Implement new SPKI parsers.

Many consumers need SPKI support (X.509, TLS, QUIC, WebCrypto), each
with different ways to set signature parameters. SPKIs themselves can
get complex with id-RSASSA-PSS keys which come with various constraints
in the key parameters. This suggests we want a common in-library
representation of an SPKI.

This adds two new functions EVP_parse_public_key and
EVP_marshal_public_key which converts EVP_PKEY to and from SPKI and
implements X509_PUBKEY functions with them. EVP_PKEY seems to have been
intended to be able to express the supported SPKI types with
full-fidelity, so these APIs will continue this.

This means future support for id-RSASSA-PSS would *not* repurpose
EVP_PKEY_RSA. I'm worried about code assuming EVP_PKEY_RSA implies
acting on the RSA* is legal. Instead, it'd add an EVP_PKEY_RSA_PSS and
the data pointer would be some (exposed, so the caller may still check
key size, etc.) RSA_PSS_KEY struct. Internally, the EVP_PKEY_CTX
implementation would enforce the key constraints. If RSA_PSS_KEY would
later need its own API, that code would move there, but that seems
unlikely.

Ideally we'd have a 1:1 correspondence with key OID, although we may
have to fudge things if mistakes happen in standardization. (Whether or
not X.509 reuses id-ecPublicKey for Ed25519, we'll give it a separate
EVP_PKEY type.)

DSA parsing hooks are still implemented, missing parameters and all for
now. This isn't any worse than before.

Decoupling from the giant crypto/obj OID table will be a later task.

BUG=522228

Change-Id: I0e3964edf20cb795a18b0991d17e5ca8bce3e28c
Reviewed-on: https://boringssl-review.googlesource.com/6861
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/evp/evp_tests.txt b/crypto/evp/evp_tests.txt
index 97ddaa0..2320125 100644
--- a/crypto/evp/evp_tests.txt
+++ b/crypto/evp/evp_tests.txt
@@ -1,9 +1,8 @@
 # Public key algorithm tests
 
-# Private keys used for PKEY operations.
+# Keys used for PKEY operations.
 
 # RSA 2048 bit key.
-
 PrivateKey = RSA-2048
 -----BEGIN PRIVATE KEY-----
 MIIEvAIBADANBgkqhkiG9w0BAQEFAASCBKYwggSiAgEAAoIBAQDNAIHqeyrh6gbV
@@ -34,8 +33,22 @@
 fMkTd7GabVourqIZdgvu1Q==
 -----END PRIVATE KEY-----
 
-# EC P-256 key
+# The public half of the same key encoded as a SubjectPublicKeyInfo.
+PublicKey = RSA-2048-SPKI
+Type = RSA
+Input = 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
 
+# The same key but with missing parameters rather than a NULL.
+PublicKey = RSA-2048-SPKI-Invalid
+Input = 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
+Error = DECODE_ERROR
+
+# The same key but with an incorrectly-encoded length prefix.
+PublicKey = RSA-2048-SPKI-Invalid2
+Input = 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
+Error = DECODE_ERROR
+
+# EC P-256 key
 PrivateKey = P-256
 -----BEGIN PRIVATE KEY-----
 MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgiocvtiiTxNH/xbnw
@@ -43,6 +56,27 @@
 +JQkBywnGX14szuSDpXNtmTpkNzwz+oNlOKo5q+dDlgFbmUxBJJbn+bJ
 -----END PRIVATE KEY-----
 
+# The public half of the same key encoded as a PublicKey.
+PublicKey = P-256-SPKI
+Type = EC
+Input = 3059301306072a8648ce3d020106082a8648ce3d030107034200042c150f429ce70f216c252cf5e062ce1f639cd5d165c7f89424072c27197d78b33b920e95cdb664e990dcf0cfea0d94e2a8e6af9d0e58056e653104925b9fe6c9
+
+# The same as above, but with the curve explicitly spelled out.
+PublicKey = P-256-SPKI
+Input = 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
+Error = DECODE_ERROR
+
+# A DSA key.
+PublicKey = DSA-1024
+Type = DSA
+Input = 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
+
+# The same key as above, but without the parameters.
+PublicKey = DSA-1024-No-Params
+Type = DSA
+Input = 308192300906072a8648ce38040103818400028180258c30ebbb7f34fdc873ce679f6cea373c7886d75d4421b90920db034daedd292c64d8edd8cdbdd7f3ad23d74cfa2135247d0cef6ecf2e14f99e19d22a8c1266bd8fb8719c0e5667c716c45c7adbdabe548085bdad2dfee636f8d52fd6adb2193df6c4f0520fbd171b91882e0e4f321f8250ffecf4dbea00e114427d3ef96c1a
+
+
 # RSA tests
 
 Sign = RSA-2048
@@ -55,6 +89,11 @@
 Input = "0123456789ABCDEF1234"
 Output = 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
 
+Verify = RSA-2048-SPKI
+Digest = SHA1
+Input = "0123456789ABCDEF1234"
+Output = 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
+
 # Digest too long
 Sign = RSA-2048
 Digest = SHA1
@@ -125,6 +164,11 @@
 Input = "0123456789ABCDEF1234"
 Output = 3045022100b1d1cb1a577035bccdd5a86c6148c2cc7c633cd42b7234139b593076d041e15202201898cdd52b41ca502098184b409cf83a21bc945006746e3b7cea52234e043ec8
 
+Verify = P-256-SPKI
+Digest = SHA1
+Input = "0123456789ABCDEF1234"
+Output = 3045022100b1d1cb1a577035bccdd5a86c6148c2cc7c633cd42b7234139b593076d041e15202201898cdd52b41ca502098184b409cf83a21bc945006746e3b7cea52234e043ec8
+
 # Digest too long
 Verify = P-256
 Digest = SHA1