OPENSSL_riscvcap - the RISC-V processor capabilities vector
env OPENSSL_riscvcap=... <application>libcrypto supports RISC-V instruction set extensions. These extensions are denoted by individual extension names in the capabilities vector. For Linux platform, when libcrypto is initialized, the results returned by the RISC-V Hardware Probing syscall (hwprobe) are stored in the vector. Otherwise all capabilities are disabled.
To override the set of instructions available to an application, you can set the OPENSSL_riscvcap environment variable before you start the application.
The environment variable is similar to the RISC-V ISA string defined in the RISC-V Instruction Set Manual. It is case insensitive. Though due to the limit of the environment variable parser inside libcrypto, an extension must be prefixed with an underscore to make it recognizable. This also applies to the Vector extension.
OPENSSL_riscvcap="rv64gc_v_zba_zbb_zbs..."Note that extension implication is currently not implemented. For example, when "rv64gc_b" is provided as the environment variable, zba/zbb/zbs would not be implied in the capability vector.
Currently only these extensions are recognized:
Address Generation
Could be detected using hwprobe for Linux kernel >= 6.5
Basic bit-manipulation
Could be detected using hwprobe for Linux kernel >= 6.5
Carry-less multiplication
Could be detected using hwprobe for Linux kernel >= 6.8
Single-bit instructions
Could be detected using hwprobe for Linux kernel >= 6.5
Bit-manipulation for Cryptography
Could be detected using hwprobe for Linux kernel >= 6.8
Carry-less multiplication for Cryptography
Could be detected using hwprobe for Linux kernel >= 6.8
Crossbar permutations
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: AES Decryption
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: AES Encryption
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: Hash Function Instructions
Could be detected using hwprobe for Linux kernel >= 6.8
ShangMi Suite: SM4 Block Cipher Instructions
Could be detected using hwprobe for Linux kernel >= 6.8
ShangMi Suite: SM3 Hash Function Instructions
Could be detected using hwprobe for Linux kernel >= 6.8
Entropy Source Extension
Data Independent Execution Latency
Could be detected using hwprobe for Linux kernel >= 6.8
Vector Extension for Application Processors
Could be detected using hwprobe for Linux kernel >= 6.5
Vector Basic Bit-manipulation
Could be detected using hwprobe for Linux kernel >= 6.8
Vector Carryless Multiplication
Could be detected using hwprobe for Linux kernel >= 6.8
Vector Cryptography Bit-manipulation
Could be detected using hwprobe for Linux kernel >= 6.8
Vector GCM/GMAC
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: Vector AES Block Cipher
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: Vector SHA-2 Secure Hash
Could be detected using hwprobe for Linux kernel >= 6.8
NIST Suite: Vector SHA-2 Secure Hash
Could be detected using hwprobe for Linux kernel >= 6.8
ShangMi Suite: SM4 Block Cipher
Could be detected using hwprobe for Linux kernel >= 6.8
ShangMi Suite: SM3 Secure Hash
Could be detected using hwprobe for Linux kernel >= 6.8
Not available.
Check currently detected capabilities
$ openssl info -cpusettings
OPENSSL_riscvcap=ZBA_ZBB_ZBC_ZBS_VDisables all instruction set extensions:
OPENSSL_riscvcap="rv64gc"Only enable the vector extension:
OPENSSL_riscvcap="rv64gc_v"Copyright 2024 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.