diff options
Diffstat (limited to 'providers/implementations/ciphers/ciphercommon_gcm.c')
| -rw-r--r-- | providers/implementations/ciphers/ciphercommon_gcm.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/providers/implementations/ciphers/ciphercommon_gcm.c b/providers/implementations/ciphers/ciphercommon_gcm.c new file mode 100644 index 0000000000..803f810a30 --- /dev/null +++ b/providers/implementations/ciphers/ciphercommon_gcm.c @@ -0,0 +1,495 @@ +/* + * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved. + * + * Licensed under the Apache License 2.0 (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html + */ + +/* Dispatch functions for gcm mode */ + +#include "prov/ciphercommon.h" +#include "prov/ciphercommon_gcm.h" +#include "prov/providercommonerr.h" +#include "crypto/rand.h" +#include "prov/provider_ctx.h" + +static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len); +static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv, + size_t len); +static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen, + const unsigned char *in, size_t len); +static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out, + size_t *padlen, const unsigned char *in, + size_t len); + +void gcm_initctx(void *provctx, PROV_GCM_CTX *ctx, size_t keybits, + const PROV_GCM_HW *hw, size_t ivlen_min) +{ + ctx->pad = 1; + ctx->mode = EVP_CIPH_GCM_MODE; + ctx->taglen = UNINITIALISED_SIZET; + ctx->tls_aad_len = UNINITIALISED_SIZET; + ctx->ivlen_min = ivlen_min; + ctx->ivlen = (EVP_GCM_TLS_FIXED_IV_LEN + EVP_GCM_TLS_EXPLICIT_IV_LEN); + ctx->keylen = keybits / 8; + ctx->hw = hw; + ctx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx); +} + +static int gcm_init(void *vctx, const unsigned char *key, size_t keylen, + const unsigned char *iv, size_t ivlen, int enc) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + + ctx->enc = enc; + + if (iv != NULL) { + if (ivlen < ctx->ivlen_min || ivlen > sizeof(ctx->iv)) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH); + return 0; + } + ctx->ivlen = ivlen; + memcpy(ctx->iv, iv, ivlen); + ctx->iv_state = IV_STATE_BUFFERED; + } + + if (key != NULL) { + if (keylen != ctx->keylen) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH); + return 0; + } + return ctx->hw->setkey(ctx, key, ctx->keylen); + } + return 1; +} + +int gcm_einit(void *vctx, const unsigned char *key, size_t keylen, + const unsigned char *iv, size_t ivlen) +{ + return gcm_init(vctx, key, keylen, iv, ivlen, 1); +} + +int gcm_dinit(void *vctx, const unsigned char *key, size_t keylen, + const unsigned char *iv, size_t ivlen) +{ + return gcm_init(vctx, key, keylen, iv, ivlen, 0); +} + +int gcm_get_ctx_params(void *vctx, OSSL_PARAM params[]) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + OSSL_PARAM *p; + size_t sz; + + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN); + if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->ivlen)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_KEYLEN); + if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->keylen)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAGLEN); + if (p != NULL) { + size_t taglen = (ctx->taglen != UNINITIALISED_SIZET) ? ctx->taglen : + GCM_TAG_MAX_SIZE; + + if (!OSSL_PARAM_set_size_t(p, taglen)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + } + + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV); + if (p != NULL) { + if (ctx->iv_gen != 1 && ctx->iv_gen_rand != 1) + return 0; + if (ctx->ivlen != p->data_size) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH); + return 0; + } + if (!OSSL_PARAM_set_octet_string(p, ctx->iv, ctx->ivlen)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + } + + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD_PAD); + if (p != NULL && !OSSL_PARAM_set_size_t(p, ctx->tls_aad_pad_sz)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_AEAD_TAG); + if (p != NULL) { + sz = p->data_size; + if (sz == 0 + || sz > EVP_GCM_TLS_TAG_LEN + || !ctx->enc + || ctx->taglen == UNINITIALISED_SIZET) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG); + return 0; + } + if (!OSSL_PARAM_set_octet_string(p, ctx->buf, sz)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER); + return 0; + } + } + + return 1; +} + +int gcm_set_ctx_params(void *vctx, const OSSL_PARAM params[]) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + const OSSL_PARAM *p; + size_t sz; + void *vp; + + p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG); + if (p != NULL) { + vp = ctx->buf; + if (!OSSL_PARAM_get_octet_string(p, &vp, EVP_GCM_TLS_TAG_LEN, &sz)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); + return 0; + } + if (sz == 0 || ctx->enc) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAG); + return 0; + } + ctx->taglen = sz; + } + + p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN); + if (p != NULL) { + if (!OSSL_PARAM_get_size_t(p, &sz)) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); + return 0; + } + if (sz == 0 || sz > sizeof(ctx->iv)) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IV_LENGTH); + return 0; + } + ctx->ivlen = sz; + } + + p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_AAD); + if (p != NULL) { + if (p->data_type != OSSL_PARAM_OCTET_STRING) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); + return 0; + } + sz = gcm_tls_init(ctx, p->data, p->data_size); + if (sz == 0) { + ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_AAD); + return 0; + } + ctx->tls_aad_pad_sz = sz; + } + + p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TLS1_IV_FIXED); + if (p != NULL) { + if (p->data_type != OSSL_PARAM_OCTET_STRING) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); + return 0; + } + if (gcm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) { + ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER); + return 0; + } + } + + return 1; +} + +int gcm_stream_update(void *vctx, unsigned char *out, size_t *outl, + size_t outsize, const unsigned char *in, size_t inl) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + + if (inl == 0) { + *outl = 0; + return 1; + } + + if (outsize < inl) { + ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL); + return -1; + } + + if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0) { + ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED); + return -1; + } + return 1; +} + +int gcm_stream_final(void *vctx, unsigned char *out, size_t *outl, + size_t outsize) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + int i; + + i = gcm_cipher_internal(ctx, out, outl, NULL, 0); + if (i <= 0) + return 0; + + *outl = 0; + return 1; +} + +int gcm_cipher(void *vctx, + unsigned char *out, size_t *outl, size_t outsize, + const unsigned char *in, size_t inl) +{ + PROV_GCM_CTX *ctx = (PROV_GCM_CTX *)vctx; + + if (outsize < inl) { + ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL); + return 0; + } + + if (gcm_cipher_internal(ctx, out, outl, in, inl) <= 0) + return 0; + + *outl = inl; + return 1; +} + +/* + * See SP800-38D (GCM) Section 8 "Uniqueness requirement on IVS and keys" + * + * See also 8.2.2 RBG-based construction. + * Random construction consists of a free field (which can be NULL) and a + * random field which will use a DRBG that can return at least 96 bits of + * entropy strength. (The DRBG must be seeded by the FIPS module). + */ +static int gcm_iv_generate(PROV_GCM_CTX *ctx, int offset) +{ + int sz = ctx->ivlen - offset; + + /* Must be at least 96 bits */ + if (sz <= 0 || ctx->ivlen < GCM_IV_DEFAULT_SIZE) + return 0; + + /* Use DRBG to generate random iv */ + if (rand_bytes_ex(ctx->libctx, ctx->iv + offset, sz) <= 0) + return 0; + ctx->iv_state = IV_STATE_BUFFERED; + ctx->iv_gen_rand = 1; + return 1; +} + +static int gcm_cipher_internal(PROV_GCM_CTX *ctx, unsigned char *out, + size_t *padlen, const unsigned char *in, + size_t len) +{ + size_t olen = 0; + int rv = 0; + const PROV_GCM_HW *hw = ctx->hw; + + if (ctx->tls_aad_len != UNINITIALISED_SIZET) + return gcm_tls_cipher(ctx, out, padlen, in, len); + + if (!ctx->key_set || ctx->iv_state == IV_STATE_FINISHED) + goto err; + + /* + * FIPS requires generation of AES-GCM IV's inside the FIPS module. + * The IV can still be set externally (the security policy will state that + * this is not FIPS compliant). There are some applications + * where setting the IV externally is the only option available. + */ + if (ctx->iv_state == IV_STATE_UNINITIALISED) { + if (!ctx->enc || !gcm_iv_generate(ctx, 0)) + goto err; + } + + if (ctx->iv_state == IV_STATE_BUFFERED) { + if (!hw->setiv(ctx, ctx->iv, ctx->ivlen)) + goto err; + ctx->iv_state = IV_STATE_COPIED; + } + + if (in != NULL) { + /* The input is AAD if out is NULL */ + if (out == NULL) { + if (!hw->aadupdate(ctx, in, len)) + goto err; + } else { + /* The input is ciphertext OR plaintext */ + if (!hw->cipherupdate(ctx, in, len, out)) + goto err; + } + } else { + /* The tag must be set before actually decrypting data */ + if (!ctx->enc && ctx->taglen == UNINITIALISED_SIZET) + goto err; + if (!hw->cipherfinal(ctx, ctx->buf)) + goto err; + ctx->iv_state = IV_STATE_FINISHED; /* Don't reuse the IV */ + goto finish; + } + olen = len; +finish: + rv = 1; +err: + *padlen = olen; + return rv; +} + +static int gcm_tls_init(PROV_GCM_CTX *dat, unsigned char *aad, size_t aad_len) +{ + unsigned char *buf; + size_t len; + + if (aad_len != EVP_AEAD_TLS1_AAD_LEN) + return 0; + + /* Save the aad for later use. */ + buf = dat->buf; + memcpy(buf, aad, aad_len); + dat->tls_aad_len = aad_len; + dat->tls_enc_records = 0; + + len = buf[aad_len - 2] << 8 | buf[aad_len - 1]; + /* Correct length for explicit iv. */ + if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN) + return 0; + len -= EVP_GCM_TLS_EXPLICIT_IV_LEN; + + /* If decrypting correct for tag too. */ + if (!dat->enc) { + if (len < EVP_GCM_TLS_TAG_LEN) + return 0; + len -= EVP_GCM_TLS_TAG_LEN; + } + buf[aad_len - 2] = (unsigned char)(len >> 8); + buf[aad_len - 1] = (unsigned char)(len & 0xff); + /* Extra padding: tag appended to record. */ + return EVP_GCM_TLS_TAG_LEN; +} + +static int gcm_tls_iv_set_fixed(PROV_GCM_CTX *ctx, unsigned char *iv, + size_t len) +{ + /* Special case: -1 length restores whole IV */ + if (len == (size_t)-1) { + memcpy(ctx->iv, iv, ctx->ivlen); + ctx->iv_gen = 1; + ctx->iv_state = IV_STATE_BUFFERED; + return 1; + } + /* Fixed field must be at least 4 bytes and invocation field at least 8 */ + if ((len < EVP_GCM_TLS_FIXED_IV_LEN) + || (ctx->ivlen - (int)len) < EVP_GCM_TLS_EXPLICIT_IV_LEN) + return 0; + if (len > 0) + memcpy(ctx->iv, iv, len); + if (ctx->enc + && rand_bytes_ex(ctx->libctx, ctx->iv + len, ctx->ivlen - len) <= 0) + return 0; + ctx->iv_gen = 1; + ctx->iv_state = IV_STATE_BUFFERED; + return 1; +} + +/* increment counter (64-bit int) by 1 */ +static void ctr64_inc(unsigned char *counter) +{ + int n = 8; + unsigned char c; + + do { + --n; + c = counter[n]; + ++c; + counter[n] = c; + if (c > 0) + return; + } while (n > 0); +} + +/* + * Handle TLS GCM packet format. This consists of the last portion of the IV + * followed by the payload and finally the tag. On encrypt generate IV, + * encrypt payload and write the tag. On verify retrieve IV, decrypt payload + * and verify tag. + */ +static int gcm_tls_cipher(PROV_GCM_CTX *ctx, unsigned char *out, size_t *padlen, + const unsigned char *in, size_t len) +{ + int rv = 0; + size_t arg = EVP_GCM_TLS_EXPLICIT_IV_LEN; + size_t plen = 0; + unsigned char *tag = NULL; + + if (!ctx->key_set) + goto err; + + /* Encrypt/decrypt must be performed in place */ + if (out != in || len < (EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN)) + goto err; + + /* + * Check for too many keys as per FIPS 140-2 IG A.5 "Key/IV Pair Uniqueness + * Requirements from SP 800-38D". The requirements is for one party to the + * communication to fail after 2^64 - 1 keys. We do this on the encrypting + * side only. + */ + if (ctx->enc && ++ctx->tls_enc_records == 0) { + ERR_raise(ERR_LIB_PROV, EVP_R_TOO_MANY_RECORDS); + goto err; + } + + if (ctx->iv_gen == 0) + goto err; + /* + * Set IV from start of buffer or generate IV and write to start of + * buffer. + */ + if (ctx->enc) { + if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen)) + goto err; + if (arg > ctx->ivlen) + arg = ctx->ivlen; + memcpy(out, ctx->iv + ctx->ivlen - arg, arg); + /* + * Invocation field will be at least 8 bytes in size and so no need + * to check wrap around or increment more than last 8 bytes. + */ + ctr64_inc(ctx->iv + ctx->ivlen - 8); + } else { + memcpy(ctx->iv + ctx->ivlen - arg, out, arg); + if (!ctx->hw->setiv(ctx, ctx->iv, ctx->ivlen)) + goto err; + } + ctx->iv_state = IV_STATE_COPIED; + + /* Fix buffer and length to point to payload */ + in += EVP_GCM_TLS_EXPLICIT_IV_LEN; + out += EVP_GCM_TLS_EXPLICIT_IV_LEN; + len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN; + + tag = ctx->enc ? out + len : (unsigned char *)in + len; + if (!ctx->hw->oneshot(ctx, ctx->buf, ctx->tls_aad_len, in, len, out, tag, + EVP_GCM_TLS_TAG_LEN)) { + if (!ctx->enc) + OPENSSL_cleanse(out, len); + goto err; + } + if (ctx->enc) + plen = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN; + else + plen = len; + + rv = 1; +err: + ctx->iv_state = IV_STATE_FINISHED; + ctx->tls_aad_len = UNINITIALISED_SIZET; + *padlen = plen; + return rv; +} |