Implement VerifySignedData() for ECDSA, RSA PKCS#1 and RSA PSS.

net/data/verify_signed_data_unittest/rsa-pkcs1-sha1.pem

Index: net/data/verify_signed_data_unittest/rsa-pkcs1-sha1.pem
diff --git a/net/data/verify_signed_data_unittest/rsa-pkcs1-sha1.pem b/net/data/verify_signed_data_unittest/rsa-pkcs1-sha1.pem
new file mode 100644
index 0000000000000000000000000000000000000000..6073725ccf35c0a488d8d4b193c87b06c21f2d29
--- /dev/null
+++ b/net/data/verify_signed_data_unittest/rsa-pkcs1-sha1.pem
@@ -0,0 +1,46 @@
+The key, message, and signature come from Example 1 of:
+ftp://ftp.rsa.com/pub/rsalabs/tmp/pkcs1v15sign-vectors.txt
+
+(The algorithm DER was synthesized to match, and the signature enclosed in a BIT STRING).
+
+It uses an RSA key with modulus length of 1024 bits, PKCS#1 v1.5 padding, and
+SHA-1 as the digest.
+
+
+$ openssl asn1parse -i < [PUBLIC KEY]
+    0:d=0  hl=3 l= 159 cons: SEQUENCE          
+    3:d=1  hl=2 l=  13 cons:  SEQUENCE          
+    5:d=2  hl=2 l=   9 prim:   OBJECT            :rsaEncryption
+   16:d=2  hl=2 l=   0 prim:   NULL              
+   18:d=1  hl=3 l= 141 prim:  BIT STRING        
+-----BEGIN PUBLIC KEY-----
+MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQClbkoOcBAXWJpRh9x+qEHRVvLsDjatUqRN/rH
+mH3rZkdjFEFb/7bFitMDyg6EqiKOU3/Umq3KRy7MHzqv84LHf1c2VCAltWyuLbfXWce9jd8CSHL
+I8Jwpw4lmOb/idGfEFrMLT8Ms18pKA4Thrb2TE7yLh4fINDOjP+yJJvZohNwIDAQAB
+-----END PUBLIC KEY-----
+
+
+$ openssl asn1parse -i < [ALGORITHM]
+    0:d=0  hl=2 l=  13 cons: SEQUENCE          
+    2:d=1  hl=2 l=   9 prim:  OBJECT            :sha1WithRSAEncryption
+   13:d=1  hl=2 l=   0 prim:  NULL              
+-----BEGIN ALGORITHM-----
+MA0GCSqGSIb3DQEBBQUA
+-----END ALGORITHM-----
+
+
+-----BEGIN DATA-----
+zch9oiPXht87ReC7vHITJtHuKvgGzDFUdcxvDZxm4bYjcdRc4jkuGskoRMMQEC8Vag2NUsH0xAu
+jqmUJV4bLdpdXplY7qVj+0LzJhOi1F6PV9RWyO4pB50qoZ2k/kN+wYabobfqu5kRywA5fIJRXKc
+vr538Gznjgj0CY+6QfnWGTwDF+i2DUtghKy0LSnjgIo7w3LYXjMRcPy/fMctC3HClmSLOk0Q9BY
+pXQgHqmJcqydE/Z6o/SI8QlNwKYKL0WvgJUbxMP0uM7k20mduCK7RtzMYt1CgFn0A==
+-----END DATA-----
+
+
+$ openssl asn1parse -i < [SIGNATURE]
+    0:d=0  hl=3 l= 129 prim: BIT STRING        
+-----BEGIN SIGNATURE-----
+A4GBAGvDoGZWhCkwokfjDVhktNgZI2unxollhirX28TiSvKOhrtTHwM1i+X7dHd8YIb4UMrviT8
+Nb8wtDJHsATaTtOoAuAzUmqxOy1+JEa/lOa2kqPOCPR0T5HLRSQVHxlnHYX89JAh9228rcglhZ/
+wJfKsY6aRY/LY0zc6O41iUxITX
+-----END SIGNATURE-----