Guardtime's KSI Blockchain is an industrial scale blockchain platform that cryptographically ensures data integrity and proves time of existence. The KSI signatures, based on hash chains, link data to this global calendar blockchain. The checkpoints of the blockchain, published in newspapers and electronic media, enable long term integrity of any digital asset without the need to trust any system. There are many applications for KSI, a classical example is signing of any type of logs - system logs, financial transactions, call records, etc. For more, see https://guardtime.com.
libgtrfc3161 is a software development kit for developers who want to convert Guardtime's legacy signatures to
Guardtime's KSI signatures in their C/C++ based applications .
In order to install the libgtrfc3161 on CentOS/RHEL:
cd /etc/yum.repos.d
# In case of RHEL/CentOS 7
sudo curl -O https://download.guardtime.com/ksi/configuration/guardtime.el7.repo
# In case of RHEL/CentOS 8
sudo curl -O https://download.guardtime.com/ksi/configuration/guardtime.el8.repo
# In case of RHEL/CentOS 9
sudo curl -O https://download.guardtime.com/ksi/configuration/guardtime.el9.repo
yum install libgtrfc3161
In order to install the libgtrfc3161 on Debian/Ubuntu:
# Add Guardtime pgp key.
sudo curl https://download.guardtime.com/ksi/GUARDTIME-GPG-KEY-2 | sudo apt-key add -
# In case of Debian 12 (Bookworm)
sudo curl -o /etc/apt/sources.list.d/guardtime.list https://download.guardtime.com/ksi/configuration/guardtime.bookworm.list
sudo apt update
apt-get install libgtrfc3161
In order to install the libgtrfc3161 on macOS:
brew tap guardtime/ksi
brew install libgtrfc3161
To use libgtrfc3161, check out the source code from Github and build it with the rebuild.sh script. To build the legacy signature converter SDK, libksi and libksi-devel (KSI C SDK) packages are needed. libksi is available in Guardtime repository or as source code, see more at: https://github.com/GuardTime/libksi.
To use libgtrfc3161 in your C/C++ project, link it against the libksi and libgtrfc3161 libraries.
A simple example how to convert a legacy signature:
#include <ksi/ksi.h>
#include <gtrfc3161/tsconvert.h>
/* Read the legacy signature from file. */
FILE *in_file = NULL;
size_t in_size = 0;
unsigned char *in_buf = NULL;
in_file = fopen("signature.gtts", "rb");
fseek(in_file, 0, SEEK_END);
in_size = ftell(in_file);
in_buf = malloc(in_size);
fread(in_buf, 1, in_size, in_file);
/* Convert signature. */
KSI_CTX *ctx = NULL;
KSI_CTX_new(&ctx);
KSI_Signature *ksi_signature = NULL;
convert_signature(ctx, in_buf, in_size, &ksi_signature);
/* Serialize the KSI signature and write into file. */
unsigned char *out_buf = NULL;
size_t out_size = 0;
FILE *out_file = NULL;
KSI_Signature_serialize(ksi_signature, &out_buf, &out_size);
out_file = fopen("signature.ksi", "wb");
fwrite(out_buf, 1, out_size, out_file);
/* Cleanup. */
fclose(in_file);
fclose(out_file);
free(in_buf);
free(out_buf);
KSI_Signature_free(ksi_signature);
KSI_CTX_free(ctx);See CONTRIBUTING.md file.
See LICENSE file.
| Dependency | Version | License type | Source | Notes |
|---|---|---|---|---|
| libksi | >= 3.10 | Apache 2.0 | https://github.com/GuardTime/libksi | |
| CuTest | 1.5 | Zlib | Required only for testing. |
| OS/Platform | Compatibility |
|---|---|
| CentOS/RHEL 7,8,9, x86_64 architecture | Fully compatible and tested. |
| Debian 12+ | Fully compatible and tested. |
| Ubuntu | Compatible but not tested on regular basis. |
| OS X | Compatible but not tested on regular basis. |
| Windows 7, 8, 10, 11 | Compatible but not tested on a regular basis. Build combination of DLL=dll and RTL=MT(d) not supported. |