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Diffstat (limited to 'src/examples/decrypt.c')
| -rw-r--r-- | src/examples/decrypt.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/examples/decrypt.c b/src/examples/decrypt.c new file mode 100644 index 0000000..5454a4b --- /dev/null +++ b/src/examples/decrypt.c @@ -0,0 +1,138 @@ +/* + * Copyright (c) 2018, [Ribose Inc](https://www.ribose.com). + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <rnp/rnp.h> +#include <string.h> + +#define RNP_SUCCESS 0 + +/* sample pass provider implementation, which always return 'password' for key decryption and + * 'encpassword' when password is needed for file decryption. You may ask for password via + * stdin, or choose password based on key properties, whatever else */ +static bool +example_pass_provider(rnp_ffi_t ffi, + void * app_ctx, + rnp_key_handle_t key, + const char * pgp_context, + char buf[], + size_t buf_len) +{ + if (!strcmp(pgp_context, "decrypt (symmetric)")) { + strncpy(buf, "encpassword", buf_len); + return true; + } + if (!strcmp(pgp_context, "decrypt")) { + strncpy(buf, "password", buf_len); + return true; + } + + return false; +} + +static int +ffi_decrypt(bool usekeys) +{ + rnp_ffi_t ffi = NULL; + rnp_input_t keyfile = NULL; + rnp_input_t input = NULL; + rnp_output_t output = NULL; + uint8_t * buf = NULL; + size_t buf_len = 0; + int result = 1; + + /* initialize FFI object */ + if (rnp_ffi_create(&ffi, "GPG", "GPG") != RNP_SUCCESS) { + return result; + } + + /* check whether we want to use key or password for decryption */ + if (usekeys) { + /* load secret keyring, as it is required for public-key decryption. However, you may + * need to load public keyring as well to validate key's signatures. */ + if (rnp_input_from_path(&keyfile, "secring.pgp") != RNP_SUCCESS) { + fprintf(stdout, "failed to open secring.pgp. Did you run ./generate sample?\n"); + goto finish; + } + + /* we may use RNP_LOAD_SAVE_SECRET_KEYS | RNP_LOAD_SAVE_PUBLIC_KEYS as well*/ + if (rnp_load_keys(ffi, "GPG", keyfile, RNP_LOAD_SAVE_SECRET_KEYS) != RNP_SUCCESS) { + fprintf(stdout, "failed to read secring.pgp\n"); + goto finish; + } + rnp_input_destroy(keyfile); + keyfile = NULL; + } + + /* set the password provider */ + rnp_ffi_set_pass_provider(ffi, example_pass_provider, NULL); + + /* create file input and memory output objects for the encrypted message and decrypted + * message */ + if (rnp_input_from_path(&input, "encrypted.asc") != RNP_SUCCESS) { + fprintf(stdout, "failed to create input object\n"); + goto finish; + } + + if (rnp_output_to_memory(&output, 0) != RNP_SUCCESS) { + fprintf(stdout, "failed to create output object\n"); + goto finish; + } + + if (rnp_decrypt(ffi, input, output) != RNP_SUCCESS) { + fprintf(stdout, "public-key decryption failed\n"); + goto finish; + } + + /* get the decrypted message from the output structure */ + if (rnp_output_memory_get_buf(output, &buf, &buf_len, false) != RNP_SUCCESS) { + goto finish; + } + fprintf(stdout, + "Decrypted message (%s):\n%.*s\n", + usekeys ? "with key" : "with password", + (int) buf_len, + buf); + + result = 0; +finish: + rnp_input_destroy(keyfile); + rnp_input_destroy(input); + rnp_output_destroy(output); + rnp_ffi_destroy(ffi); + return result; +} + +int +main(int argc, char **argv) +{ + int res; + res = ffi_decrypt(true); + if (res) { + return res; + } + res = ffi_decrypt(false); + return res; +}
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