Curve name buffer too small

[j-kaltes]

The program uses

char curve[9];

to save the name of the curve. The possible names are:

char* ellipticcurves [] = {
	"secp224k1",
	"secp224r1",
	"secp256k1",
	"secp256r1"
};

They consist of 9 characters plus a trailing ‘\0’, so they need 10 bytes, giving:

char curve[10];

Because of this:

./ecdsa --sign priv256.pem --message adc.dat --signature sig256.pem

gives the following output:

option --sign with value `priv256.pem'
Sign/Verify the message with value `adc.dat'
Signature is stored in file sig256.pem
Curve secp256r124f749e0f9d4904e1cd9a697cece8746f0a3583caf39a87302e2b4c4de883d65 was not built-in the program 
Error occurred. Invalid signature returned !

After changing to 10 bytes:

option --sign with value `priv256.pem'
Sign/Verify the message with value `adc.dat'
Signature is stored in file sig256.pem