keylen,
45 const unsigned char *iv, size_t ivlen, int enc)
47 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
52 if (ivlen < ctx->ivlen_min || ivlen > sizeof(ctx->iv)) {
53 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
57 memcpy(ctx->iv, iv, ctx->ivlen);
58 ctx->iv_state = IV_STATE_BUFFERED;
62 if (keylen != ctx->keylen) {
63 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
66 return ctx->hw->setkey(ctx, key, ctx->keylen);
71 int gcm_einit(void *vctx, const unsigned char *key, size_t keylen,
72 const unsigned char *iv, size_t ivlen)
74 return gcm_init(vctx, key, keylen, iv, ivlen, 1);
77 int gcm_dinit(void *vctx, const unsigned char *key, size_t keylen,
78 const unsigned char *iv, size_t ivlen)
80 return gcm_init(vctx, key, keylen, iv, ivlen, 0);
83 int gcm_get_ctx_params(void *vctx, OSSL_PARAM params[])
85 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
89 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
90 if (p != NULL && !OSSL_PARAM_set_int(p, ctx->ivlen)) {
91 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
94 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN);
95 if (p != NULL && !OSSL_PARAM_set_int(p, ctx->keylen)) {
96 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
100 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
102 if (ctx->iv_gen != 1 && ctx->iv_gen_rand != 1)
104 if (ctx->ivlen != (int)p->data_size) {
105 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
108 if (!OSSL_PARAM_set_octet_string(p, ctx->iv, ctx->ivlen)) {
109 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
114 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD);
115 if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->tls_aad_pad_sz)) {
116 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
119 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAG);
122 if (sz == 0 || sz > EVP_GCM_TLS_TAG_LEN || !ctx->enc || ctx->taglen < 0) {
123 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
126 if (!OSSL_PARAM_set_octet_string(p, ctx->buf, sz)) {
127 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
134 int gcm_set_ctx_params(void *vctx, const OSSL_PARAM params[])
136 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
141 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG);
144 if (!OSSL_PARAM_get_octet_string(p, &vp, EVP_GCM_TLS_TAG_LEN, &sz)) {
145 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
148 if (sz == 0 || ctx->enc) {
149 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
155 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN);
157 if (!OSSL_PARAM_get_size_t(p, &sz)) {
158 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
161 if (sz == 0 || sz > sizeof(ctx->iv)) {
162 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
168 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD);
170 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
171 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
174 sz = gcm_tls_init(ctx, p->data, p->data_size);
176 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_AAD);
179 ctx->tls_aad_pad_sz = sz;
182 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED);
184 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
185 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
188 if (gcm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) {
189 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
195 * TODO(3.0) Temporary solution to address fuzz test crash, which will be
196 * reworked once the discussion in PR #9510 is resolved. i.e- We need a
197 * general solution for handling missing parameters inside set_params and
198 * get_params methods.
200 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_KEYLEN);
204 if (!OSSL_PARAM_get_int(p, &keylen)) {
205 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
208 /* The key length can not be modified for gcm mode */
209 if (keylen != (int)ctx->keylen)
216 int gcm_stream_update(void *vctx, unsigned char *out, size_t *outl,
217 size_t outsize, const unsigned char *in, size_t inl)
219 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
222 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
226 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0) {
227 ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
233 int gcm_stream_final(void *vctx, unsigned char *out, size_t *outl,
236 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
239 i = gcm_cipher_internal(ctx, out, outl, NULL, 0);
247 int gcm_cipher(void *vctx,
248 unsigned char *out, size_t *outl, size_t outsize,
249 const unsigned char *in, size_t inl)
251 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
254 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
258 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0)
266 * See SP800-38D (GCM) Section 8 "Uniqueness requirement on IVS and keys"
268 * See also 8.2.2 RBG-based construction.
269 * Random construction consists of a free field (which can be NULL) and a
270 * random field which will use a DRBG that can return at least 96 bits of
271 * entropy strength. (The DRBG must be seeded by the FIPS module).
273 static int gcm_iv_generate(PROV_GCM_CTX *ctx, int offset)
275 int sz = ctx->ivlen - offset;
277 /* Must be at least 96 bits */
278 if (sz <= 0 || ctx->ivlen < GCM_IV_DEFAULT_SIZE)
281 /* Use DRBG to generate random iv */
282 if (rand_bytes_ex(ctx->libctx, ctx->iv + offset, sz) <= 0)
284 ctx->iv_state = IV_STATE_BUFFERED;
285 ctx->iv_gen_rand = 1;
289 static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out,
290 size_t *padlen, const unsigned char *in,
295 const PROV_GCM_HW *hw = ctx->hw;
297 if (ctx->tls_aad_len >= 0)
298 return gcm_tls_cipher(ctx, out, padlen, in, len);
300 if (!ctx->key_set || ctx->iv_state == IV_STATE_FINISHED)
304 * FIPS requires generation of AES-GCM IV's inside the FIPS module.
305 * The IV can still be set externally (the security policy will state that
306 * this is not FIPS compliant). There are some applications
307 * where setting the IV externally is the only option available.
309 if (ctx->iv_state == IV_STATE_UNINITIALISED) {
310 if (!ctx->enc || !gcm_iv_generate(ctx, 0))
314 if (ctx->iv_state == IV_STATE_BUFFERED) {
315 if (!hw->setiv(ctx, ctx->iv, ctx->ivlen))
317 ctx->iv_state = IV_STATE_COPIED;
321 /* The input is AAD if out is NULL */
323 if (!hw->aadupdate(ctx, in, len))
326 /* The input is ciphertext OR plaintext */
327 if (!hw->cipherupdate(ctx, in, len, out))
331 /* Finished when in == NULL */
332 if (!hw->cipherfinal(ctx, ctx->buf))
334 ctx->iv_state = IV_STATE_FINISHED; /* Don't reuse the IV */
345 static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len)
350 if (aad_len != EVP_AEAD_TLS1_AAD_LEN)
353 /* Save the aad for later use. */
355 memcpy(buf, aad, aad_len);
356 dat->tls_aad_len = aad_len;
357 dat->tls_enc_records = 0;
359 len = buf[aad_len - 2] << 8 | buf[aad_len - 1];
360 /* Correct length for explicit iv. */
361 if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN)
363 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
365 /* If decrypting correct for tag too. */
367 if (len < EVP_GCM_TLS_TAG_LEN)
369 len -= EVP_GCM_TLS_TAG_LEN;
371 buf[aad_len - 2] = (unsigned char)(len >> 8);
372 buf[aad_len - 1] = (unsigned char)(len & 0xff);
373 /* Extra padding: tag appended to record. */
374 return EVP_GCM_TLS_TAG_LEN;
377 static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv,
380 /* Special case: -1 length restores whole IV */
381 if (len == (size_t)-1) {
382 memcpy(ctx->iv, iv, ctx->ivlen);
384 ctx->iv_state = IV_STATE_BUFFERED;
387 /* Fixed field must be at least 4 bytes and invocation field at least 8 */
388 if ((len < EVP_GCM_TLS_FIXED_IV_LEN)
389 || (ctx->ivlen - (int)len) < EVP_GCM_TLS_EXPLICIT_IV_LEN)
392 memcpy(ctx->iv, iv, len);
394 && rand_bytes_ex(ctx->libctx, ctx->iv + len, ctx->ivlen - len) <= 0)
397 ctx->iv_state = IV_STATE_BUFFERED;
401 /* increment counter (64-bit int) by 1 */
402 static void ctr64_inc(unsigned char *counter)
418 * Handle TLS GCM packet format. This consists of the last portion of the IV
419 * followed by the payload and finally the tag. On encrypt generate IV,
420 * encrypt payload and write the tag. On verify retrieve IV, decrypt payload
423 static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen,
424 const unsigned char *in, size_t len)
426 int rv = 0, arg = EVP_GCM_TLS_EXPLICIT_IV_LEN;
428 unsigned char *tag = NULL;
433 /* Encrypt/decrypt must be performed in place */
434 if (out != in || len < (EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN))
438 * Check for too many keys as per FIPS 140-2 IG A.5 "Key/IV Pair Uniqueness
439 * Requirements from SP 800-38D". The requirements is for one party to the
440 * communication to fail after 2^64 - 1 keys. We do this on the encrypting
443 if (ctx->enc && ++ctx->tls_enc_records == 0) {
444 ERR_raise(ERR_LIB_PROV, EVP_R_TOO_MANY_RECORDS);
448 if (ctx->iv_gen == 0)
451 * Set IV from start of buffer or generate IV and write to start of
455 if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
457 if (arg > ctx->ivlen)
459 memcpy(out, ctx->iv + ctx->ivlen - arg, arg);
461 * Invocation field will be at least 8 bytes in size and so no need
462 * to check wrap around or increment more than last 8 bytes.
464 ctr64_inc(ctx->iv + ctx->ivlen - 8);
466 memcpy(ctx->iv + ctx->ivlen - arg, out, arg);
467 if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
470 ctx->iv_state = IV_STATE_COPIED;
472 /* Fix buffer and length to point to payload */
473 in += EVP_GCM_TLS_EXPLICIT_IV_LEN;
474 out += EVP_GCM_TLS_EXPLICIT_IV_LEN;
475 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
477 tag = ctx->enc ? out + len : (unsigned char *)in + len;
478 if (!ctx->hw->oneshot(ctx, ctx->buf, ctx->tls_aad_len, in, len, out, tag,
479 EVP_GCM_TLS_TAG_LEN)) {
481 OPENSSL_cleanse(out, len);
485 plen = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
491 ctx->iv_state = IV_STATE_FINISHED;
492 ctx->tls_aad_len = -1;