3.2 KiB
Sign and verify
Pico HSM supports in place signature of arbitrary data. It supports the following algorithms:
- RSA-PKCS
- RSA-X-509
- SHA1-RSA-PKCS
- SHA256-RSA-PKCS
- SHA224-RSA-PKCS
- SHA384-RSA-PKCS
- SHA512-RSA-PKCS
- RSA-PKCS-PSS
- SHA1-RSA-PKCS-PSS
- SHA256-RSA-PKCS-PSS
- SHA224-RSA-PKCS-PSS
- SHA384-RSA-PKCS-PSS
- SHA512-RSA-PKCS-PSS
First, we generate the data:
$ echo "This is a test string. Be safe, be secure." > data
Obtain the public key and convert it to PEM format:
$ pkcs11-tool --read-object --pin 648219 --id 1 --type pubkey > 1.der
$ openssl rsa -inform DER -outform PEM -in 1.der -pubin > 1.pub
At this moment, you are able to verify with the public key in 1.pub. The signature is computed inside the Pico HSM with the private key. It never leaves the device.
RSA-PKCS
This algorithm is used to sign raw data.
To sign the data:
$ pkcs11-tool --id 1 --sign --pin 648219 --mechanism RSA-PKCS -i data -o data.sig
To verify the signature:
$ openssl pkeyutl -verify -pubin -inkey 1.pub -in data -sigfile data.sig
Signature Verified Successfully
SHA1-RSA-PKCS
This algorithm is used to sign digests computed outside. It supports SHA1, SHA224, SHA256, SHA384 and SHA512.
First, we generate a file with the digest:
openssl dgst -sha1 -binary -out data.sha1 data
To sign the data:
$ pkcs11-tool --id 1 --sign --pin 648219 --mechanism SHA1-RSA-PKCS -i data -o data.sig
To verify the signature:
$ openssl pkeyutl -verify -in data.sha1 -sigfile data.sig -pubin -inkey 1.pub -pkeyopt digest:sha1
Signature Verified Successfully
RSA-X-509
This algorithm is used for signing raw data. In this algorithm, the data must be padded with a length equal to the size of private key (128, 256, 512 bytes for RSA-1024, RSA-2048 and RSA-4096, respectively).
First, we pad the data. The original data file occupies 29 bytes. Thus, for a 2048 bits key, a padding of 227 bytes is needed:
$ cp data data_pad
$ dd if=/dev/zero bs=1 count=227 >> data_pad
To sign the data:
$ pkcs11-tool --id 1 --sign --pin 648219 --mechanism RSA-X-509 -i data_pad -o data.sig
To verify the signature:
$ openssl rsautl -verify -inkey 1.pub -in data.sig -pubin -raw
This is a test string. Be safe, be secure.
RSA-PKCS-PSS
This algorithm uses the RSA-PKCS with PSS salt to randomize the signature. Pico HSM does not support arbitrary salt lengths. Instead, it always uses the maximum salt length (the hash length). It uses the hash as the input.
To sign the data:
$ pkcs11-tool --id 1 --sign --pin 648219 --mechanism RSA-PKCS-PSS -i data.sha1 -o data.sig
To verify the signature:
$ openssl pkeyutl -verify -in data.sha1 -sigfile data.sig -pubin -inkey 1.pub -pkeyopt rsa_padding_mode:pss -pkeyopt rsa_pss_saltlen:-1 -pkeyopt digest:sha1
Signature Verified Successfully
SHA1-RSA-PKCS-PSS
This algorithm takes the file as the input and sends its hash for signing with the random salt.
To sign the data:
$ pkcs11-tool --id 1 --sign --pin 648219 --mechanism SHA1-RSA-PKCS-PSS -i data -o data.sig
To verify the signature:
$ openssl pkeyutl -verify -in data.sha1 -sigfile data.sig -pubin -inkey 1.pub -pkeyopt rsa_padding_mode:pss -pkeyopt rsa_pss_saltlen:-1
Signature Verified Successfully