text: /*
   * Copyright 2019-2020 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 ccm mode */
  
  #include "prov/ciphercommon.h"
  #include "prov/ciphercommon_ccm.h"
  #include "prov/providercommon.h"
  #include "prov/providercommonerr.h"
  
  static int ccm_cipher_internal(PROV_CCM_CTX *ctx, unsigned char *out,
                                 size_t *padlen, const unsigned char *in,
                                 size_t len);
  
  static int ccm_tls_init(PROV_CCM_CTX *ctx, unsigned char *aad, size_t alen)
  {
      size_t len;
  
      if (!ossl_prov_is_running() || alen != EVP_AEAD_TLS1_AAD_LEN)
          return 0;
  
      /* Save the aad for later use. */
      memcpy(ctx->buf, aad, alen);
      ctx->tls_aad_len = alen;
  
      len = ctx->buf[alen - 2] << 8 | ctx->buf[alen - 1];
      if (len < EVP_CCM_TLS_EXPLICIT_IV_LEN)
          return 0;
  
      /* Correct length for explicit iv. */
      len -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
  
      if (!ctx->enc) {
          if (len < ctx->m)
              return 0;
          /* Correct length for tag. */
          len -= ctx->m;
      }
      ctx->buf[alen - 2] = (unsigned char)(len >> 8);
      ctx->buf[alen - 1] = (unsigned char)(len & 0xff);
  
      /* Extra padding: tag appended to record. */
      return ctx->m;
  }
  
  static int ccm_tls_iv_set_fixed(PROV_CCM_CTX *ctx, unsigned char *fixed,
                                  size_t flen)
  {
      if (flen != EVP_CCM_TLS_FIXED_IV_LEN)
          return 0;
  
      /* Copy to first part of the iv. */
      memcpy(ctx->iv, fixed, flen);
      return 1;
  }
  
  static size_t ccm_get_ivlen(PROV_CCM_CTX *ctx)
  {
      return 15 - ctx->l;
  }
  
  int ccm_set_ctx_params(void *vctx, const OSSL_PARAM params[])
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
      const OSSL_PARAM *p;
      size_t sz;
  
      p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_TAG);
      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 ((p->data_size & 1) || (p->data_size < 4) || p->data_size > 16) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_TAGLEN);
              return 0;
          }
  
          if (p->data != NULL) {
              if (ctx->enc) {
                  ERR_raise(ERR_LIB_PROV, PROV_R_TAG_NOT_NEEDED);
                  return 0;
              }
              memcpy(ctx->buf, p->data, p->data_size);
              ctx->tag_set = 1;
          }
          ctx->m = p->data_size;
      }
  
      p = OSSL_PARAM_locate_const(params, OSSL_CIPHER_PARAM_AEAD_IVLEN);
      if (p != NULL) {
          size_t ivlen;
  
          if (!OSSL_PARAM_get_size_t(p, &sz)) {
              ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_GET_PARAMETER);
              return 0;
          }
          ivlen = 15 - sz;
          if (ivlen < 2 || ivlen > 8) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
              return 0;
          }
          ctx->l = ivlen;
      }
  
      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 = ccm_tls_init(ctx, p->data, p->data_size);
          if (sz == 0) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DATA);
              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 (ccm_tls_iv_set_fixed(ctx, p->data, p->data_size) == 0) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
              return 0;
          }
      }
  
      return 1;
  }
  
  int ccm_get_ctx_params(void *vctx, OSSL_PARAM params[])
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
      OSSL_PARAM *p;
  
      p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IVLEN);
      if (p != NULL && !OSSL_PARAM_set_size_t(p, ccm_get_ivlen(ctx))) {
          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 m = ctx->m;
  
          if (!OSSL_PARAM_set_size_t(p, m)) {
              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 (ccm_get_ivlen(ctx) > p->data_size) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
              return 0;
          }
          if (!OSSL_PARAM_set_octet_string(p, ctx->iv, p->data_size)
              && !OSSL_PARAM_set_octet_ptr(p, &ctx->iv, p->data_size)) {
              ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
              return 0;
          }
      }
  
      p = OSSL_PARAM_locate(params, OSSL_CIPHER_PARAM_IV_STATE);
      if (p != NULL) {
          if (ccm_get_ivlen(ctx) > p->data_size) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
              return 0;
          }
          if (!OSSL_PARAM_set_octet_string(p, ctx->iv, p->data_size)
              && !OSSL_PARAM_set_octet_ptr(p, &ctx->iv, p->data_size)) {
              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_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) {
          if (!ctx->enc || !ctx->tag_set) {
              ERR_raise(ERR_LIB_PROV, PROV_R_TAG_NOTSET);
              return 0;
          }
          if (p->data_type != OSSL_PARAM_OCTET_STRING) {
              ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_TO_SET_PARAMETER);
              return 0;
          }
          if (!ctx->hw->gettag(ctx, p->data, p->data_size))
              return 0;
          ctx->tag_set = 0;
          ctx->iv_set = 0;
          ctx->len_set = 0;
      }
      return 1;
  }
  
  static int ccm_init(void *vctx, const unsigned char *key, size_t keylen,
                      const unsigned char *iv, size_t ivlen, int enc)
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
  
      if (!ossl_prov_is_running())
          return 0;
  
      ctx->enc = enc;
  
      if (iv != NULL) {
          if (ivlen != ccm_get_ivlen(ctx)) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_IVLEN);
              return 0;
          }
          memcpy(ctx->iv, iv, ivlen);
          ctx->iv_set = 1;
      }
      if (key != NULL) {
          if (keylen != ctx->keylen) {
              ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEYLEN);
              return 0;
          }
          return ctx->hw->setkey(ctx, key, keylen);
      }
      return 1;
  }
  
  int ccm_einit(void *vctx, const unsigned char *key, size_t keylen,
                       const unsigned char *iv, size_t ivlen)
  {
      return ccm_init(vctx, key, keylen, iv, ivlen, 1);
  }
  
  int ccm_dinit(void *vctx, const unsigned char *key, size_t keylen,
                       const unsigned char *iv, size_t ivlen)
  {
      return ccm_init(vctx, key, keylen, iv, ivlen, 0);
  }
  
  int ccm_stream_update(void *vctx, unsigned char *out, size_t *outl,
                               size_t outsize, const unsigned char *in,
                               size_t inl)
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
  
      if (outsize < inl) {
          ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
          return 0;
      }
  
      if (!ccm_cipher_internal(ctx, out, outl, in, inl)) {
          ERR_raise(ERR_LIB_PROV, PROV_R_CIPHER_OPERATION_FAILED);
          return 0;
      }
      return 1;
  }
  
  int ccm_stream_final(void *vctx, unsigned char *out, size_t *outl,
                              size_t outsize)
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
      int i;
  
      if (!ossl_prov_is_running())
          return 0;
  
      i = ccm_cipher_internal(ctx, out, outl, NULL, 0);
      if (i <= 0)
          return 0;
  
      *outl = 0;
      return 1;
  }
  
  int ccm_cipher(void *vctx,
                        unsigned char *out, size_t *outl, size_t outsize,
                        const unsigned char *in, size_t inl)
  {
      PROV_CCM_CTX *ctx = (PROV_CCM_CTX *)vctx;
  
      if (!ossl_prov_is_running())
          return 0;
  
      if (outsize < inl) {
          ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
          return 0;
      }
  
      if (ccm_cipher_internal(ctx, out, outl, in, inl) <= 0)
          return 0;
  
      *outl = inl;
      return 1;
  }
  
  /* Copy the buffered iv */
  static int ccm_set_iv(PROV_CCM_CTX *ctx, size_t mlen)
  {
      const PROV_CCM_HW *hw = ctx->hw;
  
      if (!hw->setiv(ctx, ctx->iv, ccm_get_ivlen(ctx), mlen))
          return 0;
      ctx->len_set = 1;
      return 1;
  }
  
  static int ccm_tls_cipher(PROV_CCM_CTX *ctx,
                            unsigned char *out, size_t *padlen,
                            const unsigned char *in, size_t len)
  {
      int rv = 0;
      size_t olen = 0;
  
      if (!ossl_prov_is_running())
          goto err;
  
      /* Encrypt/decrypt must be performed in place */
      if (in == NULL || out != in || len < EVP_CCM_TLS_EXPLICIT_IV_LEN + ctx->m)
          goto err;
  
      /* If encrypting set explicit IV from sequence number (start of AAD) */
      if (ctx->enc)
          memcpy(out, ctx->buf, EVP_CCM_TLS_EXPLICIT_IV_LEN);
      /* Get rest of IV from explicit IV */
      memcpy(ctx->iv + EVP_CCM_TLS_FIXED_IV_LEN, in, EVP_CCM_TLS_EXPLICIT_IV_LEN);
      /* Correct length value */
      len -= EVP_CCM_TLS_EXPLICIT_IV_LEN + ctx->m;
      if (!ccm_set_iv(ctx, len))
          goto err;
  
      /* Use saved AAD */
      if (!ctx->hw->setaad(ctx, ctx->buf, ctx->tls_aad_len))
          goto err;
  
      /* Fix buffer to point to payload */
      in += EVP_CCM_TLS_EXPLICIT_IV_LEN;
      out += EVP_CCM_TLS_EXPLICIT_IV_LEN;
      if (ctx->enc) {
          if (!ctx->hw->auth_encrypt(ctx, in, out, len,  out + len, ctx->m))
              goto err;
          olen = len + EVP_CCM_TLS_EXPLICIT_IV_LEN + ctx->m;
      } else {
          if (!ctx->hw->auth_decrypt(ctx, in, out, len,
                                     (unsigned char *)in + len, ctx->m))
              goto err;
          olen = len;
      }
      rv = 1;
  err:
      *padlen = olen;
      return rv;
  }
  
  static int ccm_cipher_internal(PROV_CCM_CTX *ctx, unsigned char *out,
                                 size_t *padlen, const unsigned char *in,
                                 size_t len)
  {
      int rv = 0;
      size_t olen = 0;
      const PROV_CCM_HW *hw = ctx->hw;
  
      /* If no key set, return error */
      if (!ctx->key_set)
          return 0;
  
      if (ctx->tls_aad_len != UNINITIALISED_SIZET)
          return ccm_tls_cipher(ctx, out, padlen, in, len);
  
      /* EVP_*Final() doesn't return any data */
      if (in == NULL && out != NULL)
          goto finish;
  
      if (!ctx->iv_set)
          goto err;
  
      if (out == NULL) {
          if (in == NULL) {
              if (!ccm_set_iv(ctx, len))
                  goto err;
          } else {
              /* If we have AAD, we need a message length */
              if (!ctx->len_set && len)
                  goto err;
              if (!hw->setaad(ctx, in, len))
                  goto err;
          }
      } else {
          /* If not set length yet do it */
          if (!ctx->len_set && !ccm_set_iv(ctx, len))
              goto err;
  
          if (ctx->enc) {
              if (!hw->auth_encrypt(ctx, in, out, len, NULL, 0))
                  goto err;
              ctx->tag_set = 1;
          } else {
              /* The tag must be set before actually decrypting data */
              if (!ctx->tag_set)
                  goto err;
  
              if (!hw->auth_decrypt(ctx, in, out, len, ctx->buf, ctx->m))
                  goto err;
              /* Finished - reset flags so calling this method again will fail */
              ctx->iv_set = 0;
              ctx->tag_set = 0;
              ctx->len_set = 0;
          }
      }
      olen = len;
  finish:
      rv = 1;
  err:
      *padlen = olen;
      return rv;
  }
  
  void ccm_initctx(PROV_CCM_CTX *ctx, size_t keybits, const PROV_CCM_HW *hw)
  {
      ctx->keylen = keybits / 8;
      ctx->key_set = 0;
      ctx->iv_set = 0;
      ctx->tag_set = 0;
      ctx->len_set = 0;
      ctx->l = 8;
      ctx->m = 12;
      ctx->tls_aad_len = UNINITIALISED_SIZET;
      ctx->hw = hw;
  }
  
  