static int aead_cipher_decrypt(cipher_ctx_t *cipher_ctx, uint8_t *p, size_t *plen, uint8_t *m, size_t mlen, uint8_t *ad, size_t adlen, uint8_t *n, uint8_t *k) { int err = CRYPTO_ERROR; unsigned long long long_plen = 0; size_t nlen = cipher_ctx->cipher->nonce_len; size_t tlen = cipher_ctx->cipher->tag_len; switch (cipher_ctx->cipher->method) { case AES256GCM: // Only AES-256-GCM is supported by libsodium. if (cipher_ctx->aes256gcm_ctx != NULL) { // Use it if availble err = crypto_aead_aes256gcm_decrypt_afternm(p, &long_plen, NULL, m, mlen, ad, adlen, n, (const aes256gcm_ctx *)cipher_ctx->aes256gcm_ctx); *plen = (size_t)long_plen; // it's safe to cast 64bit to 32bit length here break; } // Otherwise, just use the mbedTLS one with crappy AES-NI. case AES192GCM: case AES128GCM: err = mbedtls_cipher_auth_decrypt(cipher_ctx->evp, n, nlen, ad, adlen, m, mlen - tlen, p, plen, m + mlen - tlen, tlen); break; case CHACHA20POLY1305IETF: err = crypto_aead_chacha20poly1305_ietf_decrypt(p, &long_plen, NULL, m, mlen, ad, adlen, n, k); *plen = (size_t)long_plen; // it's safe to cast 64bit to 32bit length here break; #ifdef FS_HAVE_XCHACHA20IETF case XCHACHA20POLY1305IETF: err = crypto_aead_xchacha20poly1305_ietf_decrypt(p, &long_plen, NULL, m, mlen, ad, adlen, n, k); *plen = (size_t)long_plen; // it's safe to cast 64bit to 32bit length here break; #endif default: return CRYPTO_ERROR; } return err; }
static int aead_cipher_decrypt(cipher_ctx_t *cipher_ctx, uint8_t *p, size_t *plen, uint8_t *m, size_t mlen, uint8_t *ad, size_t adlen, uint8_t *n, uint8_t *k) { int err = CRYPTO_ERROR; unsigned long long long_plen = 0; size_t nlen = cipher_ctx->cipher->nonce_len; size_t tlen = cipher_ctx->cipher->tag_len; switch (cipher_ctx->cipher->method) { case AES128GCM: case AES192GCM: case AES256GCM: err = mbedtls_cipher_auth_decrypt(cipher_ctx->evp, n, nlen, ad, adlen, m, mlen - tlen, p, plen, m + mlen - tlen, tlen); break; case CHACHA20POLY1305IETF: err = crypto_aead_chacha20poly1305_ietf_decrypt(p, &long_plen, NULL, m, mlen, ad, adlen, n, k); *plen = (size_t)long_plen; // it's safe to cast 64bit to 32bit length here break; #ifdef FS_HAVE_XCHACHA20IETF case XCHACHA20POLY1305IETF: err = crypto_aead_xchacha20poly1305_ietf_decrypt(p, &long_plen, NULL, m, mlen, ad, adlen, n, k); *plen = (size_t)long_plen; // it's safe to cast 64bit to 32bit length here break; #endif default: return CRYPTO_ERROR; } return err; }