/* Copyright (c) 2014, Google Inc. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include <openssl_grpc/aead.h> #include <assert.h> #include <string.h> #include <openssl_grpc/cipher.h> #include <openssl_grpc/err.h> #include <openssl_grpc/mem.h> #include "internal.h" #include "../../internal.h" size_t EVP_AEAD_key_length(const EVP_AEAD *aead) { return aead->key_len; } size_t EVP_AEAD_nonce_length(const EVP_AEAD *aead) { return aead->nonce_len; } size_t EVP_AEAD_max_overhead(const EVP_AEAD *aead) { return aead->overhead; } size_t EVP_AEAD_max_tag_len(const EVP_AEAD *aead) { return aead->max_tag_len; } void EVP_AEAD_CTX_zero(EVP_AEAD_CTX *ctx) { OPENSSL_memset(ctx, 0, sizeof(EVP_AEAD_CTX)); } EVP_AEAD_CTX *EVP_AEAD_CTX_new(const EVP_AEAD *aead, const uint8_t *key, size_t key_len, size_t tag_len) { EVP_AEAD_CTX *ctx = OPENSSL_malloc(sizeof(EVP_AEAD_CTX)); EVP_AEAD_CTX_zero(ctx); if (EVP_AEAD_CTX_init(ctx, aead, key, key_len, tag_len, NULL)) { return ctx; } EVP_AEAD_CTX_free(ctx); return NULL; } void EVP_AEAD_CTX_free(EVP_AEAD_CTX *ctx) { EVP_AEAD_CTX_cleanup(ctx); OPENSSL_free(ctx); } int EVP_AEAD_CTX_init(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead, const uint8_t *key, size_t key_len, size_t tag_len, ENGINE *impl) { if (!aead->init) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_NO_DIRECTION_SET); ctx->aead = NULL; return 0; } return EVP_AEAD_CTX_init_with_direction(ctx, aead, key, key_len, tag_len, evp_aead_open); } int EVP_AEAD_CTX_init_with_direction(EVP_AEAD_CTX *ctx, const EVP_AEAD *aead, const uint8_t *key, size_t key_len, size_t tag_len, enum evp_aead_direction_t dir) { if (key_len != aead->key_len) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_KEY_SIZE); ctx->aead = NULL; return 0; } ctx->aead = aead; int ok; if (aead->init) { ok = aead->init(ctx, key, key_len, tag_len); } else { ok = aead->init_with_direction(ctx, key, key_len, tag_len, dir); } if (!ok) { ctx->aead = NULL; } return ok; } void EVP_AEAD_CTX_cleanup(EVP_AEAD_CTX *ctx) { if (ctx->aead == NULL) { return; } ctx->aead->cleanup(ctx); ctx->aead = NULL; } // check_alias returns 1 if |out| is compatible with |in| and 0 otherwise. If // |in| and |out| alias, we require that |in| == |out|. static int check_alias(const uint8_t *in, size_t in_len, const uint8_t *out, size_t out_len) { if (!buffers_alias(in, in_len, out, out_len)) { return 1; } return in == out; } int EVP_AEAD_CTX_seal(const EVP_AEAD_CTX *ctx, uint8_t *out, size_t *out_len, size_t max_out_len, const uint8_t *nonce, size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *ad, size_t ad_len) { if (in_len + ctx->aead->overhead < in_len /* overflow */) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE); goto error; } if (max_out_len < in_len) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL); goto error; } if (!check_alias(in, in_len, out, max_out_len)) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT); goto error; } size_t out_tag_len; if (ctx->aead->seal_scatter(ctx, out, out + in_len, &out_tag_len, max_out_len - in_len, nonce, nonce_len, in, in_len, NULL, 0, ad, ad_len)) { *out_len = in_len + out_tag_len; return 1; } error: // In the event of an error, clear the output buffer so that a caller // that doesn't check the return value doesn't send raw data. OPENSSL_memset(out, 0, max_out_len); *out_len = 0; return 0; } int EVP_AEAD_CTX_seal_scatter( const EVP_AEAD_CTX *ctx, uint8_t *out, uint8_t *out_tag, size_t *out_tag_len, size_t max_out_tag_len, const uint8_t *nonce, size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *extra_in, size_t extra_in_len, const uint8_t *ad, size_t ad_len) { // |in| and |out| may alias exactly, |out_tag| may not alias. if (!check_alias(in, in_len, out, in_len) || buffers_alias(out, in_len, out_tag, max_out_tag_len) || buffers_alias(in, in_len, out_tag, max_out_tag_len)) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT); goto error; } if (!ctx->aead->seal_scatter_supports_extra_in && extra_in_len) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_INVALID_OPERATION); goto error; } if (ctx->aead->seal_scatter(ctx, out, out_tag, out_tag_len, max_out_tag_len, nonce, nonce_len, in, in_len, extra_in, extra_in_len, ad, ad_len)) { return 1; } error: // In the event of an error, clear the output buffer so that a caller // that doesn't check the return value doesn't send raw data. OPENSSL_memset(out, 0, in_len); OPENSSL_memset(out_tag, 0, max_out_tag_len); *out_tag_len = 0; return 0; } int EVP_AEAD_CTX_open(const EVP_AEAD_CTX *ctx, uint8_t *out, size_t *out_len, size_t max_out_len, const uint8_t *nonce, size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *ad, size_t ad_len) { if (!check_alias(in, in_len, out, max_out_len)) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT); goto error; } if (ctx->aead->open) { if (!ctx->aead->open(ctx, out, out_len, max_out_len, nonce, nonce_len, in, in_len, ad, ad_len)) { goto error; } return 1; } // AEADs that use the default implementation of open() must set |tag_len| at // initialization time. assert(ctx->tag_len); if (in_len < ctx->tag_len) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT); goto error; } size_t plaintext_len = in_len - ctx->tag_len; if (max_out_len < plaintext_len) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL); goto error; } if (EVP_AEAD_CTX_open_gather(ctx, out, nonce, nonce_len, in, plaintext_len, in + plaintext_len, ctx->tag_len, ad, ad_len)) { *out_len = plaintext_len; return 1; } error: // In the event of an error, clear the output buffer so that a caller // that doesn't check the return value doesn't try and process bad // data. OPENSSL_memset(out, 0, max_out_len); *out_len = 0; return 0; } int EVP_AEAD_CTX_open_gather(const EVP_AEAD_CTX *ctx, uint8_t *out, const uint8_t *nonce, size_t nonce_len, const uint8_t *in, size_t in_len, const uint8_t *in_tag, size_t in_tag_len, const uint8_t *ad, size_t ad_len) { if (!check_alias(in, in_len, out, in_len)) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_OUTPUT_ALIASES_INPUT); goto error; } if (!ctx->aead->open_gather) { OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_CTRL_NOT_IMPLEMENTED); goto error; } if (ctx->aead->open_gather(ctx, out, nonce, nonce_len, in, in_len, in_tag, in_tag_len, ad, ad_len)) { return 1; } error: // In the event of an error, clear the output buffer so that a caller // that doesn't check the return value doesn't try and process bad // data. OPENSSL_memset(out, 0, in_len); return 0; } const EVP_AEAD *EVP_AEAD_CTX_aead(const EVP_AEAD_CTX *ctx) { return ctx->aead; } int EVP_AEAD_CTX_get_iv(const EVP_AEAD_CTX *ctx, const uint8_t **out_iv, size_t *out_len) { if (ctx->aead->get_iv == NULL) { return 0; } return ctx->aead->get_iv(ctx, out_iv, out_len); } int EVP_AEAD_CTX_tag_len(const EVP_AEAD_CTX *ctx, size_t *out_tag_len, const size_t in_len, const size_t extra_in_len) { assert(ctx->aead->seal_scatter_supports_extra_in || !extra_in_len); if (ctx->aead->tag_len) { *out_tag_len = ctx->aead->tag_len(ctx, in_len, extra_in_len); return 1; } if (extra_in_len + ctx->tag_len < extra_in_len) { OPENSSL_PUT_ERROR(CIPHER, ERR_R_OVERFLOW); *out_tag_len = 0; return 0; } *out_tag_len = extra_in_len + ctx->tag_len; return 1; }