wolfssl-examples/ecc

Examples demonstrating ECC

Building

Build and install wolfSSL

./configure --enable-ecc --enable-ecccustcurves CFLAGS="-DWOLFSSL_TEST_CERT" && make && sudo make install

Build Example

make

gcc -o ecc-key-decode ecc-key-decode.c -Wall -I/usr/local/include -Os -L/usr/local/lib -lm -lwolfssl
gcc -o ecc-sign ecc-sign.c -Wall -I/usr/local/include -Os -L/usr/local/lib -lm -lwolfssl
gcc -o ecc-stack ecc-stack.c -Wall -I/usr/local/include -Os -L/usr/local/lib -lm -lwolfssl
gcc -o ecc-verify ecc-verify.c -Wall -I/usr/local/include -Os -L/usr/local/lib -lm -lwolfssl

Debug

To enable debug change the Makefile to:

CFLAGS+=$(DEBUG_FLAGS)
#CFLAGS+=$(OPTIMIZE)

Build wolfSSL using: ./configure --enable-ecc --enable-ecccustcurves --enable-debug CFLAGS="-DWOLFSSL_TEST_CERT" && make && sudo make install

Usage

ecc-key-decode

This example shows how to extract a public key from a certificate and load it.

./ecc-key-decode
bytes = 781
decodedCert.pubKeySize 91
publickey size: 32
Success

ecc-sign

This example demonstrates signing large data by performing the hash in chunks and signing. The sign is done multiple times to show how its normal for the signature size to vary for the same private key and hash data because a new public key is generated for each operation.

./ecc-sign
KeyGen Done
Sign ret 0, sigLen 103
Verify ret 0, is_valid_sig 1
Firmware Signature 0: Ret 0, HashLen 32, SigLen 103
Sign ret 0, sigLen 102
Verify ret 0, is_valid_sig 1
Firmware Signature 1: Ret 0, HashLen 32, SigLen 102
Sign ret 0, sigLen 102
Verify ret 0, is_valid_sig 1
Firmware Signature 2: Ret 0, HashLen 32, SigLen 102
Sign ret 0, sigLen 103
Verify ret 0, is_valid_sig 1
Firmware Signature 3: Ret 0, HashLen 32, SigLen 103
Sign ret 0, sigLen 103
Verify ret 0, is_valid_sig 1
Firmware Signature 4: Ret 0, HashLen 32, SigLen 103
Sign ret 0, sigLen 103
Verify ret 0, is_valid_sig 1
Firmware Signature 5: Ret 0, HashLen 32, SigLen 103
Sign ret 0, sigLen 102
Verify ret 0, is_valid_sig 1
Firmware Signature 6: Ret 0, HashLen 32, SigLen 102
Sign ret 0, sigLen 102
Verify ret 0, is_valid_sig 1
Firmware Signature 7: Ret 0, HashLen 32, SigLen 102
Sign ret 0, sigLen 103
Verify ret 0, is_valid_sig 1
Firmware Signature 8: Ret 0, HashLen 32, SigLen 103
Sign ret 0, sigLen 102
Verify ret 0, is_valid_sig 1
Firmware Signature 9: Ret 0, HashLen 32, SigLen 102

ecc-stack

This example show stack use for an ECC key generation.

./ecc-stack
total   Allocs   =         5
total   Deallocs =         5
total   Bytes    =     16440
peak    Bytes    =     16440
current Bytes    =         0
stack used = 25296
sizeof RNG = 32
sizeof ecc_key = 4424

ecc-verify

This example demonstrates using a Koblitz (SECP256K1) curve.

./ecc-verify
hash_firmware_verify: 0