Top (The Libgcrypt Reference Manual)

This manual is for Libgcrypt version 1.10.2 and was last updated 6 April 2023. Libgcrypt is GNU’s library of cryptographic building blocks.

Short Table of Contents

• Introduction:		What is Libgcrypt.
• Preparation:		What you should do before using the library.
• Generalities:		General library functions and data types.
• Handler Functions:		Working with handler functions.
• Symmetric cryptography:		How to use symmetric cryptography.
• Public Key cryptography:		How to use public key cryptography.
• Hashing:		How to use hash algorithms.
• Message Authentication Codes:		How to use MAC algorithms.
• Key Derivation:		How to derive keys from strings
• Random Numbers:		How to work with random numbers.
• S-expressions:		How to manage S-expressions.
• MPI library:		How to work with multi-precision-integers.
• Prime numbers:		How to use the Prime number related functions.
• Utilities:		Utility functions.
• Tools:		Utility tools.
• Configuration:		Configuration files and environment variables.
• Architecture:		How Libgcrypt works internally.
Appendices
• Self-Tests:		Description of the self-tests.
• FIPS Mode:		Description of the FIPS mode.
• Library Copying:		The GNU Lesser General Public License says how you can copy and share Libgcrypt.
• Copying:		The GNU General Public License says how you can copy and share some parts of Libgcrypt.
Indices
• Figures and Tables:		Index of figures and tables.
• Concept Index:		Index of concepts and programs.
• Function and Data Index:		Index of functions, variables and data types.

1 Introduction
- 1.1 Getting Started
- 1.2 Features
- 1.3 Overview
2 Preparation
- 2.1 Header
- 2.2 Building sources
- 2.3 Building sources using Automake
- 2.4 Initializing the library
- 2.5 Multi-Threading
- 2.6 How to enable the FIPS mode
- 2.7 How to disable the FIPS mode
- 2.8 How to disable hardware features
3 Generalities
- 3.1 Controlling the library
- 3.2 Error Handling
4 Handler Functions
- 4.1 Progress handler
- 4.2 Allocation handler
- 4.3 Error handler
- 4.4 Logging handler
5 Symmetric cryptography
- 5.1 Available ciphers
- 5.2 Available cipher modes
- 5.3 Working with cipher handles
- 5.4 General cipher functions
6 Public Key cryptography
- 6.1 Available algorithms
- 6.2 Used S-expressions
- 6.3 Cryptographic Functions
- 6.4 Dedicated functions for elliptic curves.
- 6.5 General public-key related Functions
7 Hashing
- 7.1 Available hash algorithms
- 7.2 Working with hash algorithms
8 Message Authentication Codes
- 8.1 Available MAC algorithms
- 8.2 Working with MAC algorithms
9 Key Derivation
10 Random Numbers
- 10.1 Quality of random numbers
- 10.2 Retrieving random numbers
11 S-expressions
- 11.1 Data types for S-expressions
- 11.2 Working with S-expressions
12 MPI library
- 12.1 Data types
- 12.2 Basic functions
- 12.3 MPI formats
- 12.4 Calculations
- 12.5 Comparisons
- 12.6 Bit manipulations
- 12.7 EC functions
- 12.8 Miscellaneous
13 Prime numbers
- 13.1 Generation
- 13.2 Checking
14 Utilities
- 14.1 Memory allocation
- 14.2 Context management
- 14.3 Buffer description
- 14.4 How to check Libgcrypt’s configuration.
15 Tools
- 15.1 A HMAC-SHA-256 tool
16 Configuration files and environment variables
17 Architecture
- 17.1 Public-Key Architecture
- 17.2 Symmetric Encryption Subsystem Architecture
- 17.3 Hashing and MACing Subsystem Architecture
- 17.4 Multi-Precision-Integer Subsystem Architecture
- 17.5 Prime-Number-Generator Subsystem Architecture
- 17.6 Random-Number Subsystem Architecture
  - 17.6.1 Description of the CSPRNG
  - 17.6.2 Description of the DRBG
Appendix A Description of the Self-Tests
- A.1 Power-Up Tests
- A.2 Conditional Tests
- A.3 Application Requested Tests
Appendix B Description of the FIPS Mode
- B.1 Restrictions in FIPS Mode
- B.2 FIPS Finite State Machine
- B.3 FIPS Miscellaneous Information
GNU Lesser General Public License
GNU General Public License
List of Figures and Tables
Concept Index
Function and Data Index

The Libgcrypt Reference Manual

The Libgcrypt Library

Short Table of Contents

Table of Contents