2 * Copyright 2019-2020 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 "prov/ciphercommon.h"
13 #include "prov/ciphercommon_gcm.h"
14 #include "prov/providercommonerr.h"
15 #include <openssl/rand.h>
16 #include "prov/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;
32 ctx->taglen = UNINITIALISED_SIZET;
33 ctx->tls_aad_len = UNINITIALISED_SIZET;
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 static int gcm_init(void *vctx, const unsigned char *key, size_t keylen,
42 const unsigned char *iv, size_t ivlen, int enc)
44 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
49 if (ivlen < ctx->ivlen_min || ivlen > sizeof(ctx->iv)) {
50 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
54 memcpy(ctx->iv, iv, ivlen);
55 ctx->iv_state = IV_STATE_BUFFERED;
59 if (keylen != ctx->keylen) {
60 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
63 return ctx->hw->setkey(ctx, key, ctx->keylen);
68 int gcm_einit(void *vctx, const unsigned char *key, size_t keylen,
69 const unsigned char *iv, size_t ivlen)
71 return gcm_init(vctx, key, keylen, iv, ivlen, 1);
74 int gcm_dinit(void *vctx, const unsigned char *key, size_t keylen,
75 const unsigned char *iv, size_t ivlen)
77 return gcm_init(vctx, key, keylen, iv, ivlen, 0);
80 /* increment counter (64-bit int) by 1 */
81 static void ctr64_inc(unsigned char *counter)
96 static int getivgen(PROV_GCM_CTX *ctx, unsigned char *out, size_t olen)
100 || !ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
102 if (olen == 0 || olen > ctx->ivlen)
104 memcpy(out, ctx->iv + ctx->ivlen - olen, olen);
106 * Invocation field will be at least 8 bytes in size and so no need
107 * to check wrap around or increment more than last 8 bytes.
109 ctr64_inc(ctx->iv + ctx->ivlen - 8);
110 ctx->iv_state = IV_STATE_COPIED;
114 static int setivinv(PROV_GCM_CTX *ctx, unsigned char *in, size_t inl)
121 memcpy(ctx->iv + ctx->ivlen - inl, in, inl);
122 if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen))
124 ctx->iv_state = IV_STATE_COPIED;
128 int gcm_get_ctx_params(void *vctx, OSSL_PARAM params[])
130 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
134 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
135 if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->ivlen)) {
136 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
139 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN);
140 if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->keylen)) {
141 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
144 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAGLEN);
146 size_t taglen = (ctx->taglen != UNINITIALISED_SIZET) ? ctx->taglen :
149 if (!OSSL_PARAM_set_size_t(p, taglen)) {
150 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
155 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV);
157 if (ctx->iv_gen != 1 && ctx->iv_gen_rand != 1)
159 if (ctx->ivlen > p->data_size) {
160 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
163 if (!OSSL_PARAM_set_octet_string(p, ctx->iv, ctx->ivlen)
164 && !OSSL_PARAM_set_octet_ptr(p, &ctx->iv, ctx->ivlen)) {
165 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
170 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD);
171 if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->tls_aad_pad_sz)) {
172 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
175 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAG);
179 || sz > EVP_GCM_TLS_TAG_LEN
181 || ctx->taglen == UNINITIALISED_SIZET) {
182 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
185 if (!OSSL_PARAM_set_octet_string(p, ctx->buf, sz)) {
186 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
190 p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_GET_IV_GEN);
193 || p->data_type != OSSL_PARAM_OCTET_STRING
194 || !getivgen(ctx, p->data, p->data_size))
200 int gcm_set_ctx_params(void *vctx, const OSSL_PARAM params[])
202 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
207 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG);
210 if (!OSSL_PARAM_get_octet_string(p, &vp, EVP_GCM_TLS_TAG_LEN, &sz)) {
211 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
214 if (sz == 0 || ctx->enc) {
215 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG);
221 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN);
223 if (!OSSL_PARAM_get_size_t(p, &sz)) {
224 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
227 if (sz == 0 || sz > sizeof(ctx->iv)) {
228 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH);
234 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD);
236 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
237 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
240 sz = gcm_tls_init(ctx, p->data, p->data_size);
242 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_AAD);
245 ctx->tls_aad_pad_sz = sz;
248 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED);
250 if (p->data_type != OSSL_PARAM_OCTET_STRING) {
251 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
254 if (gcm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) {
255 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
259 p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_SET_IV_INV);
262 || p->data_type != OSSL_PARAM_OCTET_STRING
263 || !setivinv(ctx, p->data, p->data_size))
271 int gcm_stream_update(void *vctx, unsigned char *out, size_t *outl,
272 size_t outsize, const unsigned char *in, size_t inl)
274 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
282 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
286 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0) {
287 ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
293 int gcm_stream_final(void *vctx, unsigned char *out, size_t *outl,
296 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
299 i = gcm_cipher_internal(ctx, out, outl, NULL, 0);
307 int gcm_cipher(void *vctx,
308 unsigned char *out, size_t *outl, size_t outsize,
309 const unsigned char *in, size_t inl)
311 PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx;
314 ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
318 if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0)
326 * See SP800-38D (GCM) Section 8 "Uniqueness requirement on IVS and keys"
328 * See also 8.2.2 RBG-based construction.
329 * Random construction consists of a free field (which can be NULL) and a
330 * random field which will use a DRBG that can return at least 96 bits of
331 * entropy strength. (The DRBG must be seeded by the FIPS module).
333 static int gcm_iv_generate(PROV_GCM_CTX *ctx, int offset)
335 int sz = ctx->ivlen - offset;
337 /* Must be at least 96 bits */
338 if (sz <= 0 || ctx->ivlen < GCM_IV_DEFAULT_SIZE)
341 /* Use DRBG to generate random iv */
342 if (RAND_bytes_ex(ctx->libctx, ctx->iv + offset, sz) <= 0)
344 ctx->iv_state = IV_STATE_BUFFERED;
345 ctx->iv_gen_rand = 1;
349 static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out,
350 size_t *padlen, const unsigned char *in,
355 const PROV_GCM_HW *hw = ctx->hw;
357 if (ctx->tls_aad_len != UNINITIALISED_SIZET)
358 return gcm_tls_cipher(ctx, out, padlen, in, len);
360 if (!ctx->key_set || ctx->iv_state == IV_STATE_FINISHED)
364 * FIPS requires generation of AES-GCM IV's inside the FIPS module.
365 * The IV can still be set externally (the security policy will state that
366 * this is not FIPS compliant). There are some applications
367 * where setting the IV externally is the only option available.
369 if (ctx->iv_state == IV_STATE_UNINITIALISED) {
370 if (!ctx->enc || !gcm_iv_generate(ctx, 0))
374 if (ctx->iv_state == IV_STATE_BUFFERED) {
375 if (!hw->setiv(ctx, ctx->iv, ctx->ivlen))
377 ctx->iv_state = IV_STATE_COPIED;
381 /* The input is AAD if out is NULL */
383 if (!hw->aadupdate(ctx, in, len))
386 /* The input is ciphertext OR plaintext */
387 if (!hw->cipherupdate(ctx, in, len, out))
391 /* The tag must be set before actually decrypting data */
392 if (!ctx->enc && ctx->taglen == UNINITIALISED_SIZET)
394 if (!hw->cipherfinal(ctx, ctx->buf))
396 ctx->iv_state = IV_STATE_FINISHED; /* Don't reuse the IV */
407 static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len)
412 if (aad_len != EVP_AEAD_TLS1_AAD_LEN)
415 /* Save the aad for later use. */
417 memcpy(buf, aad, aad_len);
418 dat->tls_aad_len = aad_len;
419 dat->tls_enc_records = 0;
421 len = buf[aad_len - 2] << 8 | buf[aad_len - 1];
422 /* Correct length for explicit iv. */
423 if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN)
425 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
427 /* If decrypting correct for tag too. */
429 if (len < EVP_GCM_TLS_TAG_LEN)
431 len -= EVP_GCM_TLS_TAG_LEN;
433 buf[aad_len - 2] = (unsigned char)(len >> 8);
434 buf[aad_len - 1] = (unsigned char)(len & 0xff);
435 /* Extra padding: tag appended to record. */
436 return EVP_GCM_TLS_TAG_LEN;
439 static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv,
442 /* Special case: -1 length restores whole IV */
443 if (len == (size_t)-1) {
444 memcpy(ctx->iv, iv, ctx->ivlen);
446 ctx->iv_state = IV_STATE_BUFFERED;
449 /* Fixed field must be at least 4 bytes and invocation field at least 8 */
450 if ((len < EVP_GCM_TLS_FIXED_IV_LEN)
451 || (ctx->ivlen - (int)len) < EVP_GCM_TLS_EXPLICIT_IV_LEN)
454 memcpy(ctx->iv, iv, len);
456 && RAND_bytes_ex(ctx->libctx, ctx->iv + len, ctx->ivlen - len) <= 0)
459 ctx->iv_state = IV_STATE_BUFFERED;
464 * Handle TLS GCM packet format. This consists of the last portion of the IV
465 * followed by the payload and finally the tag. On encrypt generate IV,
466 * encrypt payload and write the tag. On verify retrieve IV, decrypt payload
469 static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen,
470 const unsigned char *in, size_t len)
473 size_t arg = EVP_GCM_TLS_EXPLICIT_IV_LEN;
475 unsigned char *tag = NULL;
480 /* Encrypt/decrypt must be performed in place */
481 if (out != in || len < (EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN))
485 * Check for too many keys as per FIPS 140-2 IG A.5 "Key/IV Pair Uniqueness
486 * Requirements from SP 800-38D". The requirements is for one party to the
487 * communication to fail after 2^64 - 1 keys. We do this on the encrypting
490 if (ctx->enc && ++ctx->tls_enc_records == 0) {
491 ERR_raise(ERR_LIB_PROV, EVP_R_TOO_MANY_RECORDS);
496 * Set IV from start of buffer or generate IV and write to start of
500 if (!getivgen(ctx, out, arg))
503 if (!setivinv(ctx, out, arg))
507 /* Fix buffer and length to point to payload */
508 in += EVP_GCM_TLS_EXPLICIT_IV_LEN;
509 out += EVP_GCM_TLS_EXPLICIT_IV_LEN;
510 len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
512 tag = ctx->enc ? out + len : (unsigned char *)in + len;
513 if (!ctx->hw->oneshot(ctx, ctx->buf, ctx->tls_aad_len, in, len, out, tag,
514 EVP_GCM_TLS_TAG_LEN)) {
516 OPENSSL_cleanse(out, len);
520 plen = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
526 ctx->iv_state = IV_STATE_FINISHED;
527 ctx->tls_aad_len = UNINITIALISED_SIZET;