# Examples demonstrating ECC ## Building ### Build and install wolfSSL ``` ./configure --enable-ecc --enable-ecccustcurves CFLAGS="-DWOLFSSL_TEST_CERT -DWOLFSSL_DER_TO_PEM -DHAVE_ECC_KOBLITZ -DWOLFSSL_PUBLIC_MP" && 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-key-decode ecc-key-decode.c -Wall -I/usr/local/include -Os -L/usr/local/lib -lm -lwolfssl gcc -o ecc-params ecc-params.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 adding `--enable-debug` to the ./configure. To enable using the static library change the Makefile to: ``` LIBS+=$(STATIC_LIB) #LIBS+=$(DYN_LIB) ``` Build wolfSSL adding `--disable-shared` to the ./configure. ## 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 ``` ### `ecc-key-export` This example shows exporting an ECC private key and public key. ``` ./ecc-key-export ECC Key Generated: 256 bits, curve ECC_SECP256K1 ECC Private Key Exported to ./ECC_SECP256K1.der ECC Private Key Exported to ./ECC_SECP256K1.pem ECC Public Key Exported to ./ECC_SECP256K1_pub.der ECC Public Key Exported to ./ECC_SECP256K1_pub.pem ``` Example commands for parsing the generated ECC keys (see `./parsekeys.sh`): ``` openssl ec -inform der -in ECC_SECP256K1.der -text openssl ec -inform pem -in ECC_SECP256K1.pem -text openssl ec -inform der -in ECC_SECP256K1_pub.der -text -pubin openssl ec -inform pem -in ECC_SECP256K1_pub.pem -text -pubin ``` ### `ecc-params` Example for extracting curve parameters for a specific ECC curve. ``` ./ecc-params ECC Curve Parameters for SECP256R1 Prime: 32 ff ff ff ff 00 00 00 01 00 00 00 00 00 00 00 00 |................ 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff |................ Af: 32 ff ff ff ff 00 00 00 01 00 00 00 00 00 00 00 00 |................ 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff fc |................ Bf: 32 5a c6 35 d8 aa 3a 93 e7 b3 eb bd 55 76 98 86 bc |Z.5..:.....Uv... 65 1d 06 b0 cc 53 b0 f6 3b ce 3c 3e 27 d2 60 4b |e....S..;.<>'.`K Order: 32 ff ff ff ff 00 00 00 00 ff ff ff ff ff ff ff ff |................ bc e6 fa ad a7 17 9e 84 f3 b9 ca c2 fc 63 25 51 |.............c%Q Gx: 32 6b 17 d1 f2 e1 2c 42 47 f8 bc e6 e5 63 a4 40 f2 |k....,BG....c.@. 77 03 7d 81 2d eb 33 a0 f4 a1 39 45 d8 98 c2 96 |w.}.-.3...9E.... Gy: 32 4f e3 42 e2 fe 1a 7f 9b 8e e7 eb 4a 7c 0f 9e 16 |O.B........J|... 2b ce 33 57 6b 31 5e ce cb b6 40 68 37 bf 51 f5 |+.3Wk1^...@h7.Q. ``` ### `ecc-export-qx-qy` Example for extracting public key parameters from ASN.1 format to raw ECC point. The raw ECC point format, also used by [wolfBoot](https://github.com/wolfSSL/wolfBoot), represents a public key in its two coordinates (Qx,Qy) of fixed size (2 x keysize). Usage: `./ecc-export-Qx-Qy der_key_file raw_key_file` Where `der_key_file` is a file containing the ecc key in ASN.1 format, and `raw_key_file` is the output file created, containing the public key in raw ECC point format. ## Support For questions please email us at support@wolfssl.com.